JP2001249507A - Power supply mechanism and image forming apparatus - Google Patents

Abstract

(57) [Summary] In a configuration in which a predetermined voltage is supplied to a rotating body rotatable about a shaft, an adhered substance may adhere to a contact portion between the shaft and a power supply terminal. And a power supply mechanism capable of preventing poor contact and poor conduction caused by wear of the contact portion. For example, a power supply bearing 11 connected to a bias power supply 13 to form a power supply circuit 14 is used as a bearing for supporting a rotating shaft 24 of a developing roller. Thus, it is possible to prevent the occurrence of poor contact or the like due to wear of the contact portion. Further, the power supply bearing 11 is provided with a cleaning unit 12 on the developing roller side. Therefore, it is possible to prevent failure and conduction failure contact by deposits factors such scattered toner and NO _X attached to the rotational shaft 24 surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply mechanism for supplying power to a member rotatable about a shaft, and an image forming apparatus provided with such a power supply mechanism. The present invention relates to a power supply mechanism for supplying power to a developing roller, a photoreceptor, and a contact-type charging / transfer device in a forming apparatus, and an image forming apparatus including such a power supply mechanism.

[0002]

2. Description of the Related Art For example, in an electrophotographic image forming apparatus, a photosensitive drum, a developing roller provided in a developing device, or a contact type charger (main charger) having a substantially cylindrical brush or roller shape is used. ), A contact-type transfer device (transfer charger), and the like, many of which have a columnar shape and have a shaft portion and are rotatable about the shaft portion. Since various voltages are often applied to these cylindrical members, the voltages are supplied through the shafts.

[0003] The supply of voltage via the shaft will be described by taking a developing roller as an example. This developing roller usually covers a magnet roll 21 for forming a uniform magnetic field in the axial direction of the developing roller 20 and almost the entire magnet roll 21 as shown in FIGS. The developing sleeve 22 is provided so as to be rotatable around the magnet roll 21 in a state in which the developing sleeve 22 is rotated.

More specifically, the magnet roll 21 has a shaft portion 23 and a developing magnetic pole magnet 21a arranged along the shaft portion 23. One end of the shaft portion 23 is shown in the drawing. It is fixed to a frame (casing) of the image forming apparatus main body which is not used. On the other hand, the developing sleeve 22
The sleeve main body 22a is arranged so as to cover the magnet roll 21 so that the fixed magnet roll 21 is further used as a shaft. A shaft portion 24 for rotating the developing sleeve 22 is provided at the end portion. The shaft 24 is connected to a drive mechanism (not shown) via a gear.

In other words, when viewed as a whole of the developing roller 20, one end of the shaft of the developing roller 20 (the shaft 23 of the magnet roll 21) becomes a fixed shaft 23 fixed to the image forming apparatus main body. On the other hand, the other end (the shaft portion 24 of the developing sleeve 22) is a rotating shaft 24 for rotating the developing sleeve 22. Therefore, the magnet roll 21 fixed by the fixed shaft 23
In contrast, the developing sleeve 22 arranged around the
It is rotated by the rotation shaft 24.

The fixed shaft 23 is usually located on the front side (front side: abbreviated as F) in the image forming apparatus, whereas the rotating shaft 24 is located on the rear side (rear side: abbreviated as R). It has become.

A developing bias voltage is supplied to the developing roller 20 from the image forming apparatus main body side. This is for developing the electrostatic latent image on the surface of the photoconductor drum arranged opposite to the developing roller 20.

Here, between the main body of the image forming apparatus and the developing device, various wirings such as a wiring for various kinds of sensors such as a developing bias voltage and a toner concentration sensor, and a wiring for grounding (earth) must be connected. No. Therefore, the engaging portion in which the terminals for wiring are put together is the R of the image forming apparatus.
The image forming apparatus is provided on each of the image forming apparatus main body side and the developing apparatus side.

Specifically, the engaging portion includes a power supply terminal for a developing bias voltage, an output terminal of a toner density sensor, a ground terminal, and the like. Correspondingly, a concave terminal in which the above terminals are grouped is provided on the image forming apparatus main body side. The concave terminal has a certain degree of freedom on the frame on the image forming apparatus main body side (play is given,
While being in a floating state), the developing device is positioned and provided so as to be able to be connected to and released from the protruding terminal in accordance with the operation of inserting and removing the developing device from the image forming apparatus main body.
The above-mentioned wirings are connected by the engagement of the concave terminal and the convex terminal.

As described above, while the image forming apparatus main body side is a concave terminal, the developing apparatus side is a convex terminal, and as the developing apparatus is taken in and out of the image forming apparatus main body, the concave terminal and the convex terminal are formed. The configuration of the connector in which the external terminals are coupled and released is called a drawer connector.

Therefore, the developing bias voltage is supplied to the developing roller 20 from the terminal of the image forming apparatus main body to the shaft of the developing roller 20 in general. At this time, since the developing roller 20 includes the fixed shaft 23 and the rotating shaft 24, the method of supplying the developing bias voltage is performed by the method using the fixed shaft 23 or the method using the rotating shaft 24. is there.

In the power supply method from the fixed shaft 23 side, the developing bias voltage provided on the F side frame to which the fixed shaft 23 is fixed is connected to the developing bias voltage terminal located on the R side of the image forming apparatus main body. The configuration is such that a harness wire of a considerable length is routed to the voltage terminal. Thus, a developing bias voltage is appropriately guided to the developing sleeve 22 via the fixed shaft 23.

On the other hand, as a method of supplying power from the rotating shaft 24, for example, as disclosed in Japanese Patent Application Laid-Open Nos. 63-193164 and 11-7175,
The configuration is such that the terminal for the developing bias voltage located on the R side of the image forming apparatus main body and the rotating shaft 24 of the developing roller 20 which is also arranged on the R side are substantially in direct contact with each other.
As a result, the rotating shaft 24
, A developing bias voltage is appropriately guided.

As the above power supply method, there is also a power supply technique for a photosensitive drum (Japanese Patent Laid-Open No. 9-32566).
No. 7). In this technology, the rotation axis of the photosensitive drum,
The point that the terminal for the developing bias voltage provided in the power supply unit on the image forming apparatus main body side comes into contact with the image forming apparatus is similar to the above-described technologies.

[0015]

However, the above-described power supply method has a problem that various power supply failures occur due to the structure of the power supply mechanism.

In the method of supplying power from the fixed shaft 23 side, a harness wire of a certain length is routed. Therefore, for example, at the time of assembling the developing device, the harness wire is easily caught or broken by another member due to inappropriate harness wire processing. Further, in order to avoid such biting or disconnection, care must be taken in handling the harness wire, and the workability of the assembling work is reduced.

Further, the developing device provided with the developing roller 20 is used for maintenance such as toner replenishment, replacement of developer, cleaning of each part, or periodic replacement of components. Makes it removable. For this reason, troubles such as breakage of the harness wire and biting are likely to occur with this attaching / detaching operation.

On the other hand, in the method of supplying power from the rotating shaft 24, it is not necessary to use a harness wire for making the terminal on the image forming apparatus main body and the rotating shaft 24 substantially directly contact. Therefore, it is possible to avoid the problems such as the harness wire biting and breaking as described above.

However, in most cases, the terminal for the developing bias voltage on the image forming apparatus main body side used in the above-described power supply method is formed of a sheet metal or the like. Therefore, by attaching and detaching the developing device described above, the terminal on the image forming apparatus main body side and the rotating shaft 24 on the developing roller 20 side are connected.
Mechanical sliding with the terminal is repeated,
A spring member provided for bringing the terminal into contact with the rotary shaft 24 or the resiliency of the terminal itself is reduced, and a contact failure between the terminal and the rotary shaft 24 is likely to occur.

Further, in the power supply mechanism in the above-described power supply method, since the rotating shaft 24 in contact with the terminal for the developing bias voltage is in a rotating state, the terminal is worn by this, and further, the contact portion is further reduced. Because it is easily oxidized,
Poor contact and poor conduction are more likely to occur. Also,
There are also adverse effects such as an increase in the rotational resistance of the developing roller 20 and generation of sliding noise.

[0021] Moreover, since the engaging portion and the rotary shaft 24 is provided at a position where the R side of the image forming apparatus, in the above power supply method, contamination due to adhesion of toner and NO _X (nitrogen oxides) Is also a major problem that causes poor contact.

That is, at the position where the engaging portion and the rotating shaft 24 are disposed on the R side, a large amount of toner scatters and floats from the cleaning device or the developing device itself for removing the residual toner on the surface of the photosensitive drum. are doing. Moreover, at this position, the surrounding temperature is easily increased by a heating element such as a fixing device, and the temperature is relatively high as compared with other positions. Further, at this position, ozone is generated by discharge of a corona charger as a charging device or a transfer device, and NO _x (nitrogen oxide) is generated by the oxidizing action of the ozone.

Therefore, in the contact portion between the engaging portion and the rotating shaft 24 and the terminal (hereinafter collectively referred to as a contact portion),
(A) the floating toner easily adheres to the contact portion;
(B) further easily melted and adhered to the adhered toner is around a high temperature state, (c) NO _X is attached to the contact portion, it corrodes the contact portion, easily or cause rust, Such pollution occurs.

The above-mentioned contamination progresses due to the repetition of the contact / separation of the contact portion due to the attachment / detachment of the developing device described above, and the contact failure and the conduction failure are more easily caused. As a result, an abnormality occurs in the formed image due to a poor application of the developing bias voltage.

Therefore, in order to avoid contact failure and conduction failure due to the contamination, it is desirable to periodically clean the contact portion. At this time, both the technology and the technology,
Since the developing device can be pulled out to the F side of the image forming apparatus main body, the contact portion provided on the developing device side can be easily cleaned. However, since the contact portion on the main body side remains fixed to the R side of the main body of the image forming apparatus, the cleaning work becomes difficult.

Here, the technique disclosed in Japanese Patent Application Laid-Open
In Japanese Patent No. -7175, unlike the other techniques described above, a second bias terminal is provided so as to cover the first bias terminal on the image forming apparatus main body side, and the rotating shaft 24 contacts the second bias terminal. I have. In this configuration, since between the respective bias terminals are always conductive, the contact portion of the image forming apparatus main body is not or solidified or deposited toner and NO _X. Further, it the second bias terminal so provided in the casing of the developing device, has a drawable F side of the image forming apparatus main body together with the developing device, to easily clean the scattered toner and NO _X attached It is possible.

However, Japanese Patent Application Laid-Open No.
In the technique of No. 2, as described above, the rotating shaft 24 of the developing roller 20 and the second bias terminal are in constant contact with each other and are mechanically slid. Therefore, the problems of poor contact and poor conduction, increased rotational resistance of the developing roller 20, and occurrence of sliding noise cannot be avoided at all.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to supply a voltage to a member rotatable around a shaft so as to supply a developing bias voltage to a developing roller. in the structure, a feed mechanism such as NO _X and toner to the contact portion provided on the rotation axis side may adhere, caused by the contact portion is worn or may prevent contact failure and conduction failure, such feed It is an object of the present invention to provide an image forming apparatus which has a mechanism and can avoid problems such as an increase in rotational resistance of a developing roller and generation of a sliding noise without causing a contact failure or conduction failure.

[0029]

In order to solve the above-mentioned problems, a power supply mechanism according to the present invention provides a rotating body rotatable around a shaft section with a predetermined voltage from a power supply section. In the power supply mechanism for supplying power, the shaft portion is supported,
And a power supply bearing connected to a power supply for supplying a predetermined voltage to the rotating body.

According to the above configuration, the bearing for maintaining the rotation of the rotating body is used as the power supply terminal. Therefore, unlike the conventional power supply mechanism, the harness wire is not routed from the power supply unit or the terminal and the rotating shaft are not brought into contact with each other. Good power supply can be realized by avoiding problems such as poor contact due to wear.

It is preferable that the power supply mechanism further includes a sealing means disposed substantially in contact with the bearing and sealing a hole of the bearing into which the shaft is inserted.
This prevents dust and the like from entering the hole of the bearing, which is the contact portion between the shaft and the bearing. For this reason, the state of contact between the bearing and the shaft can be ensured to avoid the occurrence of poor contact or poor conduction, and the rotation of the shaft is not hindered. As a result, more favorable power supply can be realized.

In order to solve the above-mentioned problems, the image forming apparatus according to the present invention has a power supply mechanism for supplying a predetermined voltage from a power supply unit to a rotating body rotatable about a shaft. In the image forming apparatus, the power supply mechanism is configured to connect at least a bearing supporting one end of the shaft portion and the power supply portion, and to supply a voltage to the rotating body via the bearing. And a cleaning means for removing deposits adhering to the surface of the shaft near the bearing.

According to the above configuration, a harness line for applying (supplying) the developing bias voltage from the image forming apparatus main body becomes unnecessary. Also, there is no need to separately provide a power supply terminal that is used in a configuration that does not use a harness wire and that directly contacts the rotating shaft. Therefore, troubles such as breakage or biting of the harness wire and poor contact due to wear of the terminal do not occur.

In addition, in the prior art, the contact portion between the power supply terminal and the shaft portion is often exposed, and almost no protective measures have been taken to prevent the attachment from adhering to the contact portion. in the present invention, even if scattered toner or NO _X is attached to the shaft portion surface, thereby removing the above cleaning means, because the hole of the bearing can be sealed by the cleaning means, the conductive failure Can also be prevented. Therefore, it is possible to more stably supply the developing bias voltage than before.

In the image forming apparatus, one end of the shaft in the power supply mechanism is supported by a plurality of bearings arranged in series along the direction of the shaft, and at least one of the plurality of bearings is supported. The power supply circuit may be formed by connecting the power supply unit to the power supply unit.

Further, it is more preferable that the plurality of bearings in the power supply mechanism include a rolling bearing and a sliding bearing, respectively, and that a power supply unit is connected to at least the sliding bearing.

Thus, the bearing function and the function of the power supply terminal can be shared by each bearing. In particular, since the rolling bearing is provided with a rolling element portion, the shaft portion can be rotated more smoothly, so that it is used as the bearing itself, while the sliding bearing comes into contact with the shaft portion with a large area. Since the power supply unit is connected to at least the sliding bearing in addition to the provision of the sliding surface, the use of the sliding bearing as a power supply terminal can further clarify the function allocation.

Further, if a plurality of the plurality of bearings are connected to the power supply unit, a power supply circuit having a plurality of power supply paths is formed. Therefore, even if a certain power supply path is disconnected, another power supply path is used. This makes it possible to improve the reliability of the power supply mechanism.

Further, the plurality of bearings in the power supply mechanism are composed of one rolling bearing fixedly disposed and one sliding bearing disposed so as to be movable in a direction perpendicular to the shaft by the moving means. A power supply unit is connected to at least the slide bearing to form a power supply circuit, and the moving unit includes an elastic member, and the elastic member does not insert the shaft portion. In this state, it is more preferable to maintain the position of the slide bearing so that the axis of the slide bearing is shifted from the axis of the rolling bearing.

As a result, the sliding mechanism and the rolling bearing are biased by the moving mechanism having the elastic member so that the axes of the sliding bearing and the rolling bearing are shifted. Therefore, in a state where the shaft portion is inserted into the slide bearing, the surface of the shaft portion and the slide surface of the slide bearing are securely brought into close contact with each other. For this reason, the sliding bearing as the power supply terminal and the shaft portion surely contact and conduct without causing contact failure or conduction failure, so that the power supply performance of the power supply mechanism can be further improved.

In the above-described image forming apparatus, when the bearing in the power supply mechanism is a rolling bearing, it is preferable that a conductive grease is filled and sealed in a portion where the rolling element is disposed.

In the case where the bearing used as the power supply terminal is a rolling bearing, the plurality of rolling elements are usually arranged between the races formed of a combination of an inner ring and an outer ring and maintained at a predetermined interval by a retainer. It has a configuration. Therefore, the contact between the bearing ring and the rolling element becomes almost point contact, and depending on the situation, there is a possibility that poor contact or poor conductivity may occur. Therefore, by adopting the above configuration, the rolling element and the bearing ring come into contact with each other in a larger area via the conductive grease, so that the conductivity of the rolling element portion is improved, and the conductivity of the power feeding mechanism is improved. It can be made even more reliable.

In the above image forming apparatus, it is preferable that the bearing in the power supply mechanism is made of a conductive material containing at least one of a sintered metal and a conductive resin.

Since these materials are a sintered metal or a conductive resin which has been conventionally suitably used as a bearing, it is necessary to make the above-mentioned power supply mechanism having the bearing inexpensive, simple and reliable. it can.

In the above-described image forming apparatus, the rotating body supplied with power by the power supply mechanism further includes a developing roller,
Preferably, at least one of a photosensitive drum, a contact type charger, and a contact type transfer unit is used.

[0046] The shaft portion in these rotary body tends to adhere deposits such scattered toner and NO _X. Thus, by applying the power supply mechanism having the above configuration, it is possible to provide an image forming apparatus in which a power supply circuit and a ground circuit that are less likely to cause conduction failure and contact failure are formed.

In the above-described image forming apparatus, it is preferable that the cleaning unit is arranged at a position closest to the rotating body in the power supply mechanism.

In this way, even if the foreign matter adheres to the shaft surface while the rotating body is rotating, it is cleaned by the cleaning means (rotational cleaning function) and the foreign matter is deposited in the hole of the bearing. It can be sealed so that it does not enter (seal function). As a result, the intrusion of the deposits into the hole of the bearing is prevented, and the developing bias voltage can be reliably supplied.

In the image forming apparatus, it is preferable that the cleaning unit is fixed to a shaft of a rotating body or a bearing.

If the cleaning means is fixed to the shaft of the rotating body, the cleaning means also rotates with the rotation of the shaft, so that the above-mentioned cleaning function during rotation and the sealing function can be made more reliable. it can. In addition, since the cleaning means is fixed to the shaft, the cleaning means can be easily replaced when the shaft is removed.

On the other hand, if the cleaning means is fixed to the bearing, when the tip of the shaft is inserted into the bearing, the adhering matter on the surface of the tip is wiped off by the cleaning means, and the tip of the shaft in contact with the bearing is removed. The surface can be kept in a clean state with no deposits (cleaning function at the time of insertion). Therefore, the adhering substance is prevented from entering the hole of the bearing, and the developing bias voltage can be reliably supplied.

In the above-mentioned image forming apparatus, it is preferable that the cleaning means is a moving seal.

The above-mentioned motion seal is conventionally used to seal a fluid, a granular material or the like filled in a casing or the like so as not to leak. therefore,
Conversely, it can be favorably used as a sealing material for preventing intrusion of extraneous matter and the like into the hole of the bearing. therefore,
It is possible to obtain a cleaning unit in which the sealing function is further improved.

[0054]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4 and FIGS. In addition,
The present invention is not limited to this.

The power supply mechanism according to the present invention is suitably used in a configuration for supplying a voltage to a member rotatable by a shaft portion, and is, for example, a developing roller provided in a developing device of an image forming apparatus. The present invention can be suitably applied to the supply of the developing bias voltage with respect to.
Therefore, in the present embodiment, a case in which the developing bias voltage is supplied to the developing roller will be described as an example.

As shown in FIG. 1, the power supply mechanism 10 according to the present embodiment has a rotating shaft 24 of a developing roller inserted on the rear side (rear side: abbreviated as R) of the image forming apparatus. And a cleaning unit (cleaning means) 12 integrated with the power supply bearing 11. Note that the front side of the image forming apparatus is abbreviated to F as the front side. In addition, F of the developing roller
The side is a fixed shaft (see FIG. 14), and a magnet roll disposed in the developing sleeve of the developing roller is fixed to a frame (casing) of the image forming apparatus main body.

As shown in FIGS. 1 and 2, the power supply bearing 11 has a hole 11a penetrating the power supply bearing 11 so as to allow the rotation shaft 24 to be inserted therein. It is fixed to. The rotating shaft 24 of the developing roller is inserted from the F side to the R side into the hole 11 a of the power supply bearing 11.

The power supply bearing 11 forms a power supply circuit 14 by being electrically connected to a bias power supply (power supply unit) 13 for applying a developing bias voltage. Thus, in the power supply mechanism 10 according to the present invention, the power supply bearing 1
1 functions not only as a bearing for supporting the developing roller, but also as a power supply terminal for supplying a developing bias voltage to the developing roller via the rotating shaft 24. The power supply bearing 11 and the bias power supply 13
Is a circuit configuration required at least for the power supply circuit 14 in the present invention, and it goes without saying that other circuit configurations may be connected.

In the present embodiment, the cleaning section 12 is disposed at a position on the F side (ie, the side where the rotary shaft 24 is inserted) in the hole 11a of the power supply bearing 11. That is, looking at the positional relationship between the cleaning unit 12 and the power supply bearing 11, the cleaning unit 12 is located at the position (F
Side), and then the power supply bearing 11 is disposed.

According to the above-described structure, as shown in FIG. 3A, the attached matter (scattered toner or a discharge product such as NO _x (nitrogen oxide)) 26 is attached to the tip surface of the rotating shaft 24.
Is attached to the hole 11 of the power supply bearing 11.
3B, when the rotating shaft 24 is inserted into the feeding shaft 11, the tip surface of the rotating shaft 24 that is in contact with the power supply bearing 11 is wiped off by the cleaning unit 12 as shown in FIG.
6 (cleaning function at the time of insertion).

In the state where the developing roller is rotating,
Even if the deposit 26 adheres to the surface of the rotating shaft 24, it is cleaned by the cleaning unit 12 (rotational cleaning function). Therefore, the attachment 26 is prevented from entering the hole 11a of the power supply bearing 11, and the developing bias voltage is reliably supplied.

Further, even after the rotation shaft 24 is inserted, as shown in FIG. 3B, the adhering substance 26 is prevented from entering the hole 11a by the cleaning unit 12 (seal). function). Therefore, the contact state between the power supply bearing 11 and the rotating shaft 24 is not hindered by the deposit 26, and the rotating shaft 24 is not corroded by the deposit 26, so that the rotating shaft 24 can be rotated more smoothly. In addition, the developing bias voltage is more reliably supplied without the occurrence of contact failure or conduction failure between the power supply bearing 11 and the rotating shaft 24.

In the present invention, the cleaning unit 1
2 is required to have at least the cleaning function at the time of rotation and the sealing function, and more preferably has the cleaning function at the time of insertion. The cleaning unit 1
Since the rotary shaft 24 is inserted in a state where the rotary shaft 24 is fixed to the power supply bearing 11, the power supply bearing 2 has a ring shape having substantially the same diameter as the hole 11a of the power supply bearing 11.

Therefore, it is preferable that the cleaning section 12 is a motion seal conventionally used for sealing a moving portion of the rotating shaft 24. Specific examples of the motion seal include, for example, a lip-shaped seal (having a lip for forming a sealing surface), a V-packing (a ring-shaped molded packing having a V-shaped cross section, and a V-ring / V-shaped packing). Seals (also referred to as trade names), G seals (trade names), and the like. Each of these motion seals has a ring shape corresponding to the diameter of the rotating shaft 24. As the material of the motion seal, a material having elasticity (elastic material) such as an elastomer material such as viton rubber or neoprene rubber is preferably used, but is not particularly limited.

In the present embodiment, an example using a lip-shaped seal will be described as an example of the motion seal. As shown in FIG. 15A, the lip-shaped seal is, for example, a sheet 12a having a thickness of about 0.5 mm, which is slightly smaller than the shaft diameter (diameter) D of the rotating shaft 24. A seal hole 12b having a diameter (diameter) d is formed.
As shown in FIG. 15B, the edge of the seal hole 12b is provided with a crease 12c toward one surface of the sheet 12a.
A restoring force acts in the direction. As a particularly suitable material for the lip-shaped seal, PTFE (ethylene tetrafluoride resin) is exemplified among the elastic materials.

When the rotary shaft 24 is mounted in the seal hole 12b, as shown in FIG. 16, the bent habit 12c forms a conical (conical) lip 12d. This lip 1
Since a restoring force (arrow F in the figure) acts on 2d due to the elastic force of the material of the sheet 12a, the lip 12d comes into contact with the peripheral surface of the rotating shaft so as to "bite".
A sealing effect is exhibited. The lip 12d having such a restoring force is called a radial lip. However, FIG.
Here, the size of the lip 12d is exaggerated for convenience of explanation. The arrow r in the figure indicates the rotation direction of the rotation shaft 24.

The ratio between the diameter d of the seal hole 12b provided with the kinks and the shaft diameter D of the rotary shaft 24 is particularly limited as long as the rotary shaft 24 is sufficiently inserted into the seal hole 12b and the sealing effect can be exhibited. However, if the shaft diameter D of the rotating shaft 24 is 6 mm, for example, the diameter d of the seal hole 12b is 5.
It is sufficient that the distance is about 5 mm (that is, D
> D, see FIG. 15 (b), where the dashed line in FIG. 15 (b) indicates the center of the seal hole 12b or the rotating shaft 24). Similarly, the thickness of the sheet 12a is not limited to about 0.5 mm, but may be appropriately changed depending on the material, shape, and the like as long as a sufficient sealing effect can be exhibited.

It should be noted that the above-mentioned lip-shaped seal is
As shown in FIG. 16, the lip 1
The bottom side of the conical shape in 2 d is fixed on the power supply bearing 11. As a result, the lip type seal becomes non-rotating with respect to the rotating shaft 24, and the seal hole 12b and the rotating shaft 2
The sealing property is exhibited by the sliding of the side surface of the fourth member.

As another example of the motion seal,
G seal. This G seal is a type of oil seal, and as shown in FIGS. 17A and 17B, a seal portion 12e is supported by a backup ring 12f provided between the power supply bearing 11 and the rotating shaft 24, and 2
It is in contact with 4 in an inclined state. The G seal shown in FIG. 17A has a backup ring 1 in the seal portion 12e.
By arranging 2f, the contact state of the seal portion 12e is maintained. The G seal shown in FIG. 17B has a backup ring 12f directly contacting the power supply bearing 11.
Is provided with a seal portion 12e on a part of the rotary shaft 24 side. Examples of the material of the seal portion 12e include an elastic material such as the elastomer material.

The cleaning unit 12 in the present invention
Any configuration may be used as long as at least both the above-mentioned rotation cleaning function and the sealing function can be realized (more preferably, the above-mentioned insertion cleaning function can also be realized). Therefore, the motion seal as the cleaning unit is not limited to the lip seal or the G seal, and the cleaning unit is not limited to the motion seal alone.

In the present embodiment, an example in which a developing roller is used as a rotating body is described. For this reason, scattered toner and N
Since O _X there are many, the cleaning unit 12 is disposed on the side close to the developing roller body. However, the position of the cleaning unit 12 is not limited to this, and any position may be used as long as it is possible to prevent various kinds of deposits 26 adhering to the surface of the rotating shaft 24 from entering the hole 11 a of the power supply bearing 11. .

As a specific configuration of the power supply bearing 11, a rolling bearing as shown in FIGS. 1 to 3 or a sliding bearing as shown in FIG. 4 is suitably used.

First, the rolling bearing is not particularly limited as long as the rolling element supports the load of the rotating shaft portion. For example, a ball bearing or a roller bearing is used. It is preferably used. Note that a portion where these rolling elements are arranged is referred to as a rolling element portion 11b (see FIGS. 2 and 3). As for the arrangement of the power supply bearing 11, the rolling element 11 b
It is preferable that the arrangement is such that it is located on the R side of 1a (the side opposite to the side where the rotary shaft 24 is inserted). This makes it more difficult for adhering substances to enter the rolling element portion 11b, and makes it easier for the rolling element portion 11b to support the load of the rotating shaft 24.

It is highly preferable that the rolling element portion 11b is filled and sealed with conductive grease. When the power supply bearing 11 is a rolling bearing, the rolling bearing
Usually, a plurality of rolling elements are arranged between races that are formed by a combination of an inner ring and an outer ring and are maintained at a predetermined interval by a retainer. Therefore, the contact between the bearing ring and the rolling element becomes almost point contact, and depending on the situation, there is a possibility that poor contact or poor conductivity may occur. Therefore, by filling and sealing the conductive grease to increase the contact area between the rolling element and the bearing ring and improve the conductivity of the rolling element portion, the conductivity as the power supply terminal in the power supply bearing 11 is improved. Be certain.

The conductive grease is not particularly limited, but in consideration of long-term durability,
A silicone-based conductive grease that causes little chemical change or deterioration is particularly preferably used. Specific examples of the silicone-based conductive grease include KS-660 (trade name: manufactured by Shin-Etsu Chemical Co., Ltd.) and NPC grease (trade name: manufactured by Nippon Mining & Oil Co., Ltd.).

Next, as shown in FIG. 4, the sliding bearing has a sliding surface 11c that comes into surface contact with the rotating shaft 24, and the sliding surface 11c and the shaft portion The configuration is not particularly limited as long as it is a configuration in which a sliding motion occurs between them.

The power supply bearing 11 is made of a conductive material regardless of the configuration of the rolling bearing and the sliding bearing. The conductive material is not particularly limited as long as it can accurately and surely support the rotating shaft 24 without hindering the rotation of the rotating shaft 24 and has conductivity. ) Or sintered metal mainly composed of Fe (iron); a resin containing a fine powder of a conductive substance such as carbon or metal; or a conductive resin material such as a resin filled with carbon fiber or metal fiber; Used for

Feeding bearing 1 formed of the above sintered metal
Specific examples of 1 include sintered oil-impregnated bearings such as copper-based oil-impregnated bearings, iron-based oil-impregnated oil-impregnated bearings, and aluminum-based oil-impregnated oil-impregnated bearings. The bearing body of these sintered oil-impregnated bearings is formed by compressing a metal powder in advance into a cylindrical green compact, then sintering the green compact and adjusting the dimensional accuracy by sizing to obtain the desired sintered body. After the body, it is further impregnated with lubricating oil. Therefore, the lubricating oil is stored in the pores included in the bearing body.

Examples of the metal powder include a powder material such as bronze, iron, and aluminum, and a powder material in which a solid lubricant such as graphite or molybdenum disulfide is added to the powder material as required. . Further, in the sintered oil-impregnated bearing, it is preferable that the entire bearing body is formed of the same material, such as a bronze-based powder material in the case of copper. As a result, the strength and dimensional stability of the bearing can be improved, and the power supply efficiency as the power supply terminal can be improved.

The conductive resin may be, for example, 60 to 90 parts by weight of a polyacetal resin,
A resin composition having a composition of 5 to 20 parts by weight of carbon black (lubricating component) having an oil absorption of 3 ml / g or more and 0 m ² / g or more and 5 to 20 parts by weight of an ethylene copolymer is preferably used. In addition, as the ethylene-based copolymer,
Examples include an ethylene-butene copolymer, an ethylene-methacrylic acid copolymer, and an ethylene-glycidyl methacrylate copolymer.

The power supply bearing 11 does not need to be entirely made of a conductive material. If the developing bias voltage can be sufficiently supplied to the rotating shaft 24, the power supply bearing 11 may be partially made of a conductive material. It may be. For example, in the case of a rolling bearing, only the rolling element portion 11b may be made of a conductive material and the biasing power supply 13 may be directly connected to the rolling material portion 11b. A configuration may be employed in which only the vicinity of the surface 11c is made of a conductive material, and this is directly connected to the bias power supply 13.

In the present invention, the power supply bearing 11 is
It is electrically insulated from the frame of the image forming apparatus main body. In the conventional developing device, the bearing that supports the developing roller does not function as a power supply terminal, so there is no need to insulate the frame (normally, a sheet metal) of the image forming apparatus main body from the bearing. Since 11 functions not only as a bearing but also as a power supply terminal, the voltage applied to the power supply bearing 11 escapes to the frame. Therefore, it is necessary to completely separate the power supply bearing 11 from the frame.

The configuration for insulation is not particularly limited. For example, a configuration in which an insulating plate made of an insulating material is interposed between the frame of the image forming apparatus main body and the power supply bearing 11 is preferable. Used for The insulating material is not particularly limited, but usually includes various plastics.

As described above, the power supply mechanism according to the present embodiment supplies a predetermined voltage from the bias power supply to the rotating body rotatable by the shaft portion. A power supply bearing that supports the shaft inserted in the hole and is connected to the bias power supply to supply a predetermined voltage to the developing roller; and an adhering substance attached to the surface of the rotating shaft inserted in the hole. And a cleaning unit for preventing the attached matter from entering the hole. Further, it is preferable that the cleaning unit is disposed at a position closest to the developing roller in the power supply mechanism.

According to the above configuration, a harness line for applying (supplying) the developing bias voltage from the image forming apparatus main body is not required, so that troubles such as disconnection and jamming of the harness line can be avoided, and the power supply bearing can be prevented. Since the power is supplied directly from the power supply, unlike the conventional configuration in which a separate power supply terminal is provided, contact failure due to wear of the terminal does not occur.

[0086] Moreover, even if scattered toner or NO _X is attached to the rotating shaft surface, is removed by the cleaning unit during the rotation of the connecting state or the developing roller of the developing roller, and since the hole portion is sealed by the cleaning unit, Corrosion due to oxidation or electric corrosion does not occur due to these deposits, and therefore, occurrence of poor conductivity can be prevented. Therefore,
The development bias voltage can be supplied more stably than before.

Further, by using a plain bearing made of sintered metal or conductive resin or a rolling bearing in which conductive grease is sealed in the rolling element portion, the power supply mechanism according to the present invention can be made inexpensive and simple. And it can be set as a reliable structure.

Embodiment 2 Another embodiment of the present invention will be described below with reference to FIGS. Note that the present invention is not limited to this. Further, for convenience of explanation, members having the same functions as those used in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.

In the power supply mechanism 10 of the first embodiment, only one bearing is provided on the rotating shaft 24 side, and the power supply circuit 14 is formed by connecting the bearing and the bias power supply 13. In the power supply mechanism 10a of the embodiment, there are a plurality of bearings on the rotating shaft 24 side, and by connecting at least one of the plurality of bearings to the bias power supply 13,
A power supply circuit is formed.

As shown in FIG. 5, in power supply mechanism 10a in the present embodiment, a plurality of, for example, two bearings are used as bearings for supporting rotating shaft 24, and are arranged in series along the direction of the shaft. I have. Of these, the bearing on the side (F side) close to the developing roller is the first bearing 15a,
It is a rolling bearing (specifically, a ball bearing). Also,
The bearing on the side (R side) away from the developing roller is the second bearing 15b, which is a sliding bearing.

As in the first embodiment, the cleaning portion 12 of the lip-shaped seal is provided at the position of the first bearing 15a on the side (F side) close to the developing roller.
The first bearing 15a is integrated and fixedly arranged.
Further, the second bearing 15b is connected to a bias power supply 13 to form a power supply circuit 14. In this state,
The rotating shaft 24 inserted into the hole 11a is connected to the first bearing 15a.
Of the second bearing 15
b is in surface contact with the sliding surface 11c. Therefore, while the first bearing 15a functions as a bearing for supporting the rotating shaft 24, the second bearing 15b mainly functions as a power supply terminal although it also functions as a bearing.

As described above, when the rotating shaft 24 of the developing roller is supported by a plurality of bearings, each bearing shares the load on the shaft portion of the developing roller, and the bearing having the main function as the main function is supplied with power. The role of the terminal can be divided into that having the main function. As a result, it is possible to more reliably supply power to the rotating developing roller.

In particular, as described above, it is preferable that the bearing mainly functioning as the bearing itself (the first bearing 15a) be a rolling bearing, and the bearing mainly functioning as a power supply terminal (the second bearing 15b). Is preferably a plain bearing. This is because it is better for a bearing functioning as a bearing itself to prioritize smooth and reliable rotation of the rotating shaft 24, and therefore, the rolling element portion 11 like a rolling bearing.
b, it is preferable that the bearing that mainly functions as a power supply terminal should give priority to feeding the power by reliably contacting the rotating shaft 24, and therefore, a slip having a large contact area with the rotating shaft 24. This is because a slide bearing having the surface 11c is preferable.

Further, by arranging the cleaning portion 12 at the position closest to the developing roller main body (on the side of the first bearing 15a), the scattered toner and NO _{X can be obtained} similarly to the first embodiment.
Is removed by the cleaning unit 12 even if it adheres to the surface of the rotating shaft 24, and the hole 11a is
2 sealed. Therefore, generation of a conductive failure can be prevented by deposits such as toner and NO _X adhering to the rotary shaft 24, also it is avoided even contact failure due to wear of the pin.

Further, in the above configuration, as shown in FIG. 5, it is preferable that the first bearing 15a and the second bearing 15b are closely arranged in series. Accordingly, the first bearing 15a to which the bias power source 13 is not connected can also function as a power supply terminal, so that the contact area between the power supply terminal and the rotating shaft 24 is increased, and the conductivity is increased, and the rotating shaft is improved. 24 can be improved in reliability. At this time, the first bearing 15 which is a rolling bearing is used.
a, in the same manner as in the first embodiment, the rolling element 11
Preferably, b is filled with a conductive grease and sealed.

In the above example, the power supply circuit 14 is formed by connecting only the second bearing 15b of the first bearing 15a and the second bearing 15b to the bias power supply 13.
As shown in FIG. 3, both the first bearing 15a and the second bearing 15b are connected to the bias power supply 13, and the power supply circuit 14a
May be formed. In the power supply circuit 14a, since the power supply path is duplicated (bypassed), even if one of the power supply paths stops functioning due to disconnection or the like, power supply to the developing roller is continued by the other power supply path. be able to. By bypassing the power supply path in this manner, the reliability of the entire power supply mechanism 10a can be improved.

Further, the first bearing 15a and the second bearing 1
When the power supply circuit 14a is formed by connecting both the bias power supply 13 and the bias power supply 13 to each other, the first bearing 15a and the second bearing 15b may be brought into close contact with each other as shown in FIG. As shown in the figure, the first bearing 15a and the second bearing 15
b may be spaced apart from each other.

In the former case, as in the configuration in which the second bearing 15b and the bias power supply 13 are connected, the contact area between the bearing as the power supply terminal and the rotary shaft 24 is increased, and the conductivity is increased. The reliability of power supply to the rotating shaft 24 can be improved. On the other hand, in the latter case, the first bearing 1
5a and the second bearing 15b and the bias power supply 13 are connected to each other. Therefore, in consideration of the occurrence rate of a problem such as disconnection, the contact area is sufficiently increased without necessarily bringing the bearings into contact with each other. Can be regarded as increasing. Conversely, by providing a gap between each bearing,
There is an advantage that the load on the rotating shaft 24 can be more dispersed. Further, by providing a certain distance between the bearings, even if toner or the like enters the second bearing 15b, which is a sliding bearing, the first bearing 15a, which is a rolling bearing,
The transfer of toner and the like can be suppressed.

Further, in the present embodiment, a structure for further improving the contact state between the sliding surface of the second bearing 15b, which mainly functions as a power supply terminal, and the rotating shaft 24 is provided. preferable.

For example, as shown in FIG. 8, a first bearing 15a, which is a rolling bearing, is arranged on the developing roller 20 side (F side), and is arranged in series with the first bearing 15a along the direction of the rotation shaft 24. It is assumed that the disposed second bearing 15b is a sliding bearing. At this time, an oscillating mechanism (moving means) 16 that enables the second bearing 15b to oscillate along a surface of a casing (frame) 25 of the developing device arranged in a direction orthogonal to the rotation shaft 24. Further provided.

The swing mechanism 16 includes a flat terminal plate 16a having a structure for holding the second bearing 15b, a fixed plate 16b for swingably fixing the terminal plate 16a, and one of the terminal plates 16a. And a press-fit spring (elastic member) 16c for urging in the swing direction.

The fixing plate 16b is arranged so as to fit into the casing 25 as shown in FIG.
As shown in (1), there are a plurality (two in the figure) of projections 16d that define the position of the swinging terminal plate 16a. Terminal board 16
As shown in FIG. 9, a has a substantially rectangular shape having a holding structure for holding the second bearing 15b at the distal end, and rotates around a substantially central portion in the longitudinal direction as a fulcrum 16e. It is fixed with screws or the like so that it becomes possible. However, since the plurality of protrusions 16d serve as stoppers for suppressing rotation on the side opposite to the side having the holding structure, the side having the holding structure (the side holding the second bearing 15b).
Can rotate only at a certain predetermined angle, that is, can swing only within a predetermined range.

Since the terminal plate 16a functions as a bias terminal for conducting with the second bearing 15b functioning as a power supply terminal, the terminal plate 16a is formed of a conductive material such as various metals. That is, in the above configuration, the power supply circuit 14 includes the bias power supply 13, the second bearing 15b, and the terminal plate 16a.
Is included.

When the casing 25 of the developing device is conductive (for example, when the casing 25 is made of metal), the fixing plate 16b is used for the casing 2b.
5 is used to insulate the second bearing 15 from the second bearing 15b. The fixing plate 16b is made of an insulating material (various resins /
For example, as shown in FIG. 8, it is provided so as to fit into the casing 25. The configuration in which the fixing plate 16b is provided on the casing 25 is not limited to this.
In addition, in FIGS. 1 to 7 and FIGS. 11 and 12 described later, the configuration corresponding to the fixing plate 16b is not described, but when the casing 25 has conductivity, the structure corresponds to the fixing plate 16b. Bearing and casing 2
Needless to say, a member (insulating member) that insulates the second member from the second member is provided.

Further, the compression spring 16c has a linear shape bent at a substantially central portion, and is engaged with the fulcrum 16e, the held second bearing 15b, and one of the plurality of projections 16d, and the terminal plate 16a. Note that, instead of the compression spring 16c, an elastic member made of an elastomer such as hard rubber, plastic, or the like can be used.

When the rotary shaft 24 of the developing roller 20 is not inserted, as shown in FIG. 10A, the pressure spring (elastic member) 16c is connected to the shaft center of the hole 11a of the second bearing 15b.
The terminal plate 16a is urged in the swinging direction of the terminal plate 16a so as to be held in a state of being shifted (offset) from the axis of the hole portion 11a of the fixed first bearing 15a (the direction of the arrow in the drawing). ).

In the above configuration, the first bearing 15a and the second bearing 15b are arranged in series. However, since the swinging mechanism is provided, if the rotary shaft 24 is not inserted, FIG. As shown in (a), the axes of the bearings are shifted. When the rotary shaft 24 is inserted into the first bearing 15a and the second bearing 15b, as shown in FIG. 10B, the second bearing 15b whose axis is shifted from the axis of the first bearing 15a. Is moved by the rocking mechanism so that the axes coincide. Here, since the second bearing 15b is urged by the pressure spring of the swing mechanism in a direction for maintaining the state where the axis is shifted (in the direction of the arrow in the drawing), the second bearing 15b is in contact with the sliding surface of the second bearing 15b. The rotating shaft 24 is always in contact with a certain surface.

As a result, the contact state between the second bearing 15b and the rotating shaft 24 becomes good, and reliable and good conduction can be achieved, so that poor contact or poor conduction does not occur. Therefore, it is possible to prevent the interruption of the developing bias voltage, and it is possible to further improve the power supply performance of the power supply mechanism according to the present invention.

The degree of deviation of the axis between the first bearing 15a and the second bearing 15b is not particularly limited, but the structure of the present embodiment (when the diameter φ of the rotating shaft 24 is 8 m
In m), for example, the thickness is preferably in the range of 0.1 to 3 mm, and more preferably about 0.5 mm. If the deviation of the axis is out of this range, it is difficult to smoothly insert the rotating shaft 24 inserted in the first bearing 15a into the hole 11a of the adjacent second bearing 15b whose axis is deviated. Is not preferred.

As described above, the rotating shaft is supported by the plurality of bearings arranged in series along the direction of the rotating shaft. Preferably, the plurality of bearings include a rolling bearing and a sliding bearing, respectively. In this case, the bearing function and the function of the power supply terminal can be shared by each bearing. In addition, by connecting a plurality of the plurality of bearings and the power supply unit to form a power supply circuit, the reliability of the power supply mechanism can be improved.

When a bias power supply is connected to any one of the plurality of bearings, it is preferable that the bearings be in close contact with each other. Thereby, the contact area between the bearing functioning as the power supply terminal and the rotary shaft is increased, the conductivity is increased, and the reliability of power supply to the rotary shaft can be improved. Furthermore, as long as a bias power supply is connected to each of the plurality of bearings, the bearings may be closely contacted or may be separated from each other.

In addition, when two bearings are arranged in series, one of the bearings is fixed, the other bearing is connected to a bias power supply, and the direction of the fixed shaft is orthogonal to the direction of the fixed shaft by a swing mechanism or the like. The shaft centers of the bearings are slightly displaced in a state where they can be moved in the directions. As a result, the bearing movable by the swinging mechanism surely comes into contact with the fixed shaft into which the inserted shaft is inserted, so that the power feeding performance of the power feeding mechanism can be further improved.

[Embodiment 3] Still another embodiment of the present invention will be described below with reference to FIGS. Note that the present invention is not limited to this. Further, for convenience of explanation, members having the same functions as the members used in the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

In the first and second embodiments, the cleaning section 12 is fixed to the bearing at a position close to the developing roller. However, in the present embodiment, the cleaning unit 12 is configured to be fixed to the rotating shaft 24.

That is, the power supply mechanism 1 according to the present embodiment
As shown in FIG. 11 (a) or FIG. 12 (a), the configuration of Oc is that the power supply circuit 14 is formed by connecting the bias power supply 13 to the power supply bearing 11 according to the first embodiment.
However, the cleaning unit 12 is not fixedly arranged at a position on the developing roller side (F side) of the power supply bearing 11, and the cleaning unit 12 is attached to the rotating shaft 24 inserted into the hole 11 a of the power supply bearing 11. A (lip-shaped seal) is fixed to the cleaning unit mounting seat 17.

In this configuration, FIG. 11B or FIG.
As shown in (b), the cleaning unit 12 also rotates with the rotation of the rotating shaft 24. At this time, the cleaning unit 1
The tip of the second lip contacts the end face of the power supply bearing 11, cleans the surface of the rotating shaft 24 near the power supply bearing 11, and seals the hole 11 a of the power supply bearing 11. Therefore, the same effect as that of the non-rotating cleaning unit 12 in the first embodiment can be obtained.

In addition, the cleaning unit 12 is
The cleaning unit 12 can be easily replaced by removing the developing roller. Therefore, even when the performance of the cleaning unit 12 is deteriorated, it is possible to easily replace components.

Further, in the configuration of the present embodiment, the cleaning unit 12 is
Unlike the configuration in which the rotary shaft 24 is fixed, cleaning of the front end surface accompanying insertion of the rotating shaft 24 (cleaning function at the time of insertion: FIG. 3)
), But the tip of the rotating shaft 24 of the developing roller is
As the developing device is removed from the image forming apparatus main body, the developing apparatus can be pulled out to the F side of the apparatus main body, so that cleaning can be performed relatively easily during maintenance.

As described above, after the developing roller is mounted on the cleaning section 12 of the present invention, the contact section (hole section 11) between the rotating shaft 24 and the power supply bearing 11 is formed.
Since a function (a cleaning function during rotation and a sealing function) for preventing adhering substances from entering a) is given priority, the cleaning unit 12 is fixed to the rotating shaft 24 as in the present embodiment. Even with the configuration, more favorable power supply can be realized.

FIGS. 11 (a) and 11 (b) show examples where the power supply bearing 11 is a rolling bearing, and FIGS. 12 (a) and (b) show examples where the power supply bearing 11 is a slide bearing. Is shown in

Further, in each of the above-described embodiments, an example has been described in which the developing roller is used as the rotating body supplied with power by the power supply mechanism. This developing roller has, for example, a diameter φ of a rotating shaft of 8 mm and a rotation speed of 200 rpm. However, the rotating body to which the present invention can be applied is not limited to such a developing roller. Absent.

That is, the power supply mechanism according to the present invention can be very preferably applied to a rotating body which needs to apply a predetermined voltage, such as the developing roller, in an image forming apparatus.

For example, as shown in FIG. 13, in a general image forming apparatus 1 including an image reading unit 2, an image forming unit 3, a fixing unit 4, a paper feeding unit 5, a paper discharging unit 6, and the like. In addition to the developing roller 20 provided in the developing device 3a, the photosensitive drum 3
0, a contact type charger 40, and a contact type transfer unit 50. Since these rotators constitute the image forming unit 3, it is in a state in which extraneous matter such as scattered toner and NO _X is very easily adhered to the shaft (rotation axis). Therefore, by applying each of the power supply mechanisms 10, 10a, and / or 10b, it is possible to form a power supply circuit and a ground circuit that are less likely to cause poor conduction and poor contact.

Further, in the developing roller 20 in each of the above embodiments, as shown in FIGS. 14A and 14B, one end of the shaft portion is the rotating shaft 24 of the developing sleeve 22 and is supported by a bearing. But the other end is a magnet roll 21
And is fixed to a frame or the like of the image forming apparatus main body. However, since the rotating body normally supports the rotating shaft by a pair of bearings, in the power supply mechanism according to the present invention, of the pair of bearings, a structurally advantageous side (for example, a power supply unit) is used. (Adjacent side)
Is preferably selected to form a power supply circuit. Thereby, the wiring of the power supply circuit can be simplified.

In each of the above embodiments, as described above, the power supply mechanism according to the present invention is applied to the developing roller in the image forming apparatus. However, the application target of the power supply mechanism according to the present invention is not limited to the image forming apparatus, and the power supply mechanism is rotatable around a shaft that needs to supply a predetermined voltage from a power supply unit. As long as it is a rotating body, it can be applied to any configuration.

That is, the power supply mechanism according to the present invention is suitably used when a predetermined voltage is supplied from a power supply unit to a rotating body rotatable about a shaft supported by a bearing. be able to. In this case, a configuration corresponding to the cleaning unit is not necessarily required.

As a result, since the bearing is used as a power supply terminal, unlike a conventional power supply mechanism, a harness wire is not routed from the power supply unit, and the terminal does not contact the rotating shaft. Good power supply can be achieved by avoiding problems such as poor conduction due to harness wire biting or breaking, or poor contact due to wear of terminals and shafts.

Further, in an environment in which dust, extraneous matter, and the like easily enter the hole of the bearing, the seal is disposed substantially in contact with the bearing and seals the hole of the bearing into which the shaft is inserted. It is preferable to provide a means (cleaning unit). Thereby, the contact state between the bearing and the shaft is ensured to avoid the occurrence of poor contact or poor conduction, and the rotation of the shaft is not hindered and smooth rotation is possible. As a result, more favorable power supply can be realized.

[0129]

As described above, the power supply mechanism according to the present invention includes the power supply bearing that supports the shaft of the rotating body and is connected to the power supply to supply a predetermined voltage to the rotating body. Configuration.

According to the above configuration, the bearing is used as a power supply terminal.
Good power supply can be achieved by avoiding problems such as poor conduction due to harness wire biting or breaking, or poor contact due to wear of terminals and shafts.

It is preferable that the power supply mechanism further includes sealing means disposed substantially in contact with the bearing to seal a hole of the bearing into which the shaft is inserted.
As a result, the contact state between the bearing and the shaft can be ensured to avoid the occurrence of poor contact or poor conduction, and the shaft can also rotate smoothly. As a result, more favorable power supply can be realized.

As described above, the image forming apparatus according to the present invention has an image forming apparatus having a power supply mechanism for supplying a predetermined voltage from a power supply unit to a rotating body rotatable about a shaft. In the device, the power supply mechanism includes a power supply circuit configured to connect at least a bearing supporting one end of the shaft portion and the power supply portion, and to supply a voltage to the rotating body via the bearing, and a vicinity of the bearing. And cleaning means for removing extraneous matter adhering to the surface of the shaft portion.

Therefore, in the above configuration, unlike the conventional configuration, it is not necessary to separately provide a harness wire and a power supply terminal, and the occurrence of troubles such as disconnection or jamming of the harness wire and poor contact due to wear of the terminal can be avoided. can do. Moreover, in the above configuration, it is possible to remove the scattered toner and NO _X attached to the shaft portion surface by the cleaning means, the hole of the bearing is sealed by the cleaning means, these deposits entering the hole No conduction failure occurs. Therefore,
There is an effect that more stable power supply of the developing bias voltage can be performed.

In the image forming apparatus, one end of the shaft of the power supply mechanism is supported by a plurality of bearings arranged in series along the direction of the shaft, and at least one of the plurality of bearings is supported. The power supply circuit may be formed by connecting the power supply unit to the power supply unit.

Further, it is more preferable that the plurality of bearings in the power supply mechanism include a rolling bearing and a sliding bearing, respectively, and that a power supply unit is connected to at least the sliding bearing.

Thus, each bearing can share the bearing function and the function of the power supply terminal. In particular, since the rolling bearing is provided with a rolling element portion, the shaft portion can be rotated more smoothly, so that it is used as the bearing itself, while the sliding bearing comes into contact with the shaft portion with a large area. Since the sliding surface is provided and the power supply unit is connected to at least the sliding bearing, the use of the sliding bearing as a power supply terminal has an effect that the functions can be more clearly assigned.

If a plurality of bearings are connected to a power supply unit, a power supply circuit having a plurality of power supply paths is formed. Therefore, even if one power supply path is disconnected, another power supply path is used. It is also possible to improve the reliability of the power supply mechanism.

Further, a plurality of bearings in the power supply mechanism are composed of one fixed rolling bearing and one sliding bearing movably arranged in a direction orthogonal to the shaft by the moving means. A power supply unit is connected to at least the slide bearing to form a power supply circuit, and the moving unit includes an elastic member, and the elastic member does not insert the shaft portion. In this state, it is more preferable to maintain the position of the slide bearing so that the axis of the slide bearing is shifted from the axis of the rolling bearing.

Thus, the sliding mechanism and the rolling bearing are urged by the moving mechanism having the elastic member so that the axes of the sliding bearing and the rolling bearing are displaced. Therefore, in a state where the shaft portion is inserted into the slide bearing, the surface of the shaft portion and the slide surface of the slide bearing are securely brought into close contact with each other. For this reason, the sliding bearing as the power supply terminal and the shaft portion are reliably brought into contact with each other without causing contact failure or conduction failure, so that the power supply performance of the power supply mechanism can be further improved. .

In the image forming apparatus, when the bearing in the power supply mechanism is a rolling bearing, it is preferable that a conductive grease is filled and sealed in a portion where the rolling element is disposed. As a result, the rolling element and the bearing ring come into contact with each other in a larger area via the conductive grease, so that the conductivity of the rolling element portion is improved, and the conductivity of the power feeding mechanism is further ensured. It has the effect of being able to.

[0141] In the image forming apparatus, it is preferable that the bearing in the power supply mechanism is made of a conductive material containing at least one of a sintered metal and a conductive resin. As a result, a bearing which has been conventionally used as a bearing is used as a bearing which also serves as a power supply terminal, so that the power supply mechanism can be inexpensively, simply, and reliably configured. .

In the above-described image forming apparatus, the rotating body supplied with power by the power supply mechanism further includes a developing roller,
Preferably, at least one of a photosensitive drum, a contact type charger, and a contact type transfer unit is used. Thus, an effect that with respect to said rotary member deposits such scattered toner and NO _X are used in an environment easy to adhere, it is possible to implement a reliable power supply.

In the above-described image forming apparatus, it is preferable that the cleaning unit is disposed at a position closest to the rotating body in the power supply mechanism. As a result, it is possible to reliably realize a rotation cleaning function for cleaning the deposits on the shaft portion surface even when the rotating body is rotating, and a sealing function for sealing the deposits so that the deposits do not enter the holes. it can. Therefore, there is an effect that the developing bias voltage can be more reliably supplied.

In the image forming apparatus, it is preferable that the cleaning means is fixed to a shaft of a rotating body or a bearing.

If the cleaning means is fixed to the shaft of the rotating body, the cleaning means also rotates with the rotation of the shaft, so that the above-described cleaning function during rotation and the sealing function can be further ensured. In addition, since the cleaning means is fixed to the shaft, the cleaning means can be easily replaced with the removal of the shaft.

On the other hand, if the cleaning means is fixed to the bearing, when the tip of the shaft is inserted into the bearing, the cleaning means wipes off the deposits on the surface of the tip, and the tip of the shaft which comes into contact with the bearing. The surface can be kept in a clean state with no deposits (cleaning function at the time of insertion). Therefore, the adhering matter is prevented from entering the hole of the bearing, and the developing bias voltage can be reliably supplied.

In the above-described image forming apparatus, it is preferable that the cleaning means is a moving seal. Accordingly, it is possible to prevent intrusion of extraneous matter or the like into the hole of the bearing, so that it is possible to obtain a cleaning unit having a further improved sealing function.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a power supply mechanism according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an example of a relationship between a power supply circuit and a cleaning unit in the power supply mechanism illustrated in FIG. 1 and a rotation shaft of a developing roller.

FIG. 3A is an explanatory diagram showing a cleaning function at the time of insertion of the cleaning unit shown in FIGS. 1 and 2;
(B) is an explanatory view showing a sealing function of the cleaning unit.

FIG. 4 is an explanatory diagram showing another example of the relationship between the power supply circuit and the cleaning unit in the power supply mechanism shown in FIG. 1 and the rotation axis of the developing roller.

FIG. 5 is an explanatory diagram illustrating an example of a relationship between a power supply circuit, a cleaning unit, and a rotation shaft of a developing roller in a power supply mechanism according to another embodiment of the present invention.

6 is an explanatory diagram showing another example of the relationship between the power supply circuit and the cleaning unit in the power supply mechanism shown in FIG.

FIG. 7 is an explanatory diagram showing still another example of the relationship between the power supply circuit and the cleaning unit in the power supply mechanism shown in FIG. 5 and the rotation shaft of the developing roller.

8 is a side view showing a state of a swing mechanism and a second bearing held by the swing mechanism in the power feeding mechanism shown in FIG. 5;

FIG. 9 is a plan view showing an example of the swing mechanism shown in FIG.

FIGS. 10 (a) and (b) are explanatory views illustrating a state where a rotary shaft is inserted into a second bearing provided with the swing mechanism shown in FIGS. 8 and 9. FIG.

FIGS. 11A and 11B are explanatory diagrams illustrating an example of a relationship between a power supply circuit, a cleaning unit, and a rotation shaft of a developing roller in a power supply mechanism according to another embodiment of the present invention.

FIGS. 12A and 12B are explanatory diagrams showing another example of the relationship between the power supply circuit, the cleaning unit, and the rotation shaft of the developing roller in the power supply mechanism according to another embodiment of the present invention. is there.

FIG. 13 is an explanatory diagram illustrating a schematic configuration of an image forming apparatus to which the power supply mechanism according to the present invention is applied.

FIGS. 14A and 14B are explanatory views showing a configuration of a conventional developing roller to which a power supply mechanism according to the present invention is applied.

FIG. 15A is a schematic external view showing a configuration of a lip-shaped seal used as a cleaning unit of the power supply mechanism according to the present invention, and FIG. 15B is a state in which the lip-shaped seal has a habit; FIG.

16 is an explanatory diagram illustrating a state in which the lip-shaped seal shown in FIG. 14 is mounted on a rotating shaft.

FIGS. 17A and 17B are explanatory diagrams showing a configuration of a G seal used as a cleaning unit of the power supply mechanism according to the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 power supply mechanism 10 a power supply mechanism 10 b power supply mechanism 11 power supply bearing (bearing) 11 a hole 12 cleaning unit (cleaning unit / seal unit) 13 bias power supply (power supply unit) 14 power supply circuit 15 a first bearing 15 b second bearing 16 swing mechanism (Moving means) 16c Compression spring (elastic member) 20 Developing roller (rotary member) 24 Rotary shaft (shaft) 30 Photoconductor drum (rotary member) 40 Contact type charger (rotary member) 50 Contact type transfer device (rotary member) )

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16J 15/32 311 F16J 15/32 311Z H01R 39/00 H01R 39 / 00Z (72) Inventor Toshihiko Kimura Sharp Co., Ltd. (72) Inventor Europe 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 2H071 BA20 DA06 DA08 DA09 DA13 DA15 DA34 3J006 AE15 AE19 3J011 AA02 BA02 RA02 SB19 SC01 3J103 AA02 DA01 DA05 FA21 GA02 GA03 GA54

Claims (12)

[Claims] A power supply mechanism for supplying a predetermined voltage from a power supply to a rotating body rotatable about a shaft, wherein the power supply mechanism supports the shaft and is connected to the power supply. A power supply mechanism comprising a power supply bearing for supplying a predetermined voltage to the rotating body. 2. The power supply mechanism according to claim 1, further comprising sealing means disposed substantially in contact with the bearing to seal a hole of the bearing into which the shaft is inserted. 3. An image forming apparatus having a power supply mechanism for supplying a predetermined voltage from a power supply unit to a rotating body rotatable about a shaft portion, wherein the power supply mechanism includes at least the shaft portion. And a power supply circuit configured to connect a bearing supporting one end of the power supply unit to the power supply unit and supplying a voltage to the rotating body via the bearing, and removing a substance adhering to a surface of the shaft near the bearing. An image forming apparatus comprising: a cleaning unit. 4. One end of the shaft is supported by a plurality of bearings arranged in series along the direction of the shaft, and at least one of the plurality of bearings is connected to a power supply. The image forming apparatus according to claim 3, wherein the power supply circuit is formed. 5. The image forming apparatus according to claim 4, wherein the plurality of bearings include a rolling bearing and a sliding bearing, respectively, and at least a power supply unit is connected to the sliding bearing. apparatus. 6. A plurality of bearings, one of which is fixedly arranged and one of which is movably arranged in a direction orthogonal to a shaft by a moving means. A power supply unit is connected to at least the slide bearing to form a power supply circuit.Furthermore, the moving unit includes an elastic member, and the elastic member does not insert a shaft portion. The image forming apparatus according to claim 4, wherein the position of the slide bearing is held so that the axis of the slide bearing is shifted from the axis of the rolling bearing. 7. The method according to claim 3, wherein when the bearing is a rolling bearing, a conductive grease is filled and sealed in a portion where the rolling element is disposed. The image forming apparatus as described in the above. 8. The image forming apparatus according to claim 3, wherein said bearing is made of a conductive material containing at least one of a sintered metal and a conductive resin. 9. The apparatus according to claim 3, wherein the rotating body supplied by said power supply mechanism is at least one of a developing roller, a photosensitive drum, a contact type charger and a contact type transfer unit. The image forming apparatus according to claim 1. 10. An image forming apparatus according to claim 3, wherein said cleaning means is arranged at a position closest to said rotating body in said power supply mechanism. 11. An image forming apparatus according to claim 10, wherein said cleaning means is fixed to a shaft of a rotating body or a bearing. 12. The apparatus according to claim 3, wherein said cleaning means is a motion seal.
Item 10. The image forming apparatus according to item 1.