JPH0874754A - Scroll type compressor - Google Patents

Abstract

PURPOSE: To realize an oil free system of thrust bearings by reducing the thrust force of a movable scroll which is shared divisionally by autorotation preventive mechanisms. CONSTITUTION: While thrust bearings 62 and 63 are provided to at least three sets of autorotation preventive mechanisms R so as to share the thrust force operating to a movable scroll 4, a space area including the autorotation preventive mechanisms R is surrounded and sealed by a sealing means 64, and the system is composed to provide a force to balance with the compressive reaction operating to the movable scroll 4 as a thrust force by a pressure gas led in the surrounded blocking space area 70. As a result, the reduction of the friction force proportional to a vertical drag improves the durability of the thrust bearings without relying on a lubricant, and it contributes to a true oil free system of a compressor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor which is particularly suitable for making oil free.

[0002]

2. Description of the Related Art As a conventional scroll type compressor, for example, one disclosed in Japanese Patent Laid-Open No. 62-199983 is known. In this compressor, a fixed scroll composed of a fixed side plate and a fixed scroll is fixed to a housing, and a movable scroll composed of a movable side plate and a movable scroll is meshed with the fixed scroll by 180 ° out of phase with each other. A drive shaft is rotatably supported by a housing via a bearing, and a drive pin is provided at an inner end of the drive shaft so as to be eccentric from the drive shaft center. A boss of the movable side plate is supported by the drive pin via a bearing, and a plurality of sets of rotation preventing mechanisms are provided between the housing and the movable side plate at the radial position of the drive pin. Here, each rotation prevention mechanism is fixed to the housing and has a cylindrical first regulation pin that extends in the axial direction, and a second regulation pin that has a cylindrical shape and that is fixed to the movable side plate and that extends in the axial direction. The restriction pin and the second restriction pin are inserted, and the restriction inner surface extending in the axial direction makes sliding contact with the peripheral surfaces of the first restriction pin and the second restriction pin to allow only the revolution of the orbiting scroll. It is configured.

In this compressor, the rotation of the drive shaft is revolved around the movable scroll by the drive pin and the rotation preventing mechanism, whereby the working chambers (compression chambers) formed by the engagement of the fixed scroll and the movable scroll are sequentially formed. Since the volume is reduced and the volume is moved toward the center, the gas taken into the working chamber is sequentially compressed and discharged. At this time, in this compressor, the first and second regulation pins of each rotation prevention mechanism are brought into sliding contact with the respective regulation rings, so that the radial force generated based on the reaction force and the compression reaction force associated with the revolution of the movable scroll is generated. I have received it.

However, in this compressor, although each rotation preventing mechanism supports the radial force, no consideration is given to the reception of the thrust force. In particular, in the movable scroll, the gas pressure in the working chamber acts on the side surface of the spiral body, and this action point and the action point of the power for driving the movable scroll are eccentrically distributed in the axial direction. The so-called overturning moment acts. Since this load is a rotating load that rotates, the orbiting scroll performs a rasping motion, but this compressor does not take any concrete measures for supporting such a moment.

On the other hand, as a scroll type compressor which points out such a problem and attempts to improve it, Japanese Patent Publication No. 6-01
The one described in Japanese Patent No. 7674 is also known. This compressor is equipped with a plurality of pin cranks on its back to prevent rotation of the movable scroll, and a supporting member for receiving the thrust force of the movable scroll is installed in the vicinity of the pin crank to lubricate them in order to improve their sliding performance. A seal member is provided so as to enclose the agent and prevent these lubricants from flowing out during operation so as to enclose these components.

[0006]

However, as described above, a thrust force supporting member is added to the rotation preventing mechanism,
With a structure in which these parts are sealed with a filled lubricant together with a sealing member, it is practically difficult to completely prevent leakage of the enclosed lubricant, such as grease, and even if the leaked lubricant is activated In addition to the anxiety that it will enter the room, regular maintenance of lubricant replenishment is also required. Of course, it is conceivable that at least the self-lubricating material is adopted for the thrust force supporting member and the use of the lubricant is abolished, but the thrust force is too large, and there are many difficulties in terms of wear resistance.

The present invention acts as a compression reaction force on the orbiting scroll and rationally reduces the thrust force shared by the respective rotation preventing mechanisms, whereby a lubricant-free true oil-free compressor is provided. Achieving this is a technical issue to be solved.

[0008]

A scroll type compressor according to claim 1 for solving the above-mentioned problems, comprises a fixed scroll,
There is provided a movable scroll that meshes with the fixed scroll by shifting the phases of the scroll bodies from each other, and at least three sets of rotation preventing mechanisms arranged between the rear surface of the movable scroll and the facing surface of the housing that supports the movable scroll. Then, the movable scroll revolves in a state in which its rotation is restrained by the rotation preventing mechanism, so that the volume of the working chamber formed between both spiral bodies is reduced, and the movable scroll is sequentially moved toward the center. In a scroll compressor in which the pressure of the gas taken into the chamber is increased and discharged, the rotation prevention mechanism extends in the axial direction and fits with each other, and is revolved into a movable scroll by relative movement regulation. A restricting pin and a restricting ring which allow only the above, and a thrust bearing which is arranged in an outer peripheral area of the restricting ring and supports the movable scroll, Further provided with a sealing means for all these 囲封 the outer circumferential region of the rolling preventing mechanism is characterized in that it has disposed Shirube圧 means for introducing pressurized gas into 囲封 occlusive airspace by said sealing means.

According to a second aspect of the present invention, there is provided a scroll type compressor according to the first aspect, wherein the pressure guiding means communicates the closed space surrounded by the sealing means with the working chamber. It is characterized by being pressure pores. The scroll compressor according to claim 3 is the scroll compressor according to claim 1.
In the scroll compressor described, the pressure guiding means,
It is characterized in that it is a pressure guiding passage that connects the closed air space surrounded by the sealing means and the discharge pipe of the compressor via the pressure reducing means.

The scroll type compressor according to claim 4 is the scroll type compressor according to claim 1, 2 or 3, wherein
The thrust bearing is a slide bearing, and its relative sliding portion is formed of a self-lubricating material. A scroll type compressor according to a fifth aspect is the scroll type compressor according to the fourth aspect, characterized in that a relative sliding portion between the regulation pin and the regulation ring is formed of a self-lubricating material.

Examples of the self-lubricating material include inorganic materials such as ceramics and graphite, sliding materials such as tetrafluororesin, and solid lubricants such as graphite, molybdenum disulfide and fluororesin on the surface. The material with which the coating is coated is selected.

[0012]

In the scroll compressor according to the first aspect of the present invention, the thrust bearing acting on the orbiting scroll is distributed by the thrust bearings arranged in at least three sets of the rotation preventing mechanisms, whereby the overturning moment is rationalized. On the other hand, the air space including each rotation prevention mechanism is enclosed by the sealing means, and by the drag force of the pressure gas introduced into the enclosed closed air space,
Since it is configured to balance with the compression reaction force acting as a thrust force on the orbiting scroll, the reduction of the frictional force proportional to the normal force improves the durability of the thrust bearing without depending on the lubricant, that is, the compressor's true Contribute to the oil-free.

In the scroll compressor according to claim 2,
Since the pressure gas is directly introduced from the working chamber (compression chamber) formed between both spiral bodies through the pressure guiding pores into the enclosed enclosed space, it is suitable for simplifying the structure. The gas pressure to be introduced is selected according to the opening position of the pressure guiding pore in the working chamber. In the scroll compressor according to claim 3, since the pressure gas is introduced into the enclosed closed air space by the pressure guiding passage connected from the discharge pipe line of the compressor via the pressure reducing means, the introduction gas is adjusted. Easy to press and stabilize.

In the scroll compressor according to claim 4,
Since the thrust bearing is a slide bearing and at least the relative sliding portion is formed of a self-lubricating material, the adaptability as a non-lubricated bearing is enhanced and the durability is further improved. In the scroll compressor according to the fifth aspect, at least the relative sliding portion between the restriction pin and the restriction ring is formed of a self-lubricating material, so that the durability of the radial force receiving member is also improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the scroll type compressor of the present invention will be described below with reference to the drawings. This compressor is
As shown in FIG. 1, the fixed side plate 21 and the fixed side plate 21
A fixed scroll 2 composed of a shell portion 22 integrally formed with the movable side plate 21 and an outer shell, and a fixed scroll 23 formed by an involute curve or the like inside the fixed side plate 21 includes a movable side plate 41 and an inner side of the movable side plate 41. By engaging with the movable scroll 4 composed of the movable scroll 42 formed by an involute curve or the like,
A working chamber 39 is formed between the two. At the tips of the fixed spiral body 23 and the movable spiral body 42, P should be slid on the movable side plate 41 and the fixed side plate 21 respectively while maintaining airtightness.
TFE chip seals 23a and 42a are mounted, while a similar chip seal 41a that surrounds the working chamber 39 is also mounted on the sliding surface between the movable side plate 41 and the shell portion 22.

A low pressure working chamber 3 is provided on the outer peripheral side of the fixed side plate 21.
The discharge pipe 1 connected to the suction pipe 11 communicating with the region including 9 and communicating with the high pressure working chamber 39 in the center of the fixed side plate 21.
2 is connected, and the discharge pipe 12 is appropriately connected to demand equipment. In addition, a drive bush 38 having an eccentric hole 38a is rotatably fitted into a recess formed on the back surface of the movable side plate 41 via a radial bearing 36 and a rubber lip 37, and the shell portion 22 of the fixed scroll 2 is provided.
And a housing 30 that is coupled to the housing 30 by fastening means (not shown).
The drive bush 38 has a rotation gap formed therein, and three sets of rotation preventing mechanisms R are equidistantly arranged in the radial direction between the housing 30 and the back surface of the movable side plate 41 opposed thereto. .

A storage container (not shown) whose both sides and a bottom are opened is fixed to the housing 30 via a spacer 31, and the AC electric motor 50 is stored in the storage container. The motor 50 is formed with a flange 50b projecting slightly rearward from the end face of the front end 50a in the direction perpendicular to the axis, and the front end 50a of the motor 50 is fitted to the spacer 31 that is fastened together with the flange 50b on the housing 30. A positioning recess 31a is formed. The output shaft 50c of the motor 50 is connected to the counter weight 32 fitted to the drive bush 38 by a key 33.

The rotation preventing mechanism R, which is a characteristic component of the present invention, will now be described in more detail. A regulation pin 60 extending in the axial direction is fixed to the housing 30, a sleeve (flat bearing) 60a is mounted on the exposed portion of the regulation pin 60, and the rear surface of the movable side plate 41 is similarly axially oriented. A cylindrical restricting ring 61 extending in is embedded. The inner diameter D of the restriction ring 61 has a relationship of D = 2r + d between the outer diameter d of the relatively sliding sleeve 60a and the revolution radius r of the orbiting scroll 4, and the orbiting scroll 4 only revolves. Is allowed.

Further, a disk-shaped thrust plate 62 is embedded in the housing 30 concentrically with the restriction pin 60, and the disk-shaped thrust plate 62 is interposed on the rear surface of the movable side plate 41 so as to surround the restriction ring 61. These elements 62, 6 which are in abutting contact with the thrust race 63 and which are arranged in the three sets of rotation preventing mechanisms R and respectively configure thrust bearings.
3 is configured to share the thrust force acting on the movable scroll 4. In addition, the sleeve 60
a, the restriction ring 61, the thrust plate 62, and the thrust trace 63 are all made of self-lubricating materials such as ceramics, an inorganic material such as graphite, or a sliding material such as tetrafluororesin, or the surface thereof, graphite, disulfide. A material coated with a solid lubricant film made of molybdenum, fluororesin, or the like is used.

Further, in the further outer peripheral area of each of the rotation preventing mechanisms R, between the housing 30 and the rear surface of the movable side plate 41 facing the housing 30, a backup enclosing all of the rotation preventing mechanisms R is provided. A ring-equipped seal means 64 is provided, and the closed space 70 surrounded by the seal means 64 operates via pressure guiding means, that is, pressure guiding pores 71 formed in the movable scroll 4. It communicates with the inside of the chamber 39. In this way, the pressure gas is introduced from the working chamber 39 into the closed space 70 through the pressure guiding fine holes 71, and the gas pressure introduced is determined by the opening position of the pressure guiding fine holes 71 in the working chamber 39. , Is selected so as to balance with the compression reaction force acting on the movable scroll 4 as a thrust force. Note that, although FIG. 1 shows only a mode in which the pressure guiding pores 71 that open to the working chamber 39 communicate with a set of closed air spaces 70, the pressure guiding pores 71 branch appropriately from the middle thereof. The other closed air spaces 70 are similarly communicated with the working chamber 39 via the holes. Further, the pressure atmosphere in the working chamber 39 connected to the opening of the pressure guiding fine hole 71 constantly repeats fluctuations, but the throttling action of the pressure guiding fine holes 71 effectively suppresses the pressure fluctuation in the closed air space 70. It

The compressor of this embodiment is constructed as described above, and when the output shaft 50c of the motor 50 is rotated, the eccentric bush 38 is rotationally driven and cooperates with each rotation preventing mechanism R. The movable scroll 4 is revolved by. Since the working chamber 39 formed by the two spiral bodies 23 and 42 is moved toward the center while the volume is successively reduced, the suction pipe 11
The gas taken into the working chamber 39 through is compressed as the working chamber 39 moves, and is appropriately sent to the demanding device through the discharge pipe 12. The counterweight 32 offsets the eccentric moment that the output shaft 50c receives from the movable scroll 4 and absorbs the dynamic imbalance of the movable scroll 4.

As described above, while the compressor continues to operate, in each rotation preventing mechanism R, the inner peripheral surface of the restriction ring 61 makes sliding contact with the outer peripheral surface of the sleeve 60a mounted on the restriction pin 60. The thrust trace 63, which receives the radial force generated based on the reaction force and the compression reaction force associated with the revolution of the orbiting scroll 4, and which is interposed so as to surround the restriction ring 61, is a plane orthogonal to the axial direction. By sliding on the thrust plate 62 that abuts against the shaft, the thrust force generated based on the compression reaction force is received. That is, the thrust force acting on the movable scroll 4 is shared by these three sets of thrust slide bearings 62 and 63, and reasonably supports the above-mentioned overturning moment.

However, between the housing 30 and the rear surface of the movable side plate 41 facing the housing 30, a seal means 6 with a backup ring for enclosing the entire rotation preventing mechanism R is provided.
4 is provided, and the enclosed closed air space 70 is ensured to be airtight with high accuracy, and the closed air space 70 is always kept by the pressure gas introduced from the working chamber 39 through the pressure guiding fine holes 71. The pressure is kept within the required range. In particular, this holding pressure is set so that the drag force acting on the total pressure receiving area of each closed air region 70 is approximately balanced with the thrust force acting on the movable scroll 4, so the thrust plate 62 and the thrust trace 63 proportional to the vertical drag force. The frictional force between them is extremely reduced, and sufficient durability can be secured without depending on the enclosed lubricant.

The specific structure of the thrust bearing is not limited to the above embodiment, but a rolling bearing can be applied. However, considering the adaptability and durability of self-lubricating material selection as a non-lubricated bearing. For example, it is most preferable to use the sliding bearing structure as in the embodiment. Further, the application of the self-lubricating material to the relative sliding portions of the restriction pin 60 and the restriction ring 61 that receive the radial force is more preferable from the viewpoint of improving the overall durability of the rotation preventing mechanism R.

FIG. 2 shows another embodiment of the pressure guiding means which replaces the pressure guiding pores 71. The pressure guiding means of this embodiment is branched from the discharge pipe 12 system, and includes the housing 30 and the thrust plate 62. A pressure guiding passage 72 connected to the closed air space 70 through the pressure guiding passage 72 is provided, and pressure reducing means 73 for pressure adjustment is arranged in the pressure guiding passage 72. There is no difference with.
In this embodiment as well, it is needless to say that the tributary flow path of the pressure guiding passage 72, which is appropriately branched from the downstream side of the pressure reducing means 73, is connected in the same manner as the other closed air space 70.

Therefore, in this compressor, the closed air space 70
It is extremely easy to regulate the pressure of the introduced gas for increasing the pressure, and has the advantage of excellent stability.

[0027]

As described above in detail, in the scroll compressor according to the present invention, thrust bearings are arranged in at least three sets of rotation preventing mechanisms so as to share the thrust force acting on the movable scroll. A structure in which an air space including each rotation prevention mechanism is enclosed by seal means, and the compressed gas introduced into the enclosed closed air space is balanced with a compression reaction force acting as a thrust force on the movable scroll. Therefore, the reduction of the frictional force proportional to the normal force improves the durability of the thrust bearing without depending on the lubricant, and contributes to making the compressor truly oil-free.

In particular, if a self-lubricating material is applied to the relative sliding portions of the components of the anti-rotation mechanism that receive the thrust force and the radial force, even better durability can be guaranteed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a scroll compressor according to another embodiment of the present invention.

[Explanation of symbols]

2 is a fixed scroll, 4 is a movable scroll, 23 is a fixed spiral body, 39 is a working chamber, 42 is a movable spiral body, 60 is a restriction pin, 61 is a restriction ring, 62 is a thrust plate, 6
3 is a thrust trace, 64 is a seal means, 70 is a closed air space, 71 is a pressure guiding pore, 72 is a pressure guiding passage, 73 is a pressure reducing means, and R is a rotation preventing mechanism.

Claims (5)

[Claims] 1. A fixed scroll, a movable scroll which meshes with the fixed scroll by shifting the phases of the spirals from each other, and at least disposed between a back surface of the movable scroll and an opposing surface of a housing supporting the movable scroll. The movable scroll has three sets of rotation preventing mechanisms, and the movable scroll revolves in a state where the rotation is restrained by the rotation preventing mechanism, so that the volume of the working chamber formed between both spiral bodies is reduced and the center is sequentially centered. In the scroll compressor in which the pressure of the gas taken into the working chamber is increased by this, and the gas is discharged, the rotation preventing mechanism extends in the axial direction and fits with each other. Restriction pin and restriction ring that allow the movable scroll to orbit only by dynamic motion restriction, and a support pin that supports the movable scroll and is arranged in the outer peripheral area of the restriction ring. And a seal bearing for enclosing all of them in the outer peripheral area of the rotation preventing mechanism, and for introducing pressure gas into the closed air space enclosed by the seal means. A scroll type compressor characterized by being provided with. 2. The scroll compressor according to claim 1, wherein the pressure guiding means is a pressure guiding fine hole that communicates the closed space surrounded by the sealing means with the working chamber. 3. The pressure guiding means is a pressure guiding passage that connects the closed air space surrounded by the sealing means and the discharge pipe of the compressor via the pressure reducing means. The scroll compressor described. 4. The scroll compressor according to claim 1, 2 or 3, wherein the thrust bearing is a slide bearing, and the relative sliding portion is formed of a self-lubricating material. 5. The scroll compressor according to claim 4, wherein a relative sliding portion between the restriction pin and the restriction ring is formed of a self-lubricating material.