Rotating Cylinder Type Compressor

Abstract

A rotating cylinder type compressor includes: a cylinder having a cylindrical shape and rotating about a central axis; a first rotor and a second rotor each having a cylindrical shape and rotating about an eccentric axis eccentric to the central axis of the cylinder; a shaft; a first vane; and a second vane. The first vane is slidably fitted to a first groove portion defined in the first rotor to define a first compression chamber. The second vane is slidably fitted to a second groove portion defined in the second rotor to define a second compression chamber. The first rotor and the second rotor are arranged in an extending direction of the central axis of the cylinder.

Description

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application is based on Japanese Patent Application No. 2015-66056 filed on Mar. 27, 2015, the disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

[0002] The present disclosure relates to a rotating cylinder type compressor, in which a cylinder is rotated, and a compression chamber is defined in the cylinder.

BACKGROUND ART

[0003] A rotating cylinder type compressor is conventionally known, in which a cylinder is rotated and a compression chamber is defined in the cylinder. Specifically, a volume of the compression chamber is changed to compress and discharge fluid.

[0004] For example, Patent Literature 1 discloses a rotating cylinder type compressor including a cylinder, a rotor, and a vane. The cylinder is formed integrally with a rotor of an electric motor part (electric motor part). The rotor has a cylindrical shape and is arranged inside the cylinder. The vane has a tabular shape, and is slidably fitted to a groove portion (slit part) formed in the rotor to partition a compression chamber.

[0005] In this kind of rotating cylinder type compressor, the vane is displaced by rotating the cylinder and the rotor about rotation axes different from each other in the interlocked manner, so as to change the volume of the compression chamber. Furthermore, in the rotating cylinder type compressor of Patent Literature 1, a compression mechanism part is arranged on the inner circumference side of the electric motor part to downsize the compressor as a whole.

PRIOR ART LITERATURES

Patent Literature

Patent Literature 1: JP 2012-67735 A

SUMMARY OF INVENTION

[0006] In order to increase the discharge capability of the rotating cylinder type compressor of Patent Literature 1, the outer diameter of the compression chamber (the inner diameter of the cylinder) may be increased to increase the volume of the compression chamber (discharge capacity).

[0007] However, if the inner diameter of the cylinder is made larger to increase the discharge capability, the outer diameter of the electric motor part arranged on the outer circumference side of the cylinder is also made larger. In this case, it becomes difficult to acquire the above-mentioned downsizing effect as a whole compressor. Moreover, if the discharge capacity is increased, the torque fluctuations at a time of operating the compressor will also increase. As a result, noise and vibration may increase as the whole compressor.

[0008] The present disclosure is aimed to provide a rotating cylinder type compressor in which a volume of a compression chamber can be increased without size increase in the radial direction.

[0009] According to an aspect of the present disclosure, a rotating cylinder type compressor includes: a cylinder having a cylindrical shape and rotating about a central axis; a first rotor and a second rotor arranged inside the cylinder, each of the first rotor and the second rotor having a cylindrical shape and rotating about an eccentric axis eccentric to the central axis of the cylinder; a shaft that rotatably supports the first rotor and the second rotor; a first vane slidably fitted to a first groove portion defined in the first rotor to define a first compression chamber between an outer circumference surface of the first rotor and an inner circumference surface of the cylinder; and a second vane slidably fitted to a second groove portion defined in the second rotor to define a second compression chamber between an outer circumference surface of the second rotor and an inner circumference surface of the cylinder. The first rotor and the second rotor are arranged in an extending direction of the central axis of the cylinder.

[0010] Due to the first rotor and the second rotor, the first compression chamber and the second compression chamber can be formed. Therefore, the total volume of the first compression chamber and the second compression chamber (the sum of discharge capacities) can be easily increased. Furthermore, since the first rotor and the second rotor are arranged side by side in the center axial direction of the cylinder, the total discharge capacity can be increased without increase in the outer diameter of the cylinder.

[0011] As a result, a rotating cylinder type compressor can be provided, in which the capacity of the compression chamber can be increased without causing enlargement in the radial direction.

[0012] Moreover, the eccentric axis of the first rotor and the eccentric axis of the second rotor may be arranged on the same axis. In this case, the shaft can be formed easily, because it is not necessary to form portions corresponding to eccentric axes different from each other in the shaft.

[0013] Furthermore, a rotation angle of the cylinder where the fluid pressure of the first compression chamber reaches the maximum pressure and a rotation angle of the cylinder where the fluid pressure of the second compression chamber reaches the maximum pressure may be shifted from each other by 180 degrees. Accordingly, the torque fluctuations can be restricted from increasing, while the volume of the compression chamber is increased. Thus, noise and vibration can be effectively restricted from increasing as the whole compressor.

[0014] In addition, "shifted from each other by 180 degrees" does not only mean a shift by just 180 degrees, but also means a shift by 180 degrees with a slight tolerance in the manufacturing or the assembling.

BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings.

[0016] FIG. 1 is an axial cross-sectional view illustrating a compressor of a first embodiment.

[0017] FIG. 2 is a sectional view taken along a line II-II of FIG. 1.

[0018] FIG. 3 is a sectional view taken along a line III-III of FIG. 1.

[0019] FIG. 4 is an exploded perspective view illustrating a compression mechanism part of the compressor of the first embodiment.

[0020] FIG. 5 is a diagram explaining operation states of the compressor of the first embodiment.

[0021] FIG. 6 is a graph illustrating torque fluctuations of the compressor of the first embodiment.

[0022] FIG. 7 is a sectional view illustrating a compressor of a second embodiment, and corresponds to FIG. 3.

[0023] FIG. 8 is a sectional view illustrating a compressor of a third embodiment, and corresponds to FIG. 3.

DESCRIPTION OF EMBODIMENTS

First Embodiment

[0024] Hereafter, a first embodiment is described with reference to the drawings. A rotating cylinder type compressor 1 of this embodiment (hereafter referred as the compressor 1) is applied to a vapor-compression refrigeration cycle apparatus which cools air to be sent to a cabin in an air-conditioner for a vehicle. The compressor 1 compresses and discharges refrigerant which is a fluid to be compressed in the refrigeration cycle apparatus.

[0025] The refrigeration cycle apparatus adopts HFC base refrigerant (specifically, R134a) as a refrigerant, and defines a sub-critical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of refrigerant. Furthermore, the refrigerant slightly contains a lubricating oil lubricating the sliding part of the compressor 11, and a part of the oil circulates through the cycle with the refrigerant.

[0026] As shown in FIG. 1, the compressor 1 is an electric compressor including a compression mechanism part 20 that compresses and discharges the refrigerant, and an electric motor part (electric motor part) 30 that drives the compression mechanism part 20, which are housed in a housing 10 which forms the outer shape. In addition, each arrow of up and down in FIG. 1 indicates each direction of up and down in the state where the compressor 1 is mounted in the air-conditioner for a vehicle.

[0027] The housing 10 is configured by combining plural metal components, and has a tightly-closed container structure in which an approximately pillar-shaped space is defined.

[0028] More specifically, as shown in FIG. 1, the housing 10 includes a main housing 11 having a based cylindrical shape (the shape of a cup), a sub housing 12 having a based cylindrical shape arranged to close the opening of the main housing 11, and a disk-shaped lid component 13 arranged to close the opening of the sub housing 12.

[0029] A non-illustrated seal component such as O ring is disposed at contact parts among the main housing 11, the sub housing 12, and the lid component 13, such that refrigerant does not leak from each contact part.

[0030] A discharge port 11a is formed in the cylindrical side surface of the main housing 11 to discharge the high-pressure refrigerant pressurized by the compression mechanism part 20 to the exterior of the housing 10 (specifically to the refrigerant inlet side of a condenser of the refrigeration cycle apparatus). An inlet port 12a is formed in the cylindrical side surface of the sub housing 12 to draw low-pressure refrigerant (specifically, low-pressure refrigerant flowed out of an evaporator of the refrigeration cycle apparatus) from the exterior of the housing 10.

[0031] A housing side inlet passage 13a is defined between the sub housing 12 and the lid component 13 to introduce the low-pressure refrigerant drawn from the inlet port 12a to a first compression chamber Va and a second compression chamber Vb of the compression mechanism part 20. Furthermore, a drive circuit (inverter) 30a which supplies electric power to the electric motor part 30 is attached to a surface of the lid component 13 opposite from the sub housing 12.

[0032] The electric motor part 30 has a stator 31. The stator 31 includes a stator core 31a formed with a metal magnetic material, and a stator coil 31b wound around the stator core 31a. The stator 31 is fixed to the inner circumference surface of the cylindrical portion of the main housing 11 by means such as press fitting, shrinkage fitting or bolt tightening.

[0033] When electric power is supplied to the stator coil 31b from the drive circuit 30a through a non-illustrated sealed terminal (hermetic seal terminal), a revolving magnetic field occurs to rotate the cylinder 21 arranged at the inner circumference side of the stator 31. The cylinder 21 is formed of a cylindrical metal magnetic material, and defines the first and second compression chambers Va and Vb of the compression mechanism part 20 to be mentioned later.

[0034] As shown in the sectional view such as FIG. 2 and FIG. 3, a magnet (permanent magnet) 32 is fixed to the cylinder 21. Thereby, the cylinder 21 functions as a rotor of the electric motor part 30. The cylinder 21 rotates about a central axis C1 by the revolving magnetic field produced by the stator 31.

[0035] That is, the rotor of the electric motor part 30 and the cylinder 21 of the compression mechanism part 20 are integrally formed with each other in the compressors 1 of this embodiment. The rotor of the electric motor part 30 and the cylinder 21 of the compression mechanism part 20 may be formed separately from each other, and are unified into one component by means of press fitting or the like. Furthermore, the stator (the stator core 31a and the stator coil 31b) of the electric motor part 30 is arranged at the outer circumference side of the cylinder 21.

[0036] Next, the compression mechanism part 20 is explained. In this embodiment, a first compression mechanism part 20a and a second compression mechanism part 20b are provided as two of the compression mechanism parts 20. The fundamental configuration is the same between the first and second compression mechanism parts 20a and 20b. Moreover, the first and second compression mechanism parts 20a and 20b are connected in parallel to a flow of the refrigerant inside the housing 10.

[0037] As shown in FIG. 1, the first and second compression mechanism parts 20a and 20b are arranged in the center axial direction of the cylinder 21. In this embodiment, of the two compression mechanism parts, the first compression mechanism part 20a is arranged adjacent to the bottom of the main housing 11, and the second compression mechanism part 20b is arranged adjacent to the sub housing 12.

[0038] In FIG. 1 and FIG. 4, the second compression mechanism part 20b has components corresponding to components of the first compression mechanism part 20a, and the alphabet at the end of the reference number is changed from "a" to "b". For example, the second compression mechanism part 20b has the second rotor "22b" that is a component corresponding to the first rotor 22a of the first compression mechanism part 20a.

[0039] The first compression mechanism part 20a includes the cylinder 21, the first rotor 22a, the first vane 23a, and the shaft 24. The second compression mechanism part 20b includes the cylinder 21, the second rotor 22b, the second vane 23b, and the shaft 24. That is, as shown in FIG. 1, a part of the cylinder 21 and the shaft 24 adjacent to the bottom of the main housing 11 configures the first compression mechanism part 20a, and another part of the cylinder 21 and the shaft 24 adjacent to the sub housing 12 configures the second compression mechanism part 20b.

[0040] The cylinder 21 rotates about the central axis C1 as a rotor of the electric motor part 30, and is a cylindrical component which forms the first compression chamber Va of the first compression mechanism part 20a and the second compression chamber Vb of the second compression mechanism part 20b inside. A first side plate 25a which is a component for closing the open end of the cylinder 21 is fixed to one end of the cylinder 21 in the axial direction by means such as bolt tightening. Moreover, a second side plate 25b is similarly fixed to the other end of the cylinder 21 in the axial direction.

[0041] Each of the first and second side plates 25a and 25b has a disk-shaped part spreading in a direction approximately perpendicular to the rotational axis of the cylinder 21, and a boss part projected in the axial direction at the central part of the disk-shaped part. Furthermore, the boss part has a through hole passing through the first and second side plates 25a and 25b.

[0042] A non-illustrated bearing mechanism is arranged in the respective through hole. The shaft 24 is inserted in the bearing mechanism, and the cylinder 21 is supported to be rotatable relative to the shaft 24. The both ends of the shaft 24 are fixed to the housing 10 (specifically, the main housing 11 and the sub housing 12). Therefore, the shaft 24 does not rotate relative to the housing 10.

[0043] The cylinder 21 of this embodiment forms inside the first compression chamber Va and the second compression chamber Vb separated from each other. A middle side plate 25c having a disk shape is arranged between the first rotor 22a and the second rotor 22b inside the cylinder 21 to partition the first compression chamber Va and the second compression chamber Vb. The middle side plate 25c has the same function as the first and second side plates 25a and 25b.

[0044] That is, in the cylinder 21 of this embodiment, the both ends of the first compression mechanism part 20a in the axial direction are closed with the first side plate 25a and the middle side plate 25c. Moreover, in the cylinder 21, the both ends of the second compression mechanism part 20b in the axial direction are closed with the second side plate 25b and the middle side plate 25c.

[0045] In other words, the first compression chamber Va is defined by the first side plate 25a, the middle side plate 25c, and the first rotor 22a, and the second compression chamber Vb is defined by the second side plate 25b, the middle side plate 25c, and the second rotor 22b. Furthermore, the middle side plate 25c is arranged between the first rotor 22a and the second rotor 22b to define the first compression chamber Va and the second compression chamber Vb.

[0046] In this embodiment, the cylinder 21 and the middle side plate 25c are integrally formed as one-piece component. Alternatively, the cylinder 21 and the middle side plate 25c may be produced separately and connected by means of press fit. Moreover, in this embodiment, the axial length of the first rotor 22a and the axial length of the second rotor 22b are equal to each other, and the first compression chamber Va and the second compression chamber Vb are partitioned in a manner that the maximum capacity is approximately the same therebetween.

[0047] The shaft 24 is an approximately cylindrical component which rotatably supports the cylinder 21 (specifically, each side plate 25a, 25b, 25c fixed to the cylinder 21), the first rotor 22a, and the second rotor 22b.

[0048] An eccentric part 24c is defined at the central area of the shaft 24 in the axial direction, and the outer diameter of the eccentric part 24c is smaller than that of the end portion adjacent to the sub housing 12. The central axis of the eccentric part 24c is an eccentric axis C2 eccentric to the central axis C1 of the cylinder 21. Furthermore, the first and second rotors 22a and 22b are rotatably supported by the eccentric part 24c through non-illustrated bearing mechanism.

[0049] The first and second compression mechanism parts 20a and 20b of this embodiment are arranged in the central axial direction of the cylinder 21. For this reason, as shown in FIG. 1 and FIG. 4, the first rotor 22a and the second rotor 22b are arranged in the central axial direction of the cylinder 21. Furthermore, the first and second rotors 22a and 22b rotate about the common eccentric axis C2 eccentric to the central axis C1 of the cylinder 21. That is, in this embodiment, the eccentric axis of the first rotor 22a and the eccentric axis of the second rotor 22b are arranged on the same axis.

[0050] As shown in FIG. 1, a shaft side inlet passage 24d is defined in the shaft 24, and is communicated to the housing side inlet passage 13a, for leading the low-pressure refrigerant flowed from the outside toward the first and second compression chambers Va and Vb. Plural (four in this embodiment) first shaft side exit holes 240a and plural (four in this embodiment) second shaft side exit holes 240b are opened in the outer circumference surface of the shaft 24 to discharge the low-pressure refrigerant from the shaft side inlet passage 24d.

[0051] As shown in FIG. 1 and FIG. 4, a first shaft side concave portion 241a and a second shaft side concave portion 241b are formed on the outer circumference surface of the shaft 24, and are recessed inward from the outer circumference surface of the shaft 24. The first and second shaft side exit holes 240a and 240b are respectively communicated to the formation parts of the first and second shaft side concave portions 241a and 241b. For this reason, the first and second shaft side exit holes 240a and 240b are communicated to circular first and second shaft side communication spaces 242a and 242b defined in the first and second shaft side concave portions 241a and 241b, respectively.

[0052] The first rotor 22a is a cylindrical component arranged inside the cylinder 21 and extending in the central axial direction of the cylinder 21. As shown in FIG. 1, the length of the first rotor 22a in the axial direction is approximately the same as the length of a portion of the shaft 24 and the cylinder 21 which defines the first compression mechanism part 20a in the axial direction.

[0053] Furthermore, the outer diameter of the first rotor 22a is smaller than the inside diameter of the cylindrical space formed inside of the cylinder 21. In detail, as shown in FIG. 2 and FIG. 3, the outer diameter of the first rotor 22a is set such that the outer circumference surface of the first rotor 22a and the inner circumference surface of the cylinder 21 are in contact with each other at one junction point C3 when seen from the axial direction of the eccentric axis C2.

[0054] A motion transmitting mechanism is arranged between the first rotor 22a and the middle side plate 25c and between the first rotor 22a and the first side plate 25a. The motion transmitting mechanism transmits the rotation power from the cylinder 21 (specifically, the middle side plate 25c and the first side plate 25a which rotate with the cylinder 21) to the first rotor 22a, such that the first rotor 22a has synchronous rotation with the cylinder 21.

[0055] The motion transmitting mechanism, which is arranged between the first rotor 22a and the middle side plate 25c, is explained. As shown in FIG. 2, the motion transmitting mechanism includes plural (four in this embodiment) first hole parts 221a having round form and formed on a surface of the first rotor 22a adjacent to the middle side plate 25c, and plural (four in this embodiment) drive pins 251c projected from the middle side plate 25c toward the first rotor 22a in the central axial direction.

[0056] The drive pin 251c has a diameter smaller than that of the first hole part 221a, and is projected toward the rotor 22 in the axial direction and inserted in the first hole part 221a. The drive pin 251c and the first hole part 221a define a mechanism equivalent to the so-called pin-hole type rotation prevention mechanism. The motion transmitting mechanism located between the first rotor 22a and the first side plate 25a has the similar structure as the above.

[0057] When the cylinder 21 rotates about the central axis C1, according to the motion transmitting mechanism of this embodiment, the relative position (relative distance) between the drive pin 251c and the eccentric part 24c of the shaft 24 changes. The side wall surface of the first hole part 221a of the first rotor 22a receives a load from the drive pin 251c in the rotational direction, which is caused by the change in the relative position (relative distance). As a result, the first rotor 22a rotates about the eccentric axis C2, synchronizing with rotation of the cylinder 21.

[0058] The motion transmitting mechanism of this embodiment transmits the power to the rotor 22 sequentially through the drive pins 251c and the first hole parts 221a. Therefore, it is desirable that the drive pins 251c and the first hole parts 221a are arranged around the eccentric axis C2 at equal angle interval. Furthermore, a metal ring component 223a is inserted in each of the first hole parts 221a to restrict wear of the outer circumference surface to which the drive pin 251c contacts.

[0059] Moreover, as shown in a dashed line of FIG. 1, a first oil passage 225a is defined inside the first rotor 22 to extend in the axial direction of the eccentric axis C2. The first oil passage 225a penetrates the first rotor 22 from one end to the other end in the axial direction.

[0060] The first oil passage 225a is a lubricating oil passage for the lubricating oil supplied through a first oil return passage 11b defined in the bottom of the main housing 11 and an oil passage 252a defined by a clearance between the shaft 24 and the boss part of the first side plate 25a. The first oil return passage 11b is a lubricating oil passage which introduces lubricating oil toward the first oil passage 225a from the lower side of the interior space of the housing 10.

[0061] Furthermore, the first hole parts 221a of the motion transmitting mechanism between the first rotor 22a and the middle side plate 25c and between the first rotor 22a and the first side plate 25a are formed by ends of the first oil passage 225a in the axial direction.

[0062] In other words, at least one first hole part of the motion transmitting mechanism between the first rotor 22a and the first side plate 25a, and at least one first hole part 221a of the motion transmitting mechanism between the first rotor 22a and the middle side plate 25c communicate mutually through the first oil passage 225a.

[0063] Moreover, as shown in FIG. 2 and FIG. 3, a first groove portion (a first slit part) 222a is formed in the outer circumference surface of the first rotor 22a, and is recessed radially inward and extends within the all area in the axial direction. The first vane 23a to be mentioned later is slidably inserted in the first groove portion 222a.

[0064] When seen from the axial direction of the eccentric axis C2, a surface of the first groove portion 222a on which the first vane 23a slides (the friction surface with the first vane 23a) is inclined relative to the radial direction of the first rotor 22a. In detail, the surface of the first groove portion 222a on which the first vane 23a slides is inclined from the inner circumference side to the outer circumference side in the rotational direction. For this reason, the first vane 23a inserted in the first groove portion 222a is also displaced in the direction inclined to the radial direction of the first rotor 22a.

[0065] As shown in FIG. 3, a first rotor side inlet passage 224a is formed inside of the first rotor 22a, at the central part in the axial direction, similarly to the first groove portion 222a, and extends in the inclined manner relative to the radial direction. The inner circumference side (adjacent to the first shaft side communication space 242a) and the outer circumference side (adjacent to the first compression chamber Va) of the first rotor 22a are communicated with each other by the first rotor side inlet passage 224a. Thereby, the refrigerant flowing in the shaft side inlet passage 24d from the exterior is led toward the first rotor side inlet passage 224a.

[0066] Furthermore, as shown in FIG. 3, the exit of the first rotor side inlet passage 224a is opened in the outer circumference surface of the first rotor 22a on the rear side of the first groove portion 222a in the rotational direction. Moreover, the first rotor side inlet passage 224a and the first groove portion 222a are separated from each other, and formed not to communicate with each other.

[0067] The first vane 23a is a tabular partition component that defines the first compression chamber Va formed between the outer circumference surface of the first rotor 22a and the inner circumference surface of the cylinder 21. The axial length of the first vane 23a is approximately the same as the axial length of the first rotor 22a. Furthermore, the outer circumference side tip part of the first vane 23a is slidable on the inner circumference surface of the cylinder 21.

[0068] Therefore, in the first compression mechanism part 20a of this embodiment, the first compression chamber Va is formed of a space surrounded by the inner wall surface of the cylinder 21, the outer circumference surface of the first rotor 22a, the board surface of the first vane 23a, the first side plate 25a, and the middle side plate 25c. That is, the first vane 23a defines the first compression chamber Va formed between the inner circumference surface of the cylinder 21 and the outer circumference surface of the first rotor 22a.

[0069] Moreover, the first side plate 25a has a first discharge hole 251a to discharge the refrigerant compressed by the first compression chamber Va to the interior space of the housing 10. Furthermore, a first discharge valve such as a reed valve is arranged in the first side plate 25a to restrict the refrigerant flowing out of the first discharge hole 251a into the interior space of the housing 10 from flowing backwards to the first compression chamber Va through the first discharge hole 251a.

[0070] Next, the second compression mechanism part 20 is explained. The fundamental configuration of the second compression mechanism part 20b is the same as that of the first compression mechanism part 20a. As shown in FIG. 1, the second rotor 22b includes a cylindrical component with a dimension approximately equal to the axial length of a portion of the shaft 24 and the cylinder 21 which defines the second compression mechanism part 20b.

[0071] Furthermore, since the eccentric axis C2 of the second rotor 22b and the eccentric axis C2 of the first rotor 22a are arranged on the same axis, when seen from the axial direction of the eccentric axis C2, the outer circumference surface of the second rotor 22b and the inner circumference surface of the cylinder 21 are in contact with each other, like the first rotor 22a, at the junction point C3 shown in FIG. 2 and FIG. 3.

[0072] A motion transmitting mechanism is disposed between the second rotor 22b and the middle side plate 25c and between the second rotor 22b and the first side plate 25a, similarly to the motion transmitting mechanism which transmits the rotation power to the first rotor 22a. The second rotor 22b has plural second round hole parts into which the plural drive pins 251c are inserted. A ring component is inserted also in this second hole part, similarly to the first hole part 221a.

[0073] Furthermore, the drive pin 251c projected from the middle side plate 25c toward the second rotor 22b is formed by the same component as the drive pin 251c projected from the middle side plate 25c toward the first rotor 22b. That is, the drive pin 251c fixed to the middle side plate 25c is projected toward both of the first rotor 22a and the second rotor 22b in the central axial direction.

[0074] As shown in FIG. 1, a second oil passage 225b is formed in the second rotor 22b, similarly to the first oil passage 225a of the first rotor 22a, to extend in the axial direction of the eccentric axis C2, and penetrates the second rotor 22b from one end to the other end in the axial direction.

[0075] The second oil passage 225b is a lubricating oil passage for the lubricating oil supplied through a second oil return passage 12b defined in the sub housing 12 and an oil passage 252b formed by a clearance between the shaft 24 and the boss part of the second side plate 25b. The second oil return passage 12b is a lubricating oil passage which introduces the lubricating oil collected on the lower side of the interior space of the housing 10 toward the second oil passage 225b.

[0076] Furthermore, like the first oil passage 225a, the both ends of the second oil passage 225b in the axial direction form the second hole parts of the motion transmitting mechanism.

[0077] Moreover, as shown in a dashed line of FIG. 2 and FIG. 3, a second groove portion (a second slit part) 222b is formed in the outer circumference surface of the second rotor 22b, and is recessed radially inward and extends in all the area in the axial direction. The second vane 23b is slidably inserted in the second groove portion 222b, like the first vane 23a of the first groove portion 222a.

[0078] As shown in a dashed line of FIG. 3, a second rotor side inlet passage 224b is defined inside the second rotor 22b at the central part in the axial direction, and extends in the inclined manner relative to the radial direction, like the second groove portion 222b, to communicate the inner circumference side and the outer circumference side (adjacent to the second compression chamber Vb) of the second rotor 22b with each other.

[0079] Therefore, in the second compression mechanism part 20b of this embodiment, the second compression chamber Vb is formed of a space surrounded by the inner wall surface of the cylinder 21, the outer circumference surface of the second rotor 22b, the board surface of the second vane 23b, the second side plate 25b, and the middle side plate 25c. That is, the second vane 23b defines the second compression chamber Vb formed between the inner circumference surface of the cylinder 21 and the outer circumference surface of the second rotor 22b.

[0080] Moreover, a second discharge hole 251b is formed in the second side plate 25b to discharge the refrigerant compressed by the second compression chamber Vb to the interior space of the housing 10. Furthermore, a second discharge valve such as a reed valve is arranged in the second side plate 25b to restrict the refrigerant flowing out of the second discharge hole 251b into the interior space of the housing 10 from flowing backwards to the second compression chamber Vb through the second discharge hole 251b.

[0081] Furthermore, as shown in a dashed line of FIG. 2 and FIG. 3, in the second compression mechanism part 20b of this embodiment, the second vane 23b, the second rotor side inlet passage 224b, the second discharge hole 251b of the second side plate 25b, and the like are arranged at positions shifted by about 180 degrees in the phase, relative to the first vane 23a, the first rotor side inlet passage 224a, the first discharge hole 251a of the first side plate 25a, and the like of the first compression mechanism part 20a.

[0082] Next, the operations of the compressor 1 of this embodiment are explained with reference to FIG. 5. FIG. 5 is a diagram showing sequential change of the first compression chamber Va in response to the rotation of the cylinder 21, in order to explain the operation state of the compressor 1.

[0083] In the sectional views of FIG. 5, in response to change in the rotation angle .theta. of the cylinder 21, the solid line shows positions of the first rotor side inlet passage 224a and the first vane 23a, similarly to FIG. 3. Moreover, in FIG. 5, the dashed line shows positions of the second rotor side inlet passage 224b and the second vane 23b in response to change in the rotation angle .theta.. Furthermore, in FIG. 5, the reference number is given only to the sectional view in which the rotation angle .theta. of the cylinder 21 is 0 degree, for clarification in the illustration.

[0084] First, when the rotation angle .theta. is 0 degree, the outer circumference side tip part of the first vane 23a overlaps with the junction point C3. In this state, the first compression chamber Va having the maximum capacity is formed on the front side of the first vane 23a in the rotational direction, and the first compression chamber Va having the minimum capacity (that is, capacity is zero) of an admission stroke is formed on the rear side of the first vane 23a in the rotational direction.

[0085] Here, the first compression chamber Va of an admission stroke means the first compression chamber Va in a stroke to increase the capacity, and the first compression chamber Va of a compression stroke means the first compression chamber Va in a process to reduce the capacity.

[0086] In response to an increase in the rotation angle .theta. from 0 degree, as shown from 45 degrees to 315 degrees in the rotation angle .theta. of FIG. 5, the cylinder 21, the first rotor 22a, and the first vane 23a are displaced, such that the capacity of the first compression chamber Va of an admission stroke formed on the rear side of the first vane 23a in the rotational direction increases.

[0087] Thereby, the low-pressure refrigerant drawn from the inlet port 12a of the sub housing 12 flows in order of the housing side inlet passage 13a, the first shaft side exit hole 240a of the shaft side inlet passages 24d, and the first rotor side inlet passage 224a into the first compression chamber Va of an admission stroke.

[0088] At this time, since the centrifugal force acts on the first vane 23a in response to the rotation of the rotor 22, the outer circumference side tip part of the first vane 23a is forced onto the inner circumference surface of the cylinder 21. Thereby, the first vane 23a divides the first compression chamber Va of an admission stroke and the first compression chamber Va of a compression stroke from each other.

[0089] When the rotation angle .theta. becomes 360 degrees (namely, when the rotation angle .theta. returns to 0 degree), the first compression chamber Va of an admission stroke has the maximum capacity. Furthermore, when the rotation angle .theta. increases from 360 degrees, the communication between the first compression chamber Va of an admission stroke where the capacity is increased when the rotation angle .theta. increases from 0 degree to 360 degrees and the first rotor side inlet passage 224a is intercepted. Thereby, the first compression chamber Va of a compression stroke is formed on the front side of the first vane 23a in the rotational direction.

[0090] Furthermore, while the rotation angle .theta. increases from 360 degrees, as shown in point hatching of FIG. 5 where the rotation angle .theta. increases from 405 degrees to 675 degrees, the capacity of the first compression chamber Va of a compression stroke formed on the front side of the first vane 23a in the rotational direction reduces.

[0091] Thereby, the refrigerant pressure in the first compression chamber Va of a compression stroke rises. When the refrigerant pressure in the first compression chamber Va exceeds a valve open pressure of the first discharge valve (namely, the maximum pressure of the first compression chamber Va) determined based on the refrigerant pressure in the interior space of the housing 10, the refrigerant in the first compression chamber Va is discharged to the interior space of the housing 10 through the first discharge hole 251a.

[0092] The change in the first compression chamber Va is explained, in response to the change in the rotation angle .theta. from 0 degree to 720 degrees, for clarifying the operation mode of the first compression mechanism part 20a. However, in actual, an admission stroke of the refrigerant explained when the rotation angle .theta. changes from 0 degree to 360 degrees, and a compression stroke of the refrigerant explained when the rotation angle .theta. changes from 360 degrees to 720 degrees are simultaneously carried out while the cylinder 21 has one rotation.

[0093] Moreover, the second compression mechanism part 20b operates similarly, and compression and admission of refrigerant are performed. At this time, in the second compression mechanism part 20b, the second vane 23b is arranged at the position shifted by 180 degrees in phase relative to the first vane 23a of the first compression mechanism part 20a. Therefore, in the second compression chamber Vb of a compression stroke, compression and admission of refrigerant are performed at the rotation angle shifted from the first compression chamber Va by 180 degrees in phase.

[0094] For this reason, in this embodiment, the rotation angle .theta. of the cylinder 21 where the refrigerant pressure in the first compression chamber Va reaches the maximum pressure, and the rotation angle .theta. of the cylinder 21 where the refrigerant pressure in the second compression chamber Vb reaches the maximum pressure are shifted from each other by 180 degrees.

[0095] When the refrigerant pressure in the second compression chamber Vb of a compression stroke rises, and when the refrigerant pressure in the second compression chamber Vb exceeds a valve open pressure of the second discharge valve arranged at the second side plate 25b (namely, the maximum pressure of the second compression chamber Vb), the refrigerant in the second compression chamber Vb is discharged through the second discharge hole 251b to the interior space of the housing 10. The refrigerant discharged from the second compression mechanism part 20b to the interior space of the housing 10 joins the refrigerant discharged from the first compression mechanism part 20a.

[0096] The refrigerant mixed of the high-pressure gas phase refrigerant discharged from the first compression mechanism part 20a and the high-pressure gas phase refrigerant discharged from the second compression mechanism part 20b reduces the flow velocity in the interior space of the housing 10. Thereby, the lubricating oil discharged from the first and second discharge holes 251a and 251b with the high-pressure gas phase refrigerant is separated from the mixed refrigerant, due to the gravity, by falling downward.

[0097] The mixed refrigerant from which the lubricating oil is separated is discharged from the discharge port 11a of the housing 10. Meanwhile, the lubricating oil separated from the refrigerant can be stored on the lower side of the interior space of the housing 10. The lubricating oil stored on the lower side of the interior space of the housing 10 flows into the first and second oil passages 225a and 225b through the first and second oil return passages 11b and 12b, so as to be supplied to each sliding part of the shaft 24, the first and second rotors 22a and 22b, and the side plates 25a-25c.

[0098] Thus, the compressor 1 of this embodiment draws, compresses, and discharges the refrigerant (fluid) in the refrigeration cycle apparatus. Moreover, since the compression mechanism part 20 is arranged in the inner circumference side of the electric motor part 30, the compressor 1 of this embodiment can be downsized as the whole.

[0099] Furthermore, since the compressor 1 of this embodiment has the first rotor 22a (the first compression mechanism part 20a) and the second rotor 22b (the second compression mechanism part 20b), the first compression chamber Va and the second compression chamber Vb can be formed. Therefore, the total discharge capacity of the first compression chamber Va and the second compression chamber Vb can be easily increased in accordance with the system (the refrigeration cycle apparatus in this embodiment) to which the compressor is applied.

[0100] Meanwhile, since the first rotor 22a and the second rotor 22b are arranged along the central axial direction of the cylinder 21, the outer diameter of the cylinder 21 is not increased to increase the sum of the discharge capacity. Therefore, the outer diameter of the stator 31 of the electric motor part 30 is restricted from increasing, and the outer diameter of the main housing 11 which accommodates the stator 31 is restricted from increasing.

[0101] As a result, according to the compressor 1 of this embodiment, the capacity of the compression chamber (Va, Vb) can be increased without causing enlargement in the radial direction.

[0102] Moreover, since the eccentric axis C2 of the first rotor 22a and the eccentric axis C2 of the second rotor 22b are arranged on the same axis in the compressor 1 of this embodiment, it is not necessary to form portions corresponding to eccentric axes different from each other in the shaft 24. Therefore, the shaft 24 can be formed easily.

[0103] Moreover, in the compressor 1 of this embodiment, the maximum capacity is approximately the same between the first compression chamber Va and the second compression chamber Vb. Furthermore, the rotation angle .theta. of the cylinder 21 where the refrigerant in the first compression chamber Va reaches the maximum pressure, and the rotation angle .theta. of the cylinder 21 where the refrigerant in the second compression chamber Vb reaches the maximum pressure are shifted from each other by 180 degrees.

[0104] Thereby, as shown in FIG. 6, the torque fluctuations caused by increase in the capacity of the compression chamber can be restricted from increasing. Therefore, the noise and vibration can be effectively restricted from increasing as the whole compressor.

[0105] FIG. 6 is a graph comparing the total torque fluctuation of the compressor 1 of this embodiment with torque fluctuation of a rotating cylinder type compressor (compressor with a single cylinder) having a single compression mechanism part similar to the first compression mechanism part 20a. In addition, the total torque fluctuation is the sum of the torque fluctuations produced by the pressure fluctuation of the refrigerant in the first compression chamber Va of the first compression mechanism part 20a and the torque fluctuations produced by the pressure fluctuation of the refrigerant in the second compression chamber Vb of the second compression mechanism part 20b.

[0106] Furthermore, the discharge capacity of the compressor with the single cylinder shown in FIG. 6 is in agreement with the total discharge capacity of the first compression chamber Va and the second compression chamber Vb of the compressor 1 of this embodiment. Furthermore, the suction refrigerant pressure and the discharge refrigerant pressure of the compressor with the single cylinder shown in FIG. 6 are respectively set similar with the suction refrigerant pressure and the discharge refrigerant pressure of the compressor 1 of this embodiment.

[0107] Moreover, since the first and second oil passages 225a and 225b are formed in the first and second rotors 22a and 22b in the compressor 1 of this embodiment, each sliding part of the shaft 24, the first and second rotors 22a and 22b, and the side plates 25a-25c can be lubricated. As a result, the durability of the compressor 1 can be raised as a whole.

[0108] The lubricating oil can be effectively introduced into the sliding part between the first and second rotors 22a, 22b and the middle side plate 25c, positioned at the central part of the cylinder 21 in the central axial direction, due to the first and second oil passages 225a and 225b.

[0109] Since a structure similar to the so-called pin-hole type rotation prevention mechanism is adopted as a motion transmitting mechanism in the compressor 1 of this embodiment, the motion transmitting mechanism can be realized with simple structure. Furthermore, since the ring component 223a is inserted in the hole part of the motion transmitting mechanism, the wear resistance of the hole part can be raised. As a result, the durability can be raised as the whole compressor 1.

[0110] In addition, the first and second hole parts 221a are defined at the axial ends of the first and second oil passages 225a and 225b. Therefore, a space for arranging the motion transmitting mechanism can be reduced. Thus, the compressor 1 can be further downsized as the whole.

[0111] According to the compressor 1 of this embodiment, the inlet passage introducing the refrigerant drawn from the outside to the first and second compression chambers Va and Va is defined by the shaft side inlet passage 24d, the first and second rotor side inlet passages 224a and 224b, and the like. Therefore, the passage structure and the sealing structure of the inlet passage are restricted from becoming complicated, compared with a case where a part of the inlet passage is formed in the first and second side plates 25a and 25b which rotate with the cylinder 21.

[0112] Furthermore, since the first and second discharge holes 251a and 251b are respectively formed in the first and second side plates 25a and 25b, the first and second compression mechanism parts 20a and 20b can be easily connected with each other in parallel to a flow of the refrigerant, inside the housing 10.

Second Embodiment

[0113] As shown in FIG. 7, in the present embodiment, the compression mechanism part 20 is modified relative to the first embodiment. In addition, FIG. 7 is a sectional view corresponding to FIG. 3 which is explained in the first embodiment, and shows a sectional view of the first compression mechanism part 20a perpendicular to the axial direction. In FIG. 7, the same or equivalent portion as the first embodiment is attached with the same reference number. This is the same also in FIG. 8 to be explained below.

[0114] More specifically, a first hinge part 231a is formed at the outer circumference side end portion of the first vane 23a, in the first compression mechanism part 20a of this embodiment. The first hinge part 231a is supported by a groove portion formed in the inner circumference surface of the cylinder 21, and is swingable in the circumferential direction. For this reason, the vane 23 does not separate from the cylinder 21, and the inner circumference side of the first vane 23a is displaced inside of the first groove portion 222a in the sliding manner.

[0115] Furthermore, a circular part with a diameter equivalent to the width dimension of the first groove portion 222a is formed at the inner circumference side end portion of the first vane 23a. Therefore, when the first vane 23a swings in response to rotation of the cylinder 21, the inner circumference side end portion of the first vane 23a is securely made in contact with the inner wall surface of the first groove portion 222a, namely, the sealing property between the inner circumference side end portion of the first vane 23a and the inner wall surface of the first groove portion 222a is raised.

[0116] The fundamental configuration of the second compression mechanism part 20b is the same as that of the first compression mechanism part 20a. Therefore, as shown in a dashed line of FIG. 7, the outer circumference side end portion of the second vane 23b is also swingably supported by the cylinder.

[0117] The other configurations and operations are the same as those of the first embodiment. Therefore, when the compressor 1 of this embodiment is operated, the compressor operates similarly to the first embodiment. Specifically, refrigerant (fluid) can be drawn, compressed and discharged in the refrigeration cycle apparatus. Furthermore, like the first embodiment, the capacity of the compression chamber (Va, Vb) can be increased without causing enlargement in the radial direction, and noise and vibration can be restricted from increasing as the whole compressor.

Third Embodiment

[0118] As shown in FIG. 8, the compression mechanism part 20 is modified in this embodiment, relative to the second embodiment. More specifically, in the first compression mechanism part 20a of this embodiment, the inner circumference side of the first vane 23a on the radially inner side of the first hinge part 231a is formed into a plate shape.

[0119] Furthermore, a first shoe 232a is arranged in the first groove portion 222a, and has a cross-sectional form (approximately semi-circle shape) in which a part of the circle is cut off, when seen from the axial direction of the central axis C1. The first vane 23a is interposed between the first shoes 232a. The length of the first shoe 232a in the axial direction is approximately the same as the first rotor 22a and the first vane 23a. The fundamental configuration of the second compression mechanism part 20b is the same as that of the first compression mechanism part 20a.

[0120] The other configuration and operations are the same as those of the second embodiment. Therefore, when the compressor 1 of this embodiment is operated, the compressor operates like the second embodiment. Specifically, in the refrigeration cycle apparatus, the refrigerant (fluid) can be drawn, compressed and discharged. Furthermore, like the first embodiment, the capacity of the compression chamber (Va, Vb) can be increased without causing enlargement in the radial direction. The noise and vibration can be restricted from increasing as the whole compressor.

[0121] Furthermore, in the compressor 1 of this embodiment, the shoe 232a effectively raises the sealing property between the first and second vane 23a, 23b and the inner wall surface of the first and second groove portion 222a, 222b. Thereby, the compression efficiency of the compressor 1 can be raised.

Other Embodiment

[0122] The contents of the present disclosure can variously be modified within the range not deviated from the scope of present disclosure without being limited to the above-mentioned embodiments.

[0123] In the above-mentioned embodiments, the rotating cylinder type compressor 1 is applied to the refrigeration cycle of the air-conditioner for a vehicle, but the rotating cylinder type compressor 1 is not limited to be applied to this. That is, the rotating cylinder type compressor 1 may be widely applied to a compressor which compresses various fluid.

[0124] In the above-mentioned embodiments, a structure similar to a pin-hole type rotation prevention mechanism is adopted as the power transmitting device of the rotating cylinder type compressor 1, but is not limited to this. For example, a structure similar to an Oldham ring type rotation prevention mechanism may be adopted.

[0125] In the above-mentioned embodiments, the stator of the electric motor part 30 is arranged at the outer circumference side of the cylinder 21 formed integrally with the rotor, but the electric motor part 30 is not limited to this. For example, the electric motor part and the cylinder 21 may be arranged side by side in the extending direction of the central axis C1 of the cylinder 21, and the electric motor part and the cylinder 21 may be connected with each other. Moreover, the rotation power of the electric motor part may be transmitted to the cylinder 21 through a belt, without arranging the rotation center of the electric motor part and the central axis C1 of the cylinder 21 on the same axis.

Claims

1. A rotating cylinder type compressor comprising: a cylinder having a cylindrical shape and rotating about a central axis; a first rotor and a second rotor arranged inside the cylinder, each of the first rotor and the second rotor having a cylindrical shape and rotating about an eccentric axis eccentric to the central axis of the cylinder; a shaft that rotatably supports the first rotor and the second rotor; a first vane slidably fitted to a first groove portion defined in the first rotor and defining a first compression chamber between an outer circumference surface of the first rotor and an inner circumference surface of the cylinder; and a second vane slidably fitted to a second groove portion defined in the second rotor and defining a second compression chamber between an outer circumference surface of the second rotor and an inner circumference surface of the cylinder, wherein the first rotor and the second rotor are arranged in an extending direction of the central axis of the cylinder, a shaft side inlet passage is defined inside the shaft to introduce fluid drawn from outside to be compressed into the first compression chamber and the second compression chamber, a first shaft side exit hole through which the fluid flows from the shaft side inlet passage to the first compression chamber and a second shaft side exit holes through which the fluid flows from the shaft side inlet passage to the second compression chamber are defined in an outer circumference surface of the shaft, and the first compression chamber and the second compression chamber are connected in parallel to a flow of the fluid.

2. The rotating cylinder type compressor according to claim 1, wherein the eccentric axis of the first rotor and the eccentric axis of the second rotor are arranged on the same axis.

3. The rotating cylinder type compressor according to claim 1, wherein a rotation angle of the cylinder where a fluid pressure in the first compression chamber reaches the maximum pressure, and a rotation angle of the cylinder where a fluid pressure in the second compression chamber reaches the maximum pressure are shifted from each other by 180 degrees.

4. The rotating cylinder type compressor according to claim 1, wherein the first rotor has a first oil passage extending in the axial direction of the shaft, lubricating oil flowing through the first oil passage lubricating a sliding part, and the second rotor has a second oil passage extending in the axial direction of the shaft, lubricating oil flowing through the second oil passage lubricating a sliding part.

5. The rotating cylinder type compressor according to claim 1, further comprising: a motion transmitting mechanism that transmits rotation power from the cylinder to the first rotor and the second rotor so that the first rotor and the second rotor carry out synchronous rotation with the cylinder; and a middle side plate arranged between the first rotor and the second rotor to define the first compression chamber and the second compression chamber, the middle side plate rotating with the cylinder, wherein the motion transmitting mechanism includes a drive pin projected from the middle side plate toward the first rotor and the second rotor in the extending direction of the central axis, and a first hole part and a second hole part respectively formed in the first rotor and the second rotor, to which the drive pin is fitted.

6. The rotating cylinder type compressor according to claim 5, further comprising: a ring component fitted in each of the first hole part and the second hole part to restrict wear of an outer circumference side wall surface where the drive pin contacts.

7. The rotating cylinder type compressor according to claim 5, wherein the first rotor has a first oil passage extending in the axial direction of the eccentric axis, lubricating oil lubricating a sliding part flowing through the first oil passage, the first hole part is formed at an end of the first oil passage in the axial direction, the second rotor has a second oil passage extending in the axial direction of the eccentric axis, lubricating oil lubricating a sliding part flowing through the second oil passage, and the second hole part is formed at an end of the second oil passage in the axial direction.

8. The rotating cylinder type compressor according to claim 1, further comprising: a middle side plate arranged between the first rotor and the second rotor to define the first compression chamber and the second compression chamber, the middle side plate rotating with the cylinder; a first side plate fixed to one end of the cylinder in the axial direction to define the first compression chamber with the middle side plate; a second side plate fixed to the other end of the cylinder in the axial direction to define the second compression chamber with the middle side plate, wherein the first rotor has a first rotor side inlet passage, fluid to be compressed flowing into the first compression chamber through the first rotor side inlet passage, the first side plate has a first discharge hole, fluid to be compressed flowing out of the first compression chamber through the first discharge hole, the second rotor has a second rotor side inlet passage, fluid to be compressed flowing into the second compression chamber through the second rotor side inlet passage, and the second side plate has a second discharge hole, fluid to be compressed flowing out of the second compression chamber through the second discharge hole.

9. The rotating cylinder type compressor according to claim 1, further comprising: an electric motor part that rotates the cylinder, wherein the cylinder is formed integrally with a rotor of the electric motor part, and a stator of the electric motor part is arranged at an outer circumference side of the cylinder.