JPH07279879A - Volume control device for scroll compressor - Google Patents

Abstract

PURPOSE:To provide a volume control device for a scroll compressor which can compensate an axial disalignment between a motor shaft and a bypass piston. CONSTITUTION:A drive motor 66 which drives a bypass piston 62 through the connection between a screw shaft (motor shaft) 67 and a threaded hole 63 is fitted around the outer periphery thereof with a O-ring 69 so as to be resiliently supported. With this arrangement, even though the center axis of the threaded hole 73 of the bypass piston 62 is disaligned from that of the screw shaft 67 of the drive motor 66, the center axis of the threaded hole 63 and that of the screw shaft 67 can be aligned with each other through the elasticity of the O-ring 69.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor capacity control device for controlling the compression capacity of a scroll compressor.

[0002]

2. Description of the Related Art A scroll compressor employs a structure in which a pair of fixed scrolls and orbiting scrolls are meshed with each other to form a compression chamber between the wraps of both scrolls.
This scroll compressor draws in the fluid from the circumferential side by utilizing the fact that the volume of the compression chamber decreases as the orbiting scroll revolves with respect to the fixed scroll as it goes from the periphery to the center, After the fluid is compressed, it is discharged from the discharge port at the center to an external discharge chamber (neither is shown).

As such a scroll compressor, in order to enable efficient operation, there is proposed a scroll compressor called "with a capacity control mechanism" in which the compression volume is variable.

In this structure, a bypass hole is provided at the end of the fixed scroll so that the fluid compressed in the compression chamber is bypassed to the suction side. The bypass hole is opened and closed by an opening / closing mechanism built in the end plate of the fixed scroll. The structure is used.

Generally, as shown in FIG. 2, of the orbiting scrolls 4 and fixed scrolls 5 forming the compression chambers 1, 2 and 3, for example, the end plate 6 of the fixed scroll 5 is
Bypass holes 2a and 3a, which are located in the central region corresponding to the compression chambers 2 and 3 and communicate with the compression chambers 2 and 3, are provided. Further, inside the end plate 6, the bypass holes 2a and 3a are arranged. A bypass cylinder 8 that connects the bypass holes 2a, 3a and the suction chamber 7 is provided along the direction, and a bottomed cylindrical bypass piston 9 is slidably fitted in the bypass cylinder 8. Has been adopted.

The bypass piston 2 slides to open and close the bypass holes 2a and 3a to control the fluid bypassing from the middle of compression in the compression chambers 2 and 3 to the suction side.

By the way, such an opening / closing mechanism generally has a structure for controlling the position of the bypass piston 9 to generate a control pressure by using a discharge pressure gas and a suction pressure gas, and the bypass piston 9 is predetermined at the control pressure. The structure to drive is adopted.

Specifically, as shown in FIG. 2, a cylindrical housing 10 which constitutes the outer shell of the scroll compressor.
In addition, a pressure control valve 11 such as an automatic pressure control valve or an electric pressure control valve is installed to generate a required control pressure from the discharge pressure gas and the suction pressure gas, and this control pressure is applied by the urging force of the spring 14. It is conducted to the head chamber 12 at the end of the bypass piston 9 which is biased to one side. Reference numeral 9b is a communication hole provided in the peripheral wall of the bypass piston 9.

Accordingly, the position of the bypass piston 9 is controlled by controlling the pressure from the pressure control valve 11, the biasing force of the spring 14, the pressure applied to the bypass piston wake chamber 13 inside the bypass piston 9 (after the bypass piston 9). The pressure on the flow side, which is actually close to the suction pressure).

Normally, the opening / closing mechanism for driving the bypass piston 9 at the control pressure is as shown in FIG. 2 by the spring force when the compressor is not in operation (discharge pressure = suction pressure = control pressure). In addition, the bypass holes 2a and 3a are fully opened.

By the way, in this type of scroll compressor, recently, the areas of the bypass holes 2a and 3a are sufficiently large and the areas of the bypass holes 2a and 3a are sufficiently large in order to obtain a high efficiency and a wide range of capacity control rates. It is being fully expanded.

However, as described above, the bypass holes 2a, 3
When a is increased, there is a behavior in which most of the fluid sucked into the compression chambers 2 and 3 flows out from the bypass holes 2a and 3a during low speed operation such as low speed startup at low ambient temperature. .

When such a state occurs, the state in which the discharge pressure is approximately equal to the suction pressure (suction pressure = control pressure) continues, so that the bypass piston 9 cannot be controlled. That is, it is inevitable that the opening / closing mechanism that generates the control pressure from the discharge pressure gas and the suction pressure gas has a region in which the capacity control is disabled.

Therefore, in practice, it has been unavoidable to make this uncontrollable region as narrow as possible at the expense of efficiency and capacity control rate. Further, the structure in which the bypass piston 13 is driven by the control pressure generated from the discharge pressure gas and the suction pressure gas has an effect on the state of the discharge pressure gas flowing into the pressure control valve 11, that is, the amount of oil mixed, the pulsation of the discharge pressure, and the like. In response to this, the characteristics of the control pressure change inadvertently, which causes a problem of deviating from the required control characteristics.

In order to solve such a problem, therefore, a displacement control device for a scroll compressor is proposed which employs a drive motor to drive the bypass piston 9 instead of the discharge pressure and the suction pressure. Has been done.

This is a structure in which the motor shaft (output shaft) of the drive motor is directly connected to the bypass piston 9 and the bypass piston 9 is directly operated by an electric signal. Specifically, the structure shown in FIG. 3 is adopted.

Explaining the same structure, in the end plate 6 adjacent to the end portion of the bypass cylinder 8, there is provided a motor accommodating chamber 20 which is coaxial with the bypass cylinder 8 and is composed of, for example, a large-diameter cylindrical recess. Has been formed. Motor housing chamber 20
The bottom side communicates with the bypass cylinder 8 and the opening side faces the suction chamber 7.

A drive motor 21 which is, for example, a pulse motor is housed in the motor housing chamber 20.
A motor shaft 21a (output shaft) formed of a screw shaft projects from the center of the end surface of the drive motor 21 facing the bypass cylinder 8 side. A rotation stopping pin 22 projects from the eccentric position.

This motor shaft 21a is connected to the bypass piston 9
Is screwed into a screw hole 23 formed in the center of the bottom wall 9b of the shaft so that the rotation stopping pin 22 is slidably inserted into a pin hole 24 formed at a position eccentric from the same position. I am doing it.

The drive motor 21 is used in the motor housing chamber 20.
Snap ring 2 provided at the opening edge of the housing 13 side of the
5 prevents it from coming out in the radial direction.
Further, the drive motor 20 has a fixing member 26 provided on the outer peripheral portion.
The drive motor 21 is fixed in the motor housing chamber 20 by these so as not to rotate around the axis. Of course, not limited to this, although not shown, a fixed scroll 5 is provided with a stay protruding along the outer wall of the drive motor 21, and this stay is bolted to the drive motor 21.
Sometimes fixed.

A terminal 27 protruding from the outer peripheral portion of the drive motor 21 penetrates through the end plate 6 and is wired to the outside through a terminal 28 having a sealing function inside and outside the compressor and a lead wire 29. .

The rotor rotational position of the drive motor 21 thus installed can be arbitrarily set according to the sign and number of pulses. Therefore, if the pulse necessary for position control of the bypass piston 9 is applied through the wiring, the drive can be performed. The motor 21 is controlled according to the pulse, and the same rotation is converted into a linear motion by the screw shaft (motor shaft 21a) and the screw hole 23 to move the bypass piston 9 forward and backward (sliding motion), and the bypass hole 2
The opening degree of a and 3a will be controlled.

[0023]

By the way, in the opening / closing mechanism of such a scroll compressor, the bypass piston 9 is required to move smoothly. However, according to the structure in which the rotary motion of the drive motor 21 is converted into the linear motion by using the screw shaft and the screw hole 23 screwed into the screw shaft, the shaft center of the screw shaft of the drive motor 21 and the shaft center of the screw hole 23 are used. Is difficult to machine with high precision, and it is even more difficult to match the axes of both when they are combined.

That is, due to the structure, the bypass piston 9 and the motor shaft 21a are likely to be misaligned. If such an axial misalignment occurs, not only the bypass piston 9 is not smoothly driven, but also an excessive driving force is required, which causes a problem that the desired capacity control function is not fulfilled.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a displacement control device for a scroll compressor capable of correcting an axial deviation between a motor shaft and a bypass piston. To provide.

[0026]

In order to solve the above-mentioned problems, a displacement control device according to a first aspect of the present invention elastically supports a drive motor for driving a bypass piston by interposing an elastic body on the outer peripheral surface thereof. There is something I did.

In addition to the above-mentioned object, the capacity control device according to a second aspect of the invention is such that the elastic body according to the first aspect comprises an O-ring in order to achieve elastic support with simple parts. .

In addition to the above-mentioned object, the capacity control device according to a third aspect of the present invention installs the O-rings according to the second aspect at least at two positions in order to stably and elastically support the drive motor. There is something I did.

In addition to the above object, the capacity control device according to a fourth aspect of the present invention, in addition to the above object, has an end portion of the drive motor according to the first object in order to prevent the elastic body from coming off from the drive motor. The retaining part for retaining the elastic body is provided.

In addition to the above-mentioned object, the displacement control device according to a fifth aspect of the present invention, in order to suppress the movement of the drive motor in the radial direction, has an end portion on the side opposite to the motor shaft of the drive motor according to the first aspect. This is because a stopper is provided to stop the drive motor from moving in the radial direction.

In addition to the above-mentioned object, the displacement control device according to a sixth aspect of the present invention is configured such that the stopper according to the fifth aspect is composed of a spring plate in order to effectively exert the radial movement suppression of the drive motor. The elastic force of this spring plate is to apply a pressure to the drive motor.

[0032]

According to the displacement control device of the first aspect, since the drive motor is elastically supported by the elastic body on the outer peripheral surface, the shaft center of the screw hole of the bypass piston and the shaft of the motor shaft of the drive motor. Even if the center is deviated, the elastic body is elastically displaced and adjusted (corrected) so that the shaft center of the screw hole and the shaft center of the motor shaft match.

This prevents the occurrence of excessive drive resistance due to the deviation of the shaft center. This enables the drive motor to smoothly drive the bypass piston.

Moreover, since the elastic body compensates for the deviation of the shaft center, it is not necessary to process the screw hole of the bypass piston and the screw of the motor shaft with high precision, and the processing cost can be reduced.

The elastic body also functions as a drive motor and a rotation stopper. According to the capacity control device of the second aspect, it is possible to use the existing inexpensive parts such as the O-ring to compensate for the above-mentioned deviation of the axis and further prevent the rotation.

According to the capacity control device of the third aspect,
By being supported from a plurality of points by the O-ring, the entire drive motor is stably elastically supported. According to the capacity control device of the fourth aspect, the elastic body is prevented from slipping out from the outer peripheral surface of the drive motor.

According to the capacity control device of the fifth aspect,
The drive motor, which tends to move in the radial direction in response to the reaction force at the time of operation, is prevented from moving out by the stopper so as to be prevented from moving out.

According to the capacity control device of the fifth aspect,
Even if a large reaction force is generated in the drive motor due to the pressurization applied to the drive motor side by the leaf spring, the movement of the drive motor in the exit direction by the stopper is avoided.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in FIG. FIG. 1 is a partial cross-sectional view showing the structure of a hermetic scroll compressor with a capacity control device to which the present invention is applied. In the figure, 50 is a cylindrical housing forming the outer contour of the compressor, and 51 is the inside of the housing 50. The compressor part accommodated in FIG.

The compressor section 51 is constructed by combining a fixed scroll 52 and an orbiting scroll 53 which form a pair. Specifically, the fixed scroll 52 and the orbiting scroll 53 are
In each case, a spiral wrap 55 is integrally provided on one side surface of the end plate 54. The fixed scroll 53 and the orbiting scroll 53 are in phase with each other by, for example, 180 °, and the laps are meshed with each other. By this engagement,
Crescent-shaped compression chambers 56a-56c (closed) between both wraps
Is formed.

The end plate 54 of the fixed scroll 52 is screwed (not shown) and fixed to one end of the housing 50. Further, the center of the back surface of the end plate (not shown) of the orbiting scroll 53 is slidably connected to an eccentric shaft (not shown) in the output part of the electric motor unit housed in the housing 50. And the orbiting scroll 5
3 is regulated by an Oldham mechanism (not shown) so as not to rotate, and when the electric motor part is operated, it revolves around the center of the fixed scroll 52 without rotating.

The compression chambers 56a to 56c are adapted to move from the peripheral side to the central portion by the orbiting motion of the orbiting scroll 53. And this compression chamber 56a-
Volume change of 56c (compression chamber 56 as it moves to the center side)
(the volume of a to 56c decreases), the fluid is sucked from the suction chamber 57 formed around the compressor section 51 and is compressed. The fluid after the compression process is discharged from a discharge port (not shown) at the center of the end plate of the fixed scroll 52 to a discharge chamber (not shown) formed in the housing 50.

On the other hand, the end plate 54 of the fixed scroll 52 has a built-in capacity control device 58. Explaining the capacity control device 58, 59a and 59b in the figure are
The end plate 54 of the fixed scroll 52 is a bypass hole formed in the end wall portion facing the compression chamber 56c formed on the center side and the compression chamber 56b formed between the center side and the peripheral side. These bypass holes 59a and 59b are arranged so as to be aligned on a straight line, for example. The bypass hole 59
The a and 59b communicate with the compression chambers 56b and 56c.

Reference numeral 60 in the drawing denotes bypass holes 59a, 59.
It is an opening / closing mechanism for opening and closing b. The opening / closing mechanism 60 is built in the end plate of the fixed scroll 52. The opening / closing mechanism 60 has a bypass cylinder 61 that extends linearly along the direction in which the bypass holes 59a and 59b are arranged inside the end plate. Each bypass hole 59a, 59b communicates with the bypass cylinder 61.

Bypass hole 59b of the bypass cylinder 61
The end portion on the side penetrates the end plate 54 and communicates with the suction chamber 57, and from the bypass holes 59a, 59b to the compression chamber 56b,
A bypass passage for bypassing a part of the fluid compressed by 56c to the suction side is formed (return of fluid during compression).

In this bypass cylinder 61, a bottomed cylindrical bypass piston 62 is slidably inserted with its opening side facing the side communicating with the suction chamber 57. The bypass piston 62 has a screw hole 63 formed at the center of the bottom wall 62a, and a pin hole 64 for stopping rotation is formed at a position eccentric from the screw hole 63.

A motor accommodating chamber 65 is formed coaxially with the bypass cylinder 61 in the outer peripheral portion of the end plate portion adjacent to the other end of the bypass cylinder 61. The motor housing chamber 65 is composed of, for example, a large-diameter cylindrical recess, and the bottom side communicates with the bypass cylinder end.

A drive motor 66 is accommodated in the motor accommodating chamber 65 by being inserted from the outer peripheral side of the end plate 54. Specifically, the drive motor 66 is housed in the motor housing chamber 65 such that most of the main body is exposed from the outside through the recess opening.

As the drive motor 66, for example, a pulse motor is used. A motor shaft 67 formed of a screw shaft projects from the center of the end surface of the drive motor 66 facing the bypass cylinder 61 side. A rotation stop pin 68 projects from a position eccentric to the motor shaft 67.

The motor shaft 67 is screwed into the screw hole 63 of the bypass piston 62 so as to move back and forth. Further, the rotation stopping pin 68 is slidably fitted in the pin hole 64 of the bypass piston 62.

As a result, when the drive motor 66 is operated, the rotation stop pin 68 is used as a guide to push the screw hole 63 by the feed by the screw shaft.
The bypass piston 62 can be reciprocated (the rotational movement of the drive motor 66 is converted into a linear movement along the axis of the drive motor 66).

The bypass holes 59a and 59b can be opened and closed in accordance with the sliding movement of the bypass piston 62. Further, one or several O-rings 69 as elastic bodies are fitted and inserted in the outer peripheral portion of the drive motor 66. Specifically, O-rings 69 are fitted and inserted at two positions on both ends of the casing 66 a of the drive motor 66.

The O-rings 69, 69 are interposed between the O-rings 69 and 69 and the peripheral surface of the motor accommodating chamber 65. Specifically, when the drive motor 66 fitted with the O-rings 69, 69 is inserted into the motor housing chamber 65, the O-ring 69 is interposed between the casing 66a and the peripheral surface.

The drive motor 66 is elastically supported by the O-rings 69, 69.
Using the elastic displacement of 9, the shaft center of the motor shaft 67,
Absorbs the deviation from the axis of the screw hole 63, and
The drive motor 66 is utilized by utilizing the frictional force of the rings 69, 69.
It is designed to prevent the rotation by the reaction force.

On the outer periphery of the end of the casing 66a on the opening side of the recess, for example, a collar-like stopper 70 (corresponding to a retaining portion) is formed to prevent the O-rings 69, 69 from coming out of the drive motor 66. Is done.

At the open end of the motor accommodating chamber 65, a retaining mechanism 71 for restricting the accommodated drive motor 66 so as not to come out of the motor accommodating chamber 65 is provided. The retaining mechanism 71 has a retaining stopper 72 that presses the end of the drive motor 66 on the opposite side of the motor shaft 67 (the end opposite to the motor shaft).

Specifically, the stopper 72 for retaining is
For example, it is composed of a leaf spring 73 that is bent in a substantially L-shape. The short side of the plate spring 73 is the protruding portion 5 of the end plate 54 protruding outward from the recess opening of the motor housing chamber 65.
4a is fixed by screws with a fixing bolt 72a. The long side of the leaf spring 73 extends and is in contact with the end surface (the end opposite to the motor shaft 67 of the drive motor 66) exposed from the opening of the motor housing chamber 65.

The leaf spring 73 is mounted while being elastically deformed so that the leaf spring 73 is bent in an L shape from the initial state, that is, the drive motor 66 is pressed toward the bypass cylinder 61 side. That is, the leaf spring 73 causes the drive motor 66 to move to the motor housing chamber 6.
It is pressed so that it does not come out of the motor housing chamber 65 from the inlet / outlet portion of No. 5.

As a result, the drive motor 66 is given a pressure to press it into the motor housing chamber 65, and the drive motor 6 is driven.
The 6 stops moving in the radial direction. The terminal 74 protruding from the outer peripheral portion of the drive motor 66 penetrates the end plate 54 and is externally wired through a terminal 75 having a sealing function inside and outside the compressor and a lead wire 76.

By utilizing the fact that the rotor rotation position of the drive motor 66 can be arbitrarily set according to the sign and number of pulses, the position of the bypass piston 62 is freely controlled to open the opening of the bypass passage. It is controlled.

Next, the operation will be described. When the electric motor section (not shown) is excited, the orbiting scroll 53 revolves around the axis of the fixed scroll 52 (because the Oldham mechanism prevents its rotation).

Then, the crescent-shaped compression chamber 56 formed between the fixed scroll 52 and the orbiting scroll 53.
The a to 56c move from the peripheral side to the center side while reducing the volume thereof.

Utilizing this volume change, a fluid compression process is performed in which the fluid is taken from the suction chamber 57 and is compressed. Next, the fluid that has moved to the center of the fixed scroll 53 and has been compressed is discharged from the discharge port in the center and discharged to the outside through the discharge chamber and the discharge pipe (neither is shown).

When the drive motor 66 is actuated, for example, on the passage open side during such operation, the rotational movement is converted into a linear movement by the screw shaft and the screw hole 63 screwed into the screw shaft and the slide piston 62 is moved. , The rotation stop pin 68 is used as a guide for sliding drive, and the bypass holes 59a,
59b is opened and closed in a predetermined manner.

Then, the bypass hole 59 whose opening is controlled
The fluid being compressed in the compression chambers 56b and 56c is bypassed from a and 59b to the suction chamber 57 (suction side) through the bypass piston 62.

Of course, when the bypass holes 59a and 59b are controlled to be fully closed, the fluid does not return from the compression chambers 56a and 56b to the suction side. As a result, the volume-controlled compression operation is performed.

Here, the structure of the opening / closing mechanism 62 for directly connecting the motor shaft 67 to the bypass piston 62 by screwing is as follows.
It has been pointed out that an excessive drive resistance is generated due to the misalignment of the axis.

This is because it is difficult to machine the shaft center of the screw shaft serving as the motor shaft 67 and the shaft center of the screw hole 63 of the bypass piston 62 with high accuracy, which is a problem between the drive motor 67 and the bypass piston 62. This is because it appears as a misalignment with the axis.

According to the present invention, this is not the case.
That is, according to the present invention, the drive motor 66 is elastically supported by the O-rings 69, 69 which are elastic bodies.

As a result, even if the bypass piston 62
Axis of the screw hole 63 of the motor shaft 67 of the drive motor 66
Even if the axis of the (screw shaft) is misaligned, the O-ring 6
9 and 69 are elastically displaced, and the shaft center of the screw hole 63 and the shaft center of the motor shaft 67 are adjusted to match each other. That is, due to the elasticity of the O-rings 69, 69, the screw hole 6
The deviation between the shaft center of No. 3 and the shaft center of the motor shaft 67 is absorbed.

In other words, the O-rings 69 and 69 center (correct) the deviation between the axial center of the screw hole 63 and the axial center of the motor shaft 67.
Needless to say, the clearance between the pin hole 64 that serves as a detent for the bypass piston itself and the rotation stopping pin 68 is set to a size that is large enough to absorb the deviation of the shaft center.
The twisting due to the absorption of the deviation between the shaft center of No. 3 and the shaft center of the motor shaft 67 is avoided, and further, the bypass piston 62 by the fitting of the pin hole 64 and the rotation stopping pin 68 adjusts the opening degree. Needless to say, it does not inhibit the function of.

Therefore, it is possible to prevent the generation of excessive drive resistance due to the deviation of the shaft center, which has been a problem in the past. Therefore, the bypass piston 62 can be smoothly driven by the drive motor 66.

Further, this means that the O-rings 69, 69 compensate for the deviation of the shaft center. Therefore, the machining of the screw hole 63 of the bypass piston 62 and the screw shaft of the motor shaft 67 is
It is not necessary to have high precision, and the processing cost can be reduced accordingly.

In addition, since the O-rings 69, 69 are in contact with the peripheral surface of the motor accommodating chamber 65, the O-ring 6 is the same.
By utilizing the frictional force of 9, 69, it can also be used as a rotation stopper for the drive motor 66. That is, the drive motor 66 is separately provided.
No parts are required to stop the rotation, and the structure is simpler and the cost is lower.

In addition to these effects, the deviation of the shaft center is
Since it was achieved by using existing parts such as the O-rings 69, 69, the cost is low. In addition, the structure in which the O-rings 69, 69 elastically support the drive motor 66 from a plurality of spaced locations can elastically support the entire drive motor 66 in a stable posture.

A stopper 7 is attached to the end of the drive motor 66.
By providing 0, even if the O-ring 69 moves, it will not come out of the drive motor 66.

Further, since the stopper 72 for preventing the movement restricts the movement of the drive motor 66 in the radial direction from the end portion on the side opposite to the motor shaft, the drive motor 66 receives a reaction force at the time of operation, Even if an attempt is made to move in the radial direction, it is possible to prevent the drive motor 66 from coming out of the motor housing chamber 65 by suppressing the movement in the direction of coming out by the stopper stopper 72.

Moreover, since the leaf spring 73 is adopted as the stopper 72 for retaining and the elastic force of the leaf spring 73 is applied to the drive motor 66 in the pressing direction, a large reaction force is exerted. Even if occurs in the drive motor 66, it is possible to prevent the drive motor 66 from moving in the exit direction. In the embodiment, the example in which the drive motor is provided with the O-ring has been described, but the present invention is not limited to this, and another elastic body may be provided.

[0079]

As described above, according to the first aspect of the invention, the axial displacement between the motor shaft and the bypass piston can be corrected by utilizing the elastic displacement of the elastic body. Therefore, it is possible to prevent the generation of an excessive drive resistance due to the deviation of the shaft center, and it is possible to smoothly drive the bypass piston by the drive motor.

Moreover, the compensation of the axial center deviation by the elastic body means that it is not necessary to process the screw hole of the bypass piston and the screw of the motor shaft with high precision, and the processing cost is reduced accordingly. be able to.

Moreover, since the elastic body can be used also as the rotation stop of the drive motor by utilizing the frictional force of the elastic body, a separate component for stopping the rotation of the drive motor is not necessary. The configuration is simple, and the cost is low.

According to the second aspect of the present invention, in addition to the above effects, it is possible to compensate for the above-mentioned deviation of the axis center and further prevent rotation by using existing inexpensive parts such as O-rings.

According to the third aspect of the present invention, in addition to the above effects, the entire drive motor can be elastically supported in a stable posture. According to the invention described in claim 4, in addition to the above effect, even if the elastic body moves, the elastic body does not come out from the outer peripheral surface of the drive motor.

According to the invention described in claim 5, in addition to the above effects, even if the drive motor receives a reaction force at the time of operation and tries to move in the radial direction, the drive motor is prevented from coming off. You can

According to the invention described in claim 6, in addition to the above effect, a larger restraining force is given, so that even if a large reaction force is generated in the drive motor, the movement of the drive motor in the exit direction is avoided. can do.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a capacity control device for a scroll compressor according to an embodiment of the present invention together with a configuration of the scroll compressor.

FIG. 2 is a partial cross-sectional view showing a conventional displacement control device for controlling a compressor displacement by driving a bypass piston by generating control pressure.

FIG. 3 is a partial cross-sectional view showing a capacity control device that controls a compressor capacity by driving a bypass piston with the different conventional drive motor.

[Explanation of symbols]

50 ... Housing 52 ... Fixed scroll 53 ... Orbiting scroll 54 ... End plate 55 ... Wrap 56a-56c ... Compression chamber 57 ... Suction chamber 58 ... Capacity control device 59a, 59b ... Bypass hole 60 ... Opening / closing mechanism 61 ... Bypass cylinder 62 ... Bypass Piston 63 ... Screw hole 64 ... Pin hole 65 ... Motor accommodating chamber 66 ... Drive motor 67 ... Motor shaft 68 ... Rotation stop pin 69 ... O-ring (elastic body) 70 ... Stopper (retaining part) 72 ... Stopper 73 ... Leaf spring

Claims (6)

[Claims] 1. A compression chamber is formed by meshing a pair of fixed scrolls with an orbiting scroll, and the orbiting scroll is revolved to move to the center while reducing the volume of the compression chamber. And a scroll compressor that compresses the fluid sucked into the compression chamber according to a change in the volume of the compression chamber and discharges the fluid from the central portion, the fixed scroll communicates with the compression chamber, The bypass cylinder has a bypass hole for bypassing the compressed fluid to the suction side and an opening / closing mechanism for opening / closing the bypass hole, and the opening / closing mechanism includes a bypass cylinder in which the bypass hole opens to the circumferential side, and the inside of the bypass cylinder. The bypass piston slidably inserted into the bypass piston and the motor shaft directly screwed onto the bypass piston. A displacement control device for a scroll compressor, comprising a drive motor for driving, and controlling the displacement of the scroll compressor by a bypass piston driven by the drive motor, wherein the drive motor has an outer peripheral surface. With an elastic body in between,
A capacity control device for a scroll compressor, which is elastically supported. 2. The capacity control device for a scroll compressor according to claim 1, wherein the elastic body is an O-ring. 3. The capacity control device for a scroll compressor according to claim 2, wherein the O-rings are installed at at least two places with a space therebetween. 4. The displacement control device for a scroll compressor according to claim 1, wherein an end portion of the drive motor has a retaining portion for retaining the elastic body. 5. The scroll compression device according to claim 1, further comprising a stopper that is in contact with an end of the drive motor on the side opposite to the motor shaft and that stops the drive motor from moving in the radial direction. Machine capacity control device. 6. The displacement control device for a scroll compressor according to claim 5, wherein the stopper is formed of a spring plate and applies a pressure to the drive motor.