JP2015190401A - rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary compressor including an eccentric rotary type compressor mechanism (40) in which height sizes of blades (24, 34) in an axial direction of a compressor mechanism (40) are different to each other between a radial inner end and a radial outer end size and radial outer end sizes of the blades (24, 34) are formed to be larger the size of the radial inner end in which sliding loss caused by increased pushing load at the rear surfaces of the blades (24, 34) and a reduction in reliability caused by seizure are prevented.SOLUTION: There is provided an intermediate pressure communicating passage (58b) connecting blade rear pressure spaces (21g, 31g) with the fourth sucking flow passage (74) acting as an intermediate pressure portion of a compressor mechanism (40).

Description

  The present invention includes an eccentric rotation type compression mechanism in which a plurality of cylinder chambers are formed between a piston and a cylinder, and the height dimension of the blade in the axial direction of the compression mechanism is larger in diameter than the radially inner end of the blade. The present invention relates to a rotary compressor formed large at the outer end in the direction.

  Conventionally, a rotary compressor has been proposed in which a plurality of cylinder chambers are formed in a compression mechanism by disposing an annular piston inside an annular cylinder chamber of a cylinder (see, for example, Patent Document 1). ). In the compression mechanism of the compressor of Patent Document 1, four cylinder chambers are formed between the cylinder and the piston. The rotary compressor is configured to compress the refrigerant in four stages in the four cylinder chambers. This compressor is provided in a refrigerant circuit of a refrigeration apparatus such as an air conditioner.

  In the compression mechanism, specifically, four cylinder chambers are formed from three chambers on the upper surface side of the end plate of the annular piston and one chamber on the outer peripheral surface side of the end plate. In the compression mechanism, the outermost cylinder chamber is the first stage and the low pressure compression chamber, the innermost cylinder chamber is the fourth stage and the high pressure compression chamber, and the middle two cylinder chambers are the second stage. The third stage is an intermediate pressure compression chamber. This compression mechanism is provided with a blade formed so as to partition these four compression chambers into a high pressure side and a low pressure side.

  As shown in FIGS. 12A and 12B, the blade (100) includes a blade body (101) and a swing bush (102), and the swing bush (102) is a piston (103). ). In addition, the blade (100) has a different axial height of the compression mechanism between the radially inner end and the radially outer end, and the radially outer end height dimension (H2) is the radially inner end. It is formed larger than the height dimension (H1).

JP 2013-139729 A

  In the compression mechanism, the back pressure space (104) is formed on the back side of the blade (100). Although not shown, an oil reservoir for storing high-pressure lubricating oil (refrigeration oil) is provided at the bottom of the casing of the compression mechanism, and a high pressure is supplied from the oil reservoir to the back pressure space (104). The lubricating oil is supplied. Then, lubricating oil is supplied from the back pressure space (104) around the blade (100) to lubricate the blade (100). Therefore, a high pressure acts on the back surface (100c) of the blade (100).

  On the other hand, high pressure pressure acts on the first end (100a) of the blade (100) that partitions the innermost fourth-stage compression chamber, and the blade (100) that partitions the outermost first-stage compression chamber. Low pressure acts on the second end (100b).

  In any of the above configurations, since the height dimension (H2) of the radially outer end of the blade (100) on which high pressure pressure acts is larger than the height dimension (H1) of the radially inner end, FIG. As shown by arrows, the pressing force acting from the radially outer side to the radially inner side becomes stronger.

  As a result, for example, in FIG. 12A, there is a possibility that the surface pressure of the bush portion supporting the load is abnormally increased and the bush hole (105) is worn. As a result, the tip of the blade (100) may be in contact with the piston (106) due to wear of the bush hole (105) even though the tip is not in contact with the piston (106). It was. As a result, there has been a risk that the reliability of the compressor may be greatly reduced due to performance degradation due to the occurrence of sliding loss or seizure due to increased surface pressure at the tip of the blade (100).

  The present invention has been made in view of such problems, and the object thereof is that the height dimension of the blade in the axial direction of the compression mechanism is formed larger at the radially outer end than at the radially inner end. In an eccentric rotary type rotary compressor, the sliding loss due to an increase in the pressing load on the back surface of the blade and the decrease in reliability due to seizure are prevented.

  The first invention includes a cylinder (21, 31), a piston (22, 32) that rotates eccentrically in the cylinder (21, 31), the cylinder (21, 31), and a piston (22, 32). And a plurality of cylinder chambers (23a, 23b, 23c, 23d, 33a, 33b, 33c, 33d) located between the inner and outer ends in the radial direction and the intermediate portion thereof, and the cylinder (21 , 31) and a compression mechanism (40) having a blade (24, 34) slidably movable in a radial direction and having a piston (22, 32) swingably connected thereto, and the compression mechanism (40) is housed And the height dimension of the blade (24, 34) in the axial direction of the compression mechanism (40) is radially outer than the radially inner end of the blade (24, 34). It assumes a rotary compressor that is set to a large dimension at the end.

  The rotary compressor includes a blade back pressure space (21g, 31g) that is provided in the compression mechanism (40) and receives the radially outer end of the blade (24, 34), and a compression mechanism (40). An intermediate pressure communication path (58b) connecting the intermediate pressure portion (74) is provided.

  In the first aspect of the invention, the blade back pressure space (21g, 31g) becomes an intermediate pressure, so that the pressing load on the back surface of the blade (24, 34) is weaker than when the pressure is high.

  According to a second invention, in the first invention, the compression mechanism (40) includes four cylinder chambers (23a, 23b, 23c, 23d, 33a, 33b, 33c, 33d), and a four-stage compression operation. Is a four-stage compression mechanism (40) in which

  In the second aspect of the invention, the pressure in the blade back pressure space (21g, 31g) is changed to an intermediate pressure (second stage suction pressure, third stage suction pressure, fourth stage suction pressure, etc.) in the four stage compression mechanism (40). Can be set to By doing so, the pressure in the blade back pressure space (21 g, 31 g) can be made weaker than the high pressure (fourth stage discharge pressure).

  According to a third aspect, in the second aspect, the intermediate pressure portion (74) of the compression mechanism (40) connected to the blade back pressure space (21g, 31g) via the intermediate pressure communication path (58b) The compression mechanism (40) is a fourth stage suction portion (for example, a fourth stage suction flow path).

  In the third aspect of the invention, the pressure in the blade back pressure space (21g, 31g) is set to the pressure in the fourth stage suction portion of the four-stage compression mechanism (40). The pressure is weaker than the high pressure (fourth stage discharge pressure).

  According to a fourth invention, in any one of the first to third inventions, the blades (24, 34) are lubricated at a high pressure from an oil reservoir (10a) provided in the casing (10). An oil supply passage (59) for supplying oil to the sliding portion between the blade (24, 34) and the compression mechanism (40), and the oil supply passage (59) are connected to the blade back pressure space (21g, 31g) is provided with a seal portion (24s, 34s) for preventing communication.

  In the fourth aspect of the invention, high pressure lubricating oil is supplied to the blades (24, 34) from the oil supply passage, while high pressure oil is supplied to the blade back pressure space (21g, 31g) by the seal portion (24s, 34s). Entering is blocked. Accordingly, the blade back pressure space (21g, 31g) can be prevented from becoming a high pressure, and can be maintained at an intermediate pressure.

  According to the present invention, since the blade back pressure space (21g, 31g) becomes an intermediate pressure, the pressing load on the back surface of the blade (24, 34) causes the blade back pressure space (21g, 31g) to have a high pressure. The height of the blade (24, 34) in the axial direction of the compression mechanism (40) is set to be larger at the radially outer end than the radially inner end of the blade (24, 34). In the above-described configuration, it is possible to suppress sliding loss due to an increase in the pressing load on the back surface of the blade (24, 34) and a decrease in reliability due to seizure. Further, even if the blade back pressure space (21g, 31g) is set to an intermediate pressure, the lubricating performance of the sliding portion of the blade (24, 34) is not impaired.

  According to the second aspect of the invention, by setting the pressure in the blade back pressure space (21 g, 31 g) to the intermediate pressure of the four-stage compression mechanism (40), the pressing load on the back surface of the blade (24, 34) is increased. Therefore, it is possible to reliably suppress a reduction in reliability due to sliding loss and seizure.

  According to the third aspect of the invention, by setting the pressure in the blade back pressure space (21 g, 31 g) to the pressure in the fourth stage suction portion (74) of the four stage compression mechanism (40), the blade (24, 34 ), The loss of reliability due to sliding loss and seizure due to the increased pressing load on the back surface can be suppressed. In addition, a structure in which the blade back pressure space (21 g, 31 g) is set to an intermediate pressure can be realized at a relatively easy time.

  According to the fourth aspect of the invention, high-pressure lubricating oil is supplied from the oil supply path to the blades (24, 34), while high pressure is supplied from around the blades (24, 34) to the blade back pressure space (21g, 31g). Since the oil is prevented from entering by the seal portions (24s, 34s), the blade back pressure space (21g, 31g) is maintained at an intermediate pressure, not a high pressure. Therefore, it is possible to reliably suppress a reduction in reliability due to sliding loss and seizure due to an increase in the pressing load on the back surface of the blade (24, 34).

FIG. 1 is a longitudinal sectional view of a rotary compressor according to an embodiment of the present invention. FIG. 2 is an enlarged view around the compression mechanism in FIG. 3A is a cross-sectional view of the compression mechanism section, and FIG. 3B is another cross-sectional view of the compression mechanism section. FIG. 4 is a perspective view of the blade. FIG. 5 is a partially enlarged view of the compression mechanism section. FIG. 6 is an operation state diagram of the compression mechanism section. FIG. 7 is an operation state diagram of the compression mechanism section. FIG. 8 is a cross-sectional view of the main body of the middle plate. FIG. 9 is an enlarged vertical cross-sectional view of the compression mechanism, showing a structure for supplying oil to the blade and a pressure setting structure for the blade back pressure space. FIG. 10 is a ph diagram showing the refrigeration cycle during the cooling operation. FIG. 11 is a perspective view showing a modification of the blade. 12A and 12B are diagrams showing the action of the pressure in the blade back pressure space in the conventional compression mechanism. FIG. 12A is a plan view and FIG. 12B is a side view.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Overall structure>
The compressor (1) which concerns on embodiment is a rotary compressor, and as shown in FIG. 1, in a casing (10), two compression mechanism parts (a 1st compression mechanism part (20) and a 2nd compression mechanism) The compression mechanism (40) in which the portion (30) is stacked in the axial direction of the drive shaft (53) and the electric motor (50) as the drive mechanism are housed, and is configured as a completely sealed type. This compressor (1) is used, for example, in a refrigerant circuit of an air conditioner to compress refrigerant (working fluid) sucked from an evaporator and discharge it to a condenser. A middle plate (25) described later is disposed between the first compression mechanism (20) and the second compression mechanism (30).

  The casing (10) includes a cylindrical body (11), an upper end plate (12) fixed to the upper end of the body (11), and a lower part fixed to the lower end of the body (11). End plate (13). In order to guide the refrigerant to the cylinder chambers (23a,..., 23d, 33a,..., 33d) of the first compression mechanism section (20) and the second compression mechanism section (30), the details of which will be described later. Suction pipe (60, 61, 62, 63) and a discharge pipe (64, 65, 66) for discharging the refrigerant compressed in the cylinder chamber (23b, 23c, 23d, 33b, 33c, 33d) It is provided through. The upper end plate (12) is also provided with a discharge pipe (67) for discharging the refrigerant compressed in the cylinder chambers (23a, 33a). An oil reservoir (10a) for storing lubricating oil (refrigeration oil) is formed at the bottom of the casing (10).

  The electric motor (50) is disposed near the upper end plate (12) in the casing (10). The electric motor (50) includes a stator (51), a rotor (52), and a drive shaft (53). The stator (51) is fixed to the inner peripheral surface of the body (11) of the casing (10). On the other hand, the drive shaft (53) is connected to the rotor (52) so as to rotate integrally.

  The drive shaft (53) extends downward from the rotor (52), and a first eccentric part (53a) and a second eccentric part (53b) are formed in the lower part. The first eccentric portion (53a) is formed to have a larger diameter than the main shaft portion above the first eccentric portion (53a), and is eccentric by a predetermined amount from the axis of the drive shaft (53). On the other hand, the second eccentric portion (53b) is formed to have the same diameter as the first eccentric portion (53a), and is eccentric from the axis of the drive shaft (53) by the same amount as the first eccentric portion (53a). The first eccentric portion (53a) and the second eccentric portion (53b) are 180 ° out of phase with each other about the axis of the drive shaft (53).

  The first compression mechanism portion (20) and the second compression mechanism portion (30) are disposed below the electric motor (50) in the casing (10). The first compression mechanism section (20) and the second compression mechanism section (30) are stacked in two upper and lower stages, and are configured between the front head (14) and the rear head (17) fixed to the casing (10). Has been. The first compression mechanism (20) is disposed on the electric motor (50) side (upper side in FIG. 1), and the second compression mechanism (30) is disposed on the bottom side (lower side in FIG. 1) of the casing (10). ing. A muffler member (27) for forming a muffler space (27a) between the front head (14) and the upper surface of the front head (14) is attached to the upper side of the front head (14).

<First compression mechanism>
As shown in FIGS. 2 to 5, the first compression mechanism (20) includes a first cylinder (21) fixed to the inner peripheral surface of the body (11) of the casing (10), and a drive shaft (53 ) Of the first piston (22) attached to the first eccentric portion (53a) and rotating eccentrically with respect to the first cylinder (21), and the first cylinder (21) and the first piston (22) A first blade (4) that divides four cylinder chambers (23a, 23b, 23c, 23d) formed between them into a high pressure chamber (23aH, 23bH, 23cH, 23dH) and a low pressure chamber (23aL, 23bL, 23cL, 23dL) 24) and.

  The first cylinder (21) includes a cylindrical cylinder body (21c) that forms a cylinder space (S1) therein and opens vertically, and a head that closes the upper opening of the cylinder body (21c). A front head (14) as a part, a plurality of cylinder parts (21a, 21b, 21c) formed in an annular shape and concentrically with the rotating shaft of the drive shaft (53), and the cylinder body part (21c) And the middle plate (25) disposed in the lower opening.

  The front head (14) includes a cylinder space side front head (15) as a cylinder space side head portion, and a bearing portion side front head (16) as a bearing portion side head portion.

  The cylinder space-side front head (15) includes a closing portion (15a) formed in a disc shape covering the upper opening of the cylinder body (21c). The cylinder space side front head (15) is formed integrally with the cylinder body (21c). A through hole (15b) through which the drive shaft (53) is inserted is formed in the central portion of the blocking portion (15a). The through hole (15b) is formed to have a slightly larger diameter than the drive shaft (53).

  The bearing portion-side front head (16) is formed separately from the cylinder space-side front head (15), and is disposed above the cylinder space-side front head (15). The bearing portion-side front head (16) includes a disk-shaped laminated portion (16a) that is superimposed on the upper surface of the cylinder space-side front head (15), and a bearing portion (16b) that is formed integrally with the laminated portion (16a). ). A through hole (16c) through which the drive shaft (53) is inserted is formed at the center of the stacked portion (16a). The bearing portion (16b) is formed in a cylindrical shape extending upward from the opening end portion of the through hole (16c) of the laminated portion (16a). A cylindrical bearing metal (16d) for rotatably supporting the drive shaft (53) is inserted and fixed on the inner peripheral surface of the bearing portion (16b).

  The plurality of cylinder portions (21a, 21b, 21c) are formed integrally with the cylinder space front head (15) on the lower surface of the cylinder space front head (15). The plurality of cylinder parts include an annular inner cylinder part (21a) formed at the innermost side, an annular outer cylinder part (21b) formed radially outward from the inner cylinder part (21a), The cylindrical outermost cylinder part (21c) is located outside the outer cylinder part (21b) and extends downward from the outer peripheral part of the outer cylinder part (21b). The inner cylinder part (21a) is partly cut off from the ring (see FIG. 3A). A slide groove (21g) is formed at a parting position of the inner cylinder part (21a). The outermost cylinder part (21c) is composed of the cylinder body part (21c).

  The middle plate (25) is formed by two members arranged in the axial direction of the drive shaft (53). Specifically, the middle plate (25) overlaps the thick disc-shaped main body (25a) covering the lower opening of the cylinder main body (21c) and the lower surface of the main body (25a). And a disc-shaped lid (25b). A through hole (25c) through which the drive shaft (53) passes is formed at the center of the middle plate (25). The through hole (25c) is a hole having a slightly larger inner diameter than the diameters of the first eccentric portion (53a) and the second eccentric portion (53b) of the drive shaft (53). The middle plate (25) also constitutes a part of the second compression mechanism part (30).

  The first piston (22) is accommodated in a cylinder chamber (S1) formed inside a cylindrical cylinder body (21c). The first piston (22) is fitted to the first eccentric part (53a) and is located concentrically with the first eccentric part (53a), and the inner piston part (22a) An outer piston portion (22b) concentric with the inner piston portion (22a) is connected to the outer peripheral side and a lower end portion of the two piston portions (22a, 22b), and an outer peripheral surface is the inner piston portion (22a). And an outer piston part (22b) and a piston side end plate part (22c) located concentrically. The inner piston part (22a) is arranged inside the inner cylinder part (21a), and the outer piston part (22b) is arranged between the inner cylinder part (21a) and the outer cylinder part (21b), The end plate part (22c) is disposed inside the outermost cylinder part (21c). The inner piston portion (22a) has a notch (n1) formed on the outer peripheral surface, and the outer piston portion (22b) is partly cut off from the ring (see FIG. 3A). Further, a notch (n2) is formed in the outer peripheral portion of the piston side end plate portion (22c) (see FIG. 3B).

  As described above, the first piston (22) disposed in the cylinder space (S1) forms a plurality of cylinder chambers with the first cylinder (21). Specifically, an innermost cylinder chamber (23a) is formed between the inner piston part (22a) and the inner cylinder part (21a), and between the outer piston part (22b) and the inner cylinder part (21a). Is formed with an inner cylinder chamber (23b), an outer cylinder chamber (23c) is formed between the outer piston portion (22b) and the outer cylinder portion (21b), and the piston side end plate portion (22c) and the outermost portion An outermost cylinder chamber (23d) is formed between the cylinder portion (21c). That is, in the first compression mechanism (20), the innermost cylinder chamber (23a), the inner cylinder chamber (23b), and the outer cylinder chamber (23c) are arranged in order from the radially inner side to the radially outer side. A chamber (23d) is formed.

  Thus, the 1st compression mechanism part (20) is constituted so that it may have four cylinder chambers (23a, 23b, 23c, 23d).

<Second compression mechanism section>
The second compression mechanism section (30) is disposed below the first compression mechanism section (20). As shown in FIGS. 2 to 5, the second compression mechanism section (30) includes a second cylinder (31) fixed to the inner peripheral surface of the body section (11) of the casing (10), and a drive shaft (53 ) Of the second piston (32) attached to the second eccentric portion (53b) and rotating eccentrically with respect to the second cylinder (31), and the second cylinder (31) and the second piston (32) A second blade (4) that divides four cylinder chambers (33a, 33b, 33c, 33d) formed between them into a high pressure chamber (33aH, 33bH, 33cH, 33dH) and a low pressure chamber (33aL, 33bL, 33cL, 33dL) 34).

  The second cylinder (31) forms a cylinder space (S2) therein and closes the cylindrical cylinder body (31c) that opens in the vertical direction and the lower opening of the cylinder body (31c). A rear head (17) as a head portion, a plurality of cylinder portions (31a, 31b, 31c) which are formed in an annular shape and concentrically with the rotation shaft of the drive shaft (53), and the cylinder body portion (31c) A middle plate (25) disposed in the upper opening.

  The rear head (17) includes a cylinder space side rear head (18) as a cylinder space side head portion and a bearing portion side rear head (19) as a bearing portion side head portion.

  The cylinder space side rear head (18) includes a closing portion (18a) formed in a disk shape covering the lower opening of the cylinder body (31c). The cylinder space side rear head (18) is formed integrally with the cylinder body (31c). A through hole (18b) through which the drive shaft (53) is inserted is formed in the central portion of the blocking portion (18a). The through hole (18b) is formed to have a slightly larger diameter than the drive shaft (53).

  The bearing portion side rear head (19) is formed separately from the cylinder space side rear head (18), and is disposed below the cylinder space side rear head (18). The bearing portion side rear head (19) includes a disk-shaped laminated portion (19a) that is stacked on the lower surface of the cylinder space side rear head (18), and a bearing portion (19b) that is formed integrally with the laminated portion (19a). It has. A through hole (19c) through which the drive shaft (53) is inserted is formed at the center of the stacked portion (19a). The bearing portion (19b) is formed in a cylindrical shape extending downward from the opening end portion of the through hole (19c) of the laminated portion (19a). A cylindrical bearing metal (19d) for rotatably supporting the drive shaft (53) is inserted and fixed on the inner peripheral surface of the bearing portion (19b).

  The plurality of cylinder portions (31a, 31b, 31c) are formed integrally with the cylinder space side rear head (18) on the upper surface of the cylinder space side rear head (18). The plurality of cylinder parts include an annular inner cylinder part (31a) formed at the innermost side, an annular outer cylinder part (31b) formed radially outward from the inner cylinder part (31a), The cylindrical outermost cylinder part (31c) is located outside the outer cylinder part (31b) and extends upward from the outer peripheral part of the outer cylinder part (31b). The inner cylinder part (31a) is partly cut off from the ring (see FIG. 3A). A slide groove (31g) is formed at a parting position of the inner cylinder part (31a). The outermost cylinder part (31c) is composed of the cylinder body part (31c).

  The second piston (32) is accommodated in a cylinder chamber (S2) formed inside the cylindrical cylinder body (31c). The second piston (32) is fitted to the second eccentric part (53b) and is located concentrically with the second eccentric part (53b), and the inner piston part (32a) The outer piston part (32b) concentrically positioned with the inner piston part (32a) is connected to the outer peripheral side and the upper ends of the two piston parts (32a, 32b) and the outer peripheral surface is the inner piston part (32a). And an outer piston part (32b) and a piston side end plate part (32c) positioned concentrically. The inner piston part (32a) is arranged inside the inner cylinder part (31a), and the outer piston part (32b) is arranged between the inner cylinder part (31a) and the outer cylinder part (31b), The end plate part (32c) is disposed inside the outermost cylinder part (31c). The inner piston part (32a) has a notch part (n1) formed on the outer peripheral surface, and the outer piston part (32b) is partly cut off from a ring (see FIG. 3A). Further, a notch (n2) is formed in the outer peripheral portion of the piston side end plate portion (32c) (see FIG. 3B).

  As described above, the second piston (32) disposed in the cylinder space (S2) forms a plurality of cylinder chambers with the second cylinder (31). Specifically, an innermost cylinder chamber (33a) is formed between the inner piston part (32a) and the inner cylinder part (31a), and between the outer piston part (32b) and the inner cylinder part (31a). Is formed with an inner cylinder chamber (33b), an outer cylinder chamber (33c) is formed between the outer piston part (32b) and the outer cylinder part (31b), and the piston side end plate part (32c) and the outermost part. An outermost cylinder chamber (33d) is formed between the cylinder portion (31c). That is, in the second compression mechanism (30), the innermost cylinder chamber (33a), the inner cylinder chamber (33b), and the outer cylinder chamber (33c) are arranged in order from the radially inner side to the radially outer side. A chamber (33d) is formed.

  Thus, the second compression mechanism section (30) is configured to have four cylinder chambers (33a, 33b, 33c, 33d).

  The first compression mechanism part (20) and the second compression mechanism part (30) are eccentric with respect to the cylinders (first cylinder (21) and second cylinder (31)) and the cylinders (21, 31). A piston (first piston (21) and second piston (22)) having a mirror plate portion (piston side end plate portion (22c, 32c)) facing the middle plate (25) and configured to be rotatable, and a cylinder A plurality of cylinder chambers (23a, 23b, 23c, formed between the (first cylinder (21) and second cylinder (31)) and the piston (first piston (21) and second piston (22)). 23d) (33a, 33b, 33c, 33d).

<Detailed structure of compression mechanism>
Next, the internal structure of the first and second compression mechanism parts (20, 30) will be described in detail. The first and second compression mechanism parts (20, 30) have first and second pistons (22, 32). ) And the corresponding cylinder (21, 31) in the axial direction are substantially identical in configuration, so the first compression mechanism (20) will be described as a representative example. To do.

  As shown in FIGS. 4 and 5, the first blade (24) has a plate-like long part (24a) and a short part (24b) having a thickness and a pair of swings having a substantially semicircular cross section. And a bush portion (24c). These three parts (24a, 24b, 24c) are integrally formed. In the first blade (24), the front end portion indicated by L1 in FIG. 4 has a smaller axial dimension (height dimension) (H1) of the compression mechanism (40), and the rear end portion indicated by L2 is smaller than the front end portion. Also, the axial dimension (height dimension) (H2) of the compression mechanism (40) is set large.

  The long portion (24a) is disposed so as to extend in the radial direction between the closed portion (15a) of the cylinder space-side head portion (15) and the piston-side end plate portion (22c). The long portion (24a) includes an inner blade portion (B1) constituting a radially inner portion of the long portion (24a) and an outer first portion constituting a portion outside the inner blade portion (B1). It consists of a blade part (B2). The inner blade portion (B1) is inserted into the slide groove (21g) formed in the dividing portion of the inner cylinder portion (21a) so as to be slidable in the radial direction, and is the outer end portion of the outer first blade portion (B2). Are accommodated in a groove (slide groove) (21f) formed in the outer cylinder part (21b) so as to be slidable in the radial direction. The inner blade portion (B1) divides the innermost cylinder chamber (23a) and the inner cylinder chamber (23b) into a suction side and a discharge side, respectively, and the outer first blade portion (B2) separates the outer cylinder chamber ( 23c) is divided into a suction side and a discharge side. The inner end portion of the inner blade portion (B1) is opposed to the notch portion (n1) of the inner piston portion (22a) with a micron-order fine gap therebetween (see FIG. 5).

  The short part (24b) is disposed so as to extend in the radial direction between the long part (24a) and the middle plate (25). The short part (24b) is composed of an outer second blade part (B3). The radially outer portion of the short portion (24b) is accommodated in a groove (slide groove) (21f) formed in the outermost cylinder portion (21c) so as to be slidable in the radial direction. The shortest portion (24b) divides an outermost cylinder chamber (23d), which will be described later, into a suction side and a discharge side. The inner end of the short part (24b) is opposed to the notch part (n2) of the piston side end plate part (22c) with a micron-order fine gap (see FIG. 5).

  The pair of swinging bush portions (24c) is formed so as to bulge on both sides of the long portion (24a) in the vicinity of the central portion in the longitudinal direction of the long portion (24a). The outer peripheral surfaces of the pair of swing bush portions (24c) constitute a part of the outer peripheral surface of a cylinder having a predetermined radius. The pair of swinging bush portions (24c) is swingably accommodated in bush grooves (C1, C2) formed at the parting points of the outer piston portion (22b). The pair of swing bush portions (24c) is configured such that the outer piston portion (22b) swings with respect to the first blade (24).

  As shown in FIG. 5, on the rear end side of the groove (21f), pressure is applied to the first blade (24) from the rear end surface, so that the first blade (24) is compressed by the compression mechanism (40). A first blade back pressure space (21 g) is formed to urge toward the center of the first blade. Due to the pressure in the first blade back pressure space (21g), the tip end side of the blade (24) on the outer surface of the swinging bush portion (24c) comes into pressure contact with the inner surface of the bush groove (C1, C2).

  In FIG. 5, the notch (n1) constitutes a first swing allowing surface that allows the relative swinging motion of the inner blade portion (B1) with the swing bushing portion (24c) as the center. The first rocking permissible surface (n1) is based on an arc shape having a diameter slightly larger than the locus of the relative rocking motion of the inner blade part (B1) around the rocking bush part (24c). A fine gap is formed between the locus drawn by the tip of the inner blade portion (B1) when the inner blade portion (B1) swings and the first swing allowable surface (n1). In FIG. 5, the fine gap is exaggerated.

  Further, the notch (n2) constitutes a second swing allowing surface that allows the relative swing operation of the outer second blade portion (B3) with the swing bush portion (24c) as a center. The second rocking permissible surface (n2) is an arc shape having a slightly smaller diameter than the locus of the relative rocking movement of the outer second blade part (B3) centering on the rocking bush part (24c). So that a fine gap is formed between the locus drawn by the tip of the outer second blade portion (B3) when the outer second blade portion (B3) swings and the second swing allowable surface (n2). It has become. In FIG. 5, the fine gap is exaggerated.

  With the configuration as described above, the first piston (22) has the center point of the pair of swing bush portions (24c) with respect to the first blade (24) as the first eccentric portion (53a) rotates eccentrically. Oscillates around the center of the oscillating center, and advances and retracts in the same direction as the first blade (24) slides in the longitudinal direction with respect to the groove (21f) and the slide groove (21g) of the inner cylinder part (21a). To do.

  The inner piston portion (22a, 32a) and the inner cylinder portion (21a, 31a) of the first compression mechanism portion (20) and the second compression mechanism portion (30) are arranged on the outer peripheral surface and the inner side of the inner piston portion (22a, 32a). A state where the inner peripheral surface of the cylinder part (21a, 31a) is substantially in contact at one point (first contact) (strictly, there is a micron-order gap, but refrigerant leakage in the gap does not cause a problem) ), The outer peripheral surface of the inner cylinder portion (21a, 31a) and the inner peripheral surface of the outer piston portion (22b, 32b) are substantially at one point (second contact) at a position 180 degrees out of phase with the contact. The outer piston part (22b, 32b) and the outer cylinder part (21b, 31b) have an outer peripheral surface at a position that is 180 degrees out of phase with the contact (the same position as the first contact). It is substantially in contact at one point (third contact), and the outer peripheral surface of the piston side end plate part (22c, 32c) and the outermost cylinder part (21c, 31c) It faces and is in contact with the substantially at one point (4 contact).

  In the above configuration, when the drive shaft (53) rotates, the first piston (22) swings about the center point of the swing bush portion (24c), and together with the first blade (24), the first piston (22) swings. Advances and retracts in the longitudinal direction of one blade (24). Further, when the drive shaft (53) rotates, the second piston (32) swings about the center point of the swinging bush portion (34c), and the second blade (34) together with the second blade (34). 34) Move forward and backward in the longitudinal direction.

  By the above operation, the contacts (first contact to fourth contact) of the first piston (22) and the first cylinder (21) are changed to FIGS. 6 (A) to (D) and FIGS. 7 (A) to (D), respectively. Move in order. On the other hand, each contact (1st contact-4th contact) of a 2nd piston (32) and a 2nd cylinder (31) drives with respect to a corresponding contact of a 1st piston (22) and a 1st cylinder (21). It is shifted by 180 ° around the axis of the shaft (53). That is, when viewed from above the drive shaft (53), when the operating state of the first compression mechanism (20) is as shown in FIGS. 6 (A) and 7 (A), the operating state of the second compression mechanism (30). 6C and FIG. 7C.

  In the present embodiment, the compression mechanism (40) is a four-stage compression mechanism that compresses the refrigerant into four stages in the eight cylinder chambers (23a, ..., 23d, 33a, ..., 33d).

  Specifically, the cylinder chamber of the first stage compression mechanism is formed by the outermost cylinder chambers (23d, 33d) of the first compression mechanism portion (20) and the second compression mechanism portion (30). Further, a cylinder chamber of the second stage compression mechanism is formed by the outer cylinder chamber (33c) and the inner cylinder chamber (33b) of the second compression mechanism section (30), and the outer cylinder chamber of the first compression mechanism section (20). (23c) and the inner cylinder chamber (23b) form a cylinder chamber of the third-stage compression mechanism. Furthermore, the cylinder chamber of the fourth stage compression mechanism is formed by the innermost cylinder chambers (23a, 33a) of the first compression mechanism portion (20) and the second compression mechanism portion (30). In the present embodiment, the axial length of the outer piston portions (22, 32) of the first and second compression mechanisms (20, 30) and the corresponding axial length of the cylinders (21, 31) are the same. Since they are the same, the cylinder volume of the second stage compression mechanism and the cylinder volume of the third stage compression mechanism are substantially equal.

  Thus, the compressor (1) of the present embodiment includes a cylinder (21, 31) having an annular cylinder space, and an annular piston (22, 31) arranged eccentrically with respect to the cylinder (21, 31). 32), and a plurality of cylinder chambers (23a, ..., 23d, 33a, ..., 33d) are formed between the cylinders (21, 31) and the pistons (22, 32). , 23d, 33a, ..., 33d, each having a compression mechanism (20, 30) formed with one suction port and one discharge port communicating with each of the cylinder chambers (23a, ..., 23d, 33a, ..., 33d). Four cylinder chambers (23a, ..., 23d, 33a, ..., 33d) are formed between the pair of cylinders (21,31) and pistons (22,32), and these cylinder chambers (23a, ..., 23d, 33d), the cylinder chamber (23d, 33d) of the first stage compression mechanism that compresses the low-pressure refrigerant in the first stage, and the second stage compression mechanism that compresses the discharged refrigerant of the first stage compression mechanism in the second stage. Shi The cylinder chamber (33c, 33b), the cylinder chamber (23c, 23b) of the third stage compression mechanism that compresses the refrigerant discharged from the second stage compression mechanism in the third stage, and the fourth stage compression of the refrigerant discharged from the third stage compression mechanism The cylinder chamber (23a, 33a) of the fourth stage compression mechanism is formed. The refrigerant circuit is between the first stage compression mechanism and the second stage compression mechanism, between the second stage compression mechanism and the third stage compression mechanism, and between the third stage compression mechanism and the fourth stage compression mechanism. It is good to comprise so that a refrigerant can be cooled with a cooling mechanism.

<Suction passage and discharge passage>
The compression mechanism (40) includes first to fourth suction flow paths (not shown) for guiding refrigerant from the suction pipes (60 to 63) to the cylinder chambers (23a, ..., 23d, 33a, ..., 33d). 71-74) are formed. The first to fourth suction flow paths (71 to 74) constitute the suction flow paths of the first-stage compression mechanism to the fourth-stage compression mechanism, respectively. These suction passages (71 to 74) do not cross each other, and other parts formed in the compression mechanism (40) (each blade (24, 34), discharge valve (88), etc.) Is formed in the compression mechanism (40) so as not to interfere.

  The first suction channel (71) has an inflow end connected to the suction pipe (62), and an outflow end constituted by the suction ports (P1, P1) is the outermost cylinder chamber of the first compression mechanism (20) ( 23d) and the outermost cylinder chamber (33d) of the second compression mechanism (30). The second suction flow path (72) has an inflow end connected to the suction pipe (63), and an outflow end constituted by the suction port (P2) at the inner cylinder chamber (33b) of the second compression mechanism (30). Connected to the outer cylinder chamber (33c). The third suction flow path (73) has an inflow end connected to the suction pipe (60), and an outflow end constituted by the suction port (P2) at the inner cylinder chamber (23b) of the first compression mechanism (20). Connected to the outer cylinder chamber (23c). The fourth suction flow path (74), which is the fourth stage suction portion of the compression mechanism, has an inflow end connected to the suction pipe (61), and an outflow end constituted by the suction ports (P3, P3) as the first compression mechanism. The innermost cylinder chamber (23a) of the part (20) and the innermost cylinder chamber (33a) of the second compression mechanism part (30) are connected.

  The fourth suction flow path (74) includes a suction pipe side flow path (74a) extending vertically in the compression mechanism (40) and a suction port side flow path (74b) extending horizontally in the compression mechanism (40). ) And are formed. The suction port side flow path (74b) includes a facing surface of the cylinder space side front head (15) in the stacked portion (16a) of the bearing portion side front head (16) and a stacked portion of the bearing portion side rear head (19) ( It can be easily formed by notching the facing surface of the cylinder space side rear head (18) in 19a) into a groove shape.

  The compression mechanism (40) includes first to fourth refrigerants for guiding the refrigerant compressed in the cylinder chambers (23a,..., 23d, 33a,..., 33d) to the outside of the compression mechanism (40). Discharge flow paths (81 to 84) are formed. The first to fourth discharge flow paths (81 to 84) constitute discharge flow paths of the first-stage compression mechanism to the fourth-stage compression mechanism, respectively. These discharge flow paths (81 to 84) do not cross each other and other parts formed in the compression mechanism (40) (each blade (24, 34), discharge valve (88), etc.) Is formed in the compression mechanism (40) so as not to interfere.

  The first discharge flow path (81), which is the discharge portion of the first stage compression mechanism, has an inflow end constituted by discharge ports (P11, P11) at the outermost cylinder chamber (23d) of the first compression mechanism portion (20). The second compression mechanism (30) is connected to the outermost cylinder chamber (33d), and the outflow end is connected to the discharge pipe (65). The second discharge flow path (82) has an inflow end constituted by discharge ports (P12, P13) connected to the inner cylinder chamber (33b) and the outer cylinder chamber (33c) of the second compression mechanism (30), The outflow end is connected to the discharge pipe (66). The third discharge flow path (83) has an inflow end constituted by discharge ports (P12, P13) connected to the inner cylinder chamber (23b) and the outer cylinder chamber (23c) of the first compression mechanism (20), The outflow end is connected to the discharge pipe (64). The fourth discharge flow path (84) has an inflow end constituted by discharge ports (P14, P14) at the innermost cylinder chamber (23a) of the first compression mechanism (20) and the second compression mechanism (30). It is connected to the innermost cylinder chamber (33a).

  The refrigerant from the fourth discharge channel (84) connected to the innermost cylinder chamber (23a) of the first compression mechanism (20) flows upward in the casing (10) through the muffler space (27a) and is discharged. It is discharged out of the casing (10) through the pipe (67). The refrigerant from the fourth discharge flow path (84) connected to the innermost cylinder chamber (33a) of the second compression mechanism section (30) passes through the discharge junction passage (29) formed in the compression mechanism (40). Flows into the muffler space (27a), merges with the refrigerant discharged from the first compression mechanism (20), and is discharged from the discharge pipe (67) to the outside of the casing (10).

  The compression mechanism (40) includes a plurality of discharge valves (88, 88,...). The discharge valve is constituted by a reed valve, for example. This discharge valve (88,88, ...) covers each discharge port (P11, P11, ... P14, P14), and the pressure in each cylinder chamber (23a, ..., 23d, 33a, ..., 33d) When the pressure is lower than the predetermined value, the discharge ports (P11, P11, ... P14, P14) are closed, while the pressure in each cylinder chamber (23a, ..., 23d, 33a, ..., 33d) is higher than the predetermined value. If this happens, the discharge ports (P11, P11,... P14, P14) are opened.

  As shown in FIG. 2, the middle plate (25) is formed with a fourth suction passage (74) and a first discharge passage (81), which are fluid passages through which an intermediate-pressure refrigerant flows. The fourth suction flow path (74) sucks refrigerant into the cylinder chamber of the fourth stage compression mechanism (the innermost cylinder chambers (23a, 33a) of the first compression mechanism portion (20) and the second compression mechanism portion (30)). Side fluid passage. The first discharge channel (81) discharges the refrigerant to the cylinder chamber of the first stage compression mechanism (the outermost cylinder chambers (23d, 33d) of the first compression mechanism portion (20) and the second compression mechanism portion (30)). Side fluid passage. In the fourth suction flow path (74) and the first discharge flow path (81), refrigerants having intermediate pressures different from each other flow before the fourth stage compression mechanism and after the first stage compression mechanism. ing.

  A pressing mechanism (90) is provided between the middle plate (25) and each piston-side end plate (22c, 32c) to press the piston (22, 32) against the cylinder (21, 31) with the pressure of the working fluid. It has been. The pressing mechanism (90) includes a first seal ring (91) disposed around the rotation center of the piston (22, 32) and a diameter larger than that of the first seal ring (91). A second seal ring (92) disposed on the outer peripheral side of the ring (91), and an annular portion formed between the first seal ring (91) and the second seal ring (92) for introducing a working fluid ( Annular groove) (93a, 93b). This annular part (93a, 93b) is a first annular part (between the first seal ring (91) and the second seal ring (92) on the upper surface of the body part (25a) of the middle plate (25). 93a) and a second annular portion (93b) formed between the first seal ring (91) and the second seal ring (92) on the lower surface of the lid portion (25b) of the middle plate (25). Yes.

  In the compression mechanism (40), as described above, the fourth suction passage (74) and the first discharge passage (81) are formed in the middle plate (25) as a fluid passage through which the intermediate-pressure refrigerant flows. Has been. The middle plate (25) is formed with intermediate pressure introduction passages (96a, 96b) for introducing a part of the refrigerant flowing through the fluid passages (74, 81) into the annular portions (93a, 93b). Yes. The intermediate pressure introduction path (96a, 96b) is connected to the fourth suction flow path (74) and the first annular part (93a) which are the suction parts of the fourth stage compression mechanism in the first compression mechanism part (20). The first intermediate pressure introduction path (96a) that communicates with the first discharge flow path (81) and the second annular portion (93b) that are discharge portions of the first stage compression mechanism in the second compression mechanism portion (30). And a second intermediate pressure introduction passage (96b) communicating therewith.

  A detailed configuration of the fluid passage (74, 81) will be described with reference to FIG. 8 which is a cross-sectional view of the main body (25a) of the middle plate (25). As shown in FIGS. 2 and 8, the first discharge channel (81) is a rectangular parallelepiped discharge space (between the body (25a) and the lid (25b)) of the middle plate (25). 81a), and the discharge space (81a) of the first stage compression mechanism and the discharge pipe (65) communicate with each other. The discharge space (81a) communicates with the cylinder chamber (23d, 33d) of the first stage compression mechanism via the discharge port (P11, P11). Further, the lid portion (25b) of the middle plate (25) has a first stage discharge space (81a) and a second annular portion (93b) constituting a part of the first discharge flow path (discharge portion) (81). The second intermediate pressure introduction passage (96b) communicating with the second intermediate pressure passage is formed.

  The suction pipe side flow path (74a) of the fourth suction flow path (74) is formed at a position displaced by a predetermined angle in the circumferential direction with respect to the position of the suction pipe (61) of the fourth stage compression mechanism. The suction pipe (61) and the suction pipe side flow path (74a) are connected by a curved communication path (74c). The first intermediate pressure introduction passage (96a) communicates with the middle plate (25) through the communication passage (74c) and communicates with the suction portion (74) of the fourth-stage compression mechanism and the first annular groove (93a). Is formed. The suction pipe (61) of the fourth stage compression mechanism and the suction pipe (62) of the first stage compression mechanism are actually formed at the same height in FIGS. In order to clearly show the connection relationship between the fluid passages (74, 81), the positions of the suction pipe (61) and the suction pipe (62) are shifted up and down, and the shape of the passage is simplified.

  As shown in FIG. 2, the third discharge flow path (83) includes a discharge space (83a) of a third-stage compression mechanism formed in the bearing portion side front head (16), and the discharge space (83a) and The third discharge channel (83) and the discharge pipe (64) communicate with each other. The fourth discharge flow path (84) is a discharge space (84a) of the fourth stage compression mechanism formed in the bearing portion side front head (16). In this embodiment, the discharge space (83a) of the third-stage compression mechanism, which is a lower-stage compression mechanism than the fourth-stage compression mechanism, communicates with the muffler space (27a) via the relief mechanism (41). In addition, the discharge space (84a) of the fourth stage compression mechanism, which is the highest stage compression mechanism, also communicates with the muffler space (27a). Therefore, in this embodiment, the discharge space (83a) of the third-stage compression mechanism and the discharge space (84a) of the fourth-stage compression mechanism communicate with each other.

  The middle plate (25), the first compression mechanism (20) disposed above the middle plate (25), and the second compression mechanism (30) disposed below. In the compression mechanism (40), the relief mechanism (41) is provided in the first compression mechanism section (20) located on the upper side.

  The relief mechanism (41) includes a relief port (42) communicating with the discharge space (83a) and the muffler space (27a) of the third-stage compression mechanism, and a relief valve (43) attached to the relief port (42). ). As the relief valve (43), for example, a reed valve can be used. The relief valve (43) is opened under operating conditions in which the high pressure of the refrigerant circuit decreases and the discharge pressure of the third stage compression mechanism becomes higher than the high pressure.

  Therefore, in this embodiment, when the operating condition is such that the discharge pressure of the third stage compression mechanism exceeds the high pressure of the system (refrigerant circuit), the discharge valve (88) is always open in the fourth stage compression mechanism. Therefore, in the fourth stage compression mechanism, the refrigerant only passes and is not compressed. And since the discharge pressure of a 3rd stage compression mechanism equalizes to the high pressure of a refrigerant circuit and does not raise any more, it can prevent that the discharge pressure of a compressor (1) increases too much.

<Oil supply structure to blade and pressure setting structure of blade back pressure space>
As shown in FIG. 9, an oil supply pump (54) is provided at the lower end of the drive shaft (53). Inside the drive shaft (53), an oil supply passage (55) communicating with the oil supply pump (54) is formed along the axis of the drive shaft (53). The oil supply passage (55) communicates with the oil supply pump (54) at the lower end portion of the drive shaft (53), while the upper end position is slightly above the upper end of the first eccentric portion (53a). The drive shaft (53) includes a first oil supply hole (55a) that opens to the outer peripheral surface at an intermediate portion in the vertical direction of the first eccentric portion (53a) and an intermediate portion in the vertical direction of the second eccentric portion (53b). A second oil supply hole (55b) that opens to the outer peripheral surface at the portion is formed. Further, the drive shaft (53) includes a third oil supply hole (55c) opened to the outer peripheral surface of the drive shaft (53) immediately above the first eccentric portion (53a), and a second eccentric portion (53b). A fourth oil supply hole (55d) is formed immediately below and on the outer peripheral surface of the drive shaft. The first oil supply hole (55a), the second oil supply hole (55b), the third oil supply hole (55c), and the fourth oil supply hole (55d) each communicate with the oil supply passage (55).

  In the cylinder space side front head (15), the lubricating oil that has flowed out from the third oil supply hole (55c) to the outer periphery of the drive shaft (53) is moved outwardly in the radial direction of the cylinder space side front head (15). A first oil supply path (56) for guiding up to one blade (24) is formed. The cylinder space-side rear head (18) receives lubricating oil that has flowed from the fourth oil supply hole (55d) to the outer periphery of the drive shaft (53) toward the outside in the radial direction of the cylinder space-side rear head (18). A second oil supply path (57) for guiding up to two blades (34) is formed.

  The first oil supply path (56) and the second oil supply path (57) are each composed of a main groove (56a, 56b) and a communication hole (56b, 57b). The main groove (56a) of the first oil supply path (56) is a radially extending groove formed on the upper surface of the cylinder space front head (15), and the communication hole (56b) is the main groove (56a). This is a small hole communicating with the first blade (24) from the radially outer end. The main groove (57a) of the second oil supply path (57) is a radially extending groove formed in the lower surface of the cylinder space side rear head (18), and the communication hole (57b) is formed of the main groove (57a). This is a small hole communicating with the second blade (34) from the radially outer end.

  As shown in FIGS. 3, 5 and 9, the cylinder body (21c) of the first cylinder (21) has a groove (sliding groove) (21f) on the outer side in the radial direction of the first cylinder (21). The above-described first blade back pressure space (21g) that communicates is provided. Further, the second main body (31c) of the second cylinder (31) has a second blade back pressure space (communication on the radially outer side of the second cylinder (31) with respect to the groove (slide groove) (31f) ( 31g) is provided. As shown in FIG. 9, the first blade back pressure space (21g) and the second blade back pressure space (31g) communicate with each other via a back pressure communication path (58a) formed in the middle plate (25). ing. Further, as shown in FIGS. 8 and 9, the intermediate pressure communication passage (58b) connecting the back pressure communication passage (58a) and the fourth suction flow passage (74) to the main body (25a) of the middle plate (25). Is formed. As a result, the back pressure communication passage (58a) becomes an intermediate pressure (fourth suction pressure of the four-stage compression mechanism), so the first blade back pressure space (21g) and the second blade back pressure space (31g) are also It becomes the pressure of the 4th stage suction part (4th suction flow path (74)) of a 4 stage compression mechanism.

  On the other hand, as described above, the compression mechanism (40) of the present embodiment is formed between the cylinder (21, 31) and the piston (22, 32), and the inner and outer ends in the radial direction and the middle thereof. A plurality of cylinder chambers (23a, 23b, 23c, 23d) (33a, 33b, 33c, 33d) located in the section are connected to the cylinder (slidable in the radial direction) and the pistons (22, 32) can swing First and second blades (24, 34). The first and second blades (22, 32) have a height dimension (H2) in the axial direction of the compression mechanism (40) at the radially outer end of the compression mechanism (40) at the radially inner end. The dimension is set to be larger than the height dimension (H1) in the axial direction. With such a dimensional configuration, the pressure receiving area at the radially outer end of each blade (24, 34) is larger than the pressure receiving area at the radially inner end, but the blade back pressure space (21g, 31g) has an intermediate pressure, so the force to press each blade (24, 34) radially inward is smaller than in the past. Note that the pressure (high pressure) in the fourth stage compression mechanism acts on the first end portion (24d) which is the end portion of the tip end portion (L1 portion in FIG. 4) of the blade (24, 34). Since the suction pressure (low pressure) of the first stage compression mechanism acts on the second end (24e) which is the end of the rear end portion (L2 portion in FIG. 4), the blade back pressure space (21g , 31g), the pushing force of this part against the pushing force due to the back pressure is small.

  As shown in FIG. 4, the first blade (24) and the second blade (34) receive high-pressure lubricating oil from an oil reservoir (10a) provided in the casing (10). 24, 34) and an oil supply passage (59) for supplying the sliding portion between the compression mechanism (40). Specifically, the communication holes of the cylinder space side front head (15) and the cylinder space side rear head (18) are formed in the blades (24, 34) on the upper surface of the elongated portion (24a) in FIG. A first oil supply groove (59a) connected to (56b, 57b) is formed, and a second oil supply groove (59b) is formed on the lower surface of the short portion (24b). Further, a communication hole (59c) communicating with the first oil supply groove (59a) and the second oil supply groove (59b) is formed in the rear end portion of the blade (24, 34). Each blade (24, 34) is formed with two through holes (59d) that cross the communication hole (59c) and penetrate the rear end of the blade (24, 34) in the thickness direction.

  Each blade (24, 34) is provided with a seal portion (24s, 34s) for preventing the oil supply passage (59) from communicating with each blade back pressure space (21g, 31g). Specifically, a portion where the first oil groove (59a) is not formed on the upper surface of the rear end portion of the first and second blades (24, 34), and a rear end portion of the first and second blades A portion where the second oil supply groove (59b) is not formed on the lower surface of the seal portion is a seal portion (24s, 34s). The first oil supply groove (59a) and the second oil supply groove (59b) are formed so as not to be opened at the rear ends of the first and second blades (24, 34). The high pressure lubricating oil in the second oil supply groove (59b) is prevented from flowing into each blade back pressure space (21g, 31g), and each blade back pressure space (21g, 31g) (Suction pressure).

-Driving action-
Next, the operation of the compressor (1) will be described. Here, the operations of the first and second compression mechanisms (20, 30) are performed in a state where the phases are different from each other by 180 °.

  When the electric motor (50) is started, in the first compression mechanism (20), the rotation of the rotor (52) is transmitted to the first piston (22) via the first eccentric part (53a) of the drive shaft (53). The first piston (22) swings about the center point of the swing bush portion (24c) and moves forward and backward in the longitudinal direction of the first blade (24) together with the first blade (24). . As a result, the first piston (22) revolves while swinging with respect to the first cylinder (21), and is predetermined in the four cylinder chambers (23a, 23b, 23c, 23d) of the first compression mechanism (20). The compression operation is performed.

  At this time, a micron-order fine gap is formed between the tip of the inner blade part (B1) and the surface of the notch part (n1) of the inner piston part (22a), and they are not in contact with each other. . In addition, a micron-order fine gap is formed between the tip of the outer second blade (B3) and the surface of the notch (n2) of the piston side end plate (22c). It becomes. An oil film of lubricating oil is formed in the fine gap. Therefore, leakage of the refrigerant from the high pressure side to the low pressure side of the cylinder chamber (C1, C2) is not a substantial problem.

  In the innermost cylinder chamber (23a) and the outer cylinder chamber (23c), the drive shaft (53) rotates clockwise from the state shown in FIG. 6 (A) and is changed as shown in FIG. 6 (B) to FIG. 6 (D). As the state changes, the volume of the low pressure chamber (23aL, 23cL) increases, and the refrigerant is sucked into the low pressure chamber (23aL, 23cL) from the suction port (P3, P2). Further, when the drive shaft (53) makes one revolution and again enters the state of FIG. 6 (A), the suction of the refrigerant into the low pressure chambers (23aL, 23cL) is completed. The low-pressure chamber (23aL, 23cL) becomes a high-pressure chamber (23aH, 23cH) in which the refrigerant is compressed, and a new low-pressure chamber (23aL, 23cL) is formed across the first blade (24). When the drive shaft (53) further rotates, the suction of the refrigerant is repeated in the low pressure chamber (23aL, 23cL), while the volume of the high pressure chamber (23aH, 23cH) decreases, and the refrigerant is Compressed. When the pressure in the high pressure chamber (23aH, 23cH) reaches a preset value and the differential pressure from the discharge flow path (84, 83) reaches a set value, the discharge valve ( 88, 88) is opened, and the refrigerant is discharged from the fourth discharge passage (84) and the third discharge passage (83) to the outside of the first compression mechanism section (20).

  In the outermost cylinder chamber (23d), the drive shaft (53) rotates clockwise from the state shown in FIG. 7 (A) and changes from the state shown in FIG. 7 (B) to FIG. 7 (D). Accordingly, the volume of the low pressure chamber (23dL) increases, and the refrigerant is sucked into the low pressure chamber (23dL) from the suction port (P1). Further, when the drive shaft (53) makes one revolution and again enters the state of FIG. 7 (A), the suction of the refrigerant into the low pressure chamber (23dL) is completed. The low pressure chamber (23dL) becomes a high pressure chamber (23dH) in which the refrigerant is compressed, and a new low pressure chamber (23dL) is formed across the first blade (24). When the drive shaft (53) further rotates, the suction of the refrigerant is repeated in the low pressure chamber (23dL), while the volume of the high pressure chamber (23dH) is reduced, and the refrigerant is compressed in the high pressure chamber (23dH). When the pressure in the high pressure chamber (23dH) reaches a predetermined value and the differential pressure from the discharge flow path (81) reaches a set value, the discharge valve (88) is opened by the pressure of the refrigerant in the high pressure chamber (23dH), and the refrigerant Is discharged from the first discharge channel (81) to the outside of the first compression mechanism (20).

  On the other hand, in the inner cylinder chamber (23b), the drive shaft (53) rotates clockwise from the state of FIG. 6 (C) and changes to the state of FIGS. 6 (D) to 6 (B). Accordingly, the volume of the low pressure chamber (23bL) increases, and the refrigerant is sucked into the low pressure chamber (23bL) from the suction port (P2). Further, when the drive shaft (53) makes one revolution and again enters the state of FIG. 6 (C), the suction of the refrigerant into the low pressure chamber (23bL) is completed. The low pressure chamber (23bL) becomes a high pressure chamber (23bH) in which the refrigerant is compressed, and a new low pressure chamber (23bL) is formed across the first blade (24). When the drive shaft (53) further rotates, the suction of the refrigerant is repeated in the low pressure chamber (23bL), while the volume of the high pressure chamber (23bH) is reduced, and the refrigerant is compressed in the high pressure chamber (23bH). When the pressure in the high pressure chamber (23bH) reaches a predetermined value and the differential pressure with respect to the discharge flow path (83) reaches a set value, the discharge valve (88) is opened by the pressure of the refrigerant in the high pressure chamber (23bH), and the refrigerant Is discharged from the discharge flow path (83) to the outside of the first compression mechanism (20).

  The outer cylinder chamber (23c) and the inner cylinder chamber (23b) are approximately 180 degrees different in refrigerant suction start timing and discharge start timing. As a result, the discharge pulsation is reduced, and vibration and noise are reduced.

  On the other hand, in the second compression mechanism (30), the rotation of the rotor (52) is transmitted to the second piston (32) via the second eccentric part (53b) of the drive shaft (53), and the second piston ( 32) swings with the center point of the swing bush portion (34c) as the swing center, and moves forward and backward in the longitudinal direction of the second blade (34) together with the second blade (34). As a result, the second piston (32) revolves while swinging with respect to the second cylinder (31), and is predetermined in the four cylinder chambers (33a, 33b, 33c, 33d) of the second compression mechanism (30). The compression operation is performed.

  The compression operation in the second compression mechanism section (30) is substantially the same as the compression operation in the first compression mechanism section (20), and the refrigerant is compressed in each cylinder chamber (33a, 33b, 33c, 33d). The In each cylinder chamber (33a, 33b, 33c, 33d), the pressure in the high pressure chamber (33aH, 33bH, 33cH, 33dH) becomes a predetermined value and the differential pressure from each discharge flow path (84, 83, 83, 81) Reaches the set value, the discharge valve (88, 88, 88, 88) is opened by the pressure of the refrigerant in the high-pressure chamber (33aH, 33bH, 33cH, 33dH), and the refrigerant flows into each discharge channel (84, 82, 82). , 81) is discharged to the outside of the second compression mechanism section (30).

  During the operation of the compression mechanism (40), the refrigerant flows from the suction pipe (62) to the outermost cylinder chamber (23d) of the first compression mechanism section (20), which is the cylinder chamber of the first stage compression mechanism, and the second compression mechanism. The air is sucked into the outermost cylinder chamber (33d) of the section (30), compressed, and discharged from the cylinder chamber of the first stage compression mechanism through the discharge pipe (65). For example, during cooling operation, as shown in FIG. 10, the refrigerant discharged from the cylinder chamber of the first stage compression mechanism is cooled and then is supplied from the suction pipe (63) to the cylinder chamber of the second stage compression mechanism. 2 It is sucked into the outer cylinder chamber (33c) and the inner cylinder chamber (33b) of the compression mechanism section (30), further compressed, and discharged from the cylinder chamber of the second stage compression mechanism through the discharge pipe (66). After the refrigerant discharged from the cylinder chamber of the second stage compression mechanism is cooled, the outer cylinder chamber (23c) of the first compression mechanism section (20) which is the cylinder chamber of the third stage compression mechanism from the suction pipe (60). ) And the inner cylinder chamber (23b), further compressed, and discharged from the cylinder chamber of the third stage compression mechanism through the discharge pipe (64). After the refrigerant discharged from the cylinder chamber of the third-stage compression mechanism is cooled, the innermost cylinder chamber of the first compression mechanism section (20), which is the cylinder chamber of the fourth-stage compression mechanism, from the suction pipe (61) ( 23a) and the innermost cylinder chamber (33a) of the second compression mechanism section (30) and further compressed, and discharged from the cylinder chamber of the fourth stage compression mechanism through the discharge pipe (67).

  The refrigerant discharged from the cylinder chamber of the fourth-stage compression mechanism sequentially flows through a radiator, an expansion mechanism, and an evaporator of a refrigerant circuit (not shown), and is sucked into the compressor (1) again. A refrigeration cycle is performed by sequentially repeating a compression stroke in the compressor (1), a heat release stroke in the radiator, an expansion stroke in the expansion mechanism, and an evaporation stroke in the evaporator.

  During the operation of the compression mechanism (40), the lubricating oil accumulated in the oil sump (10a) at the bottom of the casing (10) is sucked up by the oil feed pump (54) and is supplied to the oil supply passage (55) of the drive shaft (53). ). The lubricating oil flowing through the oil supply passage (55) is divided into the first to fourth oil supply holes (55a to 55d). Lubricating oil is supplied from the first oil supply hole (55a) to the sliding surface between the first eccentric part (53a) and the inner piston part (22a) of the first piston (22). (55b) is supplied to the sliding surface between the second eccentric part (53b) and the inner piston part (32a) of the second piston (32).

  Lubricating oil flowing through the third oil supply hole (55c) travels from the first oil supply path (56) to the first blade (24), and lubricating oil flowing through the fourth oil supply hole (55d) flows to the second oil supply path (57). To the second blade (34). Lubricating oil in the first oil supply path (56) and the second oil supply path (57) passes from the main groove (56a, 57a) through the communication hole (56b, 57b) and is long in each blade (24, 34). It flows into the first oil supply groove (59a) formed in the part (24a, 34a), and further flows into the second oil supply groove (59b) of the short part (24b, 34b) through the communication hole (59c). The lubricating oil flowing through the communication hole (59c) leaches out from the through hole (59d) to the surface of the blade (24, 34). By supplying lubricating oil to the surface of each blade (24, 34) as described above, the sliding between each blade (24, 34), each cylinder (21, 31), and each piston (22, 32). The moving part is lubricated.

  On the other hand, the back pressure communication path (58a) between the first and second blade back pressure spaces (21g, 31g) and the fourth suction flow path (74) are connected by the intermediate pressure communication path (58b). The pressure in the second blade back pressure space (21, 31 g) is set to the fourth suction pressure of the four-stage compression mechanism. In addition, since the sealing part (24s, 34s) is provided at the rear end of the blade (24, 34), high-pressure lubricating oil flows into the first and second blades 2 back pressure space (21g, 31g). do not do. Accordingly, the pressure in each blade back pressure space (21g, 31g) is maintained at the fourth suction pressure of the four-stage compression mechanism, which is the set pressure, and does not increase beyond that. For this reason, the pressing force of each blade (24, 34) by the pressure of each blade back pressure space (21g, 31g) is maintained at the initially set pressing force, and does not become excessively strong.

  Even if the lubricating oil supplied to each blade (24, 34) flows into the first and second blade back pressure spaces (21g, 31g), the oil is sucked into the fourth stage compression chamber and then compressed. It is discharged into the casing (10) of the machine (1) and separated from the refrigerant. This lubricating oil then returns to the oil sump in the casing (10). Therefore, it is possible to prevent excess lubricating oil from being discharged outside the compressor (system side).

-Effect of the embodiment-
According to this embodiment, the first and second blade back pressure spaces (21g, 31g) are connected to the fourth suction flow path (74) by the intermediate pressure communication path (58b), whereby the fourth stage of the four-stage compression mechanism. Since it can be maintained at the stage suction pressure, the pressing load on the blade (24, 34) due to the pressure of the blade back pressure space (21g, 31g) can be suppressed. Therefore, the blade (24, 34) is strongly pressed against the bush groove (C1, C2) formed in the outer piston part (22b, 32b) of the piston (22, 32) by the swinging bush part (24c, 34c). It is possible to prevent wear and seizure due to strong wear and seizure of the inner blade (22a) at the tip of the inner blade (B1). This makes it possible to suppress mechanical loss (sliding loss) due to the operation of the blades (24, 34).

  Moreover, even if surplus lubricating oil after supplying the blades (24, 34) is sucked into the fourth stage compression mechanism, the oil is discharged into the casing (10) of the compressor (1). Separated from refrigerant. Therefore, it is possible to prevent the excess lubricating oil from being discharged out of the compressor (system side), so that it is possible to suppress the performance degradation of the system due to the excessive lubricating oil.

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

  For example, although the four-stage compression mechanism has been described in the above embodiment, the present invention describes an eccentric rotation type compression mechanism in which a plurality of cylinder chambers are formed between the piston (22, 32) and the cylinder (21, 31) ( 40) and applicable to any rotary compressor (1) whose height of the radially outer end face is larger than the radially inner end face of the blade (24, 34) of the compression mechanism (40). The target is not limited to the four-stage compression mechanism, and the intermediate pressure set in the blade back pressure space (21g, 31g) is not limited to the fourth-stage suction pressure. The intermediate pressure to be set in the blade back pressure space (21g, 31g) may be set according to the area on the front end side and rear end side of the blade (24, 34).

  Further, the oil supply path from the oil reservoir (10a) of the casing (10) to the blades (24, 34) in the above embodiment is merely an example, and may be appropriately changed. In the above embodiment, oil is not directly supplied to the swinging bush portions (24c, 34c). However, oil may be supplied directly to the swinging bush portions (24c, 34c). .

  Further, in the above embodiment, the swing bush part (24c, 34c) is integrated with the blade (24, 34). However, as shown in FIG. 11, the inner blade part of the blade (24, 34). The swinging bush portion (24c, 34c) may be configured separately from (B1). Even in this case, the tip of the blade (24, 34) is strongly pressed against the piston (22, 32) and can be prevented from being worn or seized, preventing the mechanical loss of the compression mechanism (40) from increasing. it can.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention includes an eccentric rotation type compression mechanism in which a plurality of cylinder chambers are formed between a piston and a cylinder, and the height of the radially outer end surface is higher than the radially inner end surface of the blade of the compression mechanism. Useful for rotary compressors with large dimensions.

1 Rotary compressor
10 Casing
10a Oil sump
20 First compression mechanism
21 1st cylinder
21g 1st blade back pressure space
22 First piston
23a Innermost cylinder chamber
23b Inner cylinder chamber
23c Outer cylinder chamber
23d Outermost cylinder chamber
24 First blade
24s seal part
30 Second compression mechanism
31 2nd cylinder
31g 2nd blade back pressure space
32 2nd piston
33a Innermost cylinder chamber
33b Inner cylinder chamber
33c Outer cylinder chamber
33d Outermost cylinder chamber
34 Second blade
34s Seal part
40 Compression mechanism
58b Intermediate pressure communication passage
59 Oil supply passage
74 4th suction channel (4th stage suction part)

Claims (4)

Formed between the cylinder (21, 31), the piston (22, 32) that rotates eccentrically in the cylinder (21, 31), and the cylinder (21, 31) and the piston (22, 32). And a plurality of cylinder chambers (23a, 23b, 23c, 23d, 33a, 33b, 33c, 33d) located at the inner and outer ends in the radial direction, and the radial direction of the cylinders (21, 31) A compression mechanism (40) having a blade (24, 34) slidably connected to the piston (22, 32) and a casing (10) in which the compression mechanism (40) is housed. With
The height dimension of the blade (24, 34) in the axial direction of the compression mechanism (40) is set to be larger at the radially outer end than the radially inner end of the blade (24, 34). A rotary compressor,
A blade back pressure space (21g, 31g) provided in the compression mechanism (40) and receiving the radially outer end of the blade (24, 34), and an intermediate pressure portion (74) of the compression mechanism (40) A rotary compressor comprising an intermediate pressure communication path (58b) to be connected. In claim 1,
The compression mechanism (40) has four cylinder chambers (23a, 23b, 23c, 23d) (33a, 33b, 33c, 33d), and is a four-stage compression mechanism that performs a four-stage compression operation. Features a rotary compressor. In claim 2,
The intermediate pressure portion (74) of the compression mechanism (40) connected to the blade back pressure space (21g, 31g) via the intermediate pressure communication path (58b) is a fourth stage suction portion of the compression mechanism (40). A rotary compressor characterized by being. In any one of Claims 1-3,
The blade (24, 34) slides between the blade (24, 34) and the compression mechanism (40) with high-pressure lubricating oil from an oil sump (10c) provided in the casing (10). Provided with an oil supply passage (59) for supplying to the portion and a seal portion (24s, 34s) for preventing the oil supply passage (59) from communicating with the blade back pressure space (21g, 31g). A rotary compressor characterized by that.

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