KR20050031798A - Variable capacity rotary compressor - Google Patents

Abstract

A variable displacement rotary compressor is provided to prevent eccentric bushes from slipping due to a pressure change in an upper compression chamber or lower compression chamber when an eccentric device rotate in formal or inverse direction, thereby smoothly rotating the eccentric bushes. Upper and lower compression chambers are defined in different inner volume. A rotary shaft(21) passes through the upper and lower compression chambers. Upper and lower eccentric cams(41,42) are installed at the rotary shaft. Upper and lower eccentric bushes(51,52) are arranged on outer peripheral surfaces of the upper and lower eccentric cams respectively. A slot(53) is formed between the upper eccentric bush and the lower eccentric bush. A fixing pin(43) operates with the slot for selectively converting the upper eccentric bush and the lower eccentric bush into the maximum eccentric position. A restricting device(80) is installed at the upper eccentric cam or the lower eccentric cam, having an elastic member(82) and a ball(83) for restricting the upper eccentric bush and the lower eccentric bush from slipping.

Description

Variable Capacity Rotary Compressor

The present invention relates to a rotary compressor, and more particularly, to a rotary compressor capable of varying the capacity by selectively performing compression operation in any one of two compression chambers having different contents by an eccentric device disposed on the rotary shaft. will be.

A cooling device for cooling a specific space using a refrigeration cycle such as an air conditioner and a refrigerator is provided with a compressor for compressing a refrigerant circulating in a closed circuit of the refrigeration cycle. The cooling capacity of such a cooling device is usually determined according to the compression capacity of the compressor. Therefore, when the compressor is configured to vary the compression capacity of the compressor, the cooling device is optimally optimized according to the surrounding conditions such as the difference between the actual temperature and the set temperature. By operating in a state, it is possible to appropriately cool a specific space and at the same time save energy.

Compressors used in the cooling system include a rotary compressor and a reciprocating compressor, and the present applicant selectively compresses only one of two compression chambers having different contents through Korean Patent Application No. 10-2002-0061462. This has been applied for a variable displacement rotary compressor to vary the capacity.

In each compression chamber of the variable displacement rotary compressor, an eccentric device is arranged so that the compression operation is performed only in one compression chamber according to the rotation direction of the rotation shaft. The eccentric device includes two eccentric cams provided on the outer surface of the rotating shaft passing through the compression chambers, two eccentric bushes rotatably disposed on the outer surface of the eccentric cams, and rotatably disposed on the outer surface of the eccentric bushes. And two rollers for compressing the refrigerant gas, and a locking pin installed so that one eccentric bushing is shifted to an eccentric position with respect to the center line of the rotating shaft and the other eccentric bushing is shifted to a concentric position according to the direction in which the rotating shaft is rotated. It is configured to include.

Therefore, when the rotating shaft rotates in the forward or reverse direction, the compression operation is performed only in any one of the two compression chambers having different contents by the eccentric device configured as described above, thereby changing the capacity of the compressor.

However, such a capacity-variable rotary compressor has a structure in which each eccentric bush is engaged by a locking pin protruding from the rotary shaft in a state in which each eccentric bush is disposed on the outer circumferential surface thereof and rotates together with the rotary shaft. Due to the pressure change inside the compression chamber, the eccentric bushes rotate in a certain section faster than the rotational speed of the rotating shaft, causing slippage between each eccentric cam and the eccentric bush. There was a problem that the noise is generated by collision with the eccentric bush in the process of the pin is caught in the eccentric bush.

More specifically, in the slip phenomenon, a part of the compressed gas discharged to the discharge port is introduced into the compression chamber when the maximum eccentric portion of the eccentric bush disposed in the compression chamber where the compression action is performed passes between the discharge port and the vane provided in the compression chamber. In the process of reflow and re-expansion, the eccentric bush is applied in the rotational direction to rotate the eccentric bush at a faster speed than the corresponding eccentric cam, and the collision phenomenon occurs after the slip occurs. As it disappears, the locking pin of the rotating shaft is caused by hitting the eccentric bush again.

Conventional variable displacement rotary compressors are not only noise generated by the slip phenomenon and the collision phenomenon, but also wear or damage is generated in the impact portion is to reduce the reliability and durability.

The present invention is to solve the above-described problems of the prior art, an object of the present invention is due to the pressure change occurring in each compression chamber as the rotating shaft rotates in a certain section the eccentric bush rotates at a faster speed than the rotating shaft It is to provide a variable displacement rotary compressor to avoid.

Capacity variable rotary compressor according to the present invention for achieving this object,

Upper and lower compression chambers divided into different contents, rotation shafts penetrating the upper and lower compression chambers, upper and lower eccentric cams provided on the rotation shafts, and upper and lower circumferential surfaces of the upper and lower eccentric cams, respectively; A lower eccentric bush, a slot provided between the upper and lower eccentric bushes, a locking pin that acts with the slot to selectively switch the upper and lower eccentric bushes to a maximum eccentric position, and among the upper and lower eccentric cams. It is installed on at least one and characterized in that it comprises a restraining device having an elastic member and a ball to restrain the upper eccentric bush and the lower eccentric bush from slip rotation.

The elastic member and the ball are disposed in the receiving hole formed in the transverse direction in the upper eccentric cam to cause the ball to restrain the upper eccentric bushing by the elastic force of the elastic member.

The accommodation hole is formed at an angular position that makes a phase difference of 90 degrees with the locking pin in the upper eccentric cam.

The first and second grooves are formed to be concave at each of the positions constituting a phase difference of 90 degrees with respect to the first end and the second end of the slot on the inner circumferential surface of the upper eccentric bush. The ball is restrained in the first groove or the second groove at the position caught by the end or the second end, thereby receiving the elastic force of the elastic member to restrain the upper and lower eccentric bushes without slip rotation. .

Preferably, the elastic member is made of a coil spring, the elastic force of the coil spring is greater than the slip rotational force of the upper and lower eccentric bushing constraint force that the ball acts on the upper eccentric bushing and smaller than the rotational driving force of the rotary shaft Is set to be.

The housing is fitted into the receiving hole and fixed, so that the elastic member and the ball exert a restraining force on the inner circumferential surface of the upper eccentric bush in the state accommodated in the housing.

In addition, the locking pin protrudes from the rotation shaft between the upper eccentric cam and the lower eccentric cam, and the slot is formed between the upper eccentric bush and the lower eccentric bush to accommodate the locking pin, but the slot The first stage and the second stage are formed to have a length of 180 degrees.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a longitudinal sectional view showing an approximate internal structure of a variable displacement rotary compressor according to the present invention. As shown therein, the variable displacement rotary compressor according to the present invention is installed in the sealed container 10 to generate a rotational force, and a compression unit for compressing gas by the rotational force of the drive unit 20. 30 is provided. The driving unit 20 includes a cylindrical stator 22 fixed to an inner surface of the sealed container 10, a rotor 23 rotatably installed in the stator 22, and the rotor 23. It is provided so as to extend from the center portion and is composed of a rotating shaft 21 which rotates forward (first rotation direction) or reverse rotation (second rotation direction) together with the rotor 23.

The compression unit 30 is disposed at the upper and lower ends of the housing 33 having a cylindrical upper compression chamber 31 and a lower compression chamber 32 having different contents in upper and lower portions, respectively. It is disposed between the upper flange 35 and the lower flange 36 to rotatably support the rotating shaft 21, and the upper compression chamber 31 and the lower compression chamber 32, the upper compression chamber 31 and the lower compression Intermediate plate 34 to allow the seals 32 to be partitioned from one another.

The height of the upper compression chamber 31 is formed larger than the height of the lower compression chamber 32 so that the contents of the upper compression chamber 31 are larger than the contents of the lower compression chamber 32, and thus the upper compression chamber ( 31, it is possible to compress the gas of a higher flow rate than the lower compression chamber 32, so that the rotary compressor according to the present invention has a variable capacity.

Of course, if the height of the lower compression chamber 32 is greater than the height of the upper compression chamber 31, the contents of the lower compression chamber 32 may be increased so that the gas in the lower compression chamber 32 can be compressed at a higher flow rate. It becomes larger than the content of the compression chamber 31.

The inside of the upper compression chamber 31 and the lower compression chamber 32 may be selectively compressed only in any one of the upper compression chamber 31 and the lower compression chamber 32 according to the rotational direction of the rotary shaft 21. An eccentric device 40 is disposed, and the eccentric device 40 is provided with a restraining device 80 according to the present invention for smoothly operating the eccentric device 40 without slip rotation. The structure and operation of the eccentric device 40 and the restraining device 80 will be described later with reference to FIGS. 2 to 8.

The upper compression chamber 31 and the lower compression chamber 32 are also provided with an upper roller 37 and a lower roller 38 rotatably disposed on the outer circumferential surface of the eccentric device 40, respectively, and in the housing 33. Upper and lower suction ports 63 and 64 and upper and lower discharge ports 65 and 66 (refer to FIGS. 3 and 6) are arranged to communicate with the upper compression chamber 31 and the lower compression chamber 32, respectively.

An upper vane 61 is radially disposed between the upper suction port 63 and the upper discharge port 65 in a state in which the upper vane 61 is in close contact with the upper roller 37 by the support spring 61a (see FIG. 3). Between the 64 and the lower discharge port 66, the lower vanes 62 are radially arranged in close contact with the lower roller 38 by the support spring 62a (see Fig. 6).

In addition, in the outlet tube 69a of the accumulator 69 which separates the liquid refrigerant and allows only the gas refrigerant to flow into the compressor, only the suction port side of the upper and lower suction inlets 63 and 64 formed in the housing 33 is compressed. A flow path switching device 70 for selectively opening and closing each suction flow path 67 and 68 so that a gas refrigerant is supplied is provided. The suction flow paths 67 and 68 are formed inside the flow path switching device 70 by the pressure difference between the suction flow path 67 connected to the upper suction port 63 and the suction flow path 68 connected to the lower suction port 64. The valve device 71 which opens only one of them and is supplied with the refrigerant gas is arranged to be movable left and right.

Next will be described with reference to Figure 2 the structure of the rotating shaft and the eccentric device which constitutes a characteristic configuration of the present invention.

Figure 2 is a perspective view showing a state in which the eccentric device of the present invention is separated from the rotating shaft. As shown therein, the eccentric device 40 has an upper eccentric cam 41 and a lower eccentric cam 42 provided at positions corresponding to the upper compression chamber 31 and the lower compression chamber 32, respectively, on the rotation shaft 21. Between the upper eccentric bush 51 and the lower eccentric bush 52, the upper eccentric cam 41 and the lower eccentric cam 42, which are disposed on the outer circumferential surfaces of the upper eccentric cam 41 and the lower eccentric cam 42, respectively. Installed locking pin 43, a slot 53 provided with a predetermined length between the upper eccentric bush 51 and the lower eccentric bush 52 so that the locking pin 43 is caught, and the upper eccentric bush 51 and the lower eccentric The bush 52 is provided with a restraining device 80 to prevent slip rotation of the upper eccentric cam 41 and the lower eccentric cam 42, respectively, in a particular section.

The upper eccentric cam 41 and the lower eccentric cam 42 protrude integrally in the transverse direction from the outer circumferential surface of the rotating shaft 21 and are vertically disposed in an eccentric state with respect to the center line C1-C1 of the rotating shaft 21. In addition, the upper and lower eccentric cams (41, 42) are each projected to the maximum from the upper and lower eccentric cams 41, 42 of the upper and lower eccentric cams (41) 42 and the uppermost projecting to the minimum. And an upper eccentric line L1-L1 and a lower eccentric line L2-L2 connecting the minimum eccentric portions of the lower eccentric cams 41 and 42.

The locking pin 43 is composed of a threaded body 44 and a head 45 formed with a diameter slightly larger than the body 44 at the tip of the body 44, the upper eccentric cam 41 The body portion (3) in a screw hole (46) formed at a position to form an approximately 90 degree angle with the eccentric lines (L1-L1) (L2-L2) on the rotation shaft (21) between the lower eccentric cam (42). 44 is screwed to the rotary shaft 21 is fastened.

The upper eccentric bushes 51 and the lower eccentric bushes 52 are integrally formed by connecting parts 54 connecting them, and have a width slightly larger than the diameter of the head 45 of the locking pin 43. The slot 53 having the circumferential direction is formed in the connecting portion 54.

Therefore, the upper eccentric bush 51 and the lower eccentric bush 52 formed integrally connected by the connecting portion 54 are inserted into the rotating shaft 21, and the locking pin 43 is rotated through the slot 53. When fastened to the screw hole 46 of the locking pin 43 is installed in the rotating shaft 21 in the state fitted to the slot (53).

In this state, when the locking pin 43 is caught by the first end 53a or the second end 53b of the slot 53 as the rotary shaft 21 rotates forward or reverse, the upper eccentric bush 51 and the lower end The eccentric bush 52 rotates forward or reverse with the rotation shaft 21.

On the other hand, the angle between the eccentric line (L3-L3) connecting the maximum eccentric portion and the minimum eccentric portion of the upper eccentric bush (51) and the line connecting the center of the first end (53a) of the slot 53 and the connecting portion (54) Is formed to form approximately 90 degrees, the eccentric line (L4-L4) and the second end (53b) of the slot 53 and the connecting portion (54) connecting the maximum eccentric portion and the minimum eccentric portion of the lower eccentric bush (52) The angle between the lines connecting the center is likewise formed to be approximately 90 degrees.

In addition, the eccentric line (L3-L3) of the upper eccentric bush (51) and the eccentric line (L4-L4) of the lower eccentric bush (52) are located on the same plane, but the maximum eccentric portion of the upper eccentric bush (51) and The maximum eccentric portions of the lower eccentric bush 52 are eccentrically disposed to face opposite sides, and connect the first end 53a and the second end 53b of the slot 53 formed in the circumferential direction to the connecting portion 54. The line is formed to form an angle of 180 degrees.

The locking pin 43 is caught by the first end 53a of the slot 53 by the arrangement structure as described above, so that the upper eccentric bush 51 rotates in the first rotation direction together with the rotation shaft 21 (of course, the lower portion). The eccentric bush is rotated together with the upper eccentric bush 51 at each position where the eccentric bush 51 rotates together with the maximum eccentric portion of the upper eccentric bush 41 and the maximum eccentric bush of the upper eccentric bush 51. While rotating forward with the maximum eccentricity (see FIG. 3), the lower eccentric bush 52 has the maximum eccentric portion of the lower eccentric cam 42 and the minimum eccentric portion of the lower eccentric bush 52 abut on each other. Forward rotation is made in concentric with (21) (see Fig. 4).

Contrary to the above, the lower eccentric at the angular position where the engaging pin 43 is caught by the second end 53b of the slot 53 so that the lower eccentric bush 52 rotates in the second rotation direction together with the rotation shaft 21. The bush 52 has the maximum eccentric portion of the lower eccentric cam 42 and the maximum eccentric portion of the lower eccentric bush 52 come into contact with each other to be reversely rotated in the state of being eccentrically with the rotation shaft 21 (FIG. 6). The upper eccentric bush 51 is rotated in a state in which the maximum eccentric portion of the upper eccentric cam 41 and the minimum eccentric portion of the upper eccentric bush 51 abut on each other and are concentric with the rotating shaft (see FIG. 7). ).

In the eccentric device 40 configured as described above, the upper eccentric cam 51 and the lower eccentric bush 52 are rotated at the same speed as the rotation shaft 21 without slip rotation of the upper eccentric cam. It is installed in 41.

The restraint device 80 includes a housing 81, an elastic member 82 and a ball 83 accommodated in the housing 81. In the state where the elastic member 82 and the ball 83 is accommodated in the housing 81, the elastic member 82 is compressed to apply an elastic force to the ball 83, a part of the ball 83 It protrudes outward from the housing 81 and is located.

In order to install the housing 81 on the upper eccentric cam 41, the upper eccentric cam 41 is provided with a receiving hole 84 formed to a predetermined depth. Threads are formed on the outer circumferential surface of the housing 81 and the inner circumferential surface of the accommodation hole 84 so that the housing 81 is screwed to the accommodation hole 84 to be fixed. Of course, the housing 81 may be fixed to the receiving hole 84 in other ways. In addition, the elastic member 82 and the ball 83 may be directly accommodated in the receiving hole 84 without the housing 81.

The accommodating hole 84 is an angular position that forms a phase difference of 90 degrees with the locking pin 43 in the upper eccentric cam 41, more precisely, based on the rotation shaft 21 rotating in the first direction (counterclockwise direction). As a result, the locking pin 43 is formed at an angular position leading by a phase difference of 90 degrees. Of course, the receiving hole 84 may be formed at an angular position behind the locking pin 43 by a phase difference of 90 degrees.

In addition, the restraint device 80 further includes a first groove 85 and a second groove 86 provided on an inner circumferential surface of the upper eccentric bush 51 at a height corresponding to the height at which the accommodation hole 84 is located. do.

The first and second grooves 85 and 86 are angular positions having a phase difference of 90 degrees with respect to the first end 53a and the second end 53b of the slot 53 on the inner circumferential surface of the upper eccentric bush 51. It is formed concave at. More specifically, the first groove 85 is formed at an angular position leading by a phase difference of 90 degrees with respect to the first end 53a of the slot 53 with respect to the first rotation direction of the rotation shaft 21. The two grooves 86 are formed at angular positions falling behind by a phase difference of 90 degrees with respect to the first end 53a of the slot 53 with respect to the first rotational direction of the rotation shaft 21.

The accommodation holes 84 and the first and second grooves 85 and 86 are disposed at the respective angular positions as described above, so that the locking pins 43 are engaged with the first end 53a of the slot 53. Ball 83 is placed in the first groove (85) to exert an elastic force on the upper eccentric bush (51), in the position where the engaging pin 43 is caught in the second end (53b) of the slot (53) The ball 53 is placed in the second groove 86 to exert an elastic force on the upper eccentric bush 51.

The elastic member 82 is preferably made of a coil spring. In addition, the elastic force of the elastic member 82 is the restraining force (Fr) of the ball 83 acting on the upper eccentric bush 51 is the slip rotational force (Fs) of the upper and lower eccentric bushes 51, 52 (Fig. And larger than the rotational driving force of the rotation shaft 21. Due to the elastic range of the elastic member 82, the rotation shaft 21 or the upper and lower eccentric cams 41 and 42 can be rotated relative to the upper and lower eccentric bushes 51 and 52, The upper and lower eccentric bushes 51 and 52 are not rotatable relative to the rotary shaft 21 or the upper and lower eccentric cams 41 and 42 so that slip rotation does not occur.

Hereinafter, an operation of selectively compressing refrigerant gas in the upper compression chamber or the lower compression chamber by the eccentric apparatus configured as described above with reference to FIGS. 3 to 8 will be described.

Figure 3 shows that the rotation is rotated in the first direction of rotation by the eccentric apparatus according to the invention the compression action is performed in a state that no slip occurs in the upper compression chamber, Figure 4 is a view corresponding to Figure 3, The rotating shaft rotates in the first rotational direction, and thus the compression operation is not performed in the lower compression chamber by the eccentric apparatus according to the present invention. It is shown that the upper rotary bush is not slip rotation by.

As shown in FIG. 3, the engaging pin 43 protruding from the rotating shaft 21 by rotating the rotation shaft 21 in the first rotation direction (counterclockwise in FIG. 3) is provided with the upper eccentric bush 51 and the lower eccentric. When the locking pin 43 is caught by the first end 53a of the slot 53 when the locking pin 43 is rotated at a predetermined angle while being inserted into the slot 53 formed between the bushes 52, the upper eccentric bush 51 is rotated 21. Will rotate). At this time, since the lower eccentric bush 52 is also formed integrally connected with the upper eccentric bush 51 by the connecting portion 54, the lower eccentric bush 52 rotates integrally with the upper eccentric bush 51.

In the state where the locking pin 43 is engaged with the first end 53a of the slot 53, as described above, the maximum eccentric portion of the upper eccentric cam 41 is brought into contact with the maximum eccentric portion of the upper eccentric bush 51. The upper eccentric bush 51 is rotated in a state in which the upper eccentric bush 51 is switched to the maximum eccentric position with respect to the center line C1-C1 of the rotation shaft 21, whereby the upper roller 37 forms the upper compression chamber 31. The compression operation is performed while rotating in contact with the inner circumferential surface of the housing 33.

At the same time, as shown in FIG. 4, the maximum eccentric portion of the lower eccentric cam 42 abuts the minimum eccentric portion of the lower eccentric bush 52 such that the lower eccentric bush 52 is the centerline C1- of the rotation shaft 21. It rotates while being switched to the concentric position with respect to C1), and thus the lower roller 38 is rotated while being spaced at regular intervals from the inner peripheral surface of the housing 33 forming the lower compression chamber 32 Compression will not work.

In the above position, the ball 83 of the restraining device 80 is positioned in the first groove 85 provided in the upper eccentric bush 51 to exert a restraining force on the upper eccentric bush 51.

Therefore, when the rotating shaft 21 rotates in the first rotation direction, the refrigerant gas introduced into the upper suction port 63 by the upper roller 37 is compressed in the upper compression chamber 31 having a relatively high content, and thus the upper discharge port 65. In the lower compression chamber 32, which is relatively small in content, the compression operation is not performed, so that the rotary compressor operates in a state where the compression capacity is large.

On the other hand, as shown in Figure 3, the upper roller 37 is in contact with the upper vane 61 to complete the compression operation of the refrigerant gas and at the same time when the suction operation of the refrigerant gas to the upper discharge port 65 Some of the compressed gas that could not escape through the flow back into the upper compression chamber 31 is re-expanded and the pressure is applied to the upper roller 37 and the upper eccentric bush 51 in the direction in which the rotating shaft 21 rotates. As the upper eccentric bush 51 is rotated at a faster speed than the rotation shaft 21, a slip phenomenon occurs in which the upper eccentric bush 51 slips from the upper eccentric cam 41.

In addition, when the rotation shaft 21 is further rotated in the above state, the locking pin 43 collides with the first end 53a of the slot 53 while the upper eccentric bush 51 is coupled with the rotation shaft 21. It will rotate at the same speed, which will generate noise and damage the contact area.

As described above, in the upper eccentric bush 51 at the rotational position where the upper roller 37 is in contact with the upper vane 61, the gas pressure generated when a part of the refrigerant gas flows back from the upper discharge port 65 and re-expands. As a result of the force acting in the direction in which the rotating shaft 21 rotates (first rotation direction), slip occurs in the upper eccentric bush 51, but the restraining device 80 according to the present invention installed in the upper eccentric cam 41 is provided. The friction force is generated in a direction opposite to the direction in which the upper eccentric bush 51 is slip-rotated, so that slip rotation is not generated.

That is, as shown in Fig. 5, the ball 83 of the restraining device 80 is in close contact with the first groove 85 of the upper eccentric bush 51 by the elastic member 82, the elastic member ( The elastic force of the 82 is applied, and between the ball 83 and the inner circumferential surface of the upper eccentric bush 51 by the elastic force of the elastic member 82 in the direction opposite to the rotation direction of the upper eccentric bush 51 The restraining force Fr is generated.

The frictional force Fr becomes larger as the centrifugal force generated by the high-speed rotation of the rotating shaft 21 is added to sufficiently offset the slip rotational force Fs of the upper eccentric bush 51, and thus the upper eccentric bush ( 51 is to rotate at the same speed as the rotary shaft 21 without being eccentrically rotated.

In order to achieve a compression action in the lower compression chamber 32 after the compression operation is completed without the slip rotation of the upper eccentric bush 51 in the upper compression chamber 31 by the eccentric device 40 according to the present invention. After the 21 stops, the operation of changing the direction in the second rotation direction is performed again. Next, an operation in which the compression operation is performed in the lower compression chamber 32 will be described with reference to FIGS. 6 to 8.

Figure 6 shows that the rotating shaft is rotated in the second rotation direction by the eccentric device according to the invention the compression action is performed in a state that no slip occurs in the lower compression chamber, Figure 7 is a view corresponding to Figure 6 the rotating shaft It is shown that the compression action is not performed in the upper compression chamber by the eccentric apparatus according to the present invention by rotating in the second rotation direction, and FIG. 8 shows the eccentric apparatus according to the present invention when the rotating shaft rotates in the second rotation direction. This shows that the lower rotating bush is not slip rotation.

As shown in FIG. 6, when the rotation shaft 21 rotates in the second rotation direction (clockwise in FIG. 6), the compression operation is performed only in the upper compression chamber 31 as in FIGS. 3 and 4. In operation, the compression is performed only in the lower compression chamber 32.

That is, when the rotation shaft 21 is turned at a low speed in the second rotation direction, the rotational driving force of the rotation shaft 21 acts between the upper eccentric cam 41 and the upper eccentric bush 51 by the restraining device 80. By surpassing the friction or restraining force, the locking pin 43 protruding from the rotation shaft 21 is caught by the second end 53b of the slot 53.

This switching operation causes the maximum eccentric portion of the lower eccentric cam 42 to contact the maximum eccentric portion of the lower eccentric bush 52 so that the lower eccentric bush 52 is maximum with respect to the center line C1-C1 of the rotation shaft 21. It is converted into an eccentric state and rotates together with the rotating shaft 21, and thus the lower roller 38 rotates in contact with the inner circumferential surface of the housing 33 forming the lower compression chamber 32, thereby compressing. Will be performed.

At the same time, as shown in FIG. 7, the maximum eccentric portion of the upper eccentric cam 41 abuts against the minimum eccentric portion of the upper eccentric bush 51 such that the upper eccentric bush 51 is the center line C1- of the rotation shaft 21. It is converted into a concentric state with respect to C1) and rotates, so that the upper roller 37 rotates while being spaced at a predetermined interval from the inner circumferential surface of the housing 33 forming the upper compression chamber 31. This will not be done.

In the above position, the ball 83 of the restraining device 80 is positioned in the second groove 86 provided in the upper eccentric bush 51 to exert a restraining force on the upper eccentric bush 51.

Therefore, in the lower compression chamber 32 having a relatively small inner content, the refrigerant gas introduced into the lower suction port 64 by the lower roller 38 is compressed and discharged through the lower discharge port 66. Since the compression operation is not performed in the compression chamber 31, the rotary compressor is operated in a state where the compression capacity is small.

On the other hand, as shown in Figure 6, the lower roller 38 is in contact with the lower vanes 62 to complete the compression operation of the refrigerant gas and at the same time when the suction operation of the refrigerant gas to the lower discharge port 66 Some of the compressed gas that could not escape through the flow back into the lower compression chamber 32 is re-expanded and the pressure is applied to the lower roller 38 and the lower eccentric bush 52 in the direction in which the rotating shaft 21 rotates. As a result, the lower eccentric bush 52 rotates at a higher speed than the rotation shaft 21, thereby causing a slip phenomenon in which the lower eccentric bush 52 slides from the lower eccentric cam 42.

In addition, when the rotating shaft 21 is further rotated in the above state, the locking pin 43 collides with the second end 53b of the slot 53 while the lower eccentric bush 52 is connected to the rotating shaft 21. It will rotate at the same speed, and there is a possibility that noise will be generated during this collision and damage will occur at the collision site.

However, the slip phenomenon and the collision phenomenon, as described above, by applying the frictional or restraining force to the upper eccentric bush 51 when the restraint device 80 rotates in the first rotation direction of the rotating shaft 21, the upper eccentric bush 51 ) Does not occur by acting in the same manner as preventing slip rotation.

That is, as shown in Figure 8, the upper eccentric bush 51 by the elastic force of the elastic member 82, the ball 83 of the restraining device 80 acts together with the centrifugal force in accordance with the high-speed rotation of the rotary shaft 21 It is in close contact with the inner circumferential surface of the, between the ball 83 and the second groove 86 of the upper eccentric bush 51 by the centrifugal force and the elastic force in the direction opposite to the rotation direction of the lower eccentric bush 52 frictional or restraining force (Fr) is generated to cancel the slip rotational force (Fs) of the lower eccentric bush (52). Therefore, the lower eccentric bush 51 is to rotate at the same speed as the rotation shaft 21 without being eccentrically rotated by the friction or restraining force (Fr).

As the rotation shaft 21 is rotated in the first rotation direction or the second rotation direction as described above, the upper eccentric bush 51 and the lower eccentric bush 52 are slip-rotated by the restraining device 80 according to the present invention. Without compression, the compression operation is performed in the upper compression chamber 31 and the lower compression chamber 32, respectively.

As described above, in the exemplary embodiment of the present invention, the restraining device is illustrated as being installed in the upper eccentric cam, but the present invention is not limited thereto, and the restraining device may be installed in the lower eccentric cam or installed in both the upper eccentric cam and the lower eccentric cam. . In addition, a plurality of restraining devices may be installed in the upper eccentric cam or the lower eccentric cam.

As described in detail above, the capacity-variable rotary compressor according to the present invention has a structure capable of varying the compression capacity by the eccentric device which rotates in the forward or reverse direction in the upper compression chamber and the lower compression chamber having different contents, the surrounding space In addition to being able to cool properly, there is an effect that can save energy.

In particular, the variable displacement compressor according to the present invention has an upper eccentric bush or a lower eccentric bush due to a pressure change in the upper or lower compression chamber during the rotation of the eccentric device in the forward or reverse direction by a restraint device installed in the upper eccentric cam. The slip phenomenon does not occur, so that the upper and lower eccentric bushes rotate smoothly.

1 is a longitudinal sectional view showing an approximate internal structure of a variable displacement rotary compressor according to the present invention.

2 is a perspective view showing a state in which the eccentric device according to the present invention is separated from the rotating shaft.

3 is a view showing that the compression operation is performed in a state that the slip shaft does not occur in the upper compression chamber by the eccentric apparatus according to the present invention by rotating the rotary shaft in the first rotation direction.

FIG. 4 is a view corresponding to FIG. 3, in which a rotation axis rotates in a first rotation direction, and thus a compression action is not performed in the lower compression chamber by the eccentric apparatus according to the present invention.

5 is a view showing that the upper rotating bush is not slip-rotated by the eccentric device according to the present invention when the rotating shaft rotates in the first rotation direction.

6 is a view showing that the compression operation is performed in a state in which the slip does not occur in the lower compression chamber by the eccentric apparatus according to the present invention by rotating the rotation axis in the second rotation direction.

FIG. 7 is a view corresponding to FIG. 6, in which a rotating shaft rotates in a second rotational direction, and thus the compression operation is not performed in the upper compression chamber by the eccentric apparatus according to the present invention.

8 is a view showing that the lower rotating bush is not slip-rotated by the eccentric device according to the present invention when the rotating shaft rotates in the second rotation direction.

* Description of symbols on the main parts of the drawings

21: rotating shaft 31: upper compression chamber

32: lower compression chamber 40: eccentric device

41: upper eccentric cam 42: lower eccentric cam

43: engaging pin 51: upper eccentric bush

52: lower eccentric bush 53: slot

80: restraining device 81: housing

82: elastic member 83: ball

85: first groove 86: second groove

Claims (7)

Upper and lower compression chambers divided into different contents, rotation shafts penetrating the upper and lower compression chambers, upper and lower eccentric cams provided on the rotation shafts, and upper and lower circumferential surfaces of the upper and lower eccentric cams, respectively; A lower eccentric bush, a slot provided between the upper and lower eccentric bushes, a locking pin that acts with the slot to selectively switch the upper and lower eccentric bushes to a maximum eccentric position, and among the upper and lower eccentric cams. And a restraining device provided on at least one of the plurality of elastic members and the ball to restrain the upper and lower eccentric bushes from slip rotation. The method of claim 1, wherein the elastic member and the ball is disposed in the receiving hole formed in the transverse direction in the upper eccentric cam is characterized in that the ball acts a restraint force on the upper eccentric bush by the elastic force of the elastic member. Capacity variable rotary compressors. 3. The variable displacement rotary compressor according to claim 2, wherein the accommodation hole is formed at each position forming a phase difference of 90 degrees with the locking pin in the upper eccentric cam. The concave first and second grooves of claim 3, wherein concave first and second grooves are formed at respective positions that form a phase difference of 90 degrees with respect to the first end and the second end of the slot on the inner circumferential surface of the upper eccentric bush. The upper and lower eccentric bushes are slip-rotated by being subjected to the elastic force of the elastic member in a state where the ball is placed in the first groove or the second groove at a position caught by the first end or the second end of the slot. Capacity variable rotary compressor characterized in that it is constrained without. According to claim 2, wherein the elastic member is made of a coil spring, the elastic force of the coil spring is a constraint force that the ball acts on the upper eccentric bushing is greater than the slip rotational force of the upper and lower eccentric bushing and the rotation of the rotary shaft Capacity variable rotary compressor characterized in that it is set to be smaller than the driving force. 3. The variable displacement rotary compressor according to claim 2, wherein a housing is fitted into the accommodation hole and fixed, so that the elastic member and the ball exert a restraining force on the inner circumferential surface of the upper eccentric bush in a state accommodated in the housing. The locking pin of claim 1, wherein the locking pin protrudes from the rotation shaft between the upper eccentric cam and the lower eccentric cam, and the slot is formed between the upper eccentric bush and the lower eccentric bush to accommodate the locking pin. The slot is a variable displacement rotary compressor, characterized in that the first end and the second end is formed in a length forming an angle of 180 degrees.