JP2013104360A - Rotary compressor - Google Patents

Abstract

In a rotary compressor, sliding loss and wear on a sliding surface of a thrust bearing are sufficiently reduced.
In a rotary compressor, a thrust bearing surface that is in sliding contact with the upper end surface of a rear head (35) is formed on the lower end surface of an eccentric portion. In the peripheral portion of the hole portion through which the drive shaft is inserted in the upper end surface of the rear head (35), the angle from the axis O of the drive shaft toward the blade is 0 degree, and the angle from 0 degrees to the rotation direction of the drive shaft. In the case of increasing, at least a second region that does not overlap with the first region that is not less than 360 ° and not less than the minimum gap angle at which the gap between the inner circumferential surface of the cylinder (34) and the outer circumferential surface of the piston (50) is minimized. A circular groove (61) that extends in the circumferential direction and forms an elastic bearing at the inner peripheral edge is formed in a predetermined angle range including 90 degrees.
[Selection] Figure 3

Description

    The present invention relates to a rotary compressor, and particularly relates to measures against seizure of a thrust bearing surface.

    2. Description of the Related Art Conventionally, a cylinder, a piston disposed in the cylinder and externally fitted to an eccentric portion of a drive shaft, and an end plate that closes an axial end portion of the cylinder, the piston rotates eccentrically in the cylinder. There is known a rotary compressor in which a fluid is compressed (see, for example, Patent Document 1 below).

    In the above rotary compressor, a thrust bearing surface that is in sliding contact with the upper end surface of the rear head is formed on the lower end surface of the eccentric portion, and the thrust bearing surface and the upper end surface of the rear head constitute a sliding surface of the thrust bearing. Further, lubricating oil is supplied between the sliding surfaces of the thrust bearing, and seizure of the sliding surfaces is suppressed by cooling the sliding surfaces with the lubricating oil.

    Incidentally, in the rotary compressor configured as described above, the internal pressure of the compression chamber acts on the eccentric portion of the drive shaft via the piston. For this reason, when the internal pressure of the compression chamber is relatively high during high load operation or the like, the drive shaft may be greatly bent. When the drive shaft is bent, a so-called corner contact occurs in which a corner portion formed by the upper end surface and the inner peripheral surface of the rear head is in sliding contact with the main shaft portion of the drive shaft. When the angular contact occurs, the contact surface pressure increases, the sliding loss and wear at the bearing portion of the rear head increase, and the operating efficiency and reliability of the rotary compressor are reduced.

    Therefore, in the rotary compressor, an increase in the contact surface pressure due to angular contact is suppressed by forming a so-called elastic bearing that elastically supports the drive shaft by forming an annular groove on the upper end surface of the rear head. ing.

Japanese Utility Model Publication No. 64-36692

    However, when the annular groove is provided on the upper end surface of the rear head as described above, the lubricating oil supplied to the gap between the thrust bearing surface of the eccentric portion and the upper end surface of the rear head flows into the annular groove and is depressurized. The gas fluid dissolved in the lubricating oil is separated from the lubricating oil. Since the gas fluid separated from the lubricating oil has a lower specific gravity than the lubricating oil, it reaches the upper part of the annular groove and eventually flows between the sliding surfaces of the thrust bearing to inhibit the cooling of the sliding surfaces. When the gas fluid separated from the lubricating oil impedes cooling of the sliding surface of the thrust bearing by the lubricating oil, the sliding surface of the thrust bearing slides severely at high temperatures on the high pressure chamber side. There was a problem that was not sufficiently suppressed. As a result, the surface pressure of the sliding surface of the thrust bearing is increased to increase the sliding loss and wear, resulting in a decrease in operating efficiency and reliability of the rotary compressor.

    This invention is made | formed in view of such a point, The objective is to fully reduce the sliding loss and abrasion in the sliding surface of a thrust bearing in a rotary compressor.

    The first invention includes a drive mechanism (20) having a drive shaft (23) that is formed with an eccentric portion (26) and extending vertically, and a cylindrical cylinder chamber (C2) that covers the outer periphery of the eccentric portion (26). ) Forming a cylinder (34), a piston (50) disposed in the cylinder chamber (C2) and fitted on the eccentric part (26), and extending in the radial direction of the piston (50) A blade (51) that partitions the cylinder chamber (C2) into a low pressure chamber (C21) and a high pressure chamber (C22), an upper end plate (33) that closes the upper end of the cylinder (34), and a lower end of the cylinder (34) And a compression mechanism (30) having a lower end plate (35) that closes the shaft, and a thrust bearing surface (26a) that is in sliding contact with the upper end surface of the lower end plate (35) is formed on the lower end surface of the eccentric portion (26). In the rotary compressor, a peripheral portion of the hole portion through which the drive shaft (23) is inserted in the upper end surface of the lower end plate (35) When the angle from the axis of the drive shaft (23) toward the blade (51) is 0 degree and the angle increases from 0 degree in the rotation direction of the drive shaft (23), the cylinder (34) The gap between the peripheral surface and the outer peripheral surface of the piston (50) is at least a part of the second region that does not overlap the first region that is equal to or greater than the minimum clearance angle and less than 360 degrees, and includes 90 degrees. An arc groove (61) that extends in the circumferential direction and forms an elastic bearing at the inner peripheral edge is formed in the angular range.

    In the first invention, when the drive shaft (23) rotates, the piston (50) fitted on the eccentric portion (26) rotates eccentrically in the cylinder chamber (C2). As a result, the shapes of the low pressure chamber (C21) and the high pressure chamber (C22) change, and fluid is sucked into the low pressure chamber (C21) while fluid is compressed in the high pressure chamber (C22). By the way, when the piston (50) is at the lowest position (bottom dead center) of the cylinder chamber (C2) (on the opposite side to the blade (51)), the piston (50) is inserted into the eccentric part (26) via the piston (50). The area of the pressure receiving surface on which the internal pressure of the applied high pressure chamber (C22) acts is maximized, and the load applied to the drive shaft (23) is maximized. At this time, when the angle from the shaft center toward the blade (51) is 0 degree and the angle is increased in the rotation direction of the drive shaft (23), the outer peripheral surface of the piston (50) has a range of 180 to 360 degrees. The direction of the load applied to the drive shaft (23) becomes the pressure receiving surface and is 90 degrees.

    In the first invention, the peripheral portion of the hole portion through which the drive shaft (23) is inserted in the upper end surface of the lower end plate (35) extends in the circumferential direction within a predetermined angle range including 90 degrees and extends to the inner peripheral edge portion. An arc groove (61) forming an elastic bearing is formed. That is, the elastic bearing is provided in the direction in which the load is applied to the drive shaft (23) at the bottom dead center of the piston (50) where the load applied to the drive shaft (23) is maximum. Therefore, the drive shaft (23) is elastically supported by the elastic bearing at the position where the load due to the fluid pressure is maximum. As a result, angular contact due to bending of the drive shaft (23) is avoided.

    By the way, in the rotary compressor as described above, normally, the high pressure chamber (C22) immediately before the start of discharge has a rotation angle at which the maximum pressure is reached between the inner peripheral surface of the cylinder (34) and the outer peripheral surface of the piston (50). It is designed so that the gap between them (hereinafter referred to as CP gap) is minimized (see, for example, Japanese Patent No. 4019620). This is to suppress fluid leakage from the high pressure chamber (C22) to the low pressure chamber (C21) at the maximum pressure immediately before the start of discharge. That is, when the rotation angle of the drive shaft (23) is equal to or greater than the minimum clearance angle at which the CP clearance is minimum and less than 360 degrees to complete the discharge, the pressure and temperature of the high pressure chamber (C22) are the highest. Yes. Therefore, in the first region where the sliding surface of the thrust bearing is at least the minimum clearance angle of less than 360 degrees, the sliding becomes severe, and the risk of seizure becomes larger in each step than the second region which does not overlap the first region. .

    In the first invention, the arc groove (61) is a first gap of not less than 360 degrees and not less than a minimum gap angle that is a rotation angle of the drive shaft (23) when the CP gap on the upper end surface of the lower end plate (35) is minimized. It is formed in at least a part of the second region that does not overlap the region. That is, the arc groove (61) is not formed in the first region where the risk of seizure is higher in each step than in other locations. For this reason, in the rotary compressor, the first region where seizure is likely to occur at a higher temperature than other portions is sufficiently cooled by the lubricating oil.

    In a second aspect based on the first aspect, the arc groove (61) is formed in an angle range of 0 degrees or more and 180 degrees or less on the upper end surface of the lower end plate (35).

    In the second invention, the arc groove is provided in an angle range of 0 degrees to 180 degrees on the upper end surface of the lower end plate (35). Here, the region of 0 ° to 180 ° on the sliding surface of the thrust bearing is located on the suction side compared to the region between 180 ° and 360 °, so the temperature is low, and seizure due to sliding occurs. The need for cooling with a lubricating oil is low because it is unlikely to occur. On the other hand, when the internal pressure of the high pressure chamber (C22) is relatively high (when the rotation angle of the drive shaft (23) is 180 to 360 degrees), the region of the lower end plate (35) of 0 degree or more and 180 degrees or less is The high pressure chamber (C22) serves as a location for receiving the load applied to the drive shaft (23) by the high internal pressure. For this reason, as described above, the elastic shaft is formed by forming the circular groove (61) in the angle range of 0 ° to 180 ° on the upper end surface of the lower end plate (35), whereby the drive shaft (23) is greatly bent. However, the angular contact is avoided, but the gas fluid separated from the lubricating oil in the arc groove (61) flows into the outer peripheral side of the arc groove (61) of the sliding surface of the thrust bearing and is cooled by the lubricating oil. There is no possibility that seizure will occur even if the hindrance is inhibited.

    According to a third invention, in the second invention, the lower end plate (35) is disposed at an angular position of less than 360 degrees and near 360 degrees to discharge the fluid compressed in the high pressure chamber (C22). A discharge port (56) is formed, and a discharge valve (57) for opening and closing the discharge port (56) is provided at an outlet of the discharge port (56), and the arc groove (61) It is formed in an angle range of 50 degrees to 180 degrees on the upper end surface of (35).

    In the third invention, when the fluid in the high pressure chamber (C22) is pressurized and the discharge valve (57) is opened, the compressed fluid in the high pressure chamber (C22) is discharged through the discharge port (56). At this time, since the volume of the discharge port (56) remains without being discharged, it becomes a dead volume. For this reason, the region near the discharge port (56) (near 0 degrees) of the lower end plate (35) is usually made as thin as possible to reduce the dead volume. When (61) is formed, the thickness may be further reduced and the strength may not be ensured. However, in the above configuration, the arc groove (61) is provided in an angle range of 50 degrees or more and 180 degrees or less on the upper end surface of the lower end plate (35). In other words, the circular arc groove (61) is provided at an angular position somewhat away from the discharge port (56) of the lower end plate (35).

    According to a fourth invention, in any one of the first to third inventions, the drive shaft (23) further includes an upper eccentric portion (25) above the eccentric portion (26), and the compression mechanism ( 30) includes an upper cylinder (32) that covers the outer periphery of the upper eccentric portion (25) to form a cylindrical upper cylinder chamber (C1), and the upper eccentric chamber disposed in the upper cylinder chamber (C1). An upper piston (40) externally fitted to the portion (25) and extending in the radial direction of the upper piston (40) to partition the upper cylinder chamber (C1) into a low pressure chamber (C11) and a high pressure chamber (C12) An upper blade (41) and an uppermost end plate (31) for closing the upper end of the upper cylinder (32) are further provided, and the lower end of the upper cylinder (32) is closed by the upper end plate (33).

    In the fourth invention, the compression mechanism (30) is configured as a so-called two-cylinder compression mechanism having two cylinder chambers (C1, C2). In such a two-cylinder compression mechanism, since the axial length is longer than that of the one-cylinder compression mechanism, the distance between the main bearing and the sub-bearing is also increased. As a result, the deflection of the drive shaft (23) due to the internal pressure of the high-pressure chamber (C22) becomes larger than that of the one-cylinder compression mechanism, and so-called angular contact tends to occur. However, in the above configuration, the load applied to the drive shaft (23) becomes maximum when the piston (50) is at the bottom dead center. At this time, an elastic bearing is provided in the direction in which the load is applied to the drive shaft (23). It has been. Therefore, the drive shaft (23) is elastically supported by the elastic bearing at the position where the load due to the fluid pressure is maximum, and the corner formed by the upper end surface and the inner peripheral surface of the lower end plate (35) The so-called corner contact that is in sliding contact with the main shaft portion of the drive shaft (23) is avoided.

    According to the first invention, the predetermined angle including 90 degrees of the bearing portion (the peripheral portion of the hole portion through which the drive shaft (23) is inserted) that supports the drive shaft (23) of the lower end plate (35). The range portion was configured as an elastic bearing. In other words, since the elastic bearing is provided in the direction where the load is applied to the drive shaft (23) at the bottom dead center of the piston where the load applied to the drive shaft (23) is maximum, the load due to the fluid pressure applied to the drive shaft (23) is maximum. The drive shaft (23) can be elastically supported by the elastic bearing at a rotation angle of Therefore, even if the deflection of the drive shaft (23) increases along with the load due to the fluid pressure applied to the drive shaft (23), the corner formed by the upper end surface and the inner peripheral surface of the lower end plate (35) becomes the drive shaft ( 23), the so-called angular contact with the main shaft portion can be suppressed. As a result, an increase in contact surface pressure due to corner contact can be suppressed, and an increase in sliding loss and wear in the bearing portion of the lower end plate (35) can be suppressed.

    Further, according to the first invention, a groove is not provided in the entire circumference of the peripheral portion of the hole portion through which the drive shaft (23) is inserted in the upper end surface of the lower end plate (35), but a minimum clearance angle of 360 degrees or more. The arc bearing (61) is formed in a predetermined angle range including 90 degrees at least a part of the second region that does not overlap the first region, and the elastic bearing is partially configured. In other words, the arc groove (61) is not formed in the first region where the risk of seizure on the upper end surface of the lower end plate (35) is higher than the minimum gap angle at each step and less than 360 degrees. Therefore, it is possible to prevent the gas fluid separated from the lubricating oil from flowing into the first region where there is a high risk of seizure of the sliding surface of the thrust bearing. Therefore, the sliding surface of the thrust bearing can be sufficiently cooled by the lubricating oil to prevent seizure.

    In other words, according to the first invention, the arc groove that forms the elastic bearing in a predetermined angle range including 90 degrees where the risk of hitting the corners on the upper end surface of the lower end plate (35) is higher in each step than other portions. While forming (61), the arc groove (61) that forms the elastic bearing is not formed at a location (first region) where the risk of seizure is higher in each step than the other location (second region). Thus, seizure of the bearing portion of the lower end plate (35) due to corner contact and seizure on the sliding surface of the thrust bearing can be suppressed. Therefore, an increase in sliding loss and wear in the bearing portion of the lower end plate (35) and the thrust bearing can be suppressed.

    According to the second invention, even if the deflection of the drive shaft (23) increases with the load due to the fluid pressure applied to the drive shaft (23), it is formed by the upper end surface and the inner peripheral surface of the lower end plate (35). It is possible to suppress the so-called corner contact in which the corner portion is in sliding contact with the main shaft portion of the drive shaft (23). Further, the arc groove (61) is formed at a location where the need for cooling by the lubricating oil is relatively low on the sliding surface of the thrust bearing. Therefore, even if the gas fluid dissolved in the lubricating oil in the arc groove (61) is separated and flows into the sliding surface and the cooling performance of the sliding surface by the lubricating oil is reduced, the sliding surface may be seized. Low. Therefore, an increase in sliding loss and wear in the bearing portion of the lower end plate (35) and the thrust bearing can be suppressed.

    According to the third aspect of the invention, since the arc groove (61) is formed at an angular position somewhat apart from the discharge port (56) of the lower end plate (35), the vicinity of the discharge port (56) of the lower end plate (35) is formed. Strength can be secured.

    According to the fourth aspect of the invention, in the rotary compressor provided with a so-called two-cylinder compression mechanism (30) in which the deflection of the drive shaft (23) due to the internal pressure of the high pressure chamber (C12, C22) is likely to increase. Since the elastic bearing is provided in the direction where the load is applied to the drive shaft (23) at the bottom dead center of the piston (50) where the load applied to the shaft (23) is maximum, the load due to the fluid pressure applied to the drive shaft (23) is maximum. The drive shaft (23) can be elastically supported by the elastic bearing at a rotation angle of Therefore, even if the deflection of the drive shaft (23) increases along with the load due to the fluid pressure applied to the drive shaft (23), the corner formed by the upper end surface and the inner peripheral surface of the lower end plate (35) becomes the drive shaft ( 23), the so-called angular contact with the main shaft portion can be suppressed.

FIG. 1 is a longitudinal sectional view of a compressor according to Embodiment 1 of the present invention. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a cross-sectional view of a compression mechanism of the compressor of FIG. FIG. 4 is a plan view of the rear head of the compressor shown in FIG. FIG. 5 is a plan view of the rear head of the compressor according to the second embodiment of the present invention.

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

Embodiment 1 of the Invention
The rotary compressor (10) according to Embodiment 1 of the present invention is provided, for example, in a refrigerant circuit of an air conditioner, compresses refrigerant sucked from an evaporator, and discharges the refrigerant to a radiator. As shown in FIG. 1, the rotary compressor (10) includes a casing (11), an electric motor (20), and a compression mechanism (30).

    The casing (11) includes a cylindrical body part (12), an upper end panel (13) that closes the upper end side of the body part (12), and a lower end panel that closes the lower end side of the body part (12). (14). A first suction pipe (15a) and a second suction pipe (15b) are attached to the trunk part (12) through the lower part of the trunk part (12). A discharge pipe (16) is attached to the upper part of the upper end plate (13) so as to penetrate the end plate (13). The electric motor (20) and the compression mechanism (30) are accommodated in the casing (11). Further, an oil reservoir (17) is formed at the bottom of the lower end plate (14) in which lubricating oil for lubricating the sliding portion of the compression mechanism (30) is stored.

    The electric motor (20) includes a cylindrical stator (21), a cylindrical rotor (22), and a drive shaft (23). The stator (21) is fixed to the body (12) of the casing (11). On the other hand, the rotor (22) is disposed in the hollow portion of the stator (21). A drive shaft (23) is fixed in the hollow portion of the rotor (22) so as to penetrate the rotor (22).

    The drive shaft (23) includes a main shaft portion (24) extending vertically and two eccentric portions (25, 26) formed integrally with the main shaft portion (24) near the lower end of the main shaft portion (24). have. The two eccentric parts (25, 26) are constituted by an upper upper eccentric part (25) and a lower eccentric part (26) provided below the upper eccentric part (25), both of which are main shaft parts. It has a larger diameter than (24). Each of the upper eccentric portion (25) and the lower eccentric portion (26) has an axis that is eccentric from the axis of the main shaft portion (24) by a predetermined distance. In the first embodiment, the eccentric directions of the upper eccentric portion (25) and the lower eccentric portion (26) with respect to the main shaft portion (24) are shifted by 180 degrees. A thrust bearing surface (26a) is formed on the lower end surface of the lower eccentric portion (26) so as to be in sliding contact with the upper end surface of a rear head (35) described later. As shown in FIG. 2, the thrust bearing surface (26a) is configured by an end surface of a protruding portion that protrudes downward so as to be positioned below other portions of the lower end surface of the lower eccentric portion (26). .

    As shown in FIG. 1, a centrifugal pump (27) immersed in an oil sump (18) is provided at the lower end of the drive shaft (23). An oil supply passage (oil passage) (70) in which the lubricating oil pumped up by the centrifugal pump (27) flows is formed in the drive shaft (23) in the axial direction. The first to fifth passages (70a to 70e) are connected to the oil supply passage (70). The first to fifth passages (70a to 70e) respectively extend in the radial direction of the drive shaft (23), and the respective outflow ends are opened on the outer peripheral surface of the drive shaft (23). The first passage (70a) is an exhaust gas passage for discharging the foamed refrigerant gas inside the oil supply passage (70), and the second to fifth passages (70b to 70e) are pumped into the oil supply passage (70). It is an oil outflow passage for flowing out the lubricating oil.

    Specifically, the first passage (70a) is formed near the upper end of the upper end of the compression mechanism (30) of the drive shaft (23). The second passage (70b) is formed in the vicinity of the upper eccentric portion (25) of the drive shaft (23), and the third passage (70c) is formed in the upper eccentric portion (25). The fourth passage (70d) is formed inside the lower eccentric portion (26), and the fifth passage (70e) is formed near the lower side of the lower eccentric portion (26) of the drive shaft (23). Yes. The third passage (70c) formed in the upper eccentric portion (25) and the fourth passage (70d) formed in the lower eccentric portion (26) are in an eccentric direction of each eccentric portion (25, 26). 120 ° out of phase and 180 ° out of phase with each other.

    First and second longitudinal grooves (71, 72) are formed on the outer peripheral surface of the drive shaft (23). The first vertical groove (71) extends in the axial direction on the outer peripheral surface of the upper eccentric portion (25) of the drive shaft (23), and the outflow end of the third passage (70c) is opened. The first vertical groove (71) guides the lubricating oil on the upper end surface of the upper eccentric portion (25) between the lower end surface and the upper end surface of a middle plate (33) described later. The second vertical groove (72) extends in the axial direction on the outer peripheral surface of the lower eccentric portion (26) of the drive shaft (23), and the outflow end of the fourth passage (70d) is opened. The second vertical groove (72) guides the lubricating oil on the upper end surface of the lower eccentric portion (26) between the lower end surface and the upper end surface (35b) of the rear head (35) described later.

    Moreover, the 1st and 2nd annular groove (73,74) is formed in the outer peripheral surface of a drive shaft (23). The first annular groove (73) extends in the circumferential direction on the outer peripheral surface near the upper side of the upper eccentric portion (25) of the drive shaft (23), and the outflow end of the second passage (70b) is opened. The first annular groove (73) guides the lubricating oil flowing out from the second passage (70b) in the circumferential direction between the upper end surface of the upper eccentric portion (25) and the lower end surface of the front head (31) described later. Let it flow. The second annular groove (74) extends in the circumferential direction on the outer peripheral surface near the lower side of the lower eccentric portion (26) of the drive shaft (23), and the outflow end of the fifth passage (70e) is opened. . The second annular groove (74) guides the lubricating oil flowing out from the fifth passage (70e) in the circumferential direction between the lower end surface of the lower eccentric portion (26) and the upper end surface of the rear head (35) described later. Let it flow.

    With such a configuration, the lubricating oil in the oil reservoir (17) is pumped up to the oil supply passage (70) by the centrifugal pump (27) as the drive shaft (23) rotates. The lubricating oil pumped into the oil supply passage (70) flows out from each of the second to fifth passages (70b to 70e), and the first and second longitudinal grooves (71, 72) and the first and second annular grooves. It flows to the sliding part of the compression mechanism (30) through (73, 74) and lubricates and cools the sliding part.

    The compression mechanism (30) has a front head (31), an upper cylinder (32), a middle plate (33), a lower cylinder (34), and a rear head (35) formed in an annular shape. These annular members (31 to 35) are stacked in order from the upper side to the lower side, and are fastened by a plurality of bolts extending in the axial direction. The drive shaft (23) vertically penetrates the annular member (31 to 35).

    The upper cylinder (32) and the lower cylinder (34) are each constituted by a thick cylindrical member. On the other hand, the front head (31), the middle plate (33), and the rear head (35) are constituted by thick disk members, each having a hole through which the drive shaft (23) is inserted. ing. Inner peripheral edge portions that form holes in the front head (31) and the rear head (35) have sliding bearing portions (31a, 35a) that rotatably support the main shaft portion (24) of the drive shaft (23), respectively. It is composed. In the first embodiment, the front head (31) constitutes the main bearing, and the rear head (35) constitutes the auxiliary bearing.

    The upper cylinder (32) is closed at the upper end by the front head (31) and closed at the lower end by the middle plate (33), and the inner closed space constitutes the upper cylinder chamber (C1). The upper cylinder chamber (C1) accommodates an upper piston (40) slidably fitted on the upper eccentric portion (25) of the drive shaft (23). As shown in FIG. 3, an upper blade (41) extending radially outward from the outer peripheral surface is integrally formed on the outer peripheral surface of the upper piston (40). The upper cylinder chamber (C1) is partitioned by an upper blade (41) into a low pressure chamber (C11) communicating with the first suction pipe (15a) and a high pressure chamber (C12) in which an upper discharge port (46) described later opens. ing.

    3 is a cross-sectional view of the compression mechanism (30) in the vicinity of the upper cylinder chamber (C1), but the cross-sectional configuration in the vicinity of the lower cylinder chamber (C2) is also a cross-section in the vicinity of the upper cylinder chamber (C1). Since it is almost the same as the configuration of the surface, the reference numerals of the constituent members in the lower cylinder chamber (C2) are shown in parentheses and are not shown.

    On the other hand, as shown in FIG. 1, the lower cylinder (34) is closed at the upper end by the middle plate (33) and closed at the lower end by the rear head (35). C2). The lower cylinder chamber (C2) accommodates a lower piston (50) slidably fitted on the lower eccentric portion (26) of the drive shaft (23). As shown in FIG. 3, a lower blade (51) extending radially outward from the outer peripheral surface is integrally formed on the outer peripheral surface of the lower piston (50). The lower cylinder chamber (C2) includes a low pressure chamber (C21) communicated with the second suction pipe (15b) by a lower blade (51), and a high pressure chamber (C22) in which a lower discharge port (56) described later opens. It is divided into.

    In the first embodiment, the lower cylinder (34) and the lower piston (50) are defined as a gap between the inner peripheral surface of the lower cylinder (34) and the lower piston (50) (hereinafter simply referred to as “CP gap”). Is designed so that the high pressure chamber (C22) immediately before the start of discharge is minimized near the rotation angle at which the maximum pressure is reached. Specifically, in the first embodiment, when the angle position where the CP gap is minimum is the minimum gap angle θ, the lower cylinder (34) and the lower piston are set so that the minimum gap angle θ is 270 degrees. (50) and are designed. This is to suppress the leakage of refrigerant from the high pressure chamber (C22) to the low pressure chamber (C21) at the maximum pressure immediately before the start of discharge.

    As shown in FIG. 3, the upper cylinder (32) is formed with a circular groove in plan view. The circular groove is formed in a bush groove (42) that accommodates the pair of bushes (43, 43). In the bush groove (42), a pair of bushes (43, 43) formed in a half-moon shape in plan view are fitted in a state of sandwiching the upper blade (41). On the other hand, similarly to the upper cylinder (32), the lower cylinder (34) is also formed with a circular groove in plan view. The circular groove is formed in a bush groove (52) that accommodates a pair of bushes (53, 53). In the bush groove (52), a pair of bushes (53, 53) formed in a half-moon shape in plan view is fitted in a state of sandwiching the lower blade (51).

    The upper cylinder (32) is formed with a suction through passage (44) penetrating in a radial direction between the inner peripheral surface and the outer peripheral surface. The end of the first suction pipe (15a) is inserted into the suction through passage (44) (see FIG. 1). On the other hand, the lower cylinder (34) is formed with a suction through passage (54) penetrating radially between the inner peripheral surface and the outer peripheral surface. The end of the second suction pipe (15b) is inserted into the suction through path (54).

    As shown in FIG. 1, the upper surface of the front head (31) is formed with a recess that opens upward, and the recess is covered with an inner cover (36). The upper surface of the inner cover (36) is covered with the outer cover (37). An inner discharge space (81) is formed between the upper surface of the front head (31) in which the concave portion is formed and the inner cover (36), and between the inner cover (36) and the outer cover (37). Is formed with an outer discharge space (82).

    The front head (31) is formed with an upper discharge port (46) penetrating in the vertical direction and communicating the inner discharge space (81) with the high pressure chamber (C12) of the upper cylinder chamber (C1). A discharge valve (47) for opening and closing the upper discharge port (46) is attached to the front head (31). As the discharge valve (47) opens and closes, the upper discharge port (46) intermittently communicates with a high pressure chamber (C12) formed in the upper cylinder (32). Further, the inner cover (36) is formed with a through hole (not shown) that communicates the inner discharge space (81) and the outer discharge space (82), and the outer cover (37) has an outer discharge space (82). ) And a through hole (not shown) that communicates with the internal space of the casing (11).

    A recess extending in the circumferential direction and opening downward is formed on the lower surface of the rear head (35). The recess is covered with a closing plate (38), and a closed space is formed inside. The closed space constitutes a lower discharge space (83). The lower discharge space (83) is connected to the rear head (35), the lower cylinder (34), the middle plate (33), the upper cylinder (32), and a refrigerant through hole (84) that passes through the front head (31). And communicates with an inner discharge space (81) formed between the front head (31) and the inner cover (36).

    The rear head (35) is formed with a lower discharge port (56) penetrating in the vertical direction to communicate the lower discharge space (83) and the high pressure chamber (C22) in the lower cylinder chamber (C2). Yes. In addition, a discharge valve (57) for opening and closing the lower discharge port (56) is attached to the rear head (35). As the discharge valve (57) opens and closes, the lower discharge port (56) intermittently communicates with a high pressure chamber (C22) formed in the lower cylinder (34). Further, the peripheral portion of the rear head (35) to which the discharge valve (57) is attached is formed thinner than the other portions.

    Here, as described above, the inner peripheral edge portion forming the hole portion of the rear head (35) is a sliding bearing portion (35a) that rotatably supports the lower end portion of the main shaft portion (24) of the drive shaft (23). It is configured. As shown in FIG. 4, the rear head (35) is formed with an arcuate groove (61) in plan view in the periphery of the hole through which the drive shaft (23) is inserted in the upper end surface.

    The groove (61) rotates the drive shaft (23) around the axis O of the drive shaft (23) with the angular position from the axis O of the drive shaft (23) toward the lower blade (51) as 0 degree. When the angle increases in the direction (arrow direction in FIG. 4), it is formed so as to extend in the circumferential direction within a predetermined angle range including an angular position of 90 degrees. More specifically, the groove (61) is formed in an angle range of 50 degrees or more and 180 degrees or less on the upper end surface of the rear head (35). In other words, the groove (61) is a second region (0 ° or more and less than 270 °) that does not overlap the first region of the minimum clearance angle θ (270 °) or more and less than 360 ° on the upper end surface of the rear head (35). (Region) is formed in a part of the angular range.

    A slide bearing portion that supports the lower end portion of the main shaft portion (24) of the drive shaft (23) of the rear head (35) by forming the arc-shaped groove portion (61) as described above on the upper end surface of the rear head (35). A portion inside (35a) of the groove (61) is configured as a so-called elastic bearing that elastically supports the drive shaft (23). That is, when a load is applied to the lower end portion of the main shaft portion (24) of the drive shaft (23) in the direction of the groove portion (61), the inner portion of the groove portion (61) of the sliding bearing portion (35a) is bent. The drive shaft (23) is elastically supported by being recessed into the groove (61).

    The lower discharge port (56) is formed at an angular position of less than 360 degrees and around 360 degrees of the rear head (35). That is, the groove (61) is provided at an angular position that is separated from the lower discharge port (56) of the rear head (35) to some extent.

-Driving action-
In the rotary compressor (10), the piston (40, 50) externally fitted to each eccentric part (25, 26) as the electric motor (20) is started and the drive shaft (23) rotates. Rotates eccentrically in each cylinder chamber (C1, C2). As a result, the volumes of the low pressure chambers (C11, C21) and the high pressure chambers (C12, C22) of the pistons (40, 50) and the cylinder chambers (C1, C2) are periodically changed, and the high pressure chambers (C12 , C22), the refrigerant suction operation, compression operation, and discharge operation are continuously performed.

    The refrigerant sucked from the suction pipes (15a, 15b) into the low pressure chambers (C11, C21) of the cylinder chambers (C1, C2) is supplied to the high pressure chambers (C12, C22) of the cylinder chambers (C1, C2). After being compressed in step 1, the liquid is discharged from the discharge ports (46, 56). The refrigerant discharged from the upper discharge port (46) flows into the inner discharge space (81). On the other hand, the refrigerant discharged from the lower discharge port (56) into the lower discharge space (83) flows into the inner discharge space (81) through the refrigerant through hole (84), and the inner discharge space (81 ) And the refrigerant discharged from the upper cylinder chamber (C1). The refrigerant discharged from the upper cylinder chamber (C1) and the lower cylinder chamber (C2) merged in the inner discharge space (81) flows into the outer discharge space (82) through a through hole formed in the inner cover (36). After that, it flows into the internal space of the casing (11) through the through hole formed in the outer cover (37), and eventually flows out from the discharge pipe (16) to the outside of the casing (11).

    Incidentally, in the rotary compressor (10), a thrust bearing surface (26a) is formed on the lower end surface of the lower eccentric portion (26) so as to be in sliding contact with the upper end surface of the rear head (35), and the thrust bearing surface (26a) And the upper end surface of the rear head (35) constitute a sliding surface of the thrust bearing. In the rotary compressor (10), the internal pressure of each cylinder chamber (C1, C2) acts on each eccentric part (25, 26) of the drive shaft (23) via each piston (40, 50). . Therefore, when the internal pressure of each cylinder chamber (C1, C2) is relatively high during high load operation, the drive shaft (23) may be greatly bent. When the drive shaft (23) bends, so-called corner contact occurs in which the corner portion formed by the upper end surface and the inner peripheral surface of the rear head (35) is in sliding contact with the main shaft portion (24) of the drive shaft (23). When the angular contact occurs, the contact surface pressure increases, the sliding loss and wear at the sliding bearing portion (35a) of the rear head (35) increase, and the operating efficiency and reliability of the rotary compressor are reduced. End up.

    In particular, when the lower piston (50) is at the lowermost position (bottom dead center) of the lower cylinder chamber (C2) (bottom dead center), the lower piston (50) Accordingly, the area of the pressure receiving surface on which the internal pressure of the high pressure chamber (C22) applied to the lower eccentric portion (26) acts is maximized, and the load applied to the drive shaft (23) is maximized. At this time, the range of 180 ° to 360 ° on the outer peripheral surface of the lower piston (50) is the pressure receiving surface, and the direction of the load applied to the drive shaft (23) is 90 °.

    Therefore, in the first embodiment, as described above, the arc-shaped groove portion (61) is formed in a predetermined angle range including 90 degrees on the upper end surface of the rear head (35) in a plan view, and the sliding bearing portion (35a ) Is formed as an elastic bearing. Thus, the drive shaft (23) is elastically supported by the elastic bearing at a position where the load due to the fluid pressure (refrigerant pressure) is maximized. As a result, so-called angular contact due to bending of the drive shaft (23) is avoided.

-Cooling with lubricating oil-
When the drive shaft (23) rotates, the lubricating oil in the oil reservoir (17) is pumped up into the oil supply passage (70) inside the drive shaft (23) by the centrifugal pump (27). The lubricating oil pumped up in the oil supply passage (70) flows upward from below, and then receives centrifugal force and flows out from the second to fifth passages (70b to 70e) to the outer peripheral surface of the drive shaft (23). To do.

    The lubricating oil that has flowed out of the second passage (70b) accumulates in the first annular groove (73). The lubricating oil accumulated in the first annular groove (73) is guided to the upper end of the front head (31) through a spiral groove (not shown) formed on the inner peripheral surface of the sliding bearing (31a) of the front head (31). At that time, the sliding surface between the sliding bearing portion (31a) of the front head (31) and the main shaft portion (24) of the drive shaft (23) is lubricated and cooled. The lubricating oil accumulated in the first annular groove (73) flows into the sliding surface between the upper end surface of the upper piston (40) and the lower end surface of the front head (31), and lubricates the sliding surface. And cool down.

    The lubricating oil that has flowed out of the third passage (70c) accumulates in the first vertical groove (71). The lubricating oil accumulated in the first vertical groove (71) flows into the sliding surface between the upper eccentric portion (25) of the drive shaft (23) and the sliding bearing portion of the upper piston (40), and the sliding Lubricate and cool between the surfaces. Further, the lubricating oil accumulated in the first vertical groove (71) flows into the sliding surface between the lower end surface of the upper piston (40) and the upper end surface of the middle plate (33). Lubricate and cool.

    The lubricating oil that has flowed out of the fourth passage (70d) accumulates in the second vertical groove (72). The lubricating oil accumulated in the second vertical groove (72) flows into the sliding surface between the lower eccentric portion (26) of the drive shaft (23) and the sliding bearing portion of the lower piston (50), and Lubricate and cool between the sliding surfaces. The lubricating oil accumulated in the second vertical groove (72) is the sliding surface between the upper end surface of the lower piston (50) and the lower end surface of the middle plate (33) and the lower side of the drive shaft (23). It flows between the sliding surfaces between the thrust bearing surface (26a) at the lower end surface of the eccentric portion (26) and the upper end surface (35b) of the rear head (35), and lubricates and cools between the sliding surfaces.

    The lubricating oil that has flowed out of the fifth passage (70e) accumulates in the second annular groove (74). The lubricating oil accumulated in the second annular groove (74) is the sliding surface between the sliding bearing portion (35a) of the rear head (35) and the main shaft portion (24) of the drive shaft (23) and the drive shaft (23). Flows into the sliding surface between the thrust bearing surface (26a) at the lower end surface of the lower eccentric portion (26) and the upper end surface (35b) of the rear head (35), that is, between the sliding surfaces of the thrust bearing, Lubricate and cool between each sliding surface.

    As described above, in the first embodiment, the groove portion (61) is not provided on the entire periphery of the peripheral portion of the hole portion through which the drive shaft (23) on the upper end surface of the rear head (35) is inserted. An arc-shaped groove portion (61) is formed in the angle range to partially constitute an elastic bearing. Here, when the groove (61) for forming the elastic bearing is formed in an annular shape, the gas refrigerant separated from the lubricating oil in the groove (61) is spread over the entire sliding surface of the thrust bearing. Inflow. However, according to the above configuration, since the arc-shaped groove (61) is formed only in the predetermined angle range, the inflow of the gas refrigerant to the region other than the predetermined angle range of the sliding surface of the thrust bearing is prevented. can do.

    In the rotary compressor (10), when the rotation angle of the drive shaft (23) is not less than the minimum clearance angle θ (270 degrees) and less than 360 degrees, the temperature of the high pressure chamber (C22) is the minimum clearance angle. The temperature becomes higher than that at the rotation angle of less than θ (270 degrees). Therefore, in the first region where the minimum clearance angle θ (270 degrees) and less than 360 degrees of the sliding surface of the thrust bearing is less than 360 degrees, the sliding becomes severe, and the risk of seizure is higher than each of the second regions where it does not overlap the first region. It grows in steps.

    Therefore, in the first embodiment, as described above, the arc-shaped groove portion (61) does not overlap the first region of the minimum clearance angle θ (270 degrees) or more and less than 360 degrees on the upper end surface of the rear head (35). It is formed in at least a part of the two regions. In other words, the groove (61) is not formed in the first region of the minimum clearance angle θ (270 degrees) or more and less than 360 degrees of the upper end surface of the rear head (35). That is, the arc-shaped groove portion (61) is not formed in the first region where the risk of seizure on the upper end surface of the rear head (35) is higher in each step than in other locations. Therefore, the gas refrigerant separated from the lubricating oil in the groove (61) at a position (first area) where the risk of seizure on the upper end surface of the rear head (35) is higher in each step than the other positions (second area). Does not flow in, and the angle range of the upper end surface of the rear head (35) is sufficiently cooled by the lubricating oil.

-Effect of Embodiment 1-
According to the first embodiment, a portion in a predetermined angle range including 90 degrees in the bearing portion (35a) that supports the drive shaft (23) of the rear head (35) is configured as an elastic bearing. In other words, when the lower piston (50) is at the bottom dead center, the load applied to the drive shaft (23) becomes maximum, but at that time, the elastic bearing is provided in the direction in which the load is applied to the drive shaft (23). The drive shaft (23) can be elastically supported by the elastic bearing at the rotation angle at which the load due to the fluid pressure applied to the drive shaft (23) is maximized. Therefore, even if the deflection of the drive shaft (23) increases with the load due to the fluid pressure applied to the drive shaft (23), the corner formed by the upper end surface and the inner peripheral surface of the lower end plate (35) It is possible to suppress so-called corner contact that is in sliding contact with the main shaft portion (24). As a result, an increase in contact surface pressure due to corner contact can be suppressed, and an increase in sliding loss and wear in the sliding bearing portion (35a) of the rear head (35) can be suppressed.

    In addition, according to the first embodiment, grooves are not provided in the entire periphery of the hole portion through which the drive shaft (23) is inserted in the upper end surface of the rear head (35), but the minimum clearance angle is less than 360 degrees. The arcuate groove (61) is formed in a predetermined angle range including at least a part of the second region that does not overlap with the first region and includes 90 degrees to partially constitute the elastic bearing. That is, the arc groove (61) is not formed in the first region where the risk of seizure on the upper end surface of the rear head (35) is higher than the minimum gap angle at each step and less than 360 degrees. Therefore, it is possible to prevent the gas refrigerant separated from the lubricating oil from flowing into a portion (first region) where there is a high risk of seizure of the sliding surface of the thrust bearing. Therefore, the sliding surface of the thrust bearing can be sufficiently cooled by the lubricating oil to prevent seizure.

    That is, according to the first embodiment, an elastic bearing is formed at a position where the risk of hitting the corners on the upper end surface of the rear head (35) is higher in each step than in other places, while the risk of seizure is higher than in other places. The groove for forming the elastic bearing is not formed at the high place in each step, and seizure of the sliding bearing portion (35a) of the rear head (35) due to corner contact and seizure on the sliding surface of the thrust bearing Can be suppressed. Accordingly, it is possible to suppress an increase in sliding loss and wear in the sliding bearing portion (35a) of the rear head (35) and the thrust bearing.

    In the first embodiment, the upper end surface of the rear head (35) has a relatively low temperature, so that there is little risk of seizure due to sliding, and an angle range of 0 ° to 180 ° with a low need for cooling with lubricating oil. An arc groove (61) was provided on the surface. On the other hand, an elastic groove is formed by forming an arc groove (61) in an angle range of 0 degrees or more and 180 degrees or less of the rear head (35) that receives the load applied to the drive shaft (23) by the high internal pressure of the high pressure chamber (C22). I am going to do that. Therefore, according to the first embodiment, even if the deflection of the drive shaft (23) increases with the load due to the fluid pressure applied to the drive shaft (23), the upper end surface and the inner peripheral surface of the rear head (35) are formed. The so-called corner contact in which the corner portion is in sliding contact with the main shaft portion (24) of the drive shaft (23) can be suppressed. Further, the arc groove (61) is formed at a location where the need for cooling by the lubricating oil is relatively low on the sliding surface of the thrust bearing. Therefore, even if the gas refrigerant dissolved in the lubricating oil in the arc groove (61) is separated and flows into the sliding surface and the cooling performance of the sliding surface by the lubricating oil decreases, the sliding surface may be seized. Low. Accordingly, it is possible to suppress an increase in sliding loss and wear in the sliding bearing portion (35a) of the rear head (35) and the thrust bearing.

    By the way, when the refrigerant is pressurized in the high pressure chamber (C22) of the lower cylinder chamber (C2) and the discharge valve (57) is opened, the compressed refrigerant in the high pressure chamber (C22) is discharged through the discharge port (56). . At this time, since the volume of the discharge port (56) remains without being discharged, it becomes a dead volume. For this reason, the area near the discharge port (56) (near 0 degrees) of the rear head (35) is usually made as thin as possible to reduce the dead volume. If 61) is formed, the thickness may be further reduced and the strength may not be ensured. However, according to the first embodiment, the arc groove (61) is provided in the angle range of 50 degrees or more and 180 degrees or less on the upper end surface of the rear head (35), so that it is separated from the discharge port (56) of the rear head (35) to some extent. The arc groove (61) was formed at the angular position. Therefore, the strength in the vicinity of the discharge port (56) of the rear head (35) can be ensured.

    In the first embodiment, the compression mechanism (30) is a so-called two-cylinder compression mechanism having two cylinder chambers (C1, C2). In such a two-cylinder compression mechanism, the axial length is longer than that of the one-cylinder compression mechanism, so the distance between the main bearing (front head (31)) and the sub-bearing (rear head (35)) is also small. become longer. As a result, the deflection of the drive shaft (23) due to the internal pressure of the high pressure chamber (C22) of the lower cylinder chamber (C2) becomes larger than that of the compression mechanism of one cylinder, and so-called angular contact is likely to occur. However, in the first embodiment, when the piston (50) is at the bottom dead center, the load applied to the drive shaft (23) is maximized. In this case, the elastic bearing is applied in the direction in which the load is applied to the drive shaft (23). It was decided to provide. Therefore, the drive shaft (23) can be elastically supported by the elastic bearing at the rotation angle at which the load due to the fluid pressure applied to the drive shaft (23) is maximized. Therefore, even if the deflection of the drive shaft (23) increases with the load due to the fluid pressure applied to the drive shaft (23), the corner formed by the upper end surface and the inner peripheral surface of the rear head (35) is the drive shaft (23 ) So-called angular contact with the main shaft portion (24) can be suppressed.

<< Embodiment 2 of the Invention >>
The rotary compressor (10) of the second embodiment is obtained by changing the location where the groove (61) of the first embodiment is formed. Specifically, as shown in FIG. 5, the groove (61) is formed in an angle range of 0 degrees or more and 180 degrees or less on the upper end surface of the rear head (35). Even if it forms in this way, there can exist an effect similar to Embodiment 1. FIG.

<< Other Embodiments >>
In each of the above embodiments, the rotary compressor (10) is configured as a so-called two-cylinder compression mechanism in which the compression mechanism (30) has two cylinder chambers (C1, C2). However, the compression mechanism of the rotary compressor according to the present invention may be a so-called one-cylinder compression mechanism having only the lower cylinder chamber (C2). Specifically, the lower cylinder (34) is closed at the upper end by the front head (31) and closed at the lower end by the rear head (35), and the lower cylinder chamber (C2) is constituted by the internal closed space. It may be done. Even with such a one-cylinder compression mechanism, the same effect as that of the first embodiment can be obtained by forming the arc-shaped groove portion (61) in a plan view on the upper end surface of the rear head (35).

    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 is useful for a rotary compressor.

10 Rotary compressor
20 Electric motor (drive mechanism)
23 Drive shaft
24 Spindle part
25 Upper eccentric part
26 Lower eccentric part (Eccentric part)
26a Thrust bearing surface
30 Compression mechanism
31 Front head (top plate)
32 Upper cylinder
33 Middle plate (top plate)
34 Lower cylinder (cylinder)
35 Rear head (bottom plate)
35a Bearing part
40 Upper piston
41 Upper blade
50 Lower piston
51 Lower blade
56 Lower discharge port (discharge port)
57 Discharge valve
61 Groove (arc groove)
C1 Upper cylinder chamber
C2 Lower cylinder chamber (cylinder chamber)
C11 Low pressure chamber C12 High pressure chamber C21 Low pressure chamber C22 High pressure chamber

Claims (4)

A drive mechanism (20) having a drive shaft (23) formed with an eccentric portion (26) and extending vertically;
A cylinder (34) that covers the outer periphery of the eccentric portion (26) to form a cylindrical cylinder chamber (C2), and is disposed in the cylinder chamber (C2) and is externally fitted to the eccentric portion (26). A piston (50), a blade (51) extending in the radial direction of the piston (50) to partition the cylinder chamber (C2) into a low pressure chamber (C21) and a high pressure chamber (C22), and the cylinder (34) A compression mechanism (30) having an upper end plate (33) for closing the upper end and a lower end plate (35) for closing the lower end of the cylinder (34);
A rotary compressor in which a thrust bearing surface (26a) that is in sliding contact with the upper end surface of the lower end plate (35) is formed on the lower end surface of the eccentric part (26),
The angle from the axial center of the drive shaft (23) toward the blade (51) is set to 0 degree at the periphery of the hole portion through which the drive shaft (23) is inserted in the upper end surface of the lower end plate (35). When the angle increases in the rotational direction of the drive shaft (23) from 0 degrees, the minimum gap between the inner peripheral surface of the cylinder (34) and the outer peripheral surface of the piston (50) is minimized. An arc groove (circular groove) extending in the circumferential direction and forming an elastic bearing at the inner peripheral edge within a predetermined angle range including 90 degrees that is at least part of the second area that does not overlap the first area of the gap angle of more than 360 degrees 61) A rotary compressor characterized by being formed. In claim 1,
The rotary compressor according to claim 1, wherein the arc groove (61) is formed in an angle range of 0 degrees to 180 degrees on the upper end surface of the lower end plate (35). In claim 2,
A discharge port (56) for discharging the fluid compressed in the high pressure chamber (C22) is formed at an angular position of less than 360 degrees of the lower end plate (35) and in the vicinity of 360 degrees. A discharge valve (57) for opening and closing the discharge port (56) is provided at the outlet of the discharge port (56),
The arcuate groove (61) is formed in an angle range of 50 degrees or more and 180 degrees or less on the upper end surface of the lower end plate (35). In any one of Claims 1 thru | or 3,
The drive shaft (23) further includes an upper eccentric part (25) above the eccentric part (26),
The compression mechanism (30) is disposed in the upper cylinder chamber (C1) and an upper cylinder (32) that covers the outer periphery of the upper eccentric portion (25) to form a cylindrical upper cylinder chamber (C1). The upper piston (40) externally fitted to the upper eccentric portion (25), and the upper cylinder chamber (C1) extending in the radial direction of the upper piston (40) are divided into the low pressure chamber (C11) and the high pressure chamber (C12). ) And an upper end plate (31) for closing the upper end of the upper cylinder (32), and the lower end of the upper cylinder (32) is closed by the upper end plate (33). A rotary compressor characterized by being made.

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