Technical Field

[0001] The present invention relates to a rotary compressor configured to compress refrigerant, which is used for a refrigerant circuit of a refrigeration cycle apparatus such as an air-conditioning apparatus.

Background Art

[0002] A related-art rotary compressor includes, in a vessel, an electric motor and a compression mechanism to be driven by the electric motor. The compression mechanism includes a cylinder having a cylindrical shape, a rolling piston mounted to an eccentric portion of a rotary shaft of the electric motor, which is configured to perform an eccentric motion inside the cylinder, and a vane configured to partition a space inside the cylinder into a suction chamber and a compression chamber. A suction hole and a discharge port are formed in the cylinder. Refrigerant which is sucked from the outside of the vessel via a suction pipe and the suction hole into the suction chamber is compressed along with the eccentric motion of the rolling piston. The compressed refrigerant is discharged from the compression chamber via the discharge port to the outside of the compression mechanism. An oil feed passage is formed in the rotary shaft in an axial direction thereof. During an operation of the rotary compressor, a lubricating oil stored in the vessel is fed to the compression mechanism through the oil feed passage so as to lubricate the compression mechanism.

[0003] In the rotary compressor, the rotary shaft rotates in a forward direction during the operation. As a result, the refrigerant is sucked into the suction chamber in a cylinder chamber via the suction pipe. Then, the sucked refrigerant is compressed in the compression chamber of the cylinder chamber. Thus, a pressure becomes higher in the compression chamber than in the suction chamber. Then, immediately after stop of the operation, the pressure is higher in the compression chamber than in the suction chamber. Thus, the refrigerant flows from the compression chamber into the suction chamber due to a pressure difference to rotate the rotary shaft reversely. When the reverse rotation as described above continues, the lubricating oil accumulated in a bottom portion of the vessel passes through the oil feed passage formed in the rotary shaft to flow back from the compression mechanism through the suction chamber into the suction pipe together with the refrigerant to flow out to the outside of the vessel through the suction pipe. After the lubricating oil flows to the outside of the vessel, the lubricating oil in the vessel becomes insufficient at the time of next starting.

[0004] Therefore, there is known a rotary compressor including a suction check valve provided in a flow passage extending from a suction pipe to a suction chamber (see, for example, Patent Literature 1 ). The suction check valve is opened, when a pressure on the suction pipe side exceeds a preset pressure for a pressure on the suction chamber side, and is closed when the pressure on the suction pipe side does not exceed the preset pressure. As a result, the suction check valve allows a refrigerant gas to flow from the suction pipe into the suction chamber and prevents the refrigerant from flowing back from the suction chamber into the suction pipe.

Citation List

Patent Literature

[0005] Patent Literature 1 : Japanese Unexamined Patent Application Publication No. 2016-102438

Summary of Invention

Technical Problem

[0006] As a flow passage structure extending from the suction pipe to the suction chamber, there exists not only a rotary compressor having a structure in which the suction chamber is positioned in a direction which is bent perpendicularly to a direction of connection of the suction pipe to the vessel as disclosed in Patent Literature 1, but also a rotary compressor having a structure in which the suction chamber is positioned on an extended line of the direction of connection of the suction pipe to the vessel. In the structure disclosed in Patent Literature 1 , the suction check valve is arranged on a wall surface of a bent portion of the flow passage. However, there is found no technology of providing the suction check valve in the flow passage extending from the suction pipe to the suction chamber in the latter structure. Therefore, the rotary compressor having the structure in which the suction chamber is positioned on the extended line of the direction of connection of the suction pipe to the vessel has a problem in difficulty of suppression of the reverse rotation of the rotary shaft at the time of stop of the operation so as to suppress the outflow of the lubricating oil to the outside of the vessel.

[0007] The present invention has been made to solve the problem described above, and has an object to provide a rotary compressor having a structure in which a cylinder chamber is formed on an extended line of a direction of connection of a suction pipe to a vessel, which is capable of suppressing reverse rotation of a rotary shaft at the time of stop of an operation so as to suppress outflow of a lubricating oil to the outside of the vessel.

Solution to Problem

[0008] According to one embodiment of the present invention, there is provided a rotary compressor, including: a vessel configured to store a lubricating oil therein; a suction pipe connected from an outside to pass through the vessel; a rotary shaft, which is accommodated in the vessel, and includes an oil feed passage formed therein; and a compression mechanism, which is accommodated in the vessel, and is configured to compress refrigerant through rotation of the rotary shaft, the lubricating oil being fed to the compression mechanism through the oil feed passage, the compression mechanism including: a cylinder having a through hole formed therein, the through hole being configured to cause the rotary shaft to pass therethrough; a piston, which is provided on an outer periphery of the rotary shaft, and is configured to rotate eccentrically on an inner side of the through hole; and two closing members arranged on and below the cylinder in an axial direction of the cylinder, in which the through hole of the cylinder is closed by the two closing members to form a cylinder chamber configured to receive the refrigerant sucked into the vessel from the suction pipe and compress the sucked refrigerant, in which the cylinder has a suction hole formed of a blind hole being open on an outer peripheral surface of the cylinder to extend in a radial direction of the cylinder, and the suction pipe is connected to an opening of the suction hole to form the cylinder chamber on an extended line of a direction of connection of the suction pipe to the vessel, in which the rotary compressor further includes a suction check valve, which is arranged in the suction hole, and is' configured to allow a flow of the refrigerant from the suction pipe into a suction chamber inside the cylinder chamber and to prevent a backward flow of the refrigerant, and in which the rotary compressor further includes a suction flow passage, which is configured to guide the refrigerant from the suction pipe to the suction chamber under a state in which the suction check valve is open, and is formed through intermediation of one or both of the two closing members.

Advantageous Effects of Invention

[0009] According to one embodiment of the present invention, the suction check valve is arranged in the suction hole formed of the blind hole being open on the outer peripheral surface of the cylinder to extend in the radial direction, while the suction flow passage in a state in which the suction check valve is open is ensured through intermediation of one or both of the two closing members. As a result, the suction check valve can be installed and operated in the structure in which the cylinder chamber is formed on the extended line of the direction of connection of the suction pipe to the vessel. Further, the installation of the suction check valve enables the suppression of the reverse rotation of the rotary shaft at the time of stop of the operation so as to suppress the outflow of the lubricating oil to the outside of the vessel.

Brief Description of Drawings

[0010] [Fig. 1] Fig. 1 is a schematic longitudinal sectional view of a rotary compressor according to Embodiment 1 of the present invention.

[Fig. 2] Fig. 2 is a perspective view of a cylinder illustrated in Fig. 1.

[Fig. 3] Fig. 3 is an enlarged sectional view of the cylinder illustrated in Fig. 1.

[Fig. 4] Fig. 4 is a perspective view of a first support member illustrated in Fig. 1.

[Fig. 5] Fig. 5 is a perspective view of an intermediate partition plate illustrated in

Fig. 1.

[Fig. 6] Fig. 6 is an enlarged view of a peripheral structure of a suction check valve, which is surrounded by the dotted line in Fig. 1.

[Fig. 7] Fig. 7 is an exploded perspective view of the suction check valve illustrated in Fig. 1.

[Fig. 8] Fig. 8 is an enlarged view of the peripheral structure of the suction check valve, which is surrounded by the dotted line in Fig. 1 , and is a view for illustrating a state in which the suction check valve is closed.

[Fig. 9] Fig. 9 is a view for illustrating a modification example of a pressure balance hole in the rotary compressor according to Embodiment 1 of the present invention. [Fig. 10] Fig. 10 is a view for illustrating a modification example of a position of installation of the suction check valve in the rotary compressor according to Embodiment 1 of the present invention, and is a view for illustrating a state in which the suction check valve is open.

[Fig. 1 1 ] Fig. 1 1 is a view for illustrating a modification example of the position of installation of the suction check valve in the rotary compressor according to Embodiment 1 of the present invention, and is a view for illustrating a state in which the suction check valve is closed. Description of Embodiments

[001 1 ] Now, ah embodiment of the present invention is described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference symbols, and description thereof is omitted or simplified as appropriate. Moreover, shapes, sizes, arrangements, and other factors of components illustrated in the drawings may be changed as appropriate without departing from the scope of the invention.

[0012] Embodiment 1

Fig. 1 is a schematic longitudinal sectional view of a rotary compressor according to Embodiment 1 of the present invention. Fig. 2 is a perspective view of a cylinder illustrated in Fig. 1. In order to illustrate a suction chamber 33a and a compression chamber 33b formed in a cylinder chamber 33 inside a cylinder 31 , a vane 39 and a rolling piston 32 are indicated by the dotted lines in Fig. 2. Fig. 3 is an enlarged sectional view of the cylinder illustrated in Fig. 1. Fig. 4 is a perspective view of a first support member illustrated in Fig. 1. Fig. 5 is a perspective view of an intermediate partition plate illustrated in Fig. 1. Although a twin-cylinder rotary compressor including two cylinders 31 is illustrated in Fig. 1 , the rotary compressor of the present invention is not limited to the twin-cylinder rotary compressor. A single-cylinder rotary compressor or a multiple- cylinder rotary compressor including three or more cylinders may also be used.

[0013] A rotary compressor 100 includes, in a vessel 1 , an electric motor 2 and a compressor mechanism 3 to be driven by the electric motor 2 through intermediation of a rotary shaft 4. [0014] Suction pipes 5 and a discharge pipe 6 are connected to the vessel 1. The suction pipes 5 are connected to the vessel 1 from outside so as to pass through the vessel 1. The discharge pipe 6 is configured to discharge a compressed gas. A bottom portion of the vessel 1 serves as an oil reservoir l a configured to store a lubricating oil. The lubricating oil stored in the oil reservoir la moves upward through an oil feed passage 4A formed in a center portion of the rotary shaft 4 in an axial direction of the rotary shaft 4 due to a differential pressure acting in the oil feed passage 4A, and then the lubricating oil is fed to the compression mechanism 3.

[0015] The electric motor 2 includes a rotator 2a mounted to the rotary shaft 4 and a stator 2b configured to rotationally drive the rotator 2a. By starting energization of the stator 2b, the rotator 2a is rotated to transmit rotational power to the compression mechanism 3 through intermediation of the rotary shaft 4.

[0016] The compression mechanism 3 includes a first compression section 30A provided in an upper portion, a second compression section 30B provided in a lower portion, a first support member 40 arranged on an upper end surface of the first compression section 30A, and a second support member 50 arranged on a lower end surface of the second compression section 30B.

[0017] The first support member 40 includes a bearing portion 41 having a hollow cylindrical shape, which is configured to support the rotary shaft 4 so as to be freely rotatable, and an end plate portion 42 having a flat annular shape, which is configured to close an upper opening of a through hole 31 a of the later-described cylinder 31 of the first compression section 30A. The second support member 50 similarly includes a bearing portion 51 having a hollow cylindrical shape, which is configured to support the rotary shaft 4 so as to be freely rotatable, and an end plate portion 52 having a flat annular shape, which is configured to close a lower opening of a through hole 31 a of the later-described cylinder 31 of the second compression section 30B. A discharge port (not shown) including a discharge valve therein is formed in each of the end plate portion 42 and the end plate portion 52.

[0018] An intermediate partition plate 60 is arranged between the first compression section 30A and the second compression section 30B so as to define the first corripression section 30A and the second compression section 30B. In this manner, the compression mechanism 3 is constructed of the second support member 50, the second compression section 30B, the intermediate partition plate 60, the first compression section 30A, and the first support member 40 laminated in the stated order from a lower side to an upper side.

[0019] Now, the first compression section 30A and the second compression section 30B are described. The first compression section 3 OA and the second compression section 30B basically have similar configurations, and thus the first compression section 30A is representatively described below.

[0020] The first compression section 30A includes the cylinder 31 having a cylindrical shape and a rolling piston 32. The cylinder 31 has the through hole 31a through which the rotary shaft 4 passes. The rolling piston 32 is provided on an outer periphery of an eccentric shaft portion 4a of the rotary shaft 4 and is configured to rotate eccentrically inside the through hole 31a. The first compression section 30A further includes the vane 39 arranged in a vane groove 31b formed on the cylinder 31 so as to be freely slidable therein. The through hole 31 a of the cylinder 31 is closed by the end plate portion 42 of the first support member 40 and the intermediate partition plate 60. As a result, the cylinder chamber 33 is formed between an inner peripheral surface 31 c of the through hole 31 a formed in the cylinder 31 (hereinafter referred to as "inner peripheral surface 31c of the cylinder chamber 33") and an outer peripheral surface of the rolling piston 32. The cylinder chamber 33 is partitioned by the vane 39 into the suction chamber 33a and the compression chamber 33b.

[0021 ] Further, a suction hole 34 is formed in the cylinder 31 as illustrated in Fig. 2. The suction hole 34 is formed of a blind hole which is open on an outer peripheral surface of the cylinder 31 and extends in a radial direction of the cylinder 31. The suction pipe 5 is connected to the opening of the suction hole 34 so as to pass through the vessel 1. In the cylinder 31 , a discharge cutout 35 is formed in the inner peripheral surface 31 c of the cylinder chamber 33. The discharge cutout 35 is formed by cutting out the inner peripheral surface 31 c in accordance with each of discharge ports 42a (see Fig. 4) formed in the end plate portion 42 of the first support member 40. The compression chamber 33b communicates with the discharge ports 42a via the discharge cutout 35.

[0022] In the first compression section 30A constructed as described above, when power is supplied to the electric motor 2, the rotary shaft 4 is rotated by the electric motor 2. The rotation is forward. By the rotation of the rotary shaft 4, the eccentric shaft portion 4a performs an eccentric rotating motion inside the compression chamber 33b. Along with the eccentric rotating motion of the eccentric shaft portion 4a, the rolling piston 32 performs an eccentric rotating motion inside the cylinder 31. Along with the rotation of the rolling piston 32, low-pressure refrigerant is sucked into the suction chamber 33a and is compressed in the compression chamber 33b to turn into high-pressure refrigerant. After passing through the discharge cutout 35 and the discharge ports 42a, the high-pressure refrigerant is discharged into an internal space of the vessel 1.

[0023] The second compression section 3 OB differs from the first compression section 3 OA in that members configured to close the through hole 31 a formed in approximately the center of the cylinder 31 in the second compression section 30B are the intermediate partition plate 60 and the second support member 50. For arrangement of the first compression section 30A and the second compression section 30B, the eccentric shaft portion 4a of the first compression section 30A and the eccentric shaft portion 4a of the second compression section 30B are provided so as to have a phase shift of 180 degrees therebetween. The remaining structure and operation of the second compression section 30B are basically sirrular to those of the first compression section 30A. The end plate portion 42 of the first support member 40, the intermediate partition plate 60, and the end plate portion 52 of the second support member 50 correspond to closing members of the present invention.

[0024] In the first compression section 3 OA and the second compression section 30B, the suction and the compression of the refrigerant are repeated by the rotation of the rotary shaft 4. Then, the refrigerant gas compressed in each of the first compression section 30A and the second compression section 30B to be discharged into the internal space of the vessel 1 is discharged out of the vessel 1 from the discharge pipe 6, thereby circulating the refrigerant in a refrigerant circuit.

[0025] The rotary compressor according to Embodiment 1 has a structure in which the cylinder chamber 33 is formed on an extended line of a direction of connection of the suction pipe 5 to the vessel 1. Embodiment 1 has a feature in that a suction check valve 70 configured to allow a flow of the refrigerant from the suction pipe 5 into the suction chamber 33a inside the cylinder chamber 33 and to prevent a backward flow is arranged in the suction hole 34 in this structure. In Embodiment I , the suction check valve 70 is arranged in the suction hole 34 in the first compression section 30A so that a force of stopping the reverse rotation of the rotary shaft 4 is exerted on the eccentric shaft portion 4a of the rotary shaft 4 passing through the cylinder chamber 33 in the first compression section 30A to enable suppression of the reverse rotation. Now, a structure of installation of the suction check valve 70, and effects and other elements of the suction check valve 70 are described.

[0026] Fig. 6 is an enlarged view of a peripheral structure of the suction check valve, which is surrounded by the dotted line in Fig. 1. In Fig. 6, a state in which the suction check valve 70 is open is illustrated. Fig. 7 is an exploded perspective view of the suction check valve illustrated in Fig. 1.

[0027] The suction check valve 70 includes a valve body 71 and a spring 72. The valve body 71 is configured to open and close an opening of the suction pipe 5 through movement inside the suction hole 34 in the radial direction of the cylinder 31. The spring 72 is configured to urge the valve body 71 in a direction of closing the opening of the suction pipe 5. An elastic force of the spring 72 is a spring force which enables the suction check valve 70 to be opened in cooperation with a flow rate of the sucked refrigerant. As described above, the suction hole 34 is formed of the blind hole extending in the radial direction from the outer periphery of the cylinder 31. The spring 72 is arranged between an end surface 36 in a depth direction (left direction in Fig. 6), which is a bottom surface of the suction hole 34, and the valve body 71 .

[0028] The end surface 36 of the suction hole 34 serves as a surface on which the spring 72 is installed. A circular recessed portion 36a is formed in the end surface 36. The spring 72 is seated on the circular recessed portion 36a to position the spring 72. Specifically, an outer peripheral portion of a radially inner end portion of the spring 72 is fitted to an inner peripheral surface of the circular recessed portion 36a to fix a position of the spring 72. A projecting portion which projects to a radially outer side may be formed in a center portion of the circular recessed portion 36a so that the projecting portion is fitted on an inner side of the spring 72 to fix the position of the spring 72. The end surface 36 is hereinafter referred to as "spring installation surface 36".

[0029] The valve body 71 is formed into a cylindrical shape having one closed end. A radially outer surface 71 a of the closed portion serves as a sealing surface 71 a to be held in contact with a radially inner end surface of the suction pipe 5 to close the opening of the suction pipe 5. The surface 71 a is hereinafter also referred to as "sealing surface 71 a". [0030] Two flow passage holes 80 are formed in the cylinder 31 of the first compression section 30A to pass therethrough in the axial direction. The two flow passage holes 80 are arranged so as to be aligned in the axial direction and communicated with the suction hole 34. Although each of the flow passage holes 80 is formed to have an oval shape which is elongated in a circumferential direction of the cylinder 31 on a plan view as illustrated in Fig. 2, the shape of the flow passage hole 80 is not limited thereto. The shape of the flow passage hole 80 may be rectangular or circular on the plan view. The flow passage holes 80 are positioned on a radially outer side of the sealing surface 71 a of the valve body 71 under a state in which the suction check valve 70 is open (see Fig. 6) and serve as flow passages through which the sucked refrigerant passes when the suction check valve 70 is opened.

[0031 ] For each of the end plate portion 42 of the first support member 40 and the intermediate partition plate 60, a flow passage recessed portion 81 is formed in a surface on a side closer to the suction check valve 70, as illustrated in Fig. 6. The flow passage recessed portion 81 of the end plate portion 42 of the first support member 40 is formed to be open on a lower end surface of the end plate portion 42, whereas the flow passage recessed portion 81 of the intermediate partition plate 60 is formed to be open in an upper end surface of the intermediate partition plate 60. The flow passage recessed portions 81 are formed so as to extend in the radial direction of the first support member 40 and the intermediate partition plate 60 on a plan view, as illustrated in Fig. 4 and Fig. 5. On a radial cross section, the flow passage recessed portions 81 are formed so as to bridge the flow passage holes 80 and the cylinder chamber 33 of the cylinder 31 , as illustrated in Fig. 6. Specifically, each of the flow passage recessed portions 81 is formed so that an outer periphery side end surface 81 a is flush with an outer periphery side end surface 80a of the flow passage hole 80. However, the outer periphery side end surface 81 a of the flow passage recessed portion 81 may be positioned on a radially outer side of the outer periphery side end surface 80a df the flow passage hole 80. The flow passage recessed portion 81 is formed so that an inner periphery side end surface 81 b is positioned on a radially inner side of the inner peripheral surface 31 c of the cylinder 3 1. Therefore, a portion of a radially inner side of each of the flow passage recessed portions 81 faces the cylinder chamber 33 of the cylinder 31 in the axial direction of the rotary shaft 4 and is open into the cylinder chamber 33. [0032] With the structure described above, the flow passage recessed portions 81 communicate with the respective flow passage holes 80 and the cylinder chamber 33. The flow passage holes 80 and the flow passage recessed portions 81 form suction flow passages 83 which allow communication between the suction hole 34 and the suction chamber 33a of the first compression section 30A. Although each of the flow passage recessed portions 81 has a rectangular radial cross section and a rectangular circumferential cross section, the circumferential cross section, in particular, may have an arc-like bottom surface or an inclined bottom surface.

[0033] As described above, in Embodiment 1 , the suction flow passages 83 which allow the communication between the suction pipe 5 and the suction chamber 33a are formed through the flow passage recessed portion 81 formed in the end plate portion 42 of the first support member 40, which is provided so as to be held in contact with the upper end surface of the cylinder 31 , and the flow passage recessed portion 81 formed in the intermediate partition plate 60 which is provided so as to be held in contact with the lower end surface of the cylinder 31. With the structure described above, the refrigerant from the suction pipe 5 can be guided to the suction chamber 33a in the structure in which the suction chamber 33a is formed on the extended line of the direction of connection of the suction pipes 5 to the vessel 1 .

[0034] It is desired that a flow passage sectional area of the suction flow passages 83 be larger than a flow passage sectional area of the suction hole 34 so as to ensure a suction flow rate in each of the suction flow passages 83. Specifically, each of the suction flow passages 83 includes a flow passage in the flow passage hole 80 from the suction hole 34 toward the flow passage recessed portion 81 , a flow passage to a radially inner side inside the flow passage recessed portion 81 , and a flow passage from the flow passage recessed portion 81 toward the suction chamber 33a. The two suction flow passages 83 are formed so as to be aligned in the axial direction. Therefore, it is desirable that a flow passage sectional area obtained by doubling each flow passage sectional area be set equal to or larger than a flow passage sectional area of the suction pipe 5. The "equal or larger flow passage sectional area" than the flow passage sectional area of the suction pipe 5 herein means a hydraulic diameter is equal to or larger than a hydraulic diameter of the suction pipe 5. With the structure described above, a suction flow rate can be ensured without generating a suction pressure loss. [0035] For the cylinder 31 , two pressure balance holes 90 are formed in the vicinity of the spring installation surface 36, specifically, on a radially outer side of the spring installation surface 36 to pass through the suction hole 34 in the axial direction of the end plate portion 34, and to be aligned in the axial direction. The pressure balance holes 90 are formed so as to bring the suction hole 34 and the flow passage recessed portions 81 into communication with each other. The pressure balance holes 90 have a function of bringing a space 37 (see Fig. 6) between the valve body 71 and the spring installation surface 36 (hereinafter referred to as "valve body back surface space 37") and the flow passage recessed portions 81 into communication with each other so as to adjust a pressure in the valve body back surface space 37. Positions and orientations of the pressure balance holes 90 are not limited to those illustrated in Fig. 6. The pressure balance holes 90 only need to be formed so as to bring the suction hole 34 and the flow passage recessed portions 81 into communication with each other on a radially inner side of a position of the valve body 71 under a state in which the suction check valve 70 is open.

[0036] An oil relief hole 61 having one end communicating with the flow passage recessed portion ^' 81 formed in the intermediate partition plate 60 and another end communicating with the suction chamber 33a of the second compression section 30B is formed through the intermediate partition plate 60. The high-pressure refrigerant discharged from the rotary compressor 100 contains a small amount of lubricating oil. The lubricating oil circulates through the refrigerant circuit together with the refrigerant. Therefore, the sucked refrigerant also contains the lubricating oil. The lubricating oil flows into the flow passage recessed portion 81 formed in the intermediate partition plate 60 together with the refrigerant, and thus the oil relief hole 61 is formed so that the lubricating oil flowing into the flow passage recessed portion 81 is discharged without being accumulated in the flow passage recessed portion 81. The lubricating oil accumulated in the flow passage recessed portion 81 formed in the intermediate partition plate 60 passes through the oil relief hole 61 to be fed to the suction chamber 33a of the second compression section 30B, which is positioned below the intermediate partition plate 60. The flow passage recessed portion 81 formed in the end plate portion 42 of the first support member 40 is open downward, and thus the lubricating oil is not accumulated in the flow passage recessed portion 81 formed in the end plate portion 42. [0037] In the second compression section 30B which does not include the suction check valve 70, the suction hole 34 in the cylinder 31 is formed as a through hole extending form the outer peripheral surface of the cylinder 31 to the inner peripheral surface 31 c of the cylinder 31 , in other words, a through hole passing through the cylinder 31 from a radially outer periphery thereof to the cylinder chamber 33.

[0038] Next, an operation of the suction check valve 70 is described.

[0039] Fig. 8 is an enlarged view of the peripheral structure of the suction check valve, which is surrounded by the dotted line in Fig. 1 , and is a view for illustrating a state in which the suction check valve is closed. For a state in which the suction check valve 70 is open, see Fig. 6 referred to above.

During an operation of the rotary compressor 100, the sucked refrigerant flows from the suction pipe 5 into the suction hole 34. By a force generated by a flow of the sucked refrigerant, the spring 72 is shrunk to move the valve body 71 to a radially inner side. By the radially inner movement of the valve body 71 , a volume of the valve body back surface space 37 is reduced. A pressure increased along with the reduction in volume is relieved to the flow passage recessed portions 81 via the pressure balance holes 90. In this manner, an increase in pressure of the valve body back surface space 37 is prevented to equalize the pressure in a direction of movement of the valve body 71 . As a result, the valve body 71 can be smoothly moved to the radially inner side.

[0040] Then, by the further movement of the valve body 71 to the radially inner side beyond the flow passage holes 80, the suction hole 34 is brought into communication with the flow passage recessed portions 81 through the flow passage holes 80 to bring the suction check valve 70 in an open state (Fig. 6). After the suction check valve 70 is brought into the open state in this manner, the sucked refrigerant flows from the suction hole 34 via the flow passage holes 80 and the flow passage recessed portions 81 into the suction chamber 33 a.

[0041 ] When the operation of the rotary compressor 100 is stopped, the valve body 71 is pressed by a spring force of the spring 72 from the radially inner side to the radially outer side. Further, the rotary shaft 4 is rotated reversely due to a differential pressure between the compression chamber 33b and the suction chamber 33a, and hence the high-pressure refrigerant in the compression chamber 33b flows into the flow passage recessed portions 81 via the suction chamber 33a. The refrigerant flowing into the flow passage recessed portions 81 flows into the valve body back surface space 37 through the pressure balance holes 90. In this manner, a pressure in the valve body back surface space 37 is boosted to act as a force for pressing the valve body 71 to the radially outer side.

[0042] When the operation of the rotary compressor 100 is stopped as described above, the spring force of the spring 72 and the pressure of the high-pressure refrigerant, which is generated by the reverse rotation, act on the valve body 71 in a direction of closing the valve body 71. The valve body 71 is moved from the radially inner side to the radially outer side inside the suction hole 34 by the spring force and the pressure. As a result, the opening of the suction pipe 5 is closed by the sealing surface 71 a of the valve body 71 to close the suction check valve 70. In this manner, the opening of the suction pipe 5 is closed by the suction check valve 70 to stop the reverse rotation of the rotary shaft 4. In this fashion, the backward flow of the refrigerant from the cylinder chamber 33 into the suction pipe 5 is prevented, while outflow of the lubricating oil in the oil reservoir 1 a from the suction pipe 5 through the oil feed passage 4A to outside can be suppressed.

[0043] Simultaneously with introduction of the high-pressure refrigerant from the flow passage recessed portions 81 through the pressure balance holes 90 into the valve body back surface space 37 through the reverse rotation of the rotary shaft 4, the high-pressure refrigerant is similarly introduced into a space on a side closer to the sealing surface 71 a of the valve body 71 from the flow passage recessed portions 81 through the flow passage holes 80. However, the space positioned on the radially outer side of the sealing surface 71 a of the valve body 71 communicates with a pipe outside of the vessel 1 through the suction pipe 5. Thus, a volume of the space is sufficiently larger than the volume of the valve body back surface space 37. Therefore, in the space on the radially outer side of the sealing surface 71 a of the valve body 71 , an increase in pressure does not occur as occurring in the valve body back surface space 37. Therefore, immediately after the stop of the operation, the pressure on the valve body back surface space 37 side becomes higher than the space on the radially outer side of the sealing surface 71 a of the valve body 71 . As a result, the operation of closing the suction check valve 70 is quickly performed as described above.

[0044] Further, when the operation is stopped, in addition to the spring force, the pressure of the high-pressure refrigerant, which is generated by the reverse rotation, is caused to act on the valve body 71. Therefore, even when the spring force of the spring 72 is small, the suction check valve 70 can be quickly closed, thereby preventing a delay in closing the suction check valve 70. Thus, the spring 72 having a small spring force can be used. With the use of the spring 72 having a small spring force, it is possible to avoid a situation which it is difficult to open the suction check valve 70 during the operation, failing to fully open the suction check valve 70 to result in a reduction of the suction flow passages 83. As described above, the suction check valve 70 is configured to be easily opened and easily closed.

[0045] By closing the suction check valve 70 in this manner, an outflow port for the high- pressure refrigerant flowing from the compression chamber 33b to the suction hole 34 due to the reverse rotation is closed. Thus, the rotary shaft 4 is kept from rotating reversely. A force for keeping the rotary shaft 4 from rotating reversely as described above is exerted on the rotary shaft 4 on the side closer to the first compression section 30A. As a result, even when the suction check valve 70 is not provided on the second compression section 30B side, the rotary shaft 4 is commonly used for the first compression section 30A and the second compression section 30B, and thus the reverse rotation is suppressed. Thus, the reverse rotation can be stopped in early time.

[0046] Further, the lubricating oil in the flow passage recessed portion 81 formed in the intermediate partition plate 60 is fed to the suction chamber 33a of the second compression section 30B through the oil relief hole 61 formed in the intermediate partition plate 60. Therefore, the lubricating oil is not accumulated in the flow passage recessed portion 81 formed in the intermediate partition plate 60, and thus does not close the suction flow passage 83.

[0047] As described above, according to Embodiment 1 , the suction check valve 70 is arranged in the suction hole 34. Therefore, the reverse rotation of the rotary shaft 4 at the time of stop of the operation can be suppressed. Thus, the outflow of the lubricating oil to the outside of the vessel 1 can be suppressed.

[0048] In a case of a structure in which the suction chamber is positioned in a direction bent perpendicularly to the direction of connection of the suction pipes to the vessel as disclosed in Patent Literature 1 as a flow passage structure of connection from the suction pipes 5 to the suction chamber 33a, the suction check valve only needs to be installed in a bent portion. In the case of the structure in which the suction chamber 33a is positioned on the extended line of the direction of connection of the suction pipe 5 to the vessel 1 , however, the structure has no bent portion as disclosed in Patent Literature 1. Therefore, there need efforts in installation of the suction check valve 70 and in ensuring the flow passage from the suction hole 34 to the suction chamber 33a under a state in which the suction check valve 70 is open.

[0049] For the above-mentioned efforts, in Embodiment 1 , the suction check valve 70 is arranged in the suction hole 34 formed of the blind hole formed in the cylinder 31 as described above. Further, the flow passage holes 80 are formed in the cylinder 31. At the same time, the flow passage recessed portions 81 are formed respectively on the end plate portion 42 of the first support member 40 and on the intermediate partition plate 60, which are the closing members positioned on and below the cylinder 31 in the axial direction, thereby ensuring the suction flow passages 83 from the suction hole 34 to the suction chamber 33a. In this manner, even in the structure in which the suction chamber 33a is positioned on the extended line of the direction of connection of the suction pipe 5 to the vessel 1 , the suction flow passages during the operation can be ensured. Thus, the suction flow rate can be ensured. Further, the reverse rotation of the rotary shaft 4 and the outflow of the lubricating oil to outside of the vessel 1 at the time of stop of the operation can be suppressed.

[0050] Further, when the suction check valve 70 is opened during the operation, the pressure inside the valve body back surface space 37 can be relieved from the pressure balance holes 90 to the flow passage recessed portions 81. Thus, the valve body 71 can be smoothly moved to the radially inner side. Therefore, the suction check valve 70 can be quickly opened. Further, when the operation is stopped, the high pressure from the compression chamber 33b through the pressure balance holes 90 acts in the valve body back surface space 37. As a result, the suction check valve 70 can be quickly closed. ¹ [0051 ] Further, the oil relief hole 61 is formed, and hence the lubricating oil can be prevented from being accumulated in the flow passage recessed portion 81 formed in the intermediate partition plate 60.

[0052] The rotary compressor 100 according to the present invention is not limited to the structure illustrated in Fig. 1 , and various modification examples may be carried out without departing from the gist of the present invention as follows, for example. [0053] Although the flow passage recessed portions 81 are formed in both of the end plate portion 42 of the first support member 40 and the intermediate partition plate 60 in Fig. 1 , the flow passage recessed portion 81 may be formed in any one thereof.

[0054] Further, although the pressure balance hole 90 is formed for each of the upper and lower flow passage recessed portions 81 so that the suction hole 34 communicates with each of the upper and lower flow passage recessed portions 81 in Fig. 1 , the pressure balance hole 90 may be formed for any one of the flow passage recessed portions 81.

[0055] Further, although the pressure balance holes 90 extend in the axial direction to bring the suction hole 34 and the flow passage recessed portions 81 into communication with each other in Fig. 1 , a pressure balance hole 90A may extend in the radial direction as illustrated in Fig. 9 referred to below.

[0056] Fig. 9 is a view for illustrating a modification example of the pressure balance hole in the rotary compressor according to Embodiment 1 of the present invention.

In this modification example, the pressure balance hole 90A is formed to extend from the spring installation surface 36 to the radially inner side to pass through the inner periphery surface 31c of the cylinder 31 , thereby bringing the suction hole 34 (valve body back surface space 37) and the suction chamber 33a into communication with each other.

Even with the structure described above, the pressure in the valve body back surface space 37 can be adjusted by the pressure balance hole 90A. As a result, there can be obtained similar functions and effects to those obtained in the case where the pressure balance holes 90 extending in the axial direction are formed,

[0057] Although the suction check valve 70 is provided in the first compression section 30A in Embodiment 1 , the suction check valve 70 may be provided in the second compression section 30B as illustrated in Fig. 10 referred to below.

[0058] Fig. 10 is a view for illustrating a modification example of a position of installation of the suction check valve in the rotary compressor according to Embodiment 1 of the present invention, and is a view for illustrating a state in which the suction check valve is open. Fig. 1 1 is a view for illustrating a modification example of the position of installation of the suction check valve in the rotary compressor according to Embodiment 1 of the present invention, and is a view for illustrating a state in which the suction check valve is closed. As illustrated in Fig. 10, the suction check valve 70 may be installed in the cylinder 31 of the second compression section 30B. In this case, the flow passage recessed portions 81 are formed in a surface of the intermediate partition plate 60 and a surface of the end plate portion 52 of the second support member 50, the surfaces being positioned on a side closer to the suction check valve 70. The flow passage recessed portion 81 formed in the intermediate partition plate 60 is formed to be open in the lower end surface of the intermediate partition plate 60, whereas the flow passage recessed portion 81 formed in the end plate portion 52 of the second support member 50 is formed to be open in the upper end surface of the end plate portion 52. An operation of the suction check valve 70 in this case is similar to that in the case where the suction check valve 70 is installed in the cylinder 31 of the first compression section 30A.

In this case, the suction hole 34 in the cylinder 31 is formed as a through hole passing through the cylinder 31 from the radially outer periphery of the cylinder 31 to the cylinder chamber 33 in the first compression section 30A which does not include the suction check valve 70.

[0059] Although the suction check valve 70 may be installed in any of the cylinder 31 of the first compression section 30A and the cylinder 31 of the second compression section 30B as described above, it is suitable that the suction check valve 70 be installed in the cylinder 31 of the first compression section 30A, which is positioned above the cylinder 31 of the second compression section 30B. This is because the lubricating oil accumulated in the flow passage recessed portion 81 formed in the intermediate partition plate 60 can be fed through the oil relief hole 61 to the suction chamber 33a of the second compression section 30B which is positioned below the first compression section 30A.

[0060] In the case of the structure in which the suction check valve 70 is installed in the cylinder 31 of the second compression section 30B, the oil relief hole is not formed. This is because, when the oil relief hole is formed for the flow passage recessed portion 81 of the second support member 50, the flow passage recessed portion 81 at a low pressure and an inside of the vessel 1 at a high pressure are disadvantageous^ brought into communication with each other. In this modification example, the flow passage recessed portion 81 formed in the intermediate partition plate 60 is open downward. Therefore, the lubricating oil is not accumulated in the flow passage recessed portion 81 formed in the intermediate partition plate 60 even without the oil relief hole. [0061 ] Even in the structure in which the suction check valve 70 is provided in the second compression section 30B, the flow passage recessed portion 81 may be formed in any one of the intermediate partition plate 60 and the end plate portion 52 of the second support member 50.

[0062] Further, although the present invention has been applied to the twin-cylinder rotary compressor including the two cylinders in Embodiment 1 described above, the present invention is also applicable to a single-cylinder rotary compressor including one cylinder.

[0063] Further, although the present invention has been applied to the rotary compressor including the rolling piston and the vane, which are formed independently in Embodiment 1 described above, the present invention is also applicable to a rotary compressor of a type called "swing compressor". In the swing compressor, the rolling piston and the vane are formed integrally and a pair of bushes configured to guide advancing and retreating movement of the vane are arranged so as to be held in contact respectively with both side surfaces of the vane.

Reference Signs List

[0064] 1 vessel l a oil reservoir 2 electric motor 2a rotator 2b stator 3 compression mechanism 4 rotary shaft 4A oil feed passage 4a eccentric shaft portion 5 suction pipe 6 discharge pipe 30A first compression section

30B second compression section 31 cylinder 31 a through hole 31b vane groove 31c inner peripheral surface 32 rolling piston 33 cylinder chamber

33a suction chamber 33b compression chamber 34 suction hole 35 discharge cutout 36 spring installation surface (end surface) 36a circular recessed portion 37 valve body back surface space 39 vane 40 first support member

41 bearing portion 42 end plate portion 42a discharge port 50 second support member 51 bearing portion 52 end plate portion 60 intermediate partition plate 6 Γ oil relief hole 70 suction check valve 71 valve body71 a sealing surface72 spring 80 flow passage hole 80a outer periphery side end surface

81 flow passage recessed portion 81 a outer periphery side end surface 81b inner periphery side end surface 83 suction flow passage 90 pressure balance hole 90A pressure balance hole 100 rotary compressor