Helical compressor

Abstract

[Problem] To provide a helical compressor improved in assembling workability and operating efficiency. [Solution] A helical compressor 1 comprises a cylinder 3, a roller 4 that is arranged inside the cylinder 3 and revolves with respect to the cylinder 3, and a spiral blade 8 that partitions a compression chamber 42 constituted between the cylinder 3 and the roller 4. The volume of the compression chamber 42 is reduced while advancing in a thrust direction of the cylinder 3 by the revolution of the roller 4, so that the refrigerant sucked into the compression chamber 42 is compressed. An outer casing 2 for hermetically housing the cylinder 3 and the roller 4 therein is provided, and the cylinder 3 is arranged so as to be movable in at least a radial direction inside the outer casing 2.

Description

Helical Compressor

[0001] The present invention relates to a helical compressor that compresses a working fluid by defining a compression chamber between a cylinder and a roller that revolves inside the cylinder with a helical blade.

[0002] Conventionally, helical compressors have included a cylinder, a roller installed inside the cylinder, and a blade that defines a compression chamber between the cylinder and the roller. The roller revolves around the cylinder, thereby reducing the volume of the compression chamber as it progresses in the thrust direction of the cylinder, thereby compressing the working fluid drawn into the compression chamber (see, for example, Patent Document 1).

[0003] In such cases, there have been developed methods in which a spiral groove is formed on the inner surface of a cylinder and a blade is fitted into this spiral groove so that it can be protruded and retracted (see, for example, Patent Document 2), or conversely, there have been developed methods in which a spiral groove is formed on the outer surface of a roller and a blade is fitted into this spiral groove so that it can be protruded and retracted (see, for example, Patent Document 3).

[0004] Japanese Patent No. 6024487 Japanese Patent Application Laid-Open No. 2003-28084 Japanese Patent Application Laid-Open No. 2006-77745

[0005] However, in both structures, the cylinder is fixed, and if the rollers and blades that revolve inside it are not positioned precisely, a gap will form between the rollers and the cylinder, causing a backflow of the working fluid and reducing compression efficiency.

[0006] Furthermore, in Patent Documents 1 and 3, a spiral groove into which the blade is fitted so that it can be projected and retracted is formed on the outer surface of the roller, which requires the thickness of the roller to be increased, which increases the weight and causes power loss. In particular, when a spiral groove is formed on the roller, the pressure of the working fluid in the compression chamber pushes the roller in the thrust direction via the blade, which also causes power loss.

[0007] Furthermore, in Patent Documents 1 and 2, the roller rotates, which increases the sliding speed between the roller and the blade. In this case, the blade is assumed to deform, and therefore must be made of a flexible material (e.g., PTFE). Therefore, when the sliding speed between the roller and the blade increases, the blade wears rapidly, creating a gap between the roller and the blade, which causes a backflow of the working fluid and reduces compression efficiency. Furthermore, there is a problem in that the sliding resistance between the roller and the blade increases, resulting in power loss.

[0008] The present invention has been made to solve the above-mentioned conventional technical problems, and an object of the present invention is to provide a helical compressor with improved assembly workability and operating efficiency.

[0009] The helical compressor of the present invention comprises a cylinder, a roller disposed inside the cylinder and revolving relative to the cylinder, and a spiral blade that defines a compression chamber between the cylinder and the roller. The volume of the compression chamber decreases as the roller revolves in the thrust direction of the cylinder, thereby compressing the working fluid drawn into the compression chamber. The compressor is characterized by comprising an outer casing that hermetically houses the cylinder and roller, and the cylinder is arranged inside the outer casing so as to be movable at least in the radial direction.

[0010] The helical compressor of the invention of claim 2 is characterized in that in the above invention, a helical groove is formed on the inner surface of the cylinder, and the blade is fitted into the helical groove so as to be able to appear and disappear.

[0011] The helical compressor of the present invention according to claim 3 is characterized in that, in the helical compressor of the first invention, a working fluid supply passage is formed in the cylinder and supplies the working fluid in the compression chamber between the cylinder and the outer casing.

[0012] The helical compressor of the invention according to claim 4 is characterized in that, in the above invention, a gasket is provided to separate the cylinder and the outer casing in the thrust direction.

[0013] A helical compressor according to a fifth aspect of the present invention is characterized in that, in the above invention, the gasket is made of a material having a predetermined elasticity.

[0014] The helical compressor of the invention of claim 6 is characterized in that, in the invention of claim 1, it comprises a motor that drives the rollers via a shaft, and casing side plates located at both ends of the outer casing in the thrust direction, the shaft passes through the rollers and is journaled in bearing portions formed in each casing side plate, and the shaft is formed with a discharge gas path through which the working fluid compressed in the compression chamber passes, and an oil supply orifice that connects this discharge gas path to the bearing portions.

[0015] The helical compressor of the invention of claim 7 is characterized in that in the above invention, it comprises roller wheels located at both ends of the roller in the thrust direction and through which a shaft passes, and a cam ring attached to the shaft and slidably abutting against the roller wheels to cause the roller to revolve, and the shaft is formed with an oil supply orifice that connects the discharge gas path with the sliding part of the cam ring.

[0016] The helical compressor of the invention of claim 8 is characterized in that, in the invention of claim 6, it is provided with a discharge gas path for oil separation formed on the casing side plate, which connects the compression chamber between the cylinder and the roller with the discharge gas path of the shaft.

[0017] The helical compressor of the invention of claim 9 is characterized in that in the above invention, the discharge gas path for oil separation is formed in one of the casing side plates, and the suction port that draws the working fluid into the compression chamber between the cylinder and the roller and the discharge port that discharges the working fluid from the discharge gas path of the shaft are provided in the other casing side plate.

[0018] The helical compressor of the invention of claim 10 is the helical compressor of the invention of claim 1, comprising roller wheels located at both ends of the rollers in the thrust direction, a shaft penetrating each roller wheel and passing through the rollers, a cam ring attached to the shaft and causing the rollers to revolve, and a motor attached to the rollers and driving the rollers via the shaft, the motor having a stator and a rotor attached to the shaft and rotating inside the stator, fixed legs that hold the stator in an outer casing and supply power to the stator, and the roller wheels are formed with passages through which the fixed legs can pass.

[0019] The helical compressor of the invention of claim 11 is characterized in that in the above invention, a roller rotation prevention mechanism is formed by a passing portion of the roller wheel and a fixed leg passing through this passing portion.

[0020] The helical compressor of the present invention comprises a cylinder, a roller disposed inside the cylinder and revolving relative to the cylinder, and a spiral blade that defines a compression chamber between the cylinder and the roller. The volume of the compression chamber decreases as the roller revolves in the thrust direction of the cylinder, compressing the working fluid drawn into the compression chamber. The compressor comprises an outer casing that hermetically houses the cylinder and roller, and the cylinder is disposed inside the outer casing so that it can move at least in the radial direction, allowing the cylinder to move in the radial direction as the roller revolves.

[0021] This eliminates the inconvenience of gaps occurring between the rollers and the cylinder without requiring precise positioning of the rollers or blades, improving the assembly workability of the helical compressor while also eliminating the reduction in compression efficiency due to backflow of the working fluid.

[0022] In this case, if a spiral groove is formed on the inner surface of the cylinder and the blade is fitted into the spiral groove so that it can be retracted, as in the invention of claim 2, the weight of the roller can be reduced compared to when a spiral groove is formed on the roller.In addition, the pressure of the working fluid in the compression chamber is prevented from pushing the roller in the thrust direction via the blade, which significantly reduces power loss.

[0023] Furthermore, if a working fluid supply passage is formed in the cylinder to supply the working fluid in the compression chamber between the cylinder and the outer casing, the pressure of the working fluid supplied between the cylinder and the outer casing can press the cylinder against the roller, thereby effectively eliminating backflow of working fluid from between the roller and the cylinder and preventing a decrease in compression efficiency.

[0024] In this case, if a gasket is provided to separate the cylinder and the outer casing in the thrust direction, as in the invention of claim 4, it is possible to eliminate the problem of the working fluid supplied between the cylinder and the outer casing flowing back into an area with lower pressure.

[0025] Furthermore, by constructing this gasket from a material having a predetermined elasticity, as in the invention of claim 5, the gasket can press the cylinder against the roller, making it possible to more effectively eliminate backflow of working fluid from between the roller and cylinder.

[0026] Furthermore, according to the invention of claim 6, in addition to the invention of claim 1, there is provided a motor that drives the rollers via a shaft, and casing side plates located at both ends of the outer casing in the thrust direction, the shaft passes through the rollers and is journaled on bearings formed in each of the casing side plates, and the shaft is formed with a discharge gas path through which the working fluid compressed in the compression chamber passes, and an oil supply orifice that connects this discharge gas path to the bearing, so that oil can be supplied to the bearing from the discharge gas path formed in the shaft through the oil supply orifice without hindrance, thereby lubricating it, and it is possible to suppress power loss and the risk of seizure due to sliding resistance.

[0027] Here, when the helical compressor is equipped with roller wheels positioned at both ends of the roller in the thrust direction and through which a shaft passes, and a cam ring attached to the shaft and slidably abutting against the roller wheels to cause the roller to revolve, by forming an oil supply orifice in the shaft that connects the discharge gas path with the sliding part of the cam ring, as in the invention of claim 7, oil can be supplied to the sliding part between the roller wheel and the cam ring without any hindrance, and lubricate it.

[0028] Furthermore, as in the invention of claim 8, if a discharge gas path for oil separation that connects the compression chamber between the cylinder and roller with the discharge gas path of the shaft is formed on the casing side plate, the oil that is discharged from the helical compressor together with the working fluid can be effectively separated in the discharge gas path for oil separation, making it possible to avoid seizure due to oil depletion.

[0029] In this case, as in the invention of claim 9, if the discharge gas path for oil separation is formed in one of the casing side plates, and the suction port that draws the working fluid into the compression chamber between the cylinder and the roller and the discharge port that discharges the working fluid from the discharge gas path of the shaft are provided in the other casing side plate, the suction and discharge piping connections can be completed on the other casing side plate, thereby improving assembly workability and maintenance.

[0030] Furthermore, according to the invention of claim 10, in addition to the invention of claim 1, there are provided roller wheels located at both ends of the roller in the thrust direction, a shaft that penetrates each roller wheel and passes through the inside of the roller, a cam ring that is provided on this shaft and causes the roller to revolve, and a motor that is provided inside the roller and drives the roller via the shaft, so that the motor can be housed inside the roller and the overall dimensions of the helical compressor can be reduced.

[0031] Here, the motor has a stator and a rotor that is attached to the shaft and rotates inside the stator, but in the invention of claim 10, the stator is held in an outer casing and fixed legs are provided to supply power to the stator, and a passage portion is formed in the roller wheel to allow the fixed legs to pass through, so that the motor located inside the roller can be held and power can be supplied to the stator without any problems.

[0032] In this case, if the roller rotation prevention mechanism is constructed using the roller wheel passage portion and the fixed leg that passes through this passage portion, as in the invention of claim 11, the motor holding structure will allow the roller to revolve without rotating on its own axis, making it possible to simplify the configuration compared to when a separate rotation prevention mechanism is provided.

[0033] In particular, the fixed legs that pass through the roller wheel passage prevent the roller from rotating on its axis, allowing it to only revolve, thereby avoiding the disadvantage of the increased sliding speed between the roller and the blade that would occur if the roller were rotating on its axis. This reduces wear on the blade and extends its lifespan. It also prevents the occurrence of gaps between the roller and the blade that would cause the working fluid to flow back, improving compression efficiency and reducing power loss due to sliding resistance between the roller and the blade, thereby reducing power consumption.

[0034] 1 is a longitudinal sectional side view of a helical compressor according to an embodiment of the present invention;

[0035] An embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a longitudinal side view of a helical compressor 1 of the present invention, and Fig. 2 is a cross-sectional view taken along line A-A thereof. (1) Helical Compressor 1 The helical compressor 1 of the embodiment is generally composed of a hollow, cylindrical metal outer casing 2, a cylindrical metal cylinder 3, a cylindrical metal roller 4, a motor 6, a shaft 7, and flexible spiral blades 8. The helical compressor 1 of the embodiment is used, for example, in the refrigerant circuit of a car air conditioner, and draws in, compresses, and discharges a refrigerant (including oil) as a working fluid.

[0036] (2) Outer Casing 2 The outer casing 2 is composed of a cylindrical casing body 11 that is open at both ends, and a pair of casing side plates 12, 13 that are attached to both ends of the casing body 11 in the thrust direction (axial direction of the cylinder). Of these, a bearing portion 14 is formed in the center of the inner surface of one of the casing side plates 12, and a bearing portion 16 is also formed in the center of the inner surface of the other casing side plate 13. Both ends of the shaft 7 are rotatably supported by each of the bearing portions 14, 16, as will be described later, and therefore, in this embodiment, each of the casing side plates 12, 13 constitutes a bearing member for the shaft 7.

[0037] 1, reference numerals 17 and 18 denote annular gaskets that seal the joints between the casing body 11 and each casing side plate, and reference numeral 20 denotes annular gaskets that seal the inside and outside of the outer casing 2 at each of the bearing portions 14 and 16. As a result, the outer casing 2 hermetically houses the cylinder 3, roller 4, motor 6, shaft 7, and blade 8 inside.

[0038] Furthermore, a discharge gas passage 19 for oil separation is recessed on the outer surface of one of the casing side plates 12, and this discharge gas passage 19 for oil separation is covered and sealed by a disk-shaped casing cover 21 attached to the outer surface of the casing side plate 12. The other casing side plate 13 has a discharge port 22 formed in the center and a suction port 23 formed on the outer periphery.

[0039] (3) Cylinder 3 The cylinder 3 is disposed inside the outer casing 2, and its outer diameter is set to a dimension slightly smaller than the inner diameter of the casing body 11 of the outer casing 2. The dimension of the cylinder 3 in the thrust direction is set to a dimension slightly smaller than the distance between the casing side plates 12, 13. The cylinder 3 in this embodiment is not fixed to any member, and is disposed at least inside the casing body 11 so as to be movable in the radial direction.

[0040] The cylinder 3 of the embodiment has a predetermined uniform thickness. A spiral groove 26 is formed as a continuous recess on the inner surface of the cylinder 3 from one end (the casing side plate 12 side) in the thrust direction to the other end (the casing side plate 13 side), and the pitch of the spiral groove 26 is set to gradually decrease from the other end to the one end.

[0041] Furthermore, a discharge gas path 27 on the cylinder 3 side is formed radially through one end of the cylinder 3 on the casing side plate 12 side, and the outer end of this discharge gas path 27 is connected to an annular discharge gas path 25 formed as a recess around the outer surface of the cylinder 3. Furthermore, a discharge gas path 28 is formed at one end of the casing main body 11, connecting the discharge gas path 25 of the cylinder 3 with the discharge gas path 19 of the casing side plate 12.

[0042] In this embodiment, the discharge gas path 25 is connected between the cylinder 3 and the outer casing 2, and as a result, the discharge gas path 25 forms a working fluid supply flow path that supplies the refrigerant (working fluid) from the compression chamber 42 described later between the cylinder 3 and the outer casing 2.

[0043] As described above, the cylinder 3 is disposed inside the casing body 11 and is movable in the radial direction, so a gap is formed between the cylinder 3 and the casing body 11. The gap between the cylinder 3 and the casing body 11 (outer casing 2) is defined in the thrust direction by annular gaskets 31 and 32. In this case, the gasket 31 is located on the casing side plate 12 side of the discharge gas path 25, and as a result, the gap between the cylinder 3 and the casing body 11 is defined by the discharge gas path 25 side and the casing side plate 12 side.

[0044] The gasket 32 ​​is located near the end of the blade 8 closest to the suction port 23, closer to the casing side plate 12. This defines a gap between the cylinder 3 and the casing main body 11 between the discharge gas path 25 and the casing side plate 13. In this embodiment, the gaskets 31 and 32 are made of an elastic material such as rubber, which constantly biases the cylinder 3 inward (towards the rollers 4).

[0045] (4) Roller 4 The roller 4 has roller wheels 36, 37 attached to both ends in the thrust direction. Cam bearings 38, 39 are formed in the center of each roller wheel 36, 37, and six passing sections 41, each with a shape as shown in Figure 2, are formed around each cam bearing 38, 39.

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

[0047] The rollers 4 are revolved by the rotation of the shaft 7 due to the action of a cam ring 44 (described later), and at that time, the outer surfaces of the rollers 4 are in slidable contact (line contact) with the inner surfaces of the cylinders 3. In addition, 43 in Fig. 1 denotes an annular gasket that slidably contacts the cylinders 3 on the casing side plate 12 side of the discharge gas paths 27, 25, and seals the gap between the cylinders 3 and the rollers 4.

[0048] (5) Blade 8 The blade 8 is assumed to be deformable and is made of a flexible material such as PTFE. The blade 8 is fitted retractably into the spiral groove 26 of the cylinder 3, and slidably abuts on the inner surface of the spiral groove 26 and also on the outer surface of the roller 4, thereby defining a compression chamber 42 formed between the cylinder 3 and the roller 4 in the thrust direction.

[0049] As mentioned above, the pitch of the spiral groove 26 is set to gradually decrease from the other end (the suction port 23 side of the casing side plate 13) to one end (the casing side plate 12 side where the discharge gas paths 27, 25, etc. are located), so the volume of the compression chamber 42 partitioned by the blade 8 also gradually decreases from the other end to the one end.

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

[0051] In this embodiment, cam rings 44 are attached to the shaft 7 at positions corresponding to the cam bearings 38, 39. The axis of the cam rings 44 is eccentric to the axis of the shaft 7, as shown in Figure 2. Each cam ring 44 slidably contacts the cam bearings 38, 39 of the roller wheels 36, 37, causing the rollers 4 to revolve as the shaft 7 rotates.

[0052] In addition, a discharge gas path 46 is formed through the center of the shaft 7 in the thrust direction (axial direction), and one end of this discharge gas path 46 is connected to the lower part of the discharge gas path 19 for oil separation in the casing side plate 12, and the other end is connected to the discharge port 22 via a discharge gas path 47 formed in the center of the casing side plate 13.

[0053] Furthermore, an oil supply orifice 48 is formed in the shaft 7 so as to penetrate in the radial direction, connecting the discharge gas path 46 with the bearings 14, 16. Furthermore, an oil supply orifice 49 is formed in the shaft 7 so as to penetrate in the radial direction through the shaft 7 and the cam ring 44, connecting the discharge gas path 46 with the cam bearings 38, 39 (sliding portions of the cam ring 44).

[0054] (7) Motor 6 The motor 6 comprises a stator 51 equipped with a coil and a rotor 52 that rotates inside the stator 51, and the rotor 52 is attached to the shaft 7. The stator 51 is attached to and held by the casing side plates 12, 13 with six fixed legs 53, 54 that pass through the passage portions 41 of the roller wheels 36, 37 and reach the casing side plates 12, 13. In the present embodiment, the fixed legs 54 are equipped with electrode terminals 56 that form a power supply path to the coil of the stator 51, and power is supplied to the stator 51 via these electrode terminals 56.

[0055] Furthermore, the rollers 4 cannot rotate on their own axes because the fixed legs 53, 54 are located inside the passing portions 41 of the roller wheels 36, 37. In other words, the passing portions 41 of the roller wheels 36, 37 and the fixed legs 53, 54 form a mechanism for preventing the rollers 4 from rotating on their own axes, and the rollers 4 revolve around the cylinder 3 inside the cylinder 3 without rotating on their own axes.

[0056] (8) Operation of Helical Compressor 1 Next, the operation of the helical compressor 1 configured as described above will be explained. It is assumed that a predetermined amount of lubricating oil is sealed inside the helical compressor 1. When electricity is applied to the stator 51 of the motor 6 via the electrode terminal 56, the rotor 52 of the motor 6 rotates, thereby rotating the shaft 7. When the shaft 7 rotates, the cam ring 44 also rotates, and the cam ring 44 and the aforementioned anti-rotation mechanism (passing portions 41 of the roller wheels 36, 37 and fixed legs 53, 54) work to allow the rollers 4 to revolve without rotating.

[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 casing side plate 13 side). The refrigerant drawn into the compression chamber 42 is pushed toward one end by the roller 4 that revolves while abutting against the inner surface of the cylinder 3. However, as described above, the volume of the compression chamber 42 defined by the blades 8 gradually decreases from the other end toward the one end, so that the refrigerant drawn into the compression chamber 42 at the other end is gradually compressed.

[0058] The refrigerant (including oil) compressed in this manner flows out from the discharge gas path 27 located on one end side, passes through the discharge gas path 25, and reaches the discharge gas path 28. At this time, because the discharge gas path 25 (the working fluid supply flow path in the embodiment) formed around the outer surface of the cylinder 3 communicates between the cylinder 3 and the outer casing 2 as described above, a small amount of the compressed and high-pressure refrigerant (working fluid) flows between the cylinder 3 and the outer casing 2. The pressure of this high-pressure refrigerant presses the cylinder 3 against the roller 4.

[0059] The refrigerant (working fluid) that has flowed into the discharge gas path 28 then flows into the discharge gas path 19 formed in the casing side plate 12 and descends. In the process, most of the oil contained in the refrigerant is separated and returned from the lower end of the discharge gas path 19 into the outer casing 2.

[0060] The refrigerant then flows into a discharge gas path 46 in the shaft 7, which is connected to the lower part of the discharge gas path 19, passes through the interior, and then passes through a discharge gas path 47 and is discharged to an external refrigerant circuit from the discharge port 22. In this case, because the shaft 7 is rotating, the oil remaining in the refrigerant passing through the discharge gas path 19 flows into the oil supply orifices 48 and 49 due to centrifugal force.

[0061] The oil that flows into the oil supply orifice 48 reaches the bearings 14, 16 of the casing side plates 12, 13, and lubricates the sliding portions between the bearings 14, 16 and the shaft 7. The oil that flows into the oil supply orifice 49 reaches between the cam bearings 38, 39 of the roller wheels 36, 37 and the cam ring 44, and lubricates the sliding portions.

[0062] In this compression operation of the refrigerant (working fluid), the cylinder 3 is disposed inside the outer casing 2 so as to be movable at least in the radial direction, and therefore the cylinder 3 also moves in the radial direction as the rollers 4 revolve. This makes it possible to eliminate the inconvenience of gaps occurring between the rollers 4 and the cylinder 3 without strictly adjusting the positions of the rollers 4 and the blades 8, improving the assembly workability of the helical compressor 1 and eliminating the decrease in compression efficiency due to the backflow of the refrigerant (working fluid).

[0063] In this embodiment, a spiral groove 26 is formed on the inner surface of the cylinder 3, and the blade 8 is fitted into the spiral groove 26 so as to be able to appear and disappear, so the thickness of the roller 4 can be kept to a minimum necessary to maintain strength, and the weight of the roller 4 can be reduced compared to when a spiral groove is formed in the roller 4. In addition, the roller 4 is prevented from being pushed in the thrust direction by the blade 8 due to the pressure of the refrigerant in the compression chamber 42, which significantly reduces power loss.

[0064] Furthermore, in this embodiment, the refrigerant (working fluid) in the compression chamber 42 is supplied between the cylinder 3 and the outer casing 2 from the discharge gas path 25 (working fluid supply flow path). This makes it possible to press the cylinder 3 against the roller 4 by the pressure of the refrigerant supplied between the cylinder 3 and the outer casing 2. Even if the cylinder 3 is movable, this effectively prevents the refrigerant from flowing back between the roller 4 and the cylinder 3, thereby preventing a decrease in compression efficiency.

[0065] In this case, in the embodiment, gaskets 31 and 32 are provided to separate the space between the cylinder 3 and the outer casing 2 in the thrust direction, which eliminates the problem of refrigerant supplied between the cylinder 3 and the outer casing 2 flowing back into an area with lower pressure.

[0066] In addition, in the embodiment, these gaskets 31 and 32 are made of a material having a predetermined elasticity, such as rubber, so that the gaskets 31 and 32 can constantly press the cylinder 3 against the roller 4, making it possible to more effectively prevent backflow of refrigerant from between the roller 4 and the cylinder 3.

[0067] In addition, in this embodiment, a motor 6 is provided which drives the rollers 4 via a shaft 7, and casing side plates 12, 13 are provided at both ends of the outer casing 2 in the thrust direction, with the shaft 7 passing through the rollers 4 and being supported by bearings 14, 16 formed on the casing side plates 12, 13, respectively. That is, each of the casing side plates 12, 13 of the outer casing 2 has the bearings 14, 16 for the shaft 7, forming a bearing member, so that the refrigerant is compressed by the cylinder 3 and the rollers 4 inside the outer casing 2, and the shaft 7 can be supported without hindrance by the bearings 14, 16 provided on the casing side plates 12, 13 of the outer casing 2.

[0068] The shaft 7 is formed with a discharge gas passage 46 through which the refrigerant compressed in the compression chamber 42 passes, and an oil supply orifice 48 that connects the discharge gas passage 46 with the bearings 14, 16, so that oil can be smoothly supplied to the bearings 14, 16 from the discharge gas passage 46 formed in the shaft 7 via the oil supply orifice 48 to lubricate them. This makes it possible to reduce the risk of power loss and seizure due to the sliding resistance of the shaft 7 on the bearings 14, 16.

[0069] In addition, in the embodiment, roller wheels 36, 37 are located at both ends of roller 4 in the thrust direction and through which shaft 7 passes, and cam ring 44 is provided on shaft 7, which slidably abuts against these wheels to cause roller 4 to revolve, so that roller 4 can revolve stably via shaft 7.

[0070] In addition, an oil supply orifice 49 is also formed in the shaft 7, which connects the discharge gas path 46 with the sliding portion of the cam ring 44, so that oil can be supplied without hindrance to the sliding portion between the roller wheels 46, 37 and the cam ring 44, thereby lubricating them.

[0071] In addition, in the embodiment, a discharge gas path 19 for oil separation that connects the compression chamber 42 between the cylinder 3 and the roller 4 with the discharge gas path 46 of the shaft 7 is formed in the casing side plate 12, so that the oil that is discharged together with the refrigerant from the helical compressor 1 can be effectively separated in the discharge gas path 19 for oil separation, making it possible to avoid seizure due to oil depletion.

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

[0073] In addition, in this embodiment, the motor 6 is housed inside the roller 4, which makes it possible to reduce the overall size of the helical compressor 1. In this case, the motor 6 has a stator 51 and a rotor 52 attached to a shaft 7 and rotating inside the stator 51, and the roller 4 is driven by the shaft 7, so that the roller 4 can be driven without using a special motor.

[0074] In addition, in the embodiment, the stator 51 is held in the outer casing 2 and fixed legs 53, 54 are provided to supply power to the stator 51, and the roller wheels 36, 37 are formed with passages 41 that allow the fixed legs 53, 54 to pass through, so that the motor 6 located inside the roller 4 can be held and power can be supplied to the stator 51 without any problems.

[0075] In this case, in the embodiment, the mechanism for preventing rotation of the roller 4 is constituted by the passing portion 41 of the roller wheels 36, 37 and the fixed legs 53, 54 that pass through this passing portion 41, so the holding structure of the motor 6 allows the roller 4 to revolve without rotating on its own axis, and the configuration can be simplified compared to when a separate mechanism for preventing rotation is provided.

[0076] In particular, the fixed legs 53, 54 passing through the passage portions 41 of the roller wheels 36, 37 prevent the rollers 4 from rotating on their own axes and only revolve, making it possible to avoid the disadvantage of the rollers 4 and the blades 8 sliding at a high speed, as occurs when the rollers 4 rotate on their own axes. This reduces wear on the blades 8 and extends their lifespan. It also prevents gaps from occurring between the rollers 4 and the blades 8, which can cause the refrigerant to flow back, improving compression efficiency and reducing power loss due to sliding resistance between the rollers 4 and the blades 8, thereby reducing power consumption.

[0077] (9) Other Configurations of the Working Fluid Supply Channel In the above embodiment, the discharge gas path 25 constitutes a working fluid supply channel for supplying the refrigerant in the compression chamber 42 between the cylinder 3 and the outer casing 2. However, as shown by the dashed line in FIG. 1 , a working fluid supply channel 57 that connects the compression chamber 42 with the cylinder 3 and the outer casing 2 may be provided separately through the cylinder 3 to supply the refrigerant in the middle of compression between the cylinder 3 and the outer casing 2.

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

[0079] This makes it possible to supply a desired pressure between the cylinder 3 and the outer casing 2 and set the force pressing the cylinder 3 against the roller 4 .

[0080] Furthermore, in the embodiment, the present invention is applied to a helical compressor 1 used in the refrigerant circuit of a car air conditioner, but the working fluid is not limited to the refrigerant in the embodiment, and air or other gases may also be used. Regarding applications, the present invention is effective for helical compressors used for a variety of purposes.

[0081] REFERENCE SIGNS LIST 1 helical compressor 2 outer casing 3 cylinder 4 roller 6 motor 7 shaft 8 blade 12, 13 casing side plate 14, 16 bearing portion 19, 27, 28 46, 47 discharge gas path 22 discharge port 23 suction port 25 discharge gas path (working fluid supply flow path) 26 spiral groove 31, 32 gasket 36, 37 roller wheel 38, 39 cam bearing portion 41 passage portion 42 compression chamber 44 cam ring 48, 49 oil supply orifice 51 stator 52 rotor 54 fixed leg 56 electrode terminal 57 working fluid supply flow path

Claims

A helical compressor comprising: a cylinder; a roller disposed inside the cylinder and revolving relative to the cylinder; and a spiral blade defining a compression chamber defined between the cylinder and the roller, wherein the volume of the compression chamber decreases as the roller revolves in a thrust direction of the cylinder, thereby compressing a working fluid drawn into the compression chamber; an outer casing that hermetically houses the cylinder and the roller therein; A helical compressor, characterized in that the cylinder is disposed inside the outer casing so as to be movable at least in the radial direction. 　 a spiral groove formed on the inner surface of the cylinder; 2. The helical compressor according to claim 1, wherein the blade is fitted into the spiral groove so as to be able to retract.

2. The helical compressor according to claim 1, further comprising a working fluid supply passage formed in the cylinder for supplying the working fluid in the compression chamber between the cylinder and the outer casing.

4. The helical compressor according to claim 3, further comprising a gasket that separates the cylinder and the outer casing in the thrust direction.

5. The helical compressor according to claim 4, wherein the gasket is made of a material having a predetermined elasticity. 　 a motor that drives the roller via a shaft; casing side plates located at both ends of the outer casing in a thrust direction, The shaft passes through the roller and is supported by bearings formed in the casing side plates, respectively.

2. The helical compressor according to claim 1, wherein the shaft is formed with a discharge gas passage through which the working fluid compressed in the compression chamber passes, and an oil supply orifice that connects the discharge gas passage to the bearing portion. 　 roller wheels positioned at both ends of the roller in a thrust direction and through which the shaft passes; a cam ring provided on the shaft, slidably contacting the roller wheel to cause the roller to revolve; 7. The helical compressor according to claim 6, wherein the shaft is formed with an oil supply orifice that connects the discharge gas path with the sliding portion of the cam ring.

7. The helical compressor according to claim 6, further comprising a discharge gas passage for oil separation formed in the casing side plate, which connects the compression chamber between the cylinder and the roller with the discharge gas passage of the shaft. 　 The discharge gas path for oil separation is formed in one of the casing side plates, and 9. The helical compressor according to claim 8, wherein an intake port for drawing the working fluid into a compression chamber between the cylinder and the roller, and an exhaust port for discharging the working fluid from a discharge gas path of the shaft are provided on the other of the casing side plates. 　 roller wheels located at both ends of the roller in a thrust direction; a shaft passing through each roller wheel and through the rollers; a cam ring provided on the shaft and causing the roller to revolve; a motor provided within the roller and driving the roller via the shaft; The motor has a stator and a rotor attached to the shaft and rotating inside the stator; a fixing leg for holding the stator in the outer casing and supplying power to the stator; 2. The helical compressor according to claim 1, wherein the roller wheel is formed with a passage portion through which the fixed leg passes.

11. The helical compressor according to claim 10, wherein a mechanism for preventing rotation of the roller is formed by the passing portion of the roller wheel and the fixed leg passing through the passing portion.

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