KR100621028B1 - Variable capacity device of rotary compressor - Google Patents

Abstract

A variable capacity apparatus for a rotary compressor according to the present invention includes: a plurality of cylinders having a back pressure space on a rear surface of one vane, the back pressure space being separated from the inner space of the casing and alternately supplied with the suction pressure and the discharge pressure; A plurality of bearing plates communicating with the back pressure space to form a back pressure adjusting hole so that the pressure of the discharge pressure in the casing is supplied to the back pressure space; A back pressure switching valve installed at a suction line of the cylinder so as to be opened and closed on a pipe line communicating with the back pressure space and selectively supplying a pressure of the suction pressure to the back pressure space according to the operation mode of the compressor; A valve housing communicating with the back pressure adjusting hole of the bearing plate; A back pressure regulating valve for opening and closing the back pressure adjusting hole according to the pressure of the back pressure space and the pressure of the casing; When the pressure in the back pressure space is the suction pressure, the back pressure control valve blocks the back pressure adjusting hole while the back pressure control spring is configured to open when the pressure is discharged, thereby facilitating the variable capacity control of the compressor and simplifying the piping. In addition, when the compressor is applied to the air conditioner, the mode can be easily changed to improve the comfort and energy saving, and to prevent the interference with other pipes, thereby improving the assembly of the air conditioner and reducing the number of valves, thereby reducing the production cost. can do. In addition, by modularizing the back pressure control valve assembly, it is possible to reduce the production time required for the assembly process of the entire compressor, thereby reducing the production cost.

Description

Capacity variable device of rotary compressor {MODULATION APPARATUS FOR ROTARY COMPRESSOR}

1 is a system diagram showing an example of a conventional variable displacement rotary compressor,

2A and 2B are schematic views showing a compression chamber area for normal operation and saving operation of a conventional variable displacement rotary compressor;

3 is a schematic diagram showing an example of the present invention of a variable displacement double type rotary compressor;

Figure 4 is a longitudinal sectional view showing a variable displacement double rotary compressor of the present invention;

FIG. 5 is a perspective view of the back pressure regulating valve assembly broken in the present invention.

6A and 6B are longitudinal sectional views showing a variable capacity state for normal operation and saving operation of the variable displacement double rotary compressor of the present invention;

Figure 7 is a longitudinal sectional view showing a modification to the vane restricting portion in the variable displacement double rotary compressor of the present invention.

** Description of symbols for the main parts of the drawing **

10: casing 20: electric mechanism part

30: first compression mechanism portion 40: second compression mechanism portion

41: 2nd cylinder 41a: 2nd vaneslit

41b: Back pressure space 41c: Side pressure flow path

42: lower bearing 43: second rolling piston

44: second vane 45: second discharge valve

46: second muffler 50: vane control unit

51: low pressure side connection pipe 52: back pressure switching valve

55: stopper pin 56: pin spring

60: back pressure control valve assembly 61: valve housing

61a: fixed part 61b: space part

62: back pressure control valve 62a: body

62b: opening and closing part 63: valve spring

64 housing cover 64a back pressure supply hole

h1: Communication hole h2: Communication groove

SP1, SP2: First and second gas suction pipes V1, V2: First and second compression space

The present invention relates to a variable capacity device of a rotary compressor, and in particular, a variable capacity device of a rotary compressor that constrains the reciprocating motion of the vane by using a pressure difference in the back side of the vane and a pressure inside the casing when the two-way valve is applied; The present invention relates to an air conditioner.

In general, a rotary compressor is mainly applied to an air conditioner such as an air conditioner. Recently, as the function of the air conditioner is diversified, the rotary compressor also requires a product that can vary in capacity. As a technique for varying the capacity of a rotary compressor, a so-called inverter method that controls the number of revolutions of the compressor by using an inverter motor is mainly known, but this technique is expensive because the inverter motor itself is expensive, and most of the air conditioners are statistically Considering that it is used as a cooler, it is difficult to increase the refrigerating capacity under heating conditions, which is more difficult in the cooling conditions, which is more important in the air conditioner compressor.

Accordingly, in recent years, the so-called "refrigeration capacity change technology" by changing the volume of the compression chamber by bypassing part of the refrigerant gas compressed in the cylinder to the outside of the cylinder (hereinafter referred to as "exchange volume switching"). Abbreviated as technology) is widely known.

1 is a system diagram showing an example of a conventional variable displacement rotary compressor, Figures 2a and 2b is a schematic diagram showing the compression chamber area for the normal operation and the saving operation of the conventional variable displacement rotary compressor.

As shown in the drawing, the conventional variable displacement rotary compressor forms a bypass hole 1a of the cylinder so that a part of the refrigerant compressed in the middle of the compression space of the cylinder 1 can be bypassed according to the operation state of the compressor. The bypass pipe P1 is connected to the bypass hole 1a to the outside of the casing 2, and is piped from the end of the bypass pipe P1, and one end thereof is discharged from the casing 2 and the condenser ( 3) the other end is connected to the discharge side connecting pipe (P3) in the middle of the gas discharge pipe (P2) connecting to the suction side connecting pipe in the middle of the gas suction pipe (P4) connecting the evaporator (4) and the accumulator (5) It is connected to (P5). In addition, a discharge side valve V1 and a suction side valve V2 are respectively provided in the middle of the discharge side connecting pipe P3 and the suction side connecting pipe P5, and at the inlet side end of the bypass pipe P1. The bypass valve V3 is provided to open and close the bypass hole 1a of the cylinder 1 in accordance with the opening and closing of the discharge side valve V1 and the suction side valve V2.

In the drawings, reference numeral 6 denotes a rotating shaft, 7 a rolling piston, and 8 a vane.

When the compressor operates normally in the conventional variable displacement rotary compressor as described above, a part of the refrigerant discharged to the gas discharge pipe P2 is discharged as the discharge valve V1 of FIG. 1 is opened and the suction valve V2 is closed. The high pressure refrigerant flows into the bypass pipe P1 along the solid arrow, and the high pressure refrigerant pushes the bypass valve V3 to block the bypass hole 1a of the cylinder 1, as shown in FIG. 2A. All of the refrigerant sucked into the compression space of the compression is repeated a series of processes discharged to the gas discharge pipe (P2) discharged.

On the other hand, when the compressor performs the saving operation, as the discharge valve V1 of FIG. 1 is closed and the suction valve V2 is opened, the pressure back side of the bypass valve V3 becomes the suction pressure environment, as shown in FIG. 2B. The bypass valve V3 is pushed to open the bypass hole 1a, and a part of the refrigerant compressed in the compression space through the open bypass hole 1a is connected to the suction side connection pipe P5 along the dotted arrow of FIG. 1. By bypassing to the accumulator 5 through only a portion of the refrigerant sucked into the compression space of the cylinder 1 was compressed and discharged.

However, the variable capacity device of the conventional rotary compressor as described above, by separately installing a bypass circuit on the side of the cylinder 1, the resistance is increased when gas is bypassed during the saving operation, the refrigeration capacity reduction rate is small and efficiency is lowered There was a problem.

In addition, as the bypass pipe P2, the discharge side connecting pipe P3, and the suction side connecting pipe P5 are installed outside the compressor casing 2 and connected to the air conditioning pipe, it is difficult to assemble the air conditioning pipe. In addition, since the discharge side valve (V1) and the suction side valve (V2) must be separately installed in the pipe, there is a problem in that the number of parts increases and the cost increases.

The present invention has been made in view of the problems of the conventional variable capacity of the rotary compressor as described above, to provide a variable capacity device of the rotary compressor that can increase the efficiency by increasing the refrigeration capacity reduction rate during the saving operation. have.

Another object of the present invention is to provide a variable capacity device of a rotary compressor that can easily and simply configure a variable capacity device of a compressor, as well as reduce production costs by reducing the number of parts.

In order to achieve the object of the present invention, a plurality of compression spaces are independently formed inside the casing, and the compression space is partitioned into a suction chamber and a compression chamber by respective rolling pistons and vanes, and one of the back surfaces of the vanes. A plurality of cylinders separated from an inner space of the casing and having a back pressure space to alternately supply pressures of suction pressure and discharge pressure; A plurality of bearing plates which divide a plurality of cylinders into a plurality of compression spaces, one of which communicates with the back pressure space to form a back pressure adjusting hole so that the pressure of the discharge pressure in the casing is supplied to the back pressure space; A back pressure switching valve installed at a suction line of the cylinder so as to be opened and closed on a pipe line communicating with the back pressure space and selectively supplying a pressure of the suction pressure to the back pressure space according to the operation mode of the compressor; A valve housing forming a predetermined inner space and communicating with the back pressure adjusting hole of the bearing plate; A back pressure regulating valve provided in the inner space of the valve housing to open and close the back pressure adjusting hole according to the pressure of the back pressure space and the casing pressure; A back pressure regulating spring is provided in the inner space of the valve housing together with a back pressure regulating valve so that the back pressure regulating valve closes the back pressure adjusting hole when the pressure in the back pressure space is the suction pressure, while the back pressure regulating spring is opened to open the outlet pressure. It provides a variable capacity device of a rotary compressor comprising a housing cover for supporting the back pressure control spring to cover the opening side of the valve housing and form a back pressure supply hole to communicate with the back pressure control hole at the center thereof. .

EMBODIMENT OF THE INVENTION Hereinafter, the variable capacity apparatus of the rotary compressor by this invention is demonstrated in detail based on one Example shown in an accompanying drawing.

Figure 3 is a schematic diagram showing an example of the present invention variable displacement double type rotary compressor, Figure 4 is a longitudinal sectional view showing a variable displacement double type rotary compressor of the present invention, Figure 5 is broken the back pressure control valve assembly in the present invention variable displacement double type rotary compressor. 6A and 6B are longitudinal cross-sectional views illustrating a variable capacity state for the normal operation and the saving operation of the variable displacement double rotary compressor of the present invention, and FIG. 7 is a vane restriction in the variable displacement double rotary compressor of the present invention. The longitudinal cross-sectional view which showed the modification with respect to a part.

As shown in the drawing, the double rotary compressor according to the present invention includes a casing 10 for communicating a plurality of gas suction pipes SP1 and SP2 and one gas discharge pipe DP and an upper side of the casing 10. And a first compression mechanism 30 and a second compression mechanism 40 installed under the casing 10 to compress the refrigerant by the rotational force generated by the transmission mechanism 20. ) And the second vane, which is connected between the recovery dog gas suction pipes SP1 and SP2 and the gas discharge pipe DP, and switches the back surface of the second vane 44 to be described later into a high pressure atmosphere or a low pressure atmosphere. While supporting the 44 and supplying a high-pressure pressure to the side of the second vane 44, the second is described by the difference between the pressure supplied to the back of the second vane 44 and the pressure supplied to the side The vane control unit 50 is configured to selectively restrain the vanes 44.

The electric drive unit 20 has a stator 21 fixed to the inside of the casing 10 by applying constant speed driving or inverter driving to apply power from the outside, and has a predetermined gap inside the stator 21. Rotor 22 that rotates while interacting with the stator 21, and the rotating shaft coupled to the rotor 22 to transmit the rotational force to the first compression mechanism 30 and the second compression mechanism 40 It consists of 23.

The first compression mechanism 30 is formed in an annular shape to cover the first cylinder 31 installed in the casing 10 and the upper and lower sides of the first cylinder 31 to cover the first compression space V1. While rotating the upper bearing plate (hereinafter, the upper bearing) 32 and the intermediate bearing plate (hereinafter, the middle bearing) 33 for supporting the rotating shaft 23 in the radial direction, and the upper eccentric portion of the rotating shaft 23 The first cylinder (34) and the first rolling piston (34) for compressing the refrigerant while pivoting in the first compression space (V1) of the first cylinder (31) and the outer circumferential surface of the first rolling piston (34). A first vane 35 and a first vane, each of which is radially movable to 31 to partition the first internal space V1 of the first cylinder 31 into a first suction chamber and a first compression chamber, respectively; It is provided in the vicinity of the center of the first vane spring (36) of the compression spring and the upper bearing 32 to elastically support the rear side of the 35) A first discharge valve 37 and a first discharge valve 37 which are coupled to the front end of the first discharge port 32a so as to be opened and closed to regulate the discharge of the refrigerant gas discharged from the compression chamber of the first internal space V1. It is composed of a first muffler 38 having an inner volume to accommodate the upper bearing 32.

The second compression mechanism 40 is formed in an annular shape to cover the second cylinder 41 installed below the first cylinder 31 in the casing 10, and both the upper and lower sides of the second cylinder 41. 2 to form a compression space (V2) rotatably coupled to the intermediate bearing 33 and the lower bearing 42 and the lower eccentric portion of the rotating shaft 23 to support the rotating shaft 23 in the radial and axial directions The second cylinder 41 to be pressed or spaced apart from the second rolling piston 43 that compresses the refrigerant while turning in the second compression space V2 of the second cylinder 41 and the outer circumferential surface of the second rolling piston 43. A second vane 44 and a lower bearing 42 which partition or communicate with the second compression space V2 of the second cylinder 41 to the second suction chamber and the second compression chamber, respectively, so as to be movable in a radial direction. Refrigerant gas discharged from the second compression chamber by being coupled to the front end of the second discharge port 42a provided near the center And second discharge valve 45 for controlling the discharge, so as to accommodate the second discharge valve (45) comprises a second muffler 46 is coupled to the lower bearing (42) having a predetermined internal volume.

As shown in FIG. 4, the second cylinder 41 forms a second vane slit 41a on one side of the inner circumferential surface of the second compression space V2 such that the second vanes 44 reciprocate in the radial direction. In addition, a second suction port (not shown) for guiding the refrigerant into the second compression space V2 is radially formed at one side of the second vane slit 41a, and the refrigerant is formed at the other side of the second vane slit 41a. A second discharge guide groove (not shown) discharged into the casing 10 is formed to be inclined in the axial direction. In addition, the radially back side of the second vane slit 41a communicates with the common side connecting pipe 53 of the vane control unit 50, which will be described later, so as to achieve a suction pressure or a discharge pressure atmosphere on the rear side of the second vane 44. A back pressure space 41b having a predetermined internal volume is formed, and the inside of the casing 10 and the second vane slit 41a in a direction orthogonal to the direction of movement of the second vanes 44 or having a predetermined offset angle. ), The side pressure flow passage 41c is formed so as to restrain the second vanes 44 by the discharge pressure.

The back pressure space 41b communicates with the common side connecting pipe 53 of the vane control unit 50, which will be described later, even if the second vane 44 is completely retracted and stored in the second vane slit 41a. The rear surface of the 44 is formed to have a predetermined internal volume so as to form a pressure surface with respect to the pressure supplied through the common side connecting pipe 53 described above.

The side pressure passage 41c is formed in the discharge guide groove 41c of the second cylinder 41 around the second vane 44, and a plurality of side vanes 44 are provided along the height direction of the second vane 44. , Upper and lower ends are shown). The second vane 44 is excessively constrained to form the entire cross-sectional area of the side pressure passage 41c more than or equal to the width of the pressure surface applied to the back surface of the second vane 44 through the back pressure space 41b. It is preferable because it can prevent that.

Here, the second cylinder 41 may be formed to have the same volume as or different from the volume of the first cylinder 31 and the compression space V1 as necessary. For example, in the case where the two cylinders 31 and 41 have the same volume, if one cylinder is saved, the compressor performs only 50% of the volume of the other cylinder. In the case where the volume of 41 is formed differently, the compressor performance is varied by the ratio of the volume of the remaining cylinders in normal operation.

The lower bearing 42 is formed in the shape of a disc to form a second compression space V2 together with the second cylinder 41, but a back pressure adjusting hole 42b is formed in a portion forming the back pressure space 41b, and the back pressure thereof. The adjustment hole 42b is press-fitted or screwed into the back pressure control valve assembly 60 to be described later to open and close the back pressure control hole 42b according to the pressure change of the back pressure space 41b.

The vane control unit 50 is installed in the middle of the low pressure side connecting pipe 51 communicating with the suction side of the second cylinder 41 so that the refrigerant gas having the suction pressure passes into the back pressure space 41b of the second cylinder 41. Together with the back pressure switching valve 52 which controls the inflow, and the back pressure switching valve 52, the pressure of the back pressure space 41b is maintained at the suction pressure or the discharge pressure, so that the second vane 44 The back pressure regulating valve assembly 60 for continuously contacting or spaced from the second rolling piston 43 and the second vane 44 are provided in the second vane 44. It consists of a vane constraining part which supplies a discharge pressure to the side surface of the said 2nd vane 44 so that it may be in close contact with 2 vaneslit 41a.

The back pressure regulating valve assembly 60 is provided in the inner space of the valve housing 61 and the valve housing 61 which forms a predetermined inner space and communicates with the back pressure adjusting hole 42b of the lower bearing 42. The back pressure regulating valve 62 which opens and closes the back pressure adjusting hole 42b according to the pressure of the space 41b and the internal pressure of the casing 10, and the back pressure regulating valve 62 together with the back pressure regulating valve 62. When the pressure in the back pressure space 41b is the suction pressure, the back pressure regulating valve 62 blocks the back pressure adjusting hole 42b, while in the case of the discharge pressure, the back pressure regulating spring 63 and the back pressure regulating spring are opened. And a housing cover 64 supporting the 63 to cover the opening side of the valve housing 61.

The valve housing 61 is inserted into and coupled to the back pressure adjusting hole 42b to communicate with the back pressure space 41b therein and to form a communication hole h1 to be opened and closed by the back pressure regulating valve 62. A space for integrally expanding the 61a and the fixed portion 61a to accommodate the back pressure regulating valve 62 and the back pressure regulating spring 63, and to form the pressure of the casing 10 to be guided to the communication hole h1. The portion 61b and the inner surface of the space portion 61b extend from the fixing portion 61a, and the communication hole h1 of the fixing portion 61a is continuously formed to protrude into the space portion 61b. It consists of a valve opening and closing part 61c.

The back pressure regulating valve 62 accommodates the back pressure supply hole 64a on a surface of the housing cover 64 which will be described later, in contact with the back pressure supply hole 64a to form a communication groove h2 in a negative shape. And an opening and closing portion 62b formed to protrude in a spherical shape on one side of the body portion 62a to open and close the communication hole h1. The opening and closing portion 62b is preferably formed in a spherical cross-sectional shape so as to be in line contact with the communication hole h1.

The back pressure valve spring 63 is composed of a compression coil spring, and when the pressure in the back pressure space 41b is the suction pressure, the back pressure control valve 62 blocks the communication hole h1, while the discharge pressure opens the communication hole h1. It is formed to have a modulus of elasticity.

The housing cover 64 is coupled to the opening side of the valve housing 61 so as to be press-fitted or screwed, and at the center thereof, a back pressure supply hole 64a is formed to be received in the communication groove 62a of the back pressure control valve 62. do. The back pressure supply hole 64a is preferably formed at a height that always keeps the state of the casing 10 submerged in the oil.

As described above, at least one vane restraint portion (upper and lower sides in the drawing) of the second cylinder 41 is provided such that the discharge pressure inside the casing 10 is supplied to the side surface in the thickness direction of the second vane 44. Although the side pressure flow path 41c is formed, it is preferable to form the same cross-sectional area along the height direction of the vane toward the discharge guide groove 41c based on the second vane 44.

Meanwhile, as shown in FIG. 7, the vane restraining part is slidably inserted into the pin hole 42c provided in the lower bearing 42, so that the second vane 44 depends on the pressure difference between the back pressure space 41b and the casing 10. A stopper pin 55 which is pressed toward the pinned groove 44a of the second vane 44 and restrains the pinned groove 44a, and the stopper pin 55 is returned so as to be spaced apart from the second vane 44. It may also be configured as a spring (56).

In the drawings, the same reference numerals are given to the same parts as in the prior art.

In the drawings, reference numeral 3 denotes a condenser and 4 denotes an evaporator.

Effects of the variable capacity device of the rotary compressor of the present invention as described above are as follows.

That is, when the rotor 22 is rotated by applying power to the stator 21 of the power mechanism unit 20, the rotating shaft 23 rotates together with the rotor 22 to increase the rotational force of the power mechanism unit 20 first. It is transmitted to the compression mechanism unit 30 and the second compression mechanism unit 40, and the first compression mechanism unit 30 and the second compression mechanism unit 40 are normally operated together according to the required capacity of the air conditioner to generate a large amount of cooling force. Alternatively, only the first compression mechanism unit 30 performs normal operation, and the second compression mechanism unit 40 performs the saving operation to generate a small capacity cooling power.

In this case, when the compressor or the air conditioner applying the same operates normally, as shown in FIG. 6A, the two-way back pressure switching valve 52 is closed so that the internal pressure of the back pressure space 41b is approximately at the suction pressure and the discharge pressure. It's medium. In this state, the combined force of the gas force of the back pressure space 41b and the elastic force of the back pressure regulating spring 63 becomes greater than the force of the internal pressure of the casing 10, and the back pressure switching valve 52 is pushed down. To open the communication hole h1 of the fixing part 61a, and the oil inside the casing 10 passes through the space portion 61b and the communication hole h1 through the back pressure adjusting hole 64a. The back pressure space 41b introduced into the space 41b supports a second vane 44 while forming a high-pressure atmosphere to allow the second vane 44 to reciprocate freely, and at the same time, oil is supplied to the second vane ( Lubricating between 44 and the second vane slit 41a. In this way, the first vane 35 and the second vane 44 are press-contacted to the respective rolling pistons 34 and 43 to transfer the first compression space V1 and the second compression space V2 into the suction chamber and the compression chamber. By compressing and discharging the entire refrigerant sucked into each suction chamber while partitioning, the compressor or the air conditioner applying the same is operated 100%.

Next, in the case where the compressor or the air conditioner having the same performs the saving operation, as shown in FIG. 6B, the two-way valve back pressure switching valve 52 is opened so that the back pressure space 41b becomes low pressure. The combined force of the gas force and the elastic force of the back pressure regulating spring 63 is less than the force of the internal pressure of the casing 10, while the back pressure regulating valve 62 is pushed by the internal pressure of the casing 10 to communicate with the communication hole. (h1) is closed so that the pressure of the back pressure space 41b is lower than the pressure of the second compression space V2. In this process, the second vane 44 is retracted and stored in the second vane slit 41a, and a high-pressure gas force acts on the second vane 44 through the side pressure passage 41c of the second cylinder 41. The second vane 44 is brought into close contact with the side surface of the second vane slit 41a and restrained. In this way, as the compression chamber and the suction chamber of the second cylinder 41 communicate with each other, the entire refrigerant sucked into the suction chamber of the second cylinder 41 is not compressed and moves back to the suction chamber along the trajectory of the rolling piston 43. 2, the compression mechanism 40 does not work, so the compressor or the air conditioner applying the same operates only as much as the capacity of the first compression mechanism 30.

On the other hand, when the stopper pin is used as the vane constraining part as shown in FIG. 7, the sum of the force by the pressure of the back pressure space 41b of the second cylinder 41 and the elastic force of the pin spring 56 is the second muffler. (46) While the stopper pin 55 is pushed downward because it is larger than the force due to the internal pressure, the second vane 44 freely linearly reciprocates in the second vane slit 41a, while saving. During operation, the stopper pin 55 is pushed up while the force by the pressure of the back pressure space 41b and the force of the elastic force of the pin spring 56 are smaller than the force by the pressure of the internal space of the second muffler 46. The pinned groove 44a of the second vane 44 is inserted to restrain the linear movement of the second vane 44.

The variable capacity apparatus of the rotary compressor according to the present invention uses a two-way valve back pressure switching valve and a back pressure control valve assembly to generate a pressure difference on the back and side of one vane, and selectively restrain the vane to selectively restrain the vane. By partitioning or communicating the compressed space into the suction chamber and the compression chamber, it is easy to control the variable capacity of the compressor and simplify the piping, and it is easy to change the mode when applying the compressor to the air conditioner, so that the comfort and energy saving can be achieved. It can improve the assembly of air conditioner by preventing the interference with other pipes in advance and reduce the production cost by reducing the number of valves. In addition, by modularizing the back pressure control valve assembly, it is possible to reduce the production time required for the assembly process of the entire compressor, thereby reducing the production cost.

Claims (8)

A plurality of compression spaces are formed inside the casing independently, and the compression space is partitioned into a suction chamber and a compression chamber by respective rolling pistons and vanes, and the suction is separated from the inner space of the casing on either back of the vanes. A plurality of cylinders having a back pressure space to alternately supply pressures of pressure and discharge pressure; A plurality of bearing plates which divide a plurality of cylinders into a plurality of compression spaces, one of which communicates with the back pressure space to form a back pressure adjusting hole so that the pressure of the discharge pressure in the casing is supplied to the back pressure space; A back pressure switching valve installed at a suction line of the cylinder so as to be opened and closed on a pipe line communicating with the back pressure space and selectively supplying a pressure of the suction pressure to the back pressure space according to the operation mode of the compressor; A valve housing forming a predetermined inner space and communicating with the back pressure adjusting hole of the bearing plate; A back pressure regulating valve provided in the inner space of the valve housing to open and close the back pressure adjusting hole according to the pressure of the back pressure space and the casing pressure; A back pressure regulating spring provided in the inner space of the valve housing together with the back pressure regulating valve so that the back pressure regulating valve closes the back pressure adjusting hole when the pressure in the back pressure space is the suction pressure, while the back pressure regulating spring is opened in the case of discharge pressure; A capacity of a rotary compressor comprising: a housing cover for supporting a back pressure regulating valve and a back pressure regulating spring to couple the opening side of the valve housing to the back and to form a back pressure supply hole in communication with the back pressure adjusting hole at the center thereof. Variable device. The method of claim 1, The valve housing is variable capacity device of a rotary compressor, characterized in that the back pressure control hole is pressed or screwed. The method of claim 2, The valve housing has a fixing part inserted into the back pressure adjusting hole and coupled therein to form a communication hole therein so as to be opened and closed by the back pressure regulating valve, and the fixing part accommodates the back pressure regulating valve and the back pressure adjusting spring and fixedly couples the housing cover. The variable capacity device of the rotary compressor, characterized in that consisting of a space extending to form. The method of claim 3, The back pressure regulating valve comprises a body part which receives the back pressure supply hole on the surface contacting the back pressure supply hole to form a communication groove in a negative shape, and an opening and closing part which protrudes on one side of the body part to open and close the communication hole. Capacity variable device. The method of claim 4, wherein A variable capacity device of a rotary compressor, characterized in that the opening and closing portion is formed in a spherical cross-sectional shape. The method of claim 5, The space part of the valve housing further comprises a valve opening and closing portion for receiving the communication hole and protruding in the direction of the back pressure supply hole so as to be opened and closed by the opening and closing portion. The method of claim 1, And at least one side pressure flow path is formed in the cylinder to supply the discharge pressure inside the casing to the side surface in the thickness direction of the vane so that the vane is tightly constrained to the vane slit. The method of claim 1, When the vane reaches the top dead center, a pin hole is formed in the bearing plate so that it overlaps, and the stopper pin slides into the pin hole to press the vane and restrain the vane according to the pressure difference between the back pressure space and the casing. The fork variable installation of the double rotary compressor, characterized in that the stopper pin is installed by the pin spring to return the stopper pin to be spaced apart from the vane when the pressure in the back pressure space is the discharge pressure.

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