JP2020186660A - Rotary compressor - Google Patents

Abstract

To provide a crank shaft and a rotary compressor further reduced in vibration and improved in efficiency.SOLUTION: A rotary compressor includes a crank shaft 16 rotating about an axis O, disc-shaped eccentric portions 14A, 14B disposed on the crank shaft 16 and centered on eccentric axes O1, O2 eccentric to the axis O, annular piston rotors 13A, 13B covering the eccentric portions 14A, 14B from an outer peripheral side and centered on the eccentric axes O1, O2, a compression mechanism portion housing the piston rotors 13A, 13B and provided with a compression chamber for compressing a refrigerant in accompany with rotations of the piston rotors 13A, 13B, and a bearing portion rotatably supporting the crank shaft 16. The piston rotors 13A, 13B are reduced in dimensions in directions of the eccentric axes O1, O2 gradually from a radial inner side toward an outer side with respect to the eccentric axes O1, O2.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rotary compressor.

For example, a rotary compressor is known as a device used for compressing a refrigerant in an air conditioner. This type of compressor has a crankshaft that extends along the axis, a piston rotor mounted on the eccentric part of the crankshaft, a cylinder with a compression chamber that houses the piston rotor, and both sides of the piston rotor in the axial direction. It is equipped with a bearing device that supports from. When the piston rotor rotates eccentrically in the cylinder chamber, the volume of the cylinder chamber changes and the refrigerant is compressed (see, for example, Patent Document 1 below).

Japanese Unexamined Patent Publication No. 11-166493

Here, in the compressor as described above, the piston rotor and the bearing device are in sliding contact with each other as the piston rotor rotates eccentrically. At this time, the piston rotor is heated by the frictional heat, which may cause thermal expansion. In particular, such thermal expansion is likely to occur in the outer peripheral side portion of the piston rotor. As a result, the outer peripheral portion of the piston rotor is locally worn, which may reduce the performance of the compressor. Further, when the thermal expansion of the rotor progresses, not only the performance is deteriorated, but also problems such as abnormal wear of the piston rotor and locking (seizure) may occur.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a rotary compressor having further improved performance.

According to one aspect of the present invention, the rotary compressor includes a crankshaft that rotates around an axis, a disk-shaped eccentric portion that is provided on the crankshaft and is centered on an eccentric axis that is eccentric to the axis. Compression in which the eccentric portion is covered from the outer peripheral side, an annular piston rotor centered on the eccentric shaft, and a compression chamber for accommodating the piston rotor and compressing the refrigerant as the piston rotor rotates are formed. The piston rotor includes a mechanism portion and a bearing portion that rotatably supports the crankshaft, and the size of the piston rotor decreases in the radial direction from the inside to the outside with respect to the eccentric shaft.

Here, as the piston rotor rotates eccentrically, the piston rotor and the bearing portion are in sliding contact with each other. At this time, the piston rotor is heated by the frictional heat, which may cause thermal expansion. In particular, such thermal expansion is likely to occur in the outer peripheral side portion of the piston rotor. However, according to the above configuration, the eccentric axial dimension of the piston rotor decreases toward the outer side in the radial direction. Therefore, even when the thermal expansion as described above occurs, it is possible to reduce the possibility that the size of the piston rotor in the eccentric axis direction becomes larger than that of the inner peripheral portion (eccentric portion). As a result, local wear of the piston rotor can be avoided.

In the rotary compressor, at least one of the end faces of the piston rotor facing the eccentric axis direction is from the end face of the eccentric portion facing the eccentric axis direction from the inside to the outside in the radial direction with respect to the eccentric axis. A receding surface that recedes in the eccentric axis direction may be formed.

According to the above configuration, a retracting surface is formed on at least one of the end faces facing the eccentric axis direction of the piston rotor. The receding surface recedes in the eccentric axis direction toward the outside in the radial direction. Therefore, even when the piston rotor undergoes thermal expansion in the eccentric axis direction, it is possible to reduce the possibility that the size of the piston rotor in the eccentric axis direction becomes larger than that of the inner peripheral portion. As a result, local wear of the piston rotor can be avoided.

In the rotary compressor described above, the receding surface may be recessed in a curved shape in the eccentric axis direction.

According to the above configuration, the receding surface is recessed in a curved shape in the eccentric axis direction. Therefore, it is possible to reduce the possibility that the size of the piston rotor in the eccentric axis direction becomes larger than that of the inner peripheral portion. As a result, local wear of the piston rotor can be avoided. Further, by changing the concave shape (curved surface shape) of the receding surface based on the distribution of the actual thermal expansion amount, the shape after thermal expansion can be optimized.

In the rotary compressor described above, the receding surface may be convex in a curved shape in the eccentric axis direction.

According to the above configuration, the receding surface is convex in a curved surface in the eccentric axis direction. Therefore, it is possible to reduce the possibility that the size of the piston rotor in the eccentric axis direction becomes larger than that of the inner peripheral portion. As a result, local wear of the piston rotor can be avoided. Further, by changing the convex shape (curved surface shape) of the receding surface based on the distribution of the actual thermal expansion amount, the shape after thermal expansion can be optimized.

In the rotary compressor described above, the receding surface is connected to a planar flat portion continuous with the end surface of the eccentric portion facing the eccentric axis direction and a radial outer side of the flat surface portion in the radial direction with respect to the eccentric axis. It may have an inclined portion that is inclined in the eccentric axis direction from the flat surface portion from the inside to the outside.

According to the above configuration, the receding surface has a flat surface portion and an inclined portion. Therefore, it is possible to reduce the possibility that the size of the piston rotor in the eccentric axis direction becomes larger than that of the inner peripheral portion (eccentric portion). As a result, local wear of the piston rotor can be avoided. In addition, the shape after thermal expansion can be optimized by changing the ratio of the flat surface portion and the retracted portion based on the distribution of the actual thermal expansion amount.

In the rotary compressor, the receding surface is connected to a planar flat portion continuous with the end surface of the eccentric portion facing the eccentric axis direction and radially outside the flat surface portion, and is more than the flat surface portion. It may have a receding flat surface portion that recedes in the eccentric axis direction and extends in a plane parallel to the flat surface portion.

According to the above configuration, the receding surface has a flat surface portion and a receding flat surface portion. Therefore, it is possible to reduce the possibility that the size of the piston rotor in the eccentric axis direction becomes larger than that of the inner peripheral portion (eccentric portion). As a result, local wear of the piston rotor can be avoided. Further, the shape after thermal expansion can be optimized by changing the ratio of the flat surface portion and the receding flat surface portion based on the distribution of the actual thermal expansion amount.

In the rotary compressor, a plurality of the retracting surfaces may be formed at intervals in the circumferential direction with respect to the eccentric axis.

According to the above configuration, the receding surfaces are formed at intervals in the circumferential direction. In this case, the distribution of the amount of thermal expansion in the circumferential direction can be optimized between the receding surface and the portion where the receding surface is not formed.

According to the present invention, it is possible to provide a rotary compressor having further improved performance.

It is sectional drawing which shows the structure of the compressor which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the structure of the crankshaft which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the modification of the piston rotor which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the structure of the piston rotor which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the modification of the piston rotor which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the piston rotor which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the modification of the piston rotor which concerns on 3rd Embodiment of this invention. It is a top view which shows the structure of the piston rotor which concerns on 4th Embodiment of this invention.

[First Embodiment]
The first embodiment of the present invention will be described with reference to FIGS. 1 to 3. The expressions "same" and "equivalent" in the following description indicate that the dimensions and shapes are substantially the same or equivalent, and design tolerances and manufacturing errors are allowed. As shown in FIG. 1, the compressor 100 (rotary compressor) according to the present embodiment includes an accumulator 24, suction pipes 26A and 26B, and a compressor main body 10. The compressor body 10 includes a crankshaft 16 extending along the axis O, a motor 18 for rotating the crankshaft 16, a compression mechanism portion 10A for compressing refrigerant as the crankshaft 16 rotates, a crankshaft 16, and a motor. 18 and a housing 11 that covers the compression mechanism portion 10A are provided.

The compression mechanism unit 10A accommodates the crankshaft 16 rotated by the motor 18 and the piston rotors 13A and 13B (first piston rotor 13A, second piston rotor 13B) that rotate eccentrically with the rotation of the crankshaft 16. The chamber C includes cylinders 12A and 12B formed inside.

The compression mechanism unit 10A is a so-called two-cylinder type rotary compressor in which disc-shaped cylinders 12A and 12B are provided in two upper and lower stages in a cylindrical housing 11. The housing 11 surrounds the cylinders 12A and 12B to form a discharge space V from which the compressed refrigerant is discharged. Inside the cylinders 12A and 12B, a cylindrical first piston rotor 13A and a second piston rotor 13B having an outer shape smaller than the inside of the inner wall surface of the cylinder are arranged, respectively. The first piston rotor 13A and the second piston rotor 13B are inserted and fixed to the crankshafts 14A and 14B (first crankshaft 14A, second crankshaft 14B) of the crankshaft 16, respectively.

The first piston rotor 13A of the cylinder 12A on the upper stage side and the second piston rotor 13B on the lower stage side are provided so that their phases differ from each other by 180 °. That is, the first piston rotor 13A is eccentric in the direction opposite to the eccentric direction of the second piston rotor 13B. Further, a disc-shaped partition plate 15 is provided between the upper and lower cylinders 12A and 12B. The space R in the cylinder 12A on the upper stage side and the space R on the lower stage side are partitioned from each other by the partition plate 15 to form compression chambers C1 and C2, respectively.

The cylinders 12A and 12B (compression mechanism portion 10A) are fixed to the housing 11 by the upper bearing portion 17A and the lower bearing portion 17B. More specifically, the upper bearing portion 17A has a disk shape fixed to the upper portion of the compression mechanism portion 10A, and its outer peripheral surface is fixed to the inner peripheral surface of the housing 11. The lower bearing portion 17B has a disk shape fixed to the lower portion of the compression mechanism portion 10A, and its outer peripheral surface is fixed to the inner peripheral surface of the housing 11. That is, the compression mechanism portion 10A is not directly fixed to the housing 11, but is fixed to the housing 11 via the upper bearing portion 17A and the lower bearing portion 17B.

In the compressor main body 10, an accumulator 24 for gas-liquid separation of the refrigerant prior to supply to the compressor main body 10 is fixed to the housing 11 via a stay 25. Suction pipes 26A and 26B for sucking the refrigerant in the accumulator 24 into the compressor main body 10 are provided between the accumulator 24 and the compressor main body 10. One end of the suction pipes 26A and 26B is connected to the lower part of the accumulator 24, and the other end communicates with the suction ports 23A and 23B formed in the cylinders 12A and 12B through the openings 22A and 22B, respectively.

Next, the configuration of the crankshaft 16 will be described in detail. As shown in FIG. 1, the crankshaft 16 is rotatably supported around the axis O by an upper bearing portion 17A fixed to the cylinder 12A and a lower bearing portion 17B fixed to the cylinder 12B. As shown in FIG. 2, the crankshaft 16 includes a shaft body 16H, a first crankshaft 14A (eccentric portion) into which the first piston rotor 13A is fitted, and a second crankshaft 14B (an eccentric portion) into which the second piston rotor 13B is fitted. It has an eccentric portion), an upper shaft 16A, an intermediate shaft 16B, and a lower shaft 16C.

The upper shaft 16A extends along the axis O. The first crankshaft 14A is integrally provided at one end of the upper shaft 16A in the axis O direction. The first crankshaft 14A has a disk shape having a diameter larger than that of the upper shaft 16A, centering on the first eccentric shaft O1 eccentric in the radial direction with respect to the axis O as described above. The first crankshaft 14A is housed in the compression chamber C1 described above. The intermediate shaft 16B extends along the axis O and is attached to one side of the first crankshaft 14A in the axis O direction. The intermediate shaft 16B has a diameter dimension equivalent to that of the upper shaft 16A described above. A first piston rotor 13A is attached to the first crankshaft 14A. The first piston rotor 13A has an annular shape that covers the first crankshaft 14A from the outer peripheral side. That is, the first piston rotor 13A has an annular shape centered on the first eccentric shaft O1.

As shown in FIG. 2, in the cross-sectional view including the axis O, the size of the first piston rotor 13A decreases in the direction of the first eccentric axis O1 from the inside to the outside in the radial direction with respect to the first eccentric axis O1. There is. That is, the first piston rotor 13A has a tapered shape from the inside to the outside in the radial direction in a cross-sectional view. More specifically, on at least one of the end faces of the first piston rotor 13A facing the first eccentric shaft O1, the first crankshaft 14A is located on at least one of the first crankshafts 14A in the radial direction with respect to the first eccentric shaft O1. A first receding surface R1 that recedes in the direction of the first eccentric axis O1 is formed from an end surface that faces the one eccentric axis O1 direction. The first receding surface R1 has a linear shape intersecting the first eccentric axis O1 in a cross-sectional view including the first eccentric axis O1. Further, in the present embodiment, the first retracting surface R1 is formed on both end faces of the first piston rotor 13A in the direction of the first eccentric shaft O1. That is, the first piston rotor 13A is plane-symmetrical in the direction of the first eccentric axis O1.

The second crankshaft 14B is provided on one side of the intermediate shaft 16B in the axis O direction. The second crankshaft 14B has a larger diameter than the intermediate shaft 16B, and has the same diameter as the first crankshaft 14A. The second crankshaft 14B has a disk shape centered on the second eccentric shaft O2 located on the opposite side of the first eccentric shaft O1 with reference to the axis O. An annular second piston rotor 13B that covers the second crankshaft 14B from the outer peripheral side is attached to the outer peripheral surface of the second crankshaft 14B. The size of the second piston rotor 13B in the second eccentric axis O2 direction decreases from the inside to the outside in the radial direction with respect to the second eccentric axis O2 in the cross-sectional view including the axis O. That is, the second piston rotor 13B has a tapered shape from the inside to the outside in the radial direction in a cross-sectional view. More specifically, on at least one of the end faces of the second piston rotor 13B facing the second eccentric shaft O2, the second crankshaft 14B is located on the second crankshaft 14B from the inside to the outside in the radial direction with respect to the second eccentric shaft O2. A second receding surface R2 is formed which recedes in the direction of the second eccentric axis O2 from the end surface facing the bieccentric axis O2 direction. The second receding surface R2 has a linear shape intersecting the second eccentric axis O2 in a cross-sectional view including the second eccentric axis O2. Further, in the present embodiment, the second retracting surface R2 is formed on both end faces of the second piston rotor 13B in the second eccentric axis O2 direction. That is, the second piston rotor 13B is plane-symmetrical in the second eccentric axis O2 direction.

The lower shaft 16C extends along the axis O and is attached to one side of the second crankshaft 14B in the direction of the axis O. The lower shaft 16C has the same diameter as the upper shaft 16A and the intermediate shaft 16B described above.

The upper shaft 16A projects upward from the upper bearing portion 17A (that is, in the direction in which the motor 18 is located when viewed from the compression mechanism portion 10A). The upper shaft 16A is integrally provided with a rotor 19A of a motor 18 for rotationally driving the crankshaft 16. A stator 19B is fixedly provided on the inner peripheral surface of the housing 11 so as to face the outer peripheral portion of the rotor 19A.

Subsequently, the operation of the compressor 100 according to the present embodiment will be described. When operating the compressor 100, the motor 18 is first driven by power supply from the outside. As the motor 18 is driven, the crankshaft 16 rotates around the axis O. As the crankshaft 16 rotates, the first crankshaft 14A and the second crankshaft 14B rotate around the central axis (axis O) of the crankshaft 16. The first piston rotor 13A and the second piston rotor 13B rotate eccentrically in the compression chambers C1 and C2 so as to follow this turning. The volume of the compression chambers C1 and C2 changes due to the eccentric rotation of the first piston rotor 13A and the second piston rotor 13B, and the refrigerant taken into the compression chambers C1 and C2 is compressed. The compressed refrigerant is taken out to the outside through the discharge space V in the housing 11.

Here, in the compressor 100 as described above, with the eccentric rotation of the first piston rotor 13A and the second piston rotor 13B, the first piston rotor 13A, the upper bearing portion 17A, and the second piston rotor 13B The lower bearing portions 17B are in sliding contact with each other. At this time, the first piston rotor 13A and the second piston rotor 13B are heated by the frictional heat, which may cause thermal expansion. In particular, such thermal expansion is likely to occur in the outer peripheral side portions of the first piston rotor 13A and the second piston rotor 13B. As a result, the outer peripheral side portions of the first piston rotor 13A and the second piston rotor 13B may be locally worn, and the performance of the rotary compressor 100 may be deteriorated.

Therefore, in the present embodiment, the first piston rotor 13A and the second piston rotor 13B have a tapered cross section from the inside to the outside in the radial direction as described above. According to this configuration, the dimensions of the first piston rotor 13A and the second piston rotor 13B in the first eccentric shaft O1 direction or the second eccentric shaft O2 direction even when the above thermal expansion occurs. Can be reduced as compared to the inner peripheral portion (first crankshaft 14A and second crankshaft 14B). As a result, local wear of the first piston rotor 13A and the second piston rotor 13B can be avoided.

Further, according to the above configuration, the first receding surface R1 and the first retracting surface R1 and the second Two receding surfaces R2 are formed. The first receding surface R1 and the second receding surface R2 recede in the direction of the first eccentric axis O1 or the direction of the second eccentric axis O2 toward the outside in the radial direction. Therefore, even when the first piston rotor 13A and the second piston rotor 13B undergo thermal expansion in the first eccentric shaft O1 direction or the second eccentric shaft O2 direction, the first piston rotor 13A and the second It is possible to reduce the possibility that the size of the piston rotor 13B becomes larger than that of the inner peripheral portion. As a result, local wear of the first piston rotor 13A and the second piston rotor 13B can be avoided.

The first embodiment of the present invention has been described above. It should be noted that various changes and modifications can be made to the above configuration as long as the gist of the present invention is not deviated. For example, in the first embodiment, the first retracting surfaces R1 are formed on both sides of the first piston rotor 13A in the direction of the first eccentric shaft O1, and the second piston rotor 13B is formed on both sides of the second eccentric shaft O2 direction. An example in which the receding surface R2 is formed has been described. However, as shown in FIG. 3, only the surface on one side of the first piston rotor 13A and the second piston rotor 13B in the direction of the first eccentric shaft O1 or the surface on the other side (lower side) in the direction of the second eccentric shaft O2. It is also possible to form the first receding surface R1 or the second receding surface R2, respectively. Here, although not shown in detail, the surfaces of the first piston rotor 13A and the second piston rotor 13B facing the bearing side (upper bearing 17A side and lower bearing 17B side) (that is, the above-mentioned first eccentric shaft O1). A portion (discharge port) that is more easily deformed under high pressure than the other portion is formed on the surface on one side in the direction and the surface on the other side in the second eccentric axis O2 direction. In such a portion, the clearance with the first piston rotor or the second piston rotor tends to be reduced due to deformation or the like. According to the above configuration, since the first receding surface R1 and the second receding surface R2 are formed only on the surface where the clearance tends to be small, the influence on the performance due to the thermal expansion described above is more effective. Can be reduced. Further, according to such a configuration, the man-hours for forming the first receding surface R1 and the second receding surface R2 can be reduced, so that the cost can be reduced and the construction period can be shortened.

[Second Embodiment]
Next, the second embodiment of the present invention will be described with reference to FIG. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Further, since the first receding surface R1'and the second receding surface R2'have the same configuration as each other, only the first receding surface R1'will be described below as a representative. As shown in FIG. 4, in the present embodiment, the mode of the first retracting surface R1'of the first piston rotor 13A is different from that of the first embodiment. The first receding surface R1 ′ according to the present embodiment is recessed in a curved surface in the direction of the first eccentric axis O1. More specifically, the first receding surface R1'is recessed toward one side in the direction of the first eccentric axis O1 with reference to the planar receding surface R1 described in the first embodiment. That is, the first receding surface R1'extends from one side to the other side in the direction of the first eccentric axis O1 from the inside to the outside in the radial direction with respect to the first eccentric axis O1, and from one side to the other side. It is dented in a curved shape toward.

According to the above configuration, the first receding surface R1'is recessed in a curved surface in the direction of the first eccentric axis O1. Therefore, it is possible to reduce the possibility that the size of the first piston rotor 13A in the direction of the first eccentric shaft O1 becomes larger than that of the inner peripheral portion (first clause rank shaft 14A). As a result, local wear of the first piston rotor 13A can be avoided. Further, by changing the concave shape (curved surface shape) of the first receding surface R1'based on the distribution of the actual thermal expansion amount, the shape after thermal expansion can be optimized.

The second embodiment of the present invention has been described above. It should be noted that various changes and modifications can be made to the above configuration as long as the gist of the present invention is not deviated. For example, as shown in FIG. 5, the first receding surface R1'may have a curved surface shape that is convex in the direction of the first eccentric axis O1. Even with such a configuration, the same effect as that of the second embodiment can be obtained. Further, similarly to the first embodiment, it is also possible to adopt a configuration in which the first receding surfaces R1'are formed on both sides in the direction of the first eccentric axis O1.

[Third Embodiment]
Subsequently, the third embodiment of the present invention will be described with reference to FIG. The same components as those of the above embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. Further, since the first receding surface R11 and the second receding surface R21 have the same configuration as each other, only the first receding surface R11 will be described below as a representative. As shown in FIG. 6, the first receding surface R11 has a planar flat surface portion Rp located on the inner side in the radial direction and an inclined portion Rs extending from the radial outer edge of the flat surface portion Rp toward the outer side in the radial direction. And have. The flat surface portion Rp has a flat surface shape continuous with the upper surface of the first crankshaft 14A. That is, the plane portion Rp extends in a plane orthogonal to the first eccentric axis O1. The inclined portions Rs are inclined from one side in the first eccentric axis O1 direction to the other side from the flat surface portion Rp from the inside to the outside in the radial direction with respect to the first eccentric axis O1. That is, the inclined portions Rs extend in a direction intersecting the first eccentric axis O1 direction.

According to the above configuration, the receding surface R11 has a flat surface portion Rp and an inclined portion Rs. Therefore, it is possible to reduce the possibility that the outer peripheral portion (inclined portion Rp) of the first piston rotor 13A in the direction of the first eccentric shaft O1 becomes larger than the inner peripheral portion (first crankshaft 14A). As a result, local wear of the first piston rotor 13A can be avoided. Further, the shape after thermal expansion can be optimized by changing the ratio of the flat surface portion Rp and the receding portion Rs based on the distribution of the actual thermal expansion amount.

The third embodiment of the present invention has been described above. It should be noted that various changes and modifications can be made to the above configuration as long as the gist of the present invention is not deviated. For example, as shown in FIG. 7, the first receding plane R11 retreats from the plane portion Rp toward the other side in the direction of the first eccentric axis O1 from the plane portion Rp. It is also possible to adopt a configuration having. The receding plane portion Rr extends in a plane parallel to the plane portion Rp. That is, a step is formed between the flat surface portion Rp and the receding flat surface portion Rr. Even with such a configuration, the same effects as those of the above-described embodiments can be obtained.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG. The same components as those of the above embodiments are designated by the same reference numerals, and detailed description thereof will be omitted. Further, since the first receding surface R1 and the second receding surface R2 have the same configuration as each other, only the first receding surface R1 will be described below as a representative. As shown in FIG. 8, in the present embodiment, a plurality of first receding surfaces R1 are provided at intervals in the circumferential direction of the first eccentric axis O1 when viewed from the direction of the first eccentric axis O1. In other words, the portion where the first receding surface R1 is not formed has a planar shape extending in a plane orthogonal to the first eccentric axis O1. Further, as the mode of the first receding surface R1, any of the modes described in the above-described first embodiment to the third embodiment can be applied.

According to the above configuration, the first receding surfaces R1 are formed at intervals in the circumferential direction. In this case, the distribution of the amount of thermal expansion in the circumferential direction can be optimized between the first receding surface R1 and the portion Rn on which the first receding surface R1 is not formed.

The fourth embodiment of the present invention has been described above. It should be noted that various changes and modifications can be made to the above configuration as long as the gist of the present invention is not deviated.

100 ... Compressor 10 ... Compressor body 10A ... Compressor mechanism 11 ... Housing 12A, 12B ... Cylinder 13A ... First piston rotor 13B ... Second piston rotor 14A ...・ ・ First crankshaft 14B ・ ・ ・ Second crankshaft 16 ・ ・ ・ Crankshaft 16A ・ ・ ・ Upper shaft 16B ・ ・ ・ Intermediate shaft 16C ・ ・ ・ Lower shaft 17A ・ ・ ・ Upper bearing 17B ・ ・ ・ Lower Bearing 18 ... Motor 19A ... Rotor 19B ... Stator 22A, 22B ... Opening 23A, 23B ... Suction port 24 ... Accumulator 25 ... Stay 26A, 26B ... Suction pipe C, C1, C2 ... Compressor chamber O ... Axis line O1 ... First eccentric shaft O2 ... Second eccentric shaft R1, R1', R11 ... First receding surface R2, R2', R12 ... Second receding surface Rp ... Flat surface portion Rr ... Retracting flat surface portion Rs ... Inclined portion V ... Discharge space

Claims (7)

A crankshaft that rotates around the axis and
A disk-shaped eccentric portion provided on the crankshaft and centered on an eccentric axis eccentric with respect to the axis,
An annular piston rotor centered on the eccentric axis while covering the eccentric portion from the outer peripheral side,
A compression mechanism unit for accommodating the piston rotor and forming a compression chamber for compressing the refrigerant as the piston rotor rotates.
A bearing that rotatably supports the crankshaft,
With
The piston rotor is a rotary compressor whose dimension in the eccentric axis direction decreases from the inside to the outside in the radial direction with respect to the eccentric axis. At least one of the end faces of the piston rotor facing the eccentric axis direction recedes in the eccentric axis direction from the end face of the eccentric portion facing the eccentric axis direction from the inside to the outside in the radial direction with respect to the eccentric axis. The rotary compressor according to claim 1, wherein a receding surface is formed. The rotary compressor according to claim 2, wherein the retracting surface is recessed in a curved surface in the eccentric axis direction. The rotary compressor according to claim 2, wherein the receding surface is convex in a curved surface in the eccentric axis direction. The receding surface is connected to a planar flat portion continuous with the end surface of the eccentric portion facing the eccentric axis direction and radially outward of the flat surface portion, and is connected from the inside to the outside in the radial direction with respect to the eccentric axis. The rotary compressor according to claim 2, further comprising an inclined portion inclined in the eccentric axis direction from the flat portion. The receding surface is connected to a flat flat surface portion continuous with the end surface of the eccentric portion facing the eccentric axis direction and radially outside the flat surface portion to recede in the eccentric axis direction from the flat surface portion. The rotary compressor according to claim 1 or 2, further comprising a receding flat surface portion extending in a plane parallel to the flat surface portion. The rotary compressor according to any one of claims 1 to 6, wherein a plurality of the retracting surfaces are formed at intervals in the circumferential direction with respect to the eccentric axis.

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