JPH07127583A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To improve the sealability of the fluid while the increase of the power loss and the abrasion by the friction between scroll members is suppressed. CONSTITUTION:A groove 7e is provided in the center side tip of at least either of spiral blades 7a (the illustrated reference symbol is for a movable scroll member 7) of a fixed scroll member 3 and the movable scroll member 7 in a scroll type fluid machine such as a scroll compressor, and a vane 22 is inserted, and the energizing is made to the left as shown in the figure by a coil spring 18. The vane 22 of the illustrated example is engaged with the spring 18 through a second vane 23 having a tapered surface not shown in the figure. The tip 22a of the vane 22 is pressed against the surface of the opposite spiral blade not shown in the figure, and the second vane 23 is pressed against the side plate not shown in the figure to achieve the sealing. The sealability of the working space in the vicinity of the center part where the pressure of the fluid becomes high is chiefly improved, and the leakage of the fluid is reduced on the whole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll fluid machine such as a scroll compressor suitable for use as a refrigerant compressor of a refrigerating cycle of an automobile air conditioner, and more particularly to a scroll fluid machine, The present invention relates to a sealing means capable of effectively sealing a working chamber near a central portion where a fluid having high pressure exists.

[0002]

2. Description of the Related Art In a conventional scroll compressor, as a spiral means for sealing a crescent-shaped working space formed between spiral blades of a fixed scroll member and a movable scroll member, Japanese Patent Publication No. 19
As described in Japanese Patent Publication No. 875/1975, the reaction force of fluid compression is used as a pressing force between two spiral blades, or as described in Japanese Patent Publication No. 57-49721. There is one that presses the spiral blade of the movable scroll member against the spiral blade of the fixed scroll member by utilizing the centrifugal force acting on the scroll member. In addition to such means, both scroll members are generally used. Lubricating oil is supplied to the contact points to improve the sealing performance around the crescent-shaped working space.

As shown by points a, b, c and d in FIG. 4, the contact points between the spiral blade 3a of the fixed scroll member of the scroll type fluid machine and the spiral blade 7a of the movable scroll member are usually Although there are a plurality of blades, the scroll member is a rigid body, and machining of the spiral blade involves some errors, so that the blade 3
Strictly speaking, the contact point between a and the blade 7a is only one of the first contact points a to d, and at other points, a large or small gap remains and the contact is not complete. Therefore, when the amount of lubricating oil supplied between the scroll members becomes small, or in the case of no lubrication without supplying lubricating oil, when the fluid in the crescent-shaped working space is pressurized, The fluid leaks from the gap between the portions to be contacted in the outer circumferential direction of the scroll member, which deteriorates the performance of the scroll fluid machine.

[0004]

All points to be contacted in the spiral direction (points a, b, c, d in the example of FIG. 4).
In order to close the gap of the scroll scroll blade, it is necessary to strongly press the spiral blade of the movable scroll member toward the spiral blade of the fixed scroll member to cause some deformation of the spiral blade. When the movable scroll member is pressed against the fixed scroll member with such a strong force, there is a problem that power loss and abrasion of the spiral blades are caused by an increase in sliding friction. However, due to the structure of the scroll-type fluid machine, among the plurality of crescent-shaped working spaces formed between the scroll members, the one near the outer periphery has a relatively low fluid pressure, so there is a slight gap. However, since the amount of fluid leakage is small, the points a and d near the outer peripheral portion are present despite the problems described above.
It is not a good idea to apply a strong pressing force to contact points such as.

Therefore, according to the present invention, the entire movable scroll member is not strongly pressed toward the fixed scroll member, but only the contact points that partition the working space near the center where the fluid pressure is high are closed. SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel means capable of effectively reducing fluid leakage and improving the performance of a scroll fluid machine while avoiding the problems described above.

[0006]

As a means for solving the above-mentioned problems, the present invention provides a fixed scroll member having a spiral blade and fixed to a housing, and a fixed scroll member of the fixed scroll member. A scroll-type fluid including a movable scroll member that has a spiral blade that meshes with the blade and that is driven so as to only revolve, and a rotation preventing mechanism that prevents rotation of the movable scroll member and allows only revolution. In the machine, a groove having a parallel wall surface is provided in the vicinity of the center side tip of the spiral blade of at least one of the fixed scroll member and the movable scroll member, and the groove is inserted into the groove and slides along the parallel wall surface. At least one sheet that can be sealed by the fluid by pushing its tip against the wall surface of the spiral blade of the other side by protruding And the vane provides a scroll fluid machine, characterized in that the vane is provided with an elastic member urges the wall surface of the spiral vane of the other party.

[0007]

When the movable scroll member revolves with respect to the fixed scroll member under the restriction imposed by the rotation preventing mechanism, the crescent-shaped working space formed between the spiral blades has a radius. Direction, and that the crescent-shaped working space acts as a compressor when the crescent-shaped working space moves radially inward, and the crescent-shaped working space moves radially outward. At this time, the scroll type fluid machine acts as an expander in the same manner as in the above-described related art.

In the present invention, in addition to the constructions which bring about these actions, a groove having a parallel wall surface is provided in the vicinity of the center side tip of at least one spiral blade of the fixed scroll member and the movable scroll member, and the groove is formed. At least one vane that can be inserted into the inside and slides and projects along the parallel wall surface to press the tip against the wall surface of the spiral-shaped blade of the other side to seal the fluid, and the vane of the other side. Since the elastic body that urges toward the wall surface of the spiral-shaped blade is provided, the vane is pressed by the elastic body, is slidably guided by the groove and protrudes, and comes into contact with the wall surface of the spiral-shaped blade on the other side. Completely close the gap at the sealing point that forms the working space near the center.

Whether the scroll type fluid machine is a compressor or an expander, the pressure of the fluid in the working space formed in the vicinity of the central portions of the two scroll members is in the crescent-shaped working space formed in the outer peripheral portion. Since the pressure is higher than the pressure of the fluid, the amount of fluid that leaks is greater in the vicinity of the central portion if there is a gap of the same size at the sealing location.However, by implementing the present invention, As a result of predominantly enhancing the sealing property in the vicinity of the central portion, fluid leakage can be effectively reduced without strongly pressing the entire movable scroll member toward the fixed scroll member.

[0010]

FIG. 3 shows the overall construction of a scroll compressor 1 as an embodiment of the scroll type fluid machine of the present invention. As far as shown in FIG. 3, the scroll compressor 1 has the same configuration as a conventional general scroll compressor. That is, the scroll compressor 1 is mainly composed of a fixed scroll member 3 fixed to the housing body 2 and forming a part of the housing, and a drive shaft 5 from a prime mover (which may be a hydraulic motor, an internal combustion engine, or the like) such as the electric motor 4. An eccentric wheel 6 having a balance weight attached to the shaft end of the movable scroll member 7, a movable scroll member 7 driven by the eccentric wheel 6, and the movable scroll member 7 of the movable scroll member 7 when driven, which are not shown in detail. It is composed of a rotation preventing mechanism 8 which allows only the revolution and prevents the rotation.

The fixed scroll member 3 and the movable scroll member 7 are spiral-shaped vanes 3a having substantially the same shape.
And 7a are integrally provided on one surface side of the disk-shaped side plates 3b and 7b, respectively, and grooves 3c and 7c are formed along the longitudinal direction of the spiral on the axial tip surfaces of the spiral-shaped blades. Are formed.

In the groove 7c of the movable scroll member 7, as shown enlarged in FIG. 1, a spiral tip seal 21 similar to this is inserted. The tip seal 21 is made of a resin sliding material such as fluororesin, and slides into contact with the side plate of the other scroll member to seal the gap. A groove 7e having parallel side surfaces is formed over the entire width of the blade 7a at the tip of the center of the spiral blade 7a in the spiral direction, and a tip 22a having the same axial width as the blade 7a is formed therein. Has an arcuate cross section (see FIG. 1), and the first vane 22 in which the axial width of the base portion is tapered is slidably inserted along the groove 7e (see FIG. 2). Further, at a position facing the tapered surface 22b of the first vane 22, the tapered surface 2 having a similar angle is formed.
A second vane 23 having 3a is mounted slidably along the groove 7e on the bottom side in the groove 7e.

An axial pin 24 is provided on the side plate 7b side of the first vane 22 and the first vane 22 is provided.
A groove 7f is provided on the surface of the side plate 7c in the groove 7e so that the pin 24 is allowed to move with the sliding. In addition, the compression coil spring 18 is inserted between the bottom surface 23b of the second vane 23 and the bottom surface of the parallel groove 7e to generate a thrust output of the first vane 22 and the second vane 23. Further, with respect to the protrusion of the vane 22 by the spring 18, the pin 24 and the groove 7f regulate the range of protrusion. Since the vanes 22 and 23 are both restricted from moving in the axial direction by the side plates of the other scroll member, the vanes 22 and 23 both project toward the parallel groove 7e due to the bias of the spring 18.

The movable scroll member 7 is integrally provided with a short driven shaft 7d projecting in the axial direction at the center behind the side plate 7b. The driven shaft 7d is a drive shaft 5 inside the eccentric wheel 6. Is inserted into a circular eccentric opening 6a which is open in the axial direction at a position eccentric with respect to, for example, via a needle bearing 9 or the like so as to be relatively rotatable. However, the structure of this portion is such that the crankshaft portion is formed at the shaft end of the drive shaft 5, and the crankshaft portion is formed in the opening of the driven sleeve formed by axially projecting the crankshaft portion at the center behind the side plate 7b of the movable scroll member 7. It may be replaced by a structure in which it is rotatably inserted through a needle bearing or the like.

In this embodiment, the fixed scroll member 3 also has a structure similar to that of the movable scroll member 7 described above.
First, the spiral tip seal 20 is inserted into the groove 3c formed in the axial tip surface of the spiral blade 3a of the fixed scroll member 3. The tip seal 20 is
It is made of resin sliding material such as fluororesin. Since the illustrated shape is the same as that of the movable scroll member 7, as shown by the reference numerals in parentheses in FIGS. 1 and 2,
A parallel groove 3e is formed in the center of the spiral blade 3a, and the first vane 25, the second vane 26, and the pin 2 similar to the center of the blade 7a of the movable scroll member 7 are formed.
7, the groove 3f, the compression coil spring 19 and the like are provided.
Their functions are substantially the same as those of the movable scroll 7.

The spiral blades 3a and 7a have the same length (width or height) in the axial direction. The two spiral-shaped blades 3a and 7a are combined and supported so as to mesh with each other while being out of phase with each other and being eccentric, thereby compressing the fluid between the blades. At least one crescent-shaped space for forming is formed.

Here, the maximum value of the protruding amount of the above-mentioned two first vanes 22 and 25 is set to 1/3 to 5/3 of the eccentric amount of the movable scroll member, so that the pins 24, 2 are provided.
7 and the grooves 3f, 7f. Further, as shown in FIGS. 1 and 2, the tip seal 21 (20) has a second vane 23 with a tip near the center of the spiral.
The bottom surface 23b (26b) at the time of maximum projection of (26) is further extended to a position closer to the center.

A space 15 in the housing body 2 and the front housing 2a shown in FIG. 3 is a suction chamber of the scroll compressor 1, and a fluid to be compressed is sucked into the suction chamber 15 through a suction port (not shown). It is designed to be inhaled. A discharge port 16 communicating with the outside is formed in the central portion of the spiral blade 3a of the fixed scroll member 3, and a discharge valve 17 that automatically opens and closes the discharge port 16 is provided.

The scroll compressor 1 of the embodiment shown in FIG.
Has the structure as described above, and therefore, when the drive shaft 5 and the eccentric wheel 6 are rotationally driven by the rotation of the electric motor 4, the driven shaft of the movable scroll member 7 which is eccentric to the drive shaft 5 is driven. 7d tends to rotate via the needle bearing 9, but the movable scroll member 7 is prevented from rotating by the rotation preventing mechanism 8 and therefore only revolves around the drive shaft 5. Thereby, as long as the rotation direction of the drive shaft 5 is selected so as to be adapted to the scroll compressor 1, between the spiral blade 3a of the fixed scroll member 3 and the spiral blade 7a of the movable scroll member 7. The crescent-shaped space that is formed is defined by the scroll members 3, 7
It will gradually move from the outer periphery to the center.

A crescent-shaped space is formed on both scroll members 3, 7
When it was opened in the suction chamber 15 at the outer peripheral part of
A low-pressure fluid such as air taken from the suction chamber 15 into the crescent-shaped space moves when the crescent-shaped space closes and gradually moves from the outer peripheral portions of the scroll members 3 and 7 toward the center. Since the volume of each of the scroll members 3 and 7 is compressed by being continuously reduced, the fluid compressed from the central portions of the scroll members 3 and 7 pushes the discharge valve 17 open, and the discharge port 16 is discharged.
Is sent to the outside through.

In the above-mentioned operation, when the compressor 1 is not lubricated, the sealing effect by the lubricating oil cannot be expected.
If a gap exists in the contact portion between the two blades 3a and 7a, the fluid compressed in the crescent space leaks from the gap toward the outer peripheral portion, and it is expected that the performance will be significantly deteriorated. In this case, as shown in FIG. 4, the spiral blades 3a and 7a of both scroll members are in contact with each other at a plurality of places such as a, b, c, and d, which need to be sealed. Since each of the blades 3a and 7a is a rigid body such as an aluminum alloy, due to an error in machining of the scroll members 3 and 7, when the scroll members 3 and 7 come into contact with each other at one place, they do not exactly come into contact with each other at a plurality of places. However, there is a gap,
The compressed fluid will leak. In particular, when a gap is generated at a position close to the center, the fluid pressure is high at that position, so that the amount of leakage is large and the performance is extremely deteriorated.

The present invention is intended to reduce leakage that occurs at the center of the two scroll members, and in the illustrated embodiment, the spiral blades 3a of the two scroll members. , 2a in the center of 7a
2, 25 are provided, and by the elastic force of the springs 18 and 19, as shown in (2) to (4) of FIG.
Sealing is performed by contacting the inner peripheral surfaces of a and 3a. The operation will be described in detail below.

In the state shown in FIG. 5 (1), the fluid trapped in the crescent-shaped space on the outer peripheral portion formed by the spiral blades 7a and 3a of the movable scroll member 7 and the fixed scroll member 3 is the movable scroll. Member 7
By the orbital motion of, the state moves to the crescent-shaped space on the center side of FIG. 5 (1) through the states shown in FIGS. 5 (2), (3), and (4), and the volume of the crescent-shaped space decreases. Will be compressed accordingly. In this case, when the revolution movement progresses from the state of FIG. 5 (1) to the state of (2), the inner peripheral surfaces of the spiral blades 3a, 7a forming a crescent-shaped space near the center and the vanes facing the inner peripheral surface. 22 and 25 arc-shaped tip surfaces 22a and 2
5a comes into contact with the pressing force of the compression coil springs 18 and 19 to define a space on the center side, and this pressing force prevents fluid leakage from the contact portion between the tip of the vane and the inner peripheral surface of the blade.

Further, as the orbiting motion of the movable scroll member 7 progresses as shown in FIGS. 5 (2) to 5 (6), the vanes 22, 2 are moved.
5 moves in the parallel grooves 7e, 3e, and the contact point of the vane tip is also the spiral blades 3a, 7a of the scroll member.
The internal fluid is compressed and discharged by sliding on the inner peripheral surface and reducing the volume of the central space. It goes without saying that the leakage of the fluid from the tips of the vanes 22 and 25 can be prevented during this period.

As shown in FIG. 5 (4), when the discharge is completed, the vanes 22 and 25 have the blades 3 of the scroll member.
It is separated from a and 7a and returns to the state of FIG. 5 (1) to take in the next fluid.

In this embodiment, the vanes 22, 25
The maximum value of the protrusion amount of the movable scroll member 7 is set to ⅓ to 5/3 of the eccentric amount of the movable scroll member 7, so that the range in which the vanes 22 and 25 can be sealed until the discharge is completed. 1/2 to 3/4 rotations.
In addition, in this embodiment, the vanes are shown in FIGS.
As shown in FIG. 2, the first vane 22 (2) is divided into two parts on the tapered surfaces 22b and 23a (25b and 26a).
5) and the second vane 23 (26) are provided. By the action of this taper shape, the compression coil spring 18 (19)
The second vane 23 (26), which receives the force of, is slightly displaced in the axial direction when moving along the tapered surface, and is pressed against the surfaces of the side plates 3c, 7c of the counterpart scroll members 3, 7. It is possible to prevent the fluid from leaking from this surface.

In the illustrated embodiment, the vane is divided into two on the tapered surface to form the first vane 22 (25) and the second vane 23 (26).
If the heights of the blades 3a, 7a and the vanes 22, 25 in the axial direction can be machined with high precision, they need not be divided. Further, in the illustrated embodiment, the pressing force of the vanes 22 and 25 is given by the compression coil springs 18 and 19, but the compression coil spring may be replaced with another elastic body such as a leaf spring. Further, the pressure of the compressed fluid may be introduced to the back surface of the vane as an auxiliary means such as a spring that generates a pressing force.

[0028]

According to the present invention, in a scroll type fluid machine such as a scroll compressor, the leakage of fluid from the working chamber near the central portion where the pressure becomes the highest to the outside is mainly prevented, so that a seal is provided. The sealability can be improved without increasing sliding friction.

[Brief description of drawings]

1 is a sectional view taken along the line I-I of FIG. 2, showing an enlarged main part of one embodiment of the present invention.

FIG. 2 is a II-II sectional view of a part of FIG.

FIG. 3 is a vertical cross-sectional front view illustrating the overall structure of the scroll compressor.

FIG. 4 is a side sectional view showing a contact portion of a spiral blade.

5 (1) to (4) are side sectional views sequentially showing different operating states of the scroll compressor of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Scroll compressor 3 ... Fixed scroll member 3a ... Spiral-shaped blades 3e, 3f ... Groove 5 ... Drive shaft 6 ... Eccentric ring 7 ... Movable scroll member 7a ... Spiral-shaped blade 7b ... Side plate 7d ... Driven shaft 7e, 7f ... Groove 8 ... Rotation prevention mechanism 9 ... Needle bearing 18, 19 ... Compression coil spring 20, 21 ... Tip seal 22, 25 ... 1st vane 22a, 25a ... Vane tip 23, 26 ... 2nd vane 22b, 23a, 25b, 26a ... Tapered surface 24, 27 ... Pins a to d ... Contact point

Claims (1)

[Claims] 1. A fixed scroll member having a spiral blade and fixed to a housing, and a spiral blade that meshes with the spiral blade of the fixed scroll member, and is driven only to revolve. In a scroll type fluid machine having a movable scroll member and a rotation preventing mechanism that prevents rotation of the movable scroll member and allows only revolution of the movable scroll member, in the scroll type fluid machine of at least one of the fixed scroll member and the movable scroll member. A groove having a parallel wall surface is provided in the vicinity of the tip of the blade on the center side, and the tip is pressed against the wall surface of the other spiral blade by inserting into the groove and slidingly protruding along the parallel wall surface. At least one vane capable of providing a fluid seal and facing the wall surface of the opposite spiral-shaped vane. A scroll-type fluid machine, comprising: