Screw compressor

Abstract

Provided is a screw compressor that improves assembly workability and operational efficiency. The screw compressor (1) includes: a cylinder (3); a roller (4) disposed inside the cylinder (3) and orbiting with respect to the cylinder (3); and a helical vane (8) that divides a compression chamber (42) formed between the cylinder (3) and the roller (4), and that reduces the volume of the compression chamber (42) while advancing in the axial direction of the cylinder (3) by the orbiting of the roller (4), thereby compressing refrigerant drawn into the compression chamber (42). An outer shell (2) that hermetically houses the cylinder (3) and the roller (4) inside is provided, and the cylinder (3) is disposed so as to be movable at least in the radial direction inside the outer shell (2).

Description

Technical Field

[0001] The present invention relates to a screw compressor that compresses working fluid by dividing a cylinder body into a compression chamber and rollers revolving inside the cylinder body by helical blades. Background Technology

[0002] Conventionally, a spiral compression mechanism has the following features: a cylinder; rollers disposed inside the cylinder; and blades that divide the compression chamber between the cylinder and the rollers, causing the rollers to revolve relative to the cylinder, thereby reducing the volume of the compression chamber as it travels axially along the cylinder, thus compressing the working fluid drawn into the compression chamber (see, for example, Patent Document 1).

[0003] In this case, a compressor was developed in which a spiral groove is formed on the inner surface of the cylinder, and the blades can be inserted into the spiral groove (for example, see Patent Document 2); conversely, a spiral groove is formed on the outer surface of the roller, and the blades can be inserted into the spiral groove (for example, see Patent Document 3). Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent No. 6024487 Patent Document 2: Japanese Patent Application Publication No. 2003-28084 Patent Document 3: Japanese Patent Application Publication No. 2006-77745 Summary of the Invention The problem to be solved by the present invention

[0005] However, in any structure, the cylinder is fixed. If the alignment of the rollers and blades that revolve around the inside of the cylinder is not precise, a gap will be generated between the rollers and the cylinder, causing backflow of the working fluid and resulting in reduced compression efficiency.

[0006] Furthermore, in Patent Documents 1 and 3, helical grooves that allow the blades to be inserted and withdrawn are formed on the outer surface of the rollers. This requires increasing the thickness of the rollers, increasing their weight and causing power loss. In particular, when helical grooves are formed on the rollers, the pressure of the working fluid in the compression chamber pushes the rollers axially through the blades, thus also causing power loss.

[0007] Furthermore, in Patent Documents 1 and 2, the sliding speed between the roller and the blade increases due to the roller's rotation. In this case, the blade is designed to deform, requiring a flexible material (e.g., PTFE). Therefore, if the sliding speed between the roller and the blade increases, the wear on the blade intensifies dramatically, creating a gap between the roller and the blade, causing backflow of the working fluid, and resulting in reduced compression efficiency. In addition, there is a problem of increased sliding resistance between the roller and the blade, leading to power loss.

[0008] This invention was made to solve this prior art problem, and its purpose is to provide a screw compressor that achieves improved assembly workability and operational efficiency. Methods for solving problems

[0009] The spiral compressor of the present invention is characterized by comprising: a cylinder; rollers disposed inside the cylinder and revolving relative to the cylinder; and spiral blades dividing a compression chamber formed between the cylinder and the rollers, wherein the volume of the compression chamber decreases as it travels axially in the cylinder due to the revolution of the rollers, thereby compressing the working fluid drawn into the compression chamber. The spiral compressor also comprises an outer housing that internally seals and houses the cylinder and the rollers, wherein the cylinder is disposed inside the outer housing such that it is at least radially movable.

[0010] The spiral compressor of technical solution 2 is characterized in that, in the above invention, the spiral compressor has a spiral groove formed on the inner surface of the cylinder, and the blades can be inserted into the spiral groove.

[0011] The screw compressor of the invention of technical solution 3 is characterized in that, in the invention of technical solution 1, the screw compressor has a working fluid supply channel formed in the cylinder body, which supplies working fluid to the compression chamber between the cylinder body and the outer casing.

[0012] The screw compressor of the invention of technical solution 4 is characterized in that, in the above invention, the screw compressor has a gasket that divides the cylinder and the outer housing in the axial direction.

[0013] The spiral compressor of the invention of technical solution 5 is characterized in that, in the above invention, the gasket is made of a component with a specified elasticity.

[0014] The screw compressor of technical solution 6 is characterized in that, in the invention of technical solution 1, the screw compressor includes: a motor that drives rollers via a shaft; and housing side plates located at both ends of the outer housing along the axial direction, the shaft passing through the rollers and supported on bearing portions formed on each housing side plate, and having a discharge gas path for the working fluid compressed in the compression chamber and an oil supply throttling orifice communicating the discharge gas path with the bearing portion formed on the shaft.

[0015] The screw compressor of technical solution 7 is characterized in that, in the above invention, the screw compressor includes: rollers located at both ends of the rollers along the axial direction and through which the shaft passes; and a cam ring disposed on the shaft, which slides freely against the rollers to cause the rollers to revolve, and an oil supply throttling orifice formed on the shaft to connect the exhaust gas path with the sliding part of the cam ring.

[0016] The screw compressor of technical solution 8 is characterized in that, in the invention of technical solution 6, the screw compressor has an oil separation discharge gas path, which is formed on the side plate of the housing and connects the compression chamber between the cylinder and the rollers with the discharge gas path of the shaft.

[0017] The screw compressor of technical solution 9 is characterized in that, in the above invention, the discharge gas path for oil separation is formed on one side of the housing plate, and the other side of the housing plate is provided with an inlet for drawing working fluid into the compression chamber between the cylinder and the rollers and an outlet for discharging working fluid from the discharge gas path of the shaft.

[0018] The screw compressor of technical solution 10 is characterized in that, in the invention of technical solution 1, the screw compressor includes: rollers located at both ends of the rollers along the axial direction; a shaft passing through each roller and through the inside of the rollers; a cam ring disposed on the shaft to cause the rollers to revolve; and a motor disposed inside the rollers to drive the rollers via the shaft. The motor includes a stator and a rotor mounted on the shaft and rotating inside the stator. It is provided with a fixing foot that holds the stator in the outer housing and supplies power to the stator. A passage portion is formed on the roller for the fixing foot to pass through.

[0019] The screw compressor of technical solution 11 is characterized in that, in the above invention, a roller rotation prevention mechanism is formed by using a roller passage portion and a fixed foot passing through the passage portion. Invention Effects

[0020] The spiral compressor mechanism of the present invention comprises: a cylinder; rollers disposed inside the cylinder and revolving relative to the cylinder; and spiral blades dividing a compression chamber formed between the cylinder and the rollers, wherein the volume of the compression chamber decreases as the rollers revolve along the axial direction of the cylinder, thereby compressing the working fluid drawn into the compression chamber. The spiral compressor has an outer housing that internally seals and houses the cylinder and the rollers. The cylinder is disposed inside the outer housing such that it is at least radially movable, thus being able to move radially along with the revolve of the rollers.

[0021] Therefore, the disadvantage of gaps between the rollers and the cylinder can be eliminated without the need for precise alignment of the rollers and blades, which can improve the assembly operability of the screw compressor and eliminate the reduction in compression efficiency caused by backflow of the working fluid.

[0022] In this case, as in the invention of technical solution 2, if a spiral groove is formed on the inner surface of the cylinder, and the blades can be inserted into the spiral groove, the weight of the rollers can be reduced compared to the case where a spiral groove is formed on the rollers. In addition, the pressure of the working fluid in the compression chamber that causes the rollers to be pushed axially by the blades is also suppressed, thus achieving a significant reduction in power loss.

[0023] Furthermore, as in the invention of technical solution 3, if a working fluid supply channel is formed in the cylinder body to supply the working fluid to the compression chamber between the cylinder body and the outer housing, the pressure of the working fluid supplied between the cylinder body and the outer housing can be used to press the cylinder body against the rollers. This effectively eliminates backflow of the working fluid from between the rollers and the cylinder body, preventing a decrease in compression efficiency.

[0024] In this case, as in the invention of technical solution 4, if a gasket is provided to divide the cylinder and the outer housing in the axial direction, the adverse situation of the working fluid supplied between the cylinder and the outer housing flowing back to the area with lower pressure can be eliminated.

[0025] Furthermore, as in the invention of technical solution 5, by making the pad a component with a specified elasticity, the cylinder can be pressed against the roller using the pad, which can more effectively eliminate backflow of working fluid from between the roller and the cylinder.

[0026] Furthermore, according to the invention of technical solution 6, based on the invention of technical solution 1, it includes: a motor that drives rollers via a shaft; and housing side plates located at both ends of the outer housing along the axial direction. The shaft passes through the rollers and is supported on bearing portions formed on each housing side plate. In addition, the shaft has an exhaust gas path for the working fluid compressed in the compression chamber to pass through, and an oil supply throttle hole that connects the exhaust gas path to the bearing portion. Therefore, oil can be supplied to the bearing portion for lubrication without obstruction from the exhaust gas path formed on the shaft through the oil supply throttle hole, and the risk of power loss and erosion caused by sliding resistance can be suppressed.

[0027] Here, in a screw compressor that includes: rollers located at both ends of the roller's axial direction and through which the shaft passes; and a cam ring disposed on the shaft and slidingly abutting against the rollers to allow the rollers to revolve, as in the invention of technical solution 7, an oil supply throttling orifice is formed on the shaft to connect the exhaust gas path with the sliding portion of the cam ring, thereby enabling unobstructed supply of oil to the sliding portion of the rollers and the cam ring for lubrication.

[0028] Furthermore, as in the invention of technical solution 8, if an oil separation exhaust gas path is formed on the side plate of the housing to connect the compression chamber between the cylinder and the roller with the exhaust gas path of the shaft, the oil discharged from the screw compressor along with the working fluid can be effectively separated through the oil separation exhaust gas path, thus avoiding the occurrence of burning caused by oil depletion.

[0029] In this case, as in the invention of technical solution 9, if an oil separation exhaust gas path is formed on one side of the housing, and an intake port for drawing working fluid into the compression chamber between the cylinder and the roller and an exhaust port for discharging working fluid from the exhaust gas path of the shaft are provided on the other side of the housing, then the intake and exhaust piping connection can be completed using the other side of the housing, which can improve assembly workability and maintainability.

[0030] Furthermore, according to the invention of technical solution 10, based on the invention of technical solution 1, it includes: rollers located at both ends of the roller's axial direction; a shaft passing through each roller and through the inside of the roller; a cam ring disposed on the shaft to make the roller revolve; and a motor disposed inside the roller and driving the roller via the shaft. Therefore, the motor can be housed inside the roller, and the overall size of the screw compressor can be miniaturized.

[0031] Here, the motor has a stator and a rotor mounted on the shaft and rotating inside the stator. However, in the invention of technical solution 10, a fixing foot is provided to hold the stator in the outer housing and supply power to the stator. A passage portion is formed in the roller to allow the fixing foot to pass through, so that the motor located in the roller and the power supply to the stator can be carried out without obstruction.

[0032] In this case, as in the invention of technical solution 11, if the roller's passing part and the fixed foot passing through the passing part are used to form a roller's rotation prevention mechanism, the roller can be prevented from rotating and can revolve by the motor's holding structure. Compared with the case where a separate rotation prevention mechanism is provided, the structure can be simplified.

[0033] In particular, by using fixed feet in the roller's passageway to prevent the roller from rotating on its own axis, the roller only revolves around the central axis, thus avoiding the unfavorable situation where the sliding speed between the roller and the blade increases as when the roller rotates on its own axis. This reduces blade wear and extends blade life. Furthermore, it suppresses the backflow of working fluid caused by gaps between the roller and the blade, improving compression efficiency and reducing power loss due to sliding resistance between the roller and the blade, thereby reducing power consumption. Attached Figure Description

[0034] Figure 1 This is a longitudinal sectional side view of a screw compressor according to one embodiment of the present invention. Figure 2 yes Figure 1 A sectional view of a screw compressor along line AA. Detailed Implementation

[0035] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 This is a longitudinal sectional side view of the screw compressor 1 of the present invention. Figure 2 yes Figure 1 A sectional view along line AA. (1) Screw compressor 1 The spiral compressor 1 of this embodiment includes a metal outer casing 2 that is generally hollow and cylindrical, a cylindrical metal cylinder 3, a cylindrical metal roller 4, a motor 6, a shaft 7, and spiral-shaped, flexible blades 8. The spiral compressor 1 of this embodiment is used, for example, in the refrigerant circuit of an automotive air conditioning system, to draw in and compress refrigerant (including oil) as a working fluid, and to discharge the compressed refrigerant.

[0036] (2) Outer shell 2 The outer housing 2 includes a cylindrical housing body 11 with openings at both ends, and a pair of housing side plates 12 and 13 mounted at both ends of the housing body 11 in the axial direction (the axial direction of the cylinder). A bearing portion 14 is formed at the center of the inner surface of one of the housing side plates 12, and a bearing portion 16 is also formed at the center of the inner surface of the other housing side plate 13. Moreover, as described later, both ends of the shaft 7 are rotatably supported by the bearing portions 14 and 16. Therefore, in this embodiment, each housing side plate 12 and 13 constitutes a bearing component of the shaft 7.

[0037] In addition, Figure 1 In the diagram, "17" and "18" are annular gaskets at the joint between the main body 11 of the sealing housing and each side plate of the housing, and "20" is annular gasket at each bearing part 14 and 16 that seals the inner and outer sides of the outer housing 2. Thus, the outer housing 2 seals and houses the cylinder 3, roller 4, motor 6, shaft 7, and blade 8 on its inner side.

[0038] Additionally, an oil separation exhaust gas path 19 is recessed on the outer surface of one of the housing side plates 12, and this oil separation exhaust gas path 19 is covered and sealed by a disc-shaped housing cover 21 installed on the outer surface of the housing side plate 12. On the other housing side plate 13, an exhaust port 22 is formed in the center and an intake port 23 is formed in the outer periphery.

[0039] (3) Cylinder block 3 The cylinder 3 is disposed inside the outer housing 2, and the outer diameter of the cylinder 3 is set to be slightly smaller than the inner diameter of the housing body 11 of the outer housing 2. In addition, the axial dimension of the cylinder 3 is set to be slightly smaller than the spacing between the housing side plates 12, 13. Moreover, in this embodiment, the cylinder 3 is not fixed to any component, and is disposed at least inside the housing body 11 so as to be movable in the radial direction.

[0040] In addition, the cylinder body 3 of the embodiment has a specified thickness, and the thickness dimension of the cylinder body 3 is uniform. Moreover, on the inner surface of the cylinder body 3, a spiral groove 26 is continuously recessed from one end (the side of the housing side plate 12) to the other end (the side of the housing side plate 13) in the axial direction, and the spacing of the spiral groove 26 is set to gradually decrease from the other end to the one end.

[0041] Furthermore, a gas exhaust path 27 is formed radially through one end of the cylinder body 3 on the side plate 12, and the outer end of the gas exhaust path 27 communicates with an annular gas exhaust path 25 recessed around the outer surface of the cylinder body 3. Additionally, a gas exhaust path 28 is formed at one end of the housing body 11, which connects the gas exhaust path 25 of the cylinder body 3 with the gas exhaust path 19 of the side plate 12.

[0042] Furthermore, in this embodiment, the exhaust gas path 25 is connected between the cylinder 3 and the outer housing 2, thereby constituting a working fluid supply channel for supplying the refrigerant (working fluid) to the compression chamber 42 described later between the cylinder 3 and the outer housing 2.

[0043] As described above, since the cylinder 3 is disposed inside the housing body 11 and is capable of radial movement, a gap is formed between the cylinder 3 and the housing body 11. Furthermore, the gap between the cylinder 3 and the housing body 11 (outer housing 2) is axially defined by annular gaskets 31 and 32. In this case, the gasket 31 is located on the housing side plate 12 side, which is closer to the exhaust gas path 25, thereby defining the gap between the cylinder 3 and the housing body 11 on the exhaust gas path 25 side and the housing side plate 12 side.

[0044] Furthermore, the gasket 32 ​​is located near the end of the blade 8 closest to the intake port 23 and is positioned closer to the housing side plate 12 than the blade. This creates a separation between the cylinder body 3 and the housing body 11 on the exhaust gas path 25 side and the housing side plate 13 side. In addition, each gasket 31, 32 in this embodiment is made of an elastic component such as rubber, thus ensuring that the cylinder body 3 is always subjected to force in the inward direction (roller 4 direction).

[0045] (4) Roller 4 The roller 4 has rollers 36 and 37 located at and mounted at both ends of the roller 4 along its axial direction. Cam bearing portions 38 and 39 are formed at the center of each roller 36 and 37, and six through-holes are formed around each cam bearing portion 38 and 39. Figure 2 The through portion 41 is shown in the shape.

[0046] The outer diameter of the roller 4 is set to be smaller than the inner diameter of the cylinder 3, thereby forming a refrigerant (working fluid) compression chamber 42 between the cylinder 3 and the roller 4. One end of the compression chamber 42 (the side of the housing side plate 12) is connected to the exhaust gas path 27, and the other end (the side of the housing side plate 13) is connected to the suction port 23.

[0047] Roller 4 revolves around the axis 7 via the action of cam ring 44 (described later), during which time the outer surface of roller 4 slides freely against the inner surface of cylinder 3 (line contact). Furthermore, in Figure 1 In the middle, "43" is an annular gasket that slides freely against the cylinder 3 on the side plate 12 of the housing in the gas discharge paths 27 and 25 and seals the cylinder 3 and the roller 4.

[0048] (5) Leaf 8 The blade 8 is designed to be deformable and is made of a flexible material such as PTFE. The blade 8 can be inserted into the spiral groove 26 of the cylinder 3, slide freely against the inner surface of the spiral groove 26, and slide freely against the outer surface of the roller 4, thus dividing the cylinder 3 and the roller 4 into a compression chamber 42 in the axial direction.

[0049] As described above, the spacing of the spiral grooves 26 is set to gradually decrease from the other end (the side of the intake port 23 of the housing side plate 13) toward one end (the side of the housing side plate 12 where the exhaust gas paths 27, 25, etc. exist), so the volume of the compression chamber 42 divided by the blades 8 also gradually decreases from the other end toward one end.

[0050] (6) Axis 7 Shaft 7 passes through the roller 4, and both ends of shaft 7 pass through the cam bearing portions 38 and 39 of each roller 36 and 37. Both ends are rotatably supported by the bearing portions 14 and 16 of each housing side plate 12 and 13 as described above.

[0051] In this embodiment, cam rings 44 are respectively installed at positions on shaft 7 corresponding to cam bearing portions 38 and 39. The shaft of the cam ring 44 is relative to... Figure 2 The shaft 7 shown is eccentric. Moreover, each cam ring 44 slides freely against the cam bearing portions 38 and 39 of each roller 36 and 37, causing the roller 4 to revolve as the shaft 7 rotates.

[0052] Additionally, at the center of shaft 7, a gas discharge path 46 is formed throughout the axial direction. One end of the gas discharge path 46 is connected to the lower part of the gas discharge path 19 for oil separation of the housing side plate 12, and the other end is connected to the outlet 22 through the gas discharge path 47 formed at the center of the housing side plate 13.

[0053] Furthermore, an oil supply throttling orifice 48 is formed radially through the shaft 7, connecting the exhaust gas path 46 to each bearing portion 14, 16. In addition, an oil supply throttling orifice 49 is formed radially through the shaft 7 and the cam ring 44, connecting the exhaust gas path 46 to each cam bearing portion 38, 39 (sliding portion of the cam ring 44).

[0054] (7) Motor 6 The motor 6 includes a stator 51 with coils and a rotor 52 that rotates inside the stator 51, the rotor 52 being mounted on a shaft 7. The stator 51 is mounted and held to each housing side plate 12, 13 by means of six fixing feet 53, 54 that pass through the through portions 41 of each roller 36, 37. In the embodiment, the fixing feet 54 have electrode terminals 56 that form a power supply path for supplying power to the coils of the stator 51, thus providing power to the stator 51 through the electrode terminals 56.

[0055] Furthermore, because the fixed feet 53 and 54 are located inside the passage portions 41 of the rollers 36 and 37, the roller 4 cannot rotate. That is, the roller 4 is prevented from rotating by using the passage portions 41 of the rollers 36 and 37 and the fixed feet 53 and 54 to form a rotation prevention mechanism, so the roller 4 does not rotate inside the cylinder 3 but revolves relative to the cylinder 3.

[0056] (8) Operation of the screw compressor 1 Next, the operation of the screw compressor 1 configured as described above will be explained. Furthermore, a predetermined amount of lubricating oil is pre-sealed inside the screw compressor 1. When energized through the electrode terminal 56 to the stator 51 of the motor 6, the rotor 52 of the motor 6 rotates, thereby rotating the shaft 7. If the shaft 7 rotates, the cam ring 44 also rotates. Therefore, by utilizing the cam ring 44 and the aforementioned anti-rotation mechanism (the passage portion 41 of the rollers 36 and 37 and the fixing feet 53 and 54), the roller 4 does not rotate on its own axis but revolves around the sun.

[0057] Refrigerant (working fluid) is drawn from the external refrigerant circuit through the suction port 23 and flows into the compression chamber 42 at the other end (the side of the housing side plate 13). The refrigerant drawn into the compression chamber 42 is pushed towards one end by the rollers 4 that revolve while abutting against the inner surface of the cylinder 3. As described above, since the volume of the compression chamber 42, divided by the blades 8, gradually decreases from the other end to the first end, the refrigerant drawn into the compression chamber 42 at the other end is gradually compressed.

[0058] The compressed refrigerant (containing oil) flows out from the exhaust gas path 27 located at one end, and then through the exhaust gas path 25 to the exhaust gas path 28. At this time, the exhaust gas path 25 (the working fluid supply channel in the embodiment), which is formed around the outer surface of the cylinder 3, connects the cylinder 3 and the outer housing 2 as described above. Therefore, a small amount of the compressed refrigerant (working fluid) flows into the space between the cylinder 3 and the outer housing 2. The pressure of this high-pressure refrigerant presses the cylinder 3 against the roller 4.

[0059] Additionally, the refrigerant (working fluid) flowing into the exhaust gas path 28 then flows into the exhaust gas path 19 formed on the housing side plate 12 and descends. During this process, most of the oil contained in the refrigerant is separated and returns to the outer housing 2 from the lower end of the exhaust gas path 19.

[0060] The refrigerant then flows into the discharge gas path 46 within the shaft 7, which is connected to the lower part of the discharge gas path 19. After passing through the interior, it is discharged to the external refrigerant circuit via the discharge gas path 47 and the discharge port 22. In this case, due to the rotation of the shaft 7, the oil remaining in the refrigerant passing through the discharge gas path 19 flows into the oil supply throttling orifices 48 and 49 by centrifugal force.

[0061] Oil flowing into the oil supply throttle orifice 48 reaches the bearing portions 14 and 16 of each housing side plate 12 and 13, lubricating the sliding portions of each bearing portion 14 and 16 and the shaft 7. In addition, oil flowing into the oil supply throttle orifice 49 reaches the cam bearing portions 38 and 39 of each roller 36 and 37 and the cam ring 44, lubricating their sliding portions.

[0062] In this refrigerant (working fluid) compression operation, the cylinder 3 is positioned inside the outer casing 2 so that it can move at least radially. Therefore, as the rollers 4 revolve, the cylinder 3 also moves radially. Thus, by not strictly aligning the rollers 4 and the blades 8, the unfavorable situation of gaps between the rollers 4 and the cylinder 3 can be eliminated, improving the assembly operability of the screw compressor 1 and eliminating the reduction in compression efficiency caused by refrigerant (working fluid) backflow.

[0063] In this embodiment, a spiral groove 26 is formed on the inner surface of the cylinder 3, and the blades 8 can be inserted into the spiral groove 26. Therefore, the thickness of the roller 4 only needs to be the minimum required to maintain strength, and the weight of the roller 4 can be reduced compared to the case where a spiral groove is formed on the roller 4. In addition, the pressure of the refrigerant in the compression chamber 42 is also suppressed from pushing the roller 4 axially through the blades 8, thus achieving a significant reduction in power loss.

[0064] Furthermore, in the embodiment, refrigerant (working fluid) is supplied from the exhaust gas path 25 (working fluid supply channel) to the compression chamber 42 between the cylinder 3 and the outer housing 2. Therefore, by utilizing the pressure of the refrigerant supplied between the cylinder 3 and the outer housing 2, the cylinder 3 can be pressed against the roller 4. Even when the cylinder 3 is made movable, the backflow of refrigerant from the roller 4 and the cylinder 3 can be effectively eliminated, and the reduction in compression efficiency can be prevented.

[0065] In this case, in the embodiment, gaskets 31 and 32 are provided to divide the cylinder 3 and the outer housing 2 in the axial direction, thereby eliminating the adverse situation of refrigerant supplied between the cylinder 3 and the outer housing 2 flowing back to the area with lower pressure.

[0066] In addition, in the embodiment, these gaskets 31 and 32 are made of a component with a specified elasticity, such as rubber, so that the cylinder 3 can be pressed against the roller 4 by the gaskets 31 and 32, and the backflow of refrigerant from the roller 4 and the cylinder 3 can be eliminated more effectively.

[0067] Furthermore, in this embodiment, the structure is configured as follows: a motor 6 that drives the rollers 4 via the shaft 7 is provided, along with housing side plates 12 and 13 located at both ends of the outer housing 2 along the axial direction. The shaft 7 is supported internally and axially by the rollers 4 on bearing portions 14 and 16 respectively formed on each housing side plate 12 and 13. That is, each housing side plate 12 and 13 of the outer housing 2 has bearing portions 14 and 16 of the shaft 7, thus forming a bearing component. Therefore, the refrigerant can be compressed within the outer housing 2 via the cylinder 3 and the rollers 4, and the shaft 7 can be supported axially without obstruction by the bearing portions 14 and 16 provided on the housing side plates 12 and 13 of the outer housing 2.

[0068] Furthermore, the shaft 7 has a discharge gas path 46 through which the refrigerant compressed in the compression chamber 42 passes, and an oil supply throttling orifice 48 connecting the discharge gas path 46 to the bearing portions 14 and 16. Therefore, oil can be supplied to the bearing portions 14 and 16 without obstruction from the discharge gas path 46 formed on the shaft 7 via the oil supply throttling orifice 48 to lubricate the bearing portions 14 and 16. As a result, the risk of power loss and erosion of the bearing portions 14 and 16 due to the sliding resistance of the shaft 7 can be suppressed.

[0069] In addition, in the embodiment, rollers 36 and 37 are provided at both ends of the roller 4 along the axial direction and through which the shaft 7 passes; and a cam ring 44 is provided that slides freely against them and makes the roller 4 revolve, so that the roller 4 can revolve stably through the shaft 7.

[0070] In addition, an oil supply throttle hole 49 is also formed on the shaft 7 to connect the exhaust gas path 46 with the sliding part of the cam ring 44, so that oil can be supplied to the sliding part of the rollers 46, 37 and the cam ring 44 without obstruction to lubricate the sliding part.

[0071] In addition, in the embodiment, an oil separation exhaust gas path 19 is formed on the housing side plate 12, which connects the compression chamber 42 between the cylinder 3 and the roller 4 with the exhaust gas path 46 of the shaft 7. Therefore, the oil discharged from the screw compressor 1 along with the refrigerant can be effectively separated by the oil separation exhaust gas path 19, and the burning caused by oil depletion can be avoided.

[0072] In this case, in the embodiment, a discharge gas path 19 for oil separation is formed on the housing side plate 12 at one end, and a suction port 23 for drawing refrigerant into the compression chamber 42 between the cylinder 3 and the roller 4 and a discharge port 22 for discharging refrigerant from the discharge gas path 46 of the shaft 7 are provided on the housing side plate 13 at the other end. Therefore, the piping connection for refrigerant intake and discharge can be completed using the housing side plate 13 at the other end, which can improve assembly workability and maintainability.

[0073] Furthermore, in this embodiment, the motor 6 is housed within the roller 4, thus enabling a miniaturization of the overall size of the screw compressor 1. In this case, the structure is as follows: the motor 6 has a stator 51 and a rotor 52 mounted on a shaft 7 and rotating inside the stator 51, driving the rollers via the shaft 7, thus enabling the rollers 4 to be driven without the use of a special motor.

[0074] In addition, in the embodiment, fixed feet 53 and 54 are provided to hold the stator 51 in the outer housing 2 and supply power to the stator 51. Passage portions 41 are formed in the rollers 36 and 37 to allow the fixed feet 53 and 54 to pass through. Therefore, the motor 6 located in the rollers 4 and the power supply to the stator 51 can be carried out without obstruction.

[0075] In this case, in the embodiment, the roller 4 is prevented from rotating by using the passing part 41 of the rollers 36 and 37 and the fixing feet 53 and 54 through the passing part 41. Therefore, the roller 4 can be prevented from rotating by the holding structure of the motor 6 and can revolve around the sun. Compared with the case where a separate anti-rotation mechanism is provided, the structure can be simplified.

[0076] In particular, by using the fixing feet 53 and 54 of the passage portion 41 of the rollers 36 and 37 to prevent the roller 4 from rotating on its own axis, and only allowing the roller 4 to revolve around the sun, the unfavorable situation of the increased sliding speed between the roller 4 and the blade 8, which would occur when the roller 4 rotates on its own axis, can be avoided. This reduces the wear of the blade 8 and extends its service life. Furthermore, it suppresses the formation of gaps between the roller 4 and the blade 8 that could lead to refrigerant backflow, thereby improving compression efficiency. It also suppresses power loss caused by the sliding resistance between the roller 4 and the blade 8, thus reducing power consumption.

[0077] (9) Other components of the working fluid supply channel Furthermore, in the above embodiment, the exhaust gas path 25 is configured as a working fluid supply channel for supplying refrigerant to the compression chamber 42 between the cylinder 3 and the outer housing 2, but it is not limited to this, such as... Figure 1As shown by the dashed line, a working fluid supply channel 57 can also be provided through the cylinder 3 to connect the compression chamber 42 with the cylinder 3 and the outer housing 2, supplying refrigerant during the compression process between the cylinder 3 and the outer housing 2.

[0078] However, in this case, gaskets (one of which is also gasket 31, and the other is not shown) are provided on both sides of the exhaust gas path 25 to seal between the outer housing 2 and the cylinder 3, so that the high-pressure refrigerant passing through the exhaust gas path 25 does not flow between the cylinder 3 and the outer housing 2.

[0079] Therefore, the desired pressure can be supplied between the cylinder 3 and the outer housing 2, and the force that presses the cylinder 3 toward the roller 4 can be set.

[0080] In addition, in the embodiments, the present invention is applied to a screw compressor 1 used in the refrigerant circuit of an automotive air conditioner, but the working fluid is not limited to the refrigerant of the embodiments, and may also be air and other gases. Regarding the application, the present invention is also effective for screw compressors used for various purposes. Explanation of reference numerals in the attached figures:

[0081] 1: Screw compressor; 2: Outer housing; 3: Cylinder; 4: Roller; 6: Motor; 7: Shaft; 8: Blade; 12, 13: Housing side plates; 14, 16: Bearing sections; 19, 27, 28, 46, 47: Exhaust gas paths; 22: Exhaust outlet; 23: Inlet; 25: Exhaust gas path (working fluid supply channel); 26: Spiral groove; 31, 32: Gaskets; 36, 37: Rollers; 38, 39: Cam bearing section; 41: Pass-through section; 42: Compression chamber; 44: Cam ring; 48, 49: Oil supply throttling orifice; 51: Stator; 52: Rotor; 54: Fixed foot; 56: Electrode terminal; 57: Working fluid supply channel.

Claims

1. A screw compressor, characterized in that, The screw compressor includes: a cylinder; rollers disposed inside the cylinder and revolving relative to the cylinder; and helical blades that divide a compression chamber formed between the cylinder and the rollers, the volume of which decreases as it travels axially through the cylinder due to the rotation of the rollers, thereby compressing the working fluid drawn into the compression chamber. The screw compressor has an outer housing that internally seals and houses the cylinder and the rollers. The cylinder is configured inside the outer housing to be movable at least radially.

2. The screw compressor according to claim 1, characterized in that, The screw compressor has helical grooves formed on the inner surface of the cylinder. The blades can be inserted into and out of the spiral grooves.

3. The screw compressor according to claim 1, characterized in that, The screw compressor has a working fluid supply channel formed in the cylinder, which supplies working fluid to the compression chamber between the cylinder and the outer housing.

4. The screw compressor according to claim 3, characterized in that, The screw compressor includes a gasket that divides the cylinder and the outer housing in the axial direction.

5. The screw compressor according to claim 4, characterized in that, The pad is made of a component with a specified elasticity.

6. The screw compressor according to claim 1, characterized in that, The spiral compressor comprises: A motor drives the rollers via a shaft; and The shell side plates are located at both ends of the outer shell along its axial direction. The shaft passes through the rollers and is axially supported by bearing portions formed on each of the housing side plates. The shaft has an exhaust gas path for the working fluid compressed in the compression chamber to pass through, and an oil supply throttle orifice that connects the exhaust gas path to the bearing section.

7. The screw compressor according to claim 6, characterized in that, The spiral compressor comprises: Rollers, located at both ends of the roller along its axial direction and through which the shaft passes; and A cam ring, disposed on the shaft, slides freely against the roller, causing the roller to rotate. The shaft has an oil supply throttle orifice that connects the exhaust gas path with the sliding portion of the cam ring.

8. The screw compressor according to claim 6, characterized in that, The screw compressor has an oil separation discharge gas path formed on the housing side plate, which connects the compression chamber between the cylinder and the roller with the discharge gas path of the shaft.

9. The screw compressor according to claim 8, characterized in that, The exhaust gas path for oil separation is formed on either side of the housing plate, and, The housing side plate on the other side is provided with an intake port for drawing the working fluid into the compression chamber between the cylinder and the roller, and an outlet port for discharging the working fluid from the exhaust gas path of the shaft.

10. The screw compressor according to claim 1, characterized in that, The spiral compressor comprises: Rollers are located at both ends of the roller along its axial direction; A shaft passes through each of the rollers and through the inside of the rollers; A cam ring is disposed on the shaft to cause the roller to revolve. as well as A motor, disposed within the roller, drives the roller via the shaft. The motor has a stator and a rotor mounted on the shaft and rotating inside the stator. The stator is provided with fixing feet that hold it in place within the outer housing and supply power to the stator. The roller has a passage portion for the fixed foot to pass through.

11. The screw compressor according to claim 10, characterized in that, The roller's rotation prevention mechanism is constructed using the roller's through-part and the fixed foot passing through the through-part.

Images