Compressor, refrigerant circulation system, and piston

Abstract

This compressor 3 has: a rotor 34 that operates so as to compress a refrigerant; a cylinder 33 that accommodates the rotor and that defines a space in which the rotor operates so as to compress the refrigerant; and a seal member 40 that is formed in an annular shape and that seals a gap between the rotor and the cylinder. The seal member includes a first end part 41 positioned at one end thereof, a second end part 42 positioned at the other end thereof, and an abutment part 43 where the first end part and the second end part engage. The seal member is configured such that when the first end part and the second end part engage at the abutment part, a first first protrusion 41a of the first end part is received by a second first recess 42a of the second end part, a second protrusion 42b of the second end part is received by a first recess 41b of the first end part, and a first second protrusion 41c of the first end part is received by a second second recess 42c of the second end part.

Description

Compressor, refrigerant circulation system, and piston

[0001] The present invention relates to a compressor that compresses a refrigerant, a refrigerant circulation system that circulates the refrigerant, and a piston.

[0002] Conventionally, compressors that compress refrigerant have been used in refrigeration cycles such as those used in air conditioners. These compressors typically include a movable member that compresses the refrigerant and a housing member that houses the movable member and defines a space in which the movable member compresses the refrigerant. For example, Patent Document 1 (Patent Document 1) discloses a scroll compressor using a fixed scroll and an orbiting scroll. In particular, this scroll compressor uses an annular seal member that is located on the rear side of the orbiting scroll and attached to a main frame that houses the orbiting scroll. The seal member separates the space on the rear side of the orbiting scroll into a back chamber with a discharge pressure atmosphere and a back pressure chamber with an intermediate pressure atmosphere.

[0003] Pistons are used to transport, convey, and compress fluids not only in compressors as described above, but also in various other devices such as internal combustion engines, pumps, hydraulic cylinders, liquid metal cylinders, and pneumatic cylinders. Even in these pistons, sealing members are used to prevent fluid leakage between spaces separated by the piston.

[0004] Japanese Patent Application Laid-Open No. 2020-23961

[0005] Recently, environmentally friendly technologies have been developed for vehicles and other applications that use natural refrigerants (e.g., CO2 refrigerants) in refrigeration cycles. These natural refrigerants are used at much higher pressures than conventional refrigerants. Therefore, improved sealing performance within compressors is required to prevent refrigerant leakage.

[0006] The scroll compressor described in Patent Document 1 uses an annular seal member to prevent refrigerant leakage. Such an annular seal member is effective in ensuring both low friction and sealing performance. Specifically, the annular seal member described in Patent Document 1 has a structure (abutment structure) in which one convex portion and one concave portion of each seal member engage at a joint where one end and the other end of the annular seal member engage. However, this joint structure is not sufficient to prevent leakage of refrigerant used at extremely high pressures as described above.

[0007] The present invention has been made to solve the above-mentioned problems of the conventional technology, and has an object to provide a compressor, a refrigerant circulation system, and a piston that can reliably prevent leakage of refrigerants used at extremely high pressures.

[0008] In order to achieve the above object, the present invention provides a compressor for compressing a refrigerant, the compressor comprising: a movable member that operates to compress the refrigerant; a housing member that houses the movable member and defines a space in which the movable member operates to compress the refrigerant; and a seal member formed in an annular shape and configured to seal a gap between the movable member and the housing member, the seal member including a first end portion located at one end, a second end portion located at the other end, and a joint portion where the first end portion and the second end portion engage with each other, the first end portion of the seal member being one end in a thickness direction perpendicular to the circumferential direction of the seal member and provided on the sliding surface side of the movable member or housing member that slides against the seal member, and including a first protrusion that protrudes in the circumferential direction; and a first protrusion that protrudes in the circumferential direction and is provided on the other end in the thickness direction and on the sliding surface side, and a first recess which is recessed in the circumferential direction and is provided between the first first convex portion and the first second convex portion and on the sliding surface side, and the second end of the sealing member has a second first recess which is recessed in the circumferential direction and is provided at one end in the thickness direction and on the sliding surface side, a second second recess which is recessed in the circumferential direction and is provided at the other end in the thickness direction and on the sliding surface side, and a second convex portion which protrudes in the circumferential direction and is provided between the second first recess and the second second recess and on the sliding surface side, and the sealing member is configured such that when the first end and the second end engage at the joint portion, the first first convex portion of the first end is received in the second first recess of the second end, the second convex portion of the second end is received in the first recess of the first end, and the first second convex portion of the first end is received in the second second recess of the second end.

[0009] In the present invention configured as described above, the seal member has a gap structure in which two protrusions and recesses at the first end engage with two recesses and protrusions at the second end, forming multiple bent portions in the passage within the gap and increasing the passage length within the gap. This increases flow resistance within the gap, thereby preventing refrigerant from passing through the gap (passage) within the gap. Therefore, the present invention improves the sealing performance at the gap where the first end and second end of the seal member engage. As a result, the compressor seal member can reliably prevent refrigerant leakage between the movable member and the accommodating member while ensuring low friction. In particular, the present invention can prevent leakage of refrigerants used at very high pressures (e.g., natural refrigerants).

[0010] In the present invention, preferably, a groove for holding the seal member is formed in the movable member or the housing member, and the compressor further has a biasing member disposed in the groove for biasing the seal member toward the sliding surface. According to the present invention configured in this manner, the seal member is biased against the sliding surface by the biasing member, thereby effectively improving the sealing performance of the seal member.

[0011] In the present invention, preferably, a groove for holding the seal member is formed in the movable member or the housing member, and the surface of the seal member facing the groove, or the surface of the groove facing the seal member, is formed with an uneven shape. In the present invention configured in this manner, the unevenness formed in the seal member or the groove allows the refrigerant to be introduced into the gap between the seal member and the groove, thereby urging the seal member against the sliding surface. This also effectively improves the sealing performance of the seal member.

[0012] In the present invention, it is preferable to use CO2 as the refrigerant. According to the present invention configured as described above, CO2 is used as a natural refrigerant, which makes it possible to protect the environment and curb global warming.

[0013]

[0013] In the present invention, preferably, the refrigerant circulation system that circulates a refrigerant includes a compressor that compresses the refrigerant described above, and a motor that is supplied with the refrigerant compressed by the compressor, the motor having a rotor and a stator, a rotating shaft connected to the rotor, a sliding bearing that supports the rotating shaft, and a refrigerant supply passage that supplies the refrigerant compressed by the compressor to the sliding bearing, and the sliding bearing of the motor is configured to be lubricated using the refrigerant supplied from the refrigerant supply passage as a lubricant. As described above, the compressor according to the present invention can prevent refrigerant leakage by means of a sealing member. Therefore, according to the present invention, refrigerant can be reliably supplied to the sliding bearing of the motor, and lubrication of the sliding bearing using refrigerant can be accurately ensured.

[0014] In the present invention, the motor is preferably configured to cool the rotor or stator using a refrigerant. According to the present invention configured in this manner, the refrigerant can be used to both lubricate and cool the motor, which makes it possible to simplify the system and reduce costs compared to systems that perform these functions separately.

[0015] In another aspect, the present invention is a piston for compressing and / or transporting a fluid, the piston comprising: a movable member that operates to compress and / or transport the fluid; a housing member that houses the movable member and defines a space in which the movable member operates to compress and / or transport the fluid; and a sealing member that is formed in an annular shape and configured to seal a gap between the movable member and the housing member, the sealing member including a first end portion located at one end, a second end portion located at the other end, and a joint portion where the first end portion and the second end portion engage with each other, the first end portion of the sealing member being one end in a thickness direction perpendicular to the circumferential direction of the sealing member and provided on a sliding surface side of the movable member or housing member that slides against the sealing member, and including a first protrusion that protrudes in the circumferential direction; and a second protrusion that protrudes in the circumferential direction and is provided on the other end in the thickness direction and on the sliding surface side. and a first second protrusion, and a first recess provided between the first first protrusion and the first second protrusion and on the sliding surface side, the first end of the seal member having a second first recess provided at one end in the thickness direction and on the sliding surface side, a second second recess provided at the other end in the thickness direction and on the sliding surface side, the second first recess and the second second recess provided at the other end in the thickness direction and on the sliding surface side, the second protrusion provided between the second first recess and the second second recess and on the sliding surface side, the second protrusion protruding in the circumferential direction, the seal member being configured such that when the first end and the second end engage at the abutment, the first first protrusion of the first end is received in the second first recess of the second end, the second protrusion of the second end is received in the first recess of the first end, and the first second protrusion of the first end is received in the second second recess of the second end.

[0016] The compressor, refrigerant circulation system, and piston according to the present invention can reliably prevent leakage of refrigerants used at very high pressures.

[0017] FIG. 1 is a schematic configuration diagram of a vehicle to which a compressor and a refrigerant circulation system according to an embodiment of the present invention are applied. FIG. 1 is a schematic configuration diagram of a motor according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a compressor according to an embodiment of the present invention. FIG. 3 is a perspective view showing an enlarged view of a joint of a seal member according to an embodiment of the present invention. FIG. 4 is a perspective view showing an enlarged view of a first end of a seal member according to an embodiment of the present invention. FIG. 5 is a perspective view showing an enlarged view of a second end of a seal member according to an embodiment of the present invention. FIG. 6 is an explanatory diagram of a flow of refrigerant at a joint of a seal member according to an embodiment of the present invention. FIG. 7 is a schematic configuration diagram of a first example of a biasing structure according to an embodiment of the present invention. FIG. 8 is a schematic configuration diagram of a compressor according to a first modification of an embodiment of the present invention. FIG. 9 is a schematic configuration diagram of a compressor according to a second modification of an embodiment of the present invention. FIG. 10 is a schematic configuration diagram of a rotor section in a magnetized target fusion reactor to which a piston according to a fourth modification of an embodiment of the present invention is applied. FIG. 11 is a schematic configuration diagram of a rotor section and a drive section in a magnetized target fusion reactor to which a piston according to a fourth modification of an embodiment of the present invention is applied. FIG. 12 is a schematic configuration diagram of a pusher piston according to a fourth modification of an embodiment of the present invention. FIG. 13 is a schematic configuration diagram of a drive piston according to a fourth modification of an embodiment of the present invention.

[0018] Hereinafter, a compressor and a refrigerant circulation system according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0019] [Overall Configuration] First, the overall configuration of the compressor and refrigerant circulation system according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram of a vehicle to which the compressor and refrigerant circulation system according to this embodiment is applied.

[0020] 1, vehicle 200 is, for example, an electric vehicle, and includes a refrigerant circulation system 100 that circulates a refrigerant in a refrigeration cycle. This refrigerant circulation system 100 includes a motor (electric motor) 1 that generates power to drive vehicle 200, a compressor (compressor) 3 that compresses the refrigerant to be supplied to motor 1, and a heat exchanger (condenser) 5 that includes a condenser, a fan, etc., and that cools the refrigerant compressed by compressor 3.

[0021] The refrigerant circulation system 100 circulates a natural refrigerant, such as CO2 refrigerant, which may contain oil (refrigerating machine oil) and additives. To this end, the compressor 3 is configured to compress the refrigerant to extremely high pressures. The motor 1 uses the refrigerant compressed by the compressor 3 to lubricate the sliding bearings that support the rotating shaft and to cool the rotor and stator, thereby functioning as an expansion valve and an evaporator in the refrigeration cycle (details will be described later). For example, in the refrigerant circulation system 100, a high-temperature liquid refrigerant is supplied from the compressor 3 to the heat exchanger 5, a low-temperature liquid refrigerant is supplied from the heat exchanger 5 to the motor 1, and a high-temperature gaseous refrigerant is supplied from the motor 1 to the compressor 3. In this case, the motor 1 is cooled by the latent heat of vaporization of the refrigerant. The refrigerant circulated by the refrigerant circulation system 100 may also be used for an air conditioner that conditions the interior of the vehicle 200.

[0022] [Motor Configuration] Next, the configuration of the motor 1 according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a schematic diagram of the motor 1 according to this embodiment. Specifically, Fig. 2 is a cross-sectional view of the motor 1 as seen along the axial direction.

[0023] As shown in FIG. 2 , the motor 1 is a system that mainly includes a rotor 11, a stator 12, a rotating shaft 13 that is connected to the rotor 11 and has one end connected to a transaxle (not shown) of the vehicle 200, a pair of plain bearings 14 that support the rotating shaft 13, and a housing 15 that accommodates the rotor 11, the stator 12, the rotating shaft 13, the plain bearings 14, etc.

[0024] The motor 1 also has a refrigerant supply passage 16 that supplies the refrigerant compressed by the compressor 3 to the sliding bearing 14. More specifically, the refrigerant supply passage 16 supplies the refrigerant to the gap between the rotating shaft 13 and the sliding bearing 14. The sliding bearing 14 is configured to be lubricated using the refrigerant supplied in this way from the refrigerant supply passage 16 as a lubricant. Typically, the sliding bearing 14 is lubricated using a liquid refrigerant (such as a CO2 refrigerant).

[0025] If a rolling bearing is applied to the motor 1, for example in an electric vehicle, the rotating shaft 13 of the motor 1 rotates at a high rotation speed of, for example, over 30,000 rpm, causing a problem of reduced lifespan due to rolling fatigue. On the other hand, if a typical sliding bearing that uses oil is applied to the motor 1, the loss of oil agitation resistance caused by the rotating shaft 13 becomes large. Therefore, in this embodiment, a sliding bearing 14 that uses a refrigerant (such as a CO refrigerant) that has been liquefied by compression by the compressor 3 is applied to the motor 1. This makes it possible to solve problems such as rolling fatigue and oil agitation resistance.

[0026] The refrigerant used as a lubricant in the sliding bearing 14 is then supplied to the rotor 11 and stator 12 for cooling. Specifically, in the motor 1, a coil (not shown) is provided on the stator 12, and the refrigerant is used to cool the coil of the stator 12 (note that in a motor in which a coil is provided on the rotor 11, the refrigerant can simply be used to cool the coil of the rotor 11). The motor 1 functions as an expansion valve because the refrigerant is supplied through the gap between the rotating shaft 13 and the sliding bearing 14 into the space within the housing 15 in which the rotor 11 and stator 12 are provided and reduced in pressure, and also functions as an evaporator because the refrigerant exchanges heat with the relatively high-temperature stator 12 and other components. The refrigerant used for cooling (heat exchange) is then discharged from a refrigerant discharge passage 17 of the motor 1 and returned to the compressor 3 ( FIG. 1 ). Note that, as shown in FIG. 2 , supplying the refrigerant to the rotor 11 and stator 12 is not limited to via the sliding bearing 14; the refrigerant may be supplied directly to the rotor 11 and stator 12. In this case, it is preferable to supply (inject) the refrigerant to the rotor 11 and the stator 12 via an expansion valve.

[0027] The motor 1 also has a seal member 18 for sealing the plain bearing 14 provided on the side of the rotating shaft 13 that is connected to a transaxle or the like. This seal member 18 is provided in the housing 15 so as to prevent refrigerant from leaking to the outside from the gap between the plain bearing 14 and the rotating shaft 13. On the other hand, the plain bearing 14 on the opposite side to the side of the rotating shaft 13 that is connected to a transaxle or the like is not provided with such a seal member 18, and the gap between the plain bearing 14 and the rotating shaft 13 is sealed by being covered by the housing 15.

[0028] [Configuration of Compressor] Next, the configuration of the compressor 3 according to this embodiment will be described with reference to Fig. 3. Fig. 3 is a schematic configuration diagram of the compressor 3 according to this embodiment. Specifically, Fig. 3 shows a cross-sectional view of the compressor 3.

[0029] As shown in Fig. 3, the compressor 3 is of a rotary type. Specifically, the compressor 3 mainly includes a suction passage 31 that draws in the refrigerant to be compressed, a discharge passage 32 that discharges the compressed refrigerant, a cylinder 33 that defines a space for compressing the refrigerant, a rotor (crank) 34 that is disposed eccentrically with respect to a center 35 of the cylinder 33 and operates to compress the refrigerant, and a blade 36 that is biased by a spring (not shown) to keep in contact with the rotor 34 and divides the space within the cylinder 33 into a suction chamber and a compression chamber. The rotor 34 is an example of a "movable member" in the present invention, and the cylinder 33 is an example of a "containing member" in the present invention.

[0030] The compressor 3 also has an annular seal member 40 provided on the outer wall surface of the rotor 34 facing the inner wall surface (sliding surface) of the cylinder 33 to seal the gap between the rotor 34 and the cylinder 33. Specifically, the seal member 40 is fitted into a groove 34a formed in the outer wall surface of the rotor 34. When the rotor 34 is in operation, the seal member 40 provided on the rotor 34 slides against the inner wall surface (sliding surface) of the cylinder 33. The seal member 40 is provided with a first end 41 and a second end 42, each of which has an uneven shape, located at one end and the other end, and the first end 41 and the second end 42 engage at a joint 43 to form an annular shape as a whole.

[0031] Next, the structure of the abutment 43 (abutment structure) of the seal member 40 according to this embodiment will be described in detail with reference to Figures 4 to 6. Figure 4 is an enlarged perspective view of the abutment 43 of the seal member 40 according to this embodiment, Figure 5 is an enlarged perspective view of the first end 41 of the seal member 40 according to this embodiment, and Figure 6 is an enlarged perspective view of the second end 42 of the seal member 40 according to this embodiment.

[0032] First, as shown in FIG. 5 , the first end 41 of the sealing member 40 has a first first convex portion 41 a that is provided at one end in the thickness direction (a direction (width direction) perpendicular to the circumferential direction, which corresponds to the radial direction) and on the sliding surface side of the cylinder 33 and that protrudes in the circumferential direction, a first second convex portion 41 c that is provided at the other end in the thickness direction and on the sliding surface side and that protrudes in the circumferential direction, a first concave portion 41 b that is provided between the first first convex portion 41 a and the first second convex portion 41 c and on the sliding surface side and that is recessed in the circumferential direction, and a third concave portion 41 d that is provided on the opposite side from the sliding surface and that is recessed in the circumferential direction and extends over the entire thickness direction.

[0033] Next, as shown in FIG. 6 , the second end 42 of the sealing member 40 has a second first recess 42 a that is recessed in the circumferential direction and is provided at one end in the thickness direction on the sliding surface side of the cylinder 33, a second second recess 42 c that is recessed in the circumferential direction and is provided at the other end in the thickness direction on the sliding surface side, a second convex portion 42 b that is provided between the second first recess 42 a and the second second recess 42 c on the sliding surface side and protrudes in the circumferential direction, and a third convex portion 42 d that is provided on the opposite side from the sliding surface and protrudes in the circumferential direction and extends over the entire thickness direction.

[0034] Next, as shown in Figures 4 to 6, when the first end 41 and the second end 42 of the sealing member 40 engage with each other at the joint portion 43, the first first convex portion 41a of the first end 41 is received in the second first concave portion 42a of the second end 42, the second convex portion 42b of the second end 42 is received in the first concave portion 41b of the first end 41, the first second convex portion 41c of the first end 41 is received in the second second concave portion 42c of the second end 42, and the third convex portion 42d of the second end 42 is received in the third concave portion 41d of the first end 41.

[0035] Next, the flow of refrigerant through the gap 43 of the seal member 40 according to this embodiment will be described with reference to Fig. 7. Similar to Fig. 4, Fig. 7 is an enlarged perspective view of the gap 43 of the seal member 40, with the first end 41 and the second end 42 indicated by dashed lines and solid lines, respectively. Here, an example will be given in which refrigerant is supplied to the seal member 40 from top to bottom in Fig. 7.

[0036] In this case, during operation of the rotor 34 in the cylinder 33 of the compressor 3, the refrigerant is likely to flow through the joint 43 of the seal member 40 provided on the rotor 34 as shown by the arrows in Fig. 7. Specifically, the refrigerant is likely to flow through the gap between the first first convex portion 41a of the first end portion 41 and the second first concave portion 42a of the second end portion 42, the gap between the first concave portion 41b of the first end portion 41 and the second convex portion 42b of the second end portion 42, and the gap between the first second convex portion 41c of the first end portion 41 and the second second concave portion 42c of the second end portion 42, in this order.

[0037] However, due to the abutment structure in which the two convex portions and concave portions of first end 41 engage with the two concave portions and convex portions of second end 42, there are multiple bent portions in the passage within abutment 43, and the passage length within abutment 43 is increased. Therefore, the flow resistance within abutment 43 increases, and the refrigerant does not pass through the gap (passage) within abutment 43 as described above.

[0038] Therefore, according to this embodiment, it is possible to improve the sealing performance at the abutment portion 43 where the first end portion 41 and the second end portion 42 of the seal member 40 engage with each other. As a result, according to this embodiment, the seal member 40 can ensure low friction and reliably prevent refrigerant leakage between the cylinder 33 and the rotor 34. In particular, according to this embodiment, it is possible to reliably prevent leakage of refrigerants used at very high pressures (natural refrigerants such as CO refrigerants).

[0039] According to experiments conducted by the present inventors, when a seal member having flat portions without any irregularities and simply butting one end against the other end is used as a reference, it was found that a seal member having a gap structure as described in Patent Document 1 reduces leakage by about 50%, whereas the seal member 40 according to this embodiment can reduce leakage by about 90%. Therefore, it was found that according to this embodiment, the seal member 40 can provide extremely high sealing performance compared to the configuration described in Patent Document 1.

[0040] Although Figure 7 shows an example in which the refrigerant is supplied to the sealing member 40 from top to bottom, it goes without saying that the sealing member 40 can also provide very high sealing performance in the opposite case in which the refrigerant is supplied to the sealing member 40 from bottom to top.

[0041] In this embodiment, in order to effectively improve the sealing performance of the seal member 40, a structure (hereinafter simply referred to as a "biasing structure") is employed that biases the seal member 40 against the sliding surface of the cylinder 33. This biasing structure will be described in detail with reference to Figures 8 to 10. Figures 8, 9, and 10 show first, second, and third examples of the biasing structure, respectively. Figures 8, 9, and 10 are enlarged schematic views showing a portion of the seal member 40 and a portion of the groove 34a of the cylinder 33 into which the seal member 40 is fitted.

[0042] As shown in FIG. 8 , in a first example of the biasing structure, a wave-shaped spring (biasing member) 45 is disposed between the seal member 40 and the groove 34a. This spring 45 biases the seal member 40 against the sliding surface of the cylinder 33. Next, as shown in FIG. 9 , in a second example of the biasing structure, the spring 45 as in the first example is not used, and the surface 46 of the seal member 40 facing the groove 34a is formed with an uneven shape. Furthermore, as shown in FIG. 10 , in a third example of the biasing structure, instead of the surface 46 of the seal member 40 as in the second example, the surface 34b of the groove 34a facing the seal member 40 is formed with an uneven shape. In these second and third examples, the unevenness formed on the seal member 40 or the groove 34a allows refrigerant to be introduced into the gap between the seal member 40 and the groove 34a, thereby biasing the seal member 40 against the sliding surface of the cylinder 33 (see arrows in FIGS. 9 and 10 ).

[0043] It should be noted that the second example is difficult to apply to a metal seal member 40 because it is difficult to form an uneven shape on a thin metal member. Therefore, when using a metal seal member 40, the first example is best applied. On the other hand, the second example is best applied to a resin seal member 40 because an uneven shape can be easily formed on a resin seal member 40 by injection molding. When such a resin seal member 40 is used, the elastic force of the seal member 40 itself can also be used to bias the seal member 40 against the sliding surface of the cylinder 33.

[0044] [Operations and Effects] Next, operations and effects of the compressor 3 and the refrigerant circulation system 100 according to this embodiment will be described.

[0045] The compressor 3 according to this embodiment has a seal member 40 that is formed in an annular shape and configured to seal a gap between the rotor 34 and the cylinder 33. The seal member 40 includes a first end 41 located at one end, a second end 42 located at the other end, and a joint 43 at which the first end 41 and the second end 42 engage. The first end 41 of the seal member 40 has a first first convex portion 41 a that is provided at one end in the thickness direction and on the sliding surface side and protrudes in the circumferential direction, a first second convex portion 41 c that is provided at the other end in the thickness direction and on the sliding surface side and protrudes in the circumferential direction, and a first concave portion 41 b that is provided between the first first convex portion 41 a and the first second convex portion 41 c and on the sliding surface side and is recessed in the circumferential direction. The second end 42 of the seal member 40 has a first end 41 located at one end in the thickness direction and on the sliding surface side and protrudes in the circumferential direction. a second first recess 42 a provided at one end in the thickness direction and on the sliding surface side and recessed in the circumferential direction; a second second recess 42 c provided at the other end in the thickness direction and on the sliding surface side and recessed in the circumferential direction; and a second convex portion 42 b provided between the second first recess 42 a and the second second recess 42 c and on the sliding surface side and protruding in the circumferential direction, and the sealing member 40 is configured such that when the first end 41 and the second end 42 engage with each other at the joint 43, the first first convex portion 41 a of the first end 41 is received in the second first recess 42 a of the second end 42, the second convex portion 42 b of the second end 42 is received in the first recess 41 b of the first end 41, and the first second convex portion 41 c of the first end 41 is received in the second second recess 42 c of the second end 42.

[0046] In this embodiment, the abutment structure that engages the two convex and concave portions of the first end 41 with the two concave and convex portions of the second end 42 forms multiple bent portions in the passage within the abutment 43 and increases the passage length within the abutment 43. This increases the flow resistance within the abutment 43, thereby preventing refrigerant from passing through the gap (passage) within the abutment 43. Therefore, this embodiment improves the sealing performance of the abutment 43, where the first end 41 and the second end 42 engage with each other, in the seal member 40. As a result, this embodiment can reliably prevent refrigerant leakage between the cylinder 33 and the rotor 34 while ensuring low friction using the seal member 40. In particular, this embodiment can prevent leakage of refrigerants used at very high pressures (natural refrigerants such as CO refrigerants).

[0047] Furthermore, according to this embodiment, the rotor 34 is formed with a groove 34a that holds the seal member 40, and the compressor 3 further includes a spring 45 that is disposed in the groove 34a and biases the seal member 40 toward the sliding surface of the cylinder 33 that slides against the seal member 40. This effectively improves the sealing performance of the seal member 40.

[0048] Furthermore, according to this embodiment, the rotor 34 is formed with a groove 34a that holds the seal member 40, and the surface of the seal member 40 facing the groove 34a, or the surface of the groove 34a facing the seal member 40, is formed with an uneven shape. This also effectively improves the sealing performance of the seal member 40.

[0049] Furthermore, according to this embodiment, the refrigerant circulation system 100 that circulates a refrigerant includes a compressor 3 that compresses the refrigerant, and a motor 1 to which the refrigerant compressed by the compressor 3 is supplied. The motor 1 includes a rotor 11 and a stator 12, a rotating shaft 13 connected to the rotor 11, a sliding bearing 14 that supports the rotating shaft 13, and a refrigerant supply passage 16 that supplies the refrigerant compressed by the compressor 3 to the sliding bearing 14. The sliding bearing 14 of the motor 1 is configured to be lubricated using the refrigerant supplied from the refrigerant supply passage 16 as a lubricant. As described above, the compressor 3 according to this embodiment can prevent refrigerant leakage by the seal member 40. Therefore, according to this embodiment, the refrigerant can be reliably supplied to the sliding bearing 14 of the motor 1, and lubrication of the sliding bearing 14 using the refrigerant can be accurately ensured.

[0050] Furthermore, according to this embodiment, the motor 1 is configured to use a refrigerant to cool the rotor 11 and the stator 12. This allows the refrigerant to be used both to lubricate and cool the motor 1, which makes it possible to simplify the system and reduce costs compared to systems that perform these functions separately.

[0051] [Modifications] Next, modifications of the above-described embodiment will be described.

[0052] (Modification 1) In the above-described embodiment, the present invention is applied to a compressor 3 configured as a rotary type. Modification 1 applies the present invention to a compressor configured as a scroll type. Modification 1 will be described with reference to Fig. 11. Fig. 11 is a schematic configuration diagram of a compressor according to Modification 1. Specifically, Fig. 11 is a perspective cross-sectional view of the compressor according to Modification 1 cut along the axial direction.

[0053] 11 , the compressor 3a according to the first modification mainly includes a spiral-shaped orbiting scroll 61 that operates to compress the refrigerant, a spiral-shaped fixed scroll 62 that is fixed so as to form a compression chamber between the orbiting scroll 61 and the fixed scroll 62, a housing member 63 that houses the orbiting scroll 61 and the fixed scroll 62, and a crankshaft 64 on the upper end of which the orbiting scroll 61 is disposed. Note that the orbiting scroll 61 corresponds to an example of the "movable member" in the present invention, and the housing member 63 corresponds to an example of the "housing member" in the present invention.

[0054] In the compressor 3a according to the first modification, the above-described seal member 40 is provided on the inner wall surface of the accommodating member 63 that faces the outer wall surface (sliding surface) of the orbiting scroll 61 so as to seal the gap between the orbiting scroll 61 and the accommodating member 63. Specifically, the seal member 40 is fitted into a groove 63a formed on the inner wall surface of the accommodating member 63. When the orbiting scroll 61 is in operation, the seal member 40 provided on the accommodating member 63 slides against the outer wall surface (sliding surface) of the orbiting scroll 61.

[0055] The biasing structures according to the first to third examples (FIGS. 8 to 10) of the above-described embodiment may also be applied to the compressor 3a according to Modification 1. When applying the first example, a wave-shaped spring 45 may be disposed between the seal member 40 and the groove 63a of the accommodating member 63. When applying the second or third example, a surface of the seal member 40 facing the groove 63a or a surface of the groove 63a facing the seal member 40 may be formed with an uneven shape.

[0056] (Modification 2) Next, in Modification 2, the present invention is applied to a compressor configured as a reciprocating type instead of the rotary type of the embodiment and the scroll type of Modification 1. Modification 2 will be described with reference to Fig. 12. Fig. 12 is a schematic configuration diagram of a compressor according to Modification 2. Specifically, Fig. 12 is a cross-sectional view of the compressor according to Modification 2.

[0057] 12, the compressor 3b according to the second modification mainly includes a piston 71 that operates to compress the refrigerant, a cylinder 72 that houses the piston 71, a rod 73 connected to the piston 71, and a rotating shaft 74 that is connected to the rod 73. The piston 71 corresponds to an example of the "movable member" in the present invention, and the cylinder 72 corresponds to an example of the "housing member" in the present invention.

[0058] In the compressor 3b according to the second modification, the above-described seal member 40 is provided on the outer wall surface of the piston 71 that faces the inner wall surface (sliding surface) of the cylinder 72 so as to seal the gap between the piston 71 and the cylinder 72. Specifically, the seal member 40 is fitted into a groove 71a formed on the outer wall surface of the piston 71. When the piston 71 is in operation, the seal member 40 provided on the piston 71 slides against the inner wall surface (sliding surface) of the cylinder 72.

[0059] The biasing structures according to the first to third examples (FIGS. 8 to 10) of the above-described embodiment may also be applied to the compressor 3b according to the second modification.

[0060] (Variation 3) In the above embodiment, an example was given in which CO2 was used as the refrigerant, but the application of the present invention is not limited to CO2, and the present invention can also be applied to a configuration in which propane, ammonia, or the like is used as the refrigerant.

[0061] (Variation 4) In the above-described embodiment, the present invention is applied to a compressor and a refrigerant circulation system, but in Variation 4, the present invention is applied to a piston that compresses and / or transports a fluid, particularly a piston used in a magnetized target fusion reactor. Variation 4 will be described with reference to Figures 13A, 13B, 14, and 15.

[0062] Fig. 13A is a schematic configuration diagram of a rotor section in a magnetized target fusion reactor according to Modification 4, Fig. 13B is a schematic configuration diagram of a rotor section and a drive section in a magnetized target fusion reactor according to Modification 4, Fig. 14 is a schematic configuration diagram of a pusher piston according to Modification 4, and Fig. 15 is a schematic configuration diagram of a drive piston according to Modification 4. Specifically, Fig. 13A is a transverse cross-sectional view of a rotor section in a magnetized target fusion reactor, and Fig. 13B is a longitudinal cross-sectional view of a rotor section and a drive section in a magnetized target fusion reactor.

[0063] 13A and 13B , the magnetized target fusion reactor 300 mainly comprises a rotor section 301 that is hollow and rotatable so as to accommodate a liquid metal 320, a plurality of pusher pistons 302 provided in the rotor section 301 near the outer periphery thereof, and a drive section 305 that is provided so as to surround the outside of the rotor section 301 and includes a plurality of drive pistons 306 for driving the pusher pistons 302. A plurality of pusher pistons 302 are provided along both the circumferential direction and the vertical direction, and a plurality of drive pistons 306 are provided along both the circumferential direction and the vertical direction so as to be in fluid communication with each of the plurality of pusher pistons 302. Specifically, the pusher piston 302 has a movable member 303 that operates to pump a predetermined fluid (liquid metal 320) and a housing member (cylinder) 304 that houses the movable member 303, and the drive piston 306 has a movable member 307 that operates to pump a predetermined fluid to drive the pusher piston 302 and a housing member (cylinder) 308 that houses the movable member 307.

[0064] This magnetized target fusion reactor 300 supplies (generates) plasma within the rotor section 301 and compresses it to satisfy the Lawson condition, thereby generating a continuous fusion reaction. Specifically, in the magnetized target fusion reactor 300, the drive pistons 306 precisely drive the pusher pistons 302, respectively, to pressurize the liquid metal 320 within the rotor section 301. This liquid metal 320 forms a liquid liner (defining a space 321 in which the plasma is contained) of a desired shape within the rotor section 301, and the liquid liner contracts to compress the plasma. In addition, in the magnetized target fusion reactor 300, the liquid metal 320 circulates, and the heat generated by the fusion reaction is transported by the liquid metal 320 to a heat exchanger, thereby generating electricity.

[0065] More specifically, as shown in FIG. 15 , in the drive piston 306, a predetermined gas 323 (e.g., steam) injected from an injector 309 through a passage 311 moves the movable member 307 (solid arrow), thereby pressurizing and feeding another predetermined gas 324 (e.g., steam). This causes the drive piston 306 to drive the pusher piston 302. Note that the gas 323 supplied from the injector 309 to the drive piston 306 is discharged through a passage 312 (dashed arrow). Also, as shown in FIG. 14 , in the pusher piston 302, the predetermined gas 322 (e.g., steam or an inert gas) is pressurized and fed by the drive piston 306, thereby moving the movable member 303, thereby pressurizing and feeding the liquid metal 320 (e.g., Li or Pb).

[0066] In particular, in the pusher piston 302 and drive piston 306 according to Modification 4, as shown in FIGS. 14 and 15 , the above-described seal members 40 are provided on the outer wall surfaces of the movable members 303 and 307 that face the inner wall surfaces (sliding surfaces) of the accommodating members 304 and 308, respectively, so as to seal the gaps between the movable members 303 and 307 and the accommodating members 304 and 308. Specifically, the seal members 40 are fitted into grooves formed in the outer wall surfaces of the movable members 303 and 307. During operation of the movable members 303 and 307, the seal members 40 provided on the movable members 303 and 307 slide against the inner wall surfaces (sliding surfaces) of the accommodating members 304 and 308. The pusher piston 302 and drive piston 306 according to Modification 4 can also reliably prevent fluid leakage between the spaces within the accommodating members 304 and 308 that are separated by the movable members 303 and 307.

[0067] The biasing structures (FIGS. 8 to 10) according to the first to third examples of the above-described embodiment may also be applied to the pusher piston 302 and drive piston 306 according to Modification 4. In the above example (FIG. 14), one seal member 40 is provided on the pusher piston 302, but the present invention is not limited to providing one seal member 40 on the pusher piston 302. In the above example (FIG. 15), two seal members 40 are provided on the drive piston 306, but the present invention is not limited to providing two seal members 40 on the drive piston 306.

[0068] REFERENCE SIGNS LIST 1 Motor 3, 3a, 3b Compressor 5 Heat exchanger 11 Rotor 12 Stator 13 Rotating shaft 14 Slide bearing 16 Refrigerant supply passage 33 Cylinder 34 Rotor 34a Groove 40 Sealing member 41 First end 42 Second end 43 Joint portion 45 Spring 61 Orbiting scroll 62 Fixed scroll 63 Housing member 71 Piston 72 Cylinder 100 Refrigerant circulation system 200 Vehicle 300 Magnetized target fusion reactor 301 Rotor portion 302 Pusher piston 303, 307 Movable member 304, 308 Housing member 305 Drive portion 306 Drive piston

Claims

1. A compressor that compresses a refrigerant, comprising: a movable member that operates to compress the refrigerant; a housing member that houses the movable member and defines a space in which the movable member operates to compress the refrigerant; and a sealing member formed in an annular shape and configured to seal a gap between the movable member and the housing member. The sealing member includes a first end portion located at one end, a second end portion located at the other end, and a joining portion where the first end portion and the second end portion engage with each other. The first end portion of the sealing member is provided at one end in the thickness direction orthogonal to the circumferential direction of the sealing member and on the sliding surface side of the movable member or the housing member that slides with the sealing member, and has a first first convex portion protruding in the circumferential direction, a first second convex portion provided at the other end in the thickness direction and on the sliding surface side and protruding in the circumferential direction, and a first concave portion provided between the first first convex portion and the first second convex portion and on the sliding surface side and recessed in the circumferential direction. The second end portion of the sealing member is provided at one end in the thickness direction and on the sliding surface side, and has a second first concave portion recessed in the circumferential direction, a second second concave portion provided at the other end in the thickness direction and on the sliding surface side and recessed in the circumferential direction, and a second convex portion provided between the second first concave portion and the second second concave portion and on the sliding surface side and protruding in the circumferential direction. The sealing member is configured such that when the first end portion and the second end portion engage with each other at the joining portion, the first first convex portion of the first end portion is received in the second first concave portion of the second end portion, the second convex portion of the second end portion is received in the first concave portion of the first end portion, and the first second convex portion of the first end portion is received in the second second concave portion of the second end portion. Compressor, characterized by the above.

2. The compressor according to claim 1, wherein a groove for holding the sealing member is formed in the movable member or the housing member, and further includes a biasing member disposed in the groove and biasing the sealing member toward the sliding surface.

3. The compressor according to claim 1, wherein a groove for holding the sealing member is formed in the movable member or the housing member, and a surface of the sealing member facing the groove or a surface of the groove facing the sealing member is formed in an uneven shape.

4. The compressor according to claim 1, wherein CO2 is used as the refrigerant.

5. A refrigerant circulation system for circulating a refrigerant, comprising: a compressor for compressing the refrigerant according to any one of claims 1 to 4; and a motor to which the refrigerant compressed by the compressor is supplied. The motor includes a rotor and a stator, a rotating shaft connected to the rotor, a sliding bearing for supporting the rotating shaft, and a refrigerant supply passage for supplying the refrigerant compressed by the compressor to the sliding bearing. The sliding bearing of the motor is configured to perform lubrication using the refrigerant supplied from the refrigerant supply passage as a lubricant. A refrigerant circulation system characterized by the above.

6. The refrigerant circulation system according to claim 5, wherein the motor is configured to cool the rotor or the stator using the refrigerant.

7. A piston for compressing and / or transporting a fluid, comprising: a movable member configured to compress and / or transport the fluid; a housing member that houses the movable member and defines a space in which the movable member operates to compress and / or transport the fluid; a sealing member formed in an annular shape and configured to seal a gap between the movable member and the housing member, wherein the sealing member includes a first end portion located at one end, a second end portion located at the other end, and a joining portion where the first end portion and the second end portion engage with each other; the first end portion of the sealing member is provided at one end in the thickness direction orthogonal to the circumferential direction of the sealing member and on the sliding surface side of the movable member or the housing member that slides with the sealing member, and has a first first convex portion protruding in the circumferential direction, a first second convex portion provided at the other end in the thickness direction and on the sliding surface side and protruding in the circumferential direction, and a first concave portion recessed in the circumferential direction and provided between the first first convex portion and the first second convex portion and on the sliding surface side; the second end portion of the sealing member is provided at one end in the thickness direction and on the sliding surface side, and has a second first concave portion recessed in the circumferential direction, a second second concave portion provided at the other end in the thickness direction and on the sliding surface side and recessed in the circumferential direction, and a second convex portion protruding in the circumferential direction and provided between the second first concave portion and the second second concave portion and on the sliding surface side; the sealing member is configured such that when the first end portion and the second end portion engage with each other at the joining portion, the first first convex portion of the first end portion is received in the second first concave portion of the second end portion, the second convex portion of the second end portion is received in the first concave portion of the first end portion, and the first second convex portion of the first end portion is received in the second second concave portion of the second end portion. A piston characterized by the above.

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