Scroll compressor

Abstract

Provided is a scroll compressor having an improved compression ratio. A scroll compressor 10 includes a fixed scroll 21, a movable scroll 20 disposed so as to be able to rotate in relation to the fixed scroll 21, a compression space 22 formed as a gap between the fixed scroll 21 and the movable scroll 20, a shaft 18 that imparts driving force to the movable scroll 20, a fan 17 attached to the shaft 18, and a pre-stage compression chamber 14 in which the fan 17 is housed. In the scroll compressor 10, the fan 17 and the pre-stage compression chamber 14 are disposed on the upstream side of the movable scroll 20 in the flow of a refrigerant 11.

Description

Scroll Compressor

[0001] The present invention relates to a scroll compressor, and more particularly to a scroll compressor capable of increasing the compressibility of a fluid.

[0002] In a typical scroll compressor, a fixed scroll is fixed to a scroll body, and a movable scroll is combined with the fixed scroll so that it can orbit around the fixed scroll. When the scroll compressor is operated, the movable scroll orbits around the orbital center as a rotation axis, and fluid introduced from the periphery of the scroll compressor between the fixed scroll and the movable scroll moves toward the center while being compressed between the two. The fluid that reaches the center is supplied to the outside of the system in a compressed state. A scroll compressor with such a configuration is described, for example, in Patent Document 1.

[0003] Patent No. 4635660

[0004] However, in a scroll compressor having the above-described general configuration, a fluid that is not highly pressurized is introduced into the space between the movable scroll and the fixed scroll, which poses the problem that it is not easy to obtain a high compression ratio.

[0005] Furthermore, if the rotation speed of the motor is increased in order to improve the compression ratio of the scroll compressor, the energy consumed by the scroll compressor increases.

[0006] Furthermore, if a compressor that compresses the fluid is installed in the upstream section of the scroll compressor in order to increase the compression ratio, the fluid pressurized by the compressor can be supplied to the scroll compressor, and a high compression ratio can be obtained. However, since a new separate compressor is required, there is a problem that the entire system becomes more complicated and expensive.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a scroll compressor with an improved compression ratio.

[0008] The scroll compressor of the present invention is a compressor that compresses a refrigerant used in a vapor compression refrigeration cycle, and is characterized in that it comprises a fixed scroll, a movable scroll arranged to be rotatable relative to the fixed scroll, a compression space formed as a gap between the fixed scroll and the movable scroll, a shaft that provides a driving force to the movable scroll, a fan attached to the shaft, and a front-stage compression chamber in which the fan is housed, and the fan and the front-stage compression chamber are arranged upstream of the movable scroll in the flow of the refrigerant.

[0009] In addition, in the scroll compressor of the present invention, the fan has a first fan and a second fan arranged downstream of the first fan, and the pre-stage compression chamber has a first pre-stage compression chamber in which the first fan is accommodated and a second pre-stage compression chamber in which the second fan is accommodated.

[0010] In addition, in the scroll compressor of the present invention, the fan has a main surface portion and an air blowing wall, the main surface portion being a substantially circular surface extending in a direction perpendicular to the axial direction of the shaft, and the air blowing wall being a part of the main surface portion that is partially raised and extends radially outward in a wall-like shape.

[0011] In addition, in the scroll compressor of the present invention, the main surface portion has an upstream main surface portion facing upstream in the flow of the refrigerant and a downstream main surface portion facing downstream in the flow of the refrigerant, and the blowing wall has an upstream blowing wall formed on the upstream main surface portion and a downstream blowing wall formed on the downstream main surface portion.

[0012] In the scroll compressor of the present invention, the upstream blowing wall has a middle portion that is curved so as to bulge in the rotation direction of the fan.

[0013] In the scroll compressor of the present invention, the downstream blowing wall has a middle portion that is curved so as to be recessed in the rotation direction of the fan.

[0014] The scroll compressor of the present invention further includes a fan casing configured to cover the fan, wherein the pre-stage compression chamber is a space formed between an inner wall of the fan casing and the fan, and the fan has an upstream main surface portion facing upstream in the flow of the refrigerant, a downstream main surface portion facing downstream in the flow of the refrigerant, and a side surface portion facing radially outward, and the thickness of the gap between the upstream main surface portion and the inner wall, the thickness of the gap between the downstream main surface portion and the inner wall, and the thickness of the side surface portion and the inner wall are approximately identical.

[0015] In addition, in the scroll compressor of the present invention, the distance between the lower end of the fan and the previous-stage compression chamber in the vertical direction is shorter than the distance between the upper end of the fan and the previous-stage compression chamber.

[0016] In the scroll compressor of the present invention, a protrusion protruding radially outward is formed on a side surface of the fan.

[0017] The scroll compressor according to the present invention is a compressor for compressing a refrigerant used in a vapor compression refrigeration cycle, and includes a fixed scroll, a movable scroll arranged to be rotatable relative to the fixed scroll, a compression space formed as a gap between the fixed scroll and the movable scroll, a shaft for providing a driving force to the movable scroll, a fan attached to the shaft, and a first-stage compression chamber accommodating the fan, the fan and the first-stage compression chamber being located upstream of the movable scroll in the flow of the refrigerant. According to the scroll compressor according to the embodiment of the present invention, rotation of the fan in the first-stage compression chamber allows pressurized refrigerant to be supplied to the compression space, thereby improving the compression efficiency of the scroll compressor.

[0018] In the scroll compressor of the present invention, the fan includes a first fan and a second fan disposed downstream of the first fan, and the pre-compression chamber includes a first pre-compression chamber accommodating the first fan and a second pre-compression chamber accommodating the second fan. According to the scroll compressor of the present invention, by having a plurality of fans and a plurality of pre-compression chambers arranged in series, it is possible to supply a further compressed refrigerant to the compression space.

[0019] In the scroll compressor of the present invention, the fan has a main surface portion and a blowing wall, the main surface portion is a substantially circular surface extending in a direction perpendicular to the axial direction of the shaft, and the blowing wall is a part of the main surface portion that is raised and extends radially outward in a wall-like shape. According to the scroll compressor of the present invention, the blowing wall blows the refrigerant radially outward, thereby enabling more effective compression of the refrigerant.

[0020] In the scroll compressor of the present invention, the main surface portion has an upstream main surface portion facing upstream in the refrigerant flow and a downstream main surface portion facing downstream in the refrigerant flow, and the blast wall has an upstream blast wall formed on the upstream main surface portion and a downstream blast wall formed on the downstream main surface portion. According to the scroll compressor of the present invention, the refrigerant can be compressed inside the front-stage compression chamber by the upstream blast wall and the downstream blast wall, so that the refrigerant can be compressed more effectively.

[0021] In the scroll compressor of the present invention, the upstream blowing wall has a middle portion that is curved so as to bulge in the rotation direction of the fan. According to the scroll compressor of the present invention, when the fan rotates, the upstream blowing wall blows the refrigerant radially outward, thereby more effectively compressing the refrigerant.

[0022] In the scroll compressor of the present invention, the downstream blowing wall has a middle portion that is curved so as to be recessed in the rotation direction of the fan. According to the scroll compressor of the present invention, when the fan rotates, the downstream blowing wall blows the refrigerant radially inward, thereby enabling more effective compression of the refrigerant.

[0023] In addition, the scroll compressor of the present invention further includes a fan casing configured to cover the fan, the pre-stage compression chamber being a space defined between the inner wall of the fan casing and the fan, the fan having an upstream main surface facing upstream in the refrigerant flow, a downstream main surface facing downstream in the refrigerant flow, and a side surface facing radially outward, the thickness of the gap between the upstream main surface and the inner wall being substantially the same as the thickness of the gap between the downstream main surface and the inner wall, and the thickness of the side surface and the inner wall. According to the scroll compressor of the present invention, the refrigerant can be effectively compressed between the inner wall of the fan casing and the fan.

[0024] In the scroll compressor of the present invention, the distance between the lower end of the fan and the first compression chamber in the vertical direction is shorter than the distance between the upper end of the fan and the first compression chamber. According to the scroll compressor of the present invention, the shorter distance between the lower end of the fan and the first compression chamber allows the lubricating oil stored in the lower end of the first compression chamber to be agitated and mixed with the refrigerant in the form of mist.

[0025] In the scroll compressor of the present invention, a protrusion that protrudes radially outward is formed on a side surface of the fan. According to the scroll compressor of the present invention, even if lubricating oil is accumulated at the lower end of the front-stage compression chamber during operation, the protrusion can agitate the lubricating oil and mix it with the refrigerant in a mist state.

[0026] 1 is a perspective view showing a scroll compressor according to an embodiment of the present invention; FIG. 2 is a cutaway perspective view showing a scroll compressor according to an embodiment of the present invention; FIG. 3 is a cross-sectional view showing a scroll compressor according to an embodiment of the present invention; FIG. 4 is a perspective view showing a fan casing of a scroll compressor according to an embodiment of the present invention; FIG. 5 is a cross-sectional view showing a fan casing of a scroll compressor according to an embodiment of the present invention; FIG. 6 is an exploded perspective view of a first fan and a second fan of a scroll compressor according to an embodiment of the present invention, as seen from the front; FIG. 7 is an exploded perspective view of a first fan and a second fan of a scroll compressor according to an embodiment of the present invention, as seen from the rear; FIG. 8 is a front view of a first fan of a scroll compressor according to another embodiment of the present invention, as seen from the front;

[0027] The scroll compressor 10 of this embodiment will be described below with reference to the drawings. In the following description, the same components will be assigned the same reference numerals, and duplicated descriptions will be omitted. Furthermore, in the following description, the terms up, down, front, back, left, and right will be used as appropriate, with the term "front" referring to the upstream side of the fluid flow inside the scroll compressor 10, and the term "rear" referring to the opposite side of the front. Furthermore, the terms "left" and "right" refer to the left and right sides when the scroll compressor 10 is viewed from the front.

[0028] 1A is a perspective view of a scroll compressor 10. FIG. 1B is a cutaway perspective view of the scroll compressor 10.

[0029] 1A and 1B, a scroll compressor 10 is a compressor that compresses a refrigerant 11 used in a vapor compression refrigeration cycle. The scroll compressor 10 is connected to a condenser, an expansion means, and an evaporator (not shown) via piping (not shown). Such a refrigeration cycle is used, for example, as an air conditioner for cooling or heating the passenger compartment of a vehicle.

[0030] The refrigeration cycle according to this embodiment is, for example, a mist lubrication system. In this mist lubrication system, lubricating oil dissolved in a refrigerant 11 (described later) is circulated through the refrigeration cycle together with the refrigerant 11, and the sliding parts of the compressor are lubricated by the mist of lubricating oil contained in the gaseous refrigerant 11. As described later, this embodiment has a mechanism for re-mistifying the liquefied lubricating oil, so that the refrigerant 11 always contains the mist of lubricating oil, and each device is kept in a lubricated state.

[0031] 1A and 1B, in scroll compressor 10, each component functioning as scroll compressor 10 is housed inside casing 31. Referring to Fig. 1B, fan casing 15 and motor 23 are housed on the front side of casing 31.

[0032] FIG. 2 is a cross-sectional view showing the scroll compressor 10.

[0033] 2, arranged inside casing 31 from the front side are intake port 13, front chamber 19, fan casing 15, partition wall 12, motor housing chamber 16, motor 23, movable scroll 20, fixed scroll 21, compression space 22, and discharge port 24. Furthermore, shaft 18 is arranged in the center of casing 31. Although not shown here, an orbiting mechanism that converts the rotational motion of shaft 18 into orbiting motion of movable scroll 20 is arranged in front of movable scroll 20.

[0034] The intake port 13 is an opening formed in the front surface of the casing 31. The refrigerant 11 is drawn in through the intake port 13.

[0035] The front chamber 19 is a space formed at the front end of the casing 31. The front chamber 19 is a space that houses the fan casing 15.

[0036] The fan casing 15 is a case-shaped member for accommodating a fan 17, which will be described later. The front end of the fan casing 15 is connected to the intake port 13. The rear end of the fan casing 15 communicates with the motor housing chamber 16.

[0037] The fan 17 is attached to the shaft 18 so as not to rotate relative to the shaft 18. The fan 17 has a function of compressing the refrigerant 11 introduced into the compression space 22 on the upstream side. This function will be described later with reference to Fig. 4 etc. In this embodiment, the fan 17 and a pre-stage compression chamber 14 (described later) are arranged upstream of the movable scroll 20, the fixed scroll 21, and the compression space 22 in the flow of the refrigerant 11.

[0038] The partition wall 12 is a wall-shaped member that separates the front chamber 19 and the motor storage chamber 16 inside the casing 31. A through hole is formed in approximately the center of the partition wall 12, and the front chamber 19 and the motor storage chamber 16 communicate with each other via the through hole.

[0039] The motor storage chamber 16 is a space in which the motor 23 is stored.

[0040] The motor 23 includes a rotor 25 and a stator 26. In this embodiment, the motor 23 rotates the movable scroll 20 and also rotates the fan 17.

[0041] The rotor 25 includes a plurality of magnets (not shown) arranged at approximately equal intervals along the circumferential direction. A through-hole is formed in the radial center of the rotor 25, and the shaft 18 is inserted through the through-hole. The rotor 25 and the shaft 18 are connected to each other so that they cannot rotate relative to each other. Therefore, when the rotor 25 rotates, the shaft 18 also rotates.

[0042] The stator 26 is made up of a stator core 261 and a coil 262. The stator core 261 is fitted inside the casing 31. The stator core 261 is also called an iron core. A coil 262 is wound around the stator core 261. AC power of a predetermined frequency is supplied to the coil 262 from an inverter (not shown). The stator 26 forms an electromagnet.

[0043] The shaft 18 is a generally cylindrical steel rod that provides driving force to the movable scroll 20. The front end of the shaft 18 is connected to the fan 17 so as not to rotate relative to it, the middle portion of the shaft 18 is connected to the rotor 25 so as not to rotate relative to it, and the rear end of the shaft 18 is connected to an orbiting mechanism that orbits the movable scroll 20. This orbiting mechanism is not shown here. The shaft 18 is rotatably fixed to the casing 31 via a bearing or the like.

[0044] The movable scroll 20 is connected to the rear end of the shaft 18 so as not to rotate relative to the fixed scroll 21, and is arranged so as to be able to orbit with respect to the fixed scroll 21. The movable scroll 20 orbits by rotating together with the shaft 18.

[0045] The fixed scroll 21 is fixed to the inner surface of the rear portion of the casing 31 .

[0046] The compression space 22 is formed as a gap between the fixed scroll 21 and the movable scroll 20 .

[0047] The discharge port 24 is a through-hole that penetrates the rear surface of the casing 31. The discharge port 24 communicates with the compression space 22.

[0048] 2, the flow of the refrigerant 11 inside the scroll compressor 10 will be described. In FIG. 2, the flow of the refrigerant 11 inside the scroll compressor 10 is indicated by a broken line.

[0049] First, the refrigerant 11 is introduced into the scroll compressor 10 via the intake port 13. Here, the refrigerant 11 has passed through an evaporator and is introduced into the scroll compressor 10. Next, the refrigerant 11 is introduced into the fan casing 15. The refrigerant 11 is pre-compressed by the rotation of the fan casing 15. The refrigerant 11 pre-compressed in the fan casing 15 is introduced into the motor housing chamber 16. The refrigerant 11 is then introduced into the compression space 22, where it is further compressed by the orbiting of the movable scroll 20. The refrigerant 11 is then discharged to the outside of the scroll compressor 10 via the discharge port 24. The refrigerant 11 is then sent to the condenser via piping.

[0050] As will be described later, according to this embodiment, the rotation of the fan 17 in the front-stage compression chamber 14 allows pressurized refrigerant 11 to be supplied to the compression space 22, thereby improving the compression efficiency of the scroll compressor 10.

[0051] FIG. 3 is a perspective view showing the fan casing 15 of the scroll compressor 10.

[0052] The fan casing 15 is a generally cylindrical member having a central axis along the front-rear direction. The side of the fan casing 15 is disposed so as to abut against the inner surface of the casing 31 shown in FIG. 2. The fan 17 described above is housed inside the fan casing 15. A front-stage inlet 32 ​​is formed in the center of the front of the fan casing 15. The front-stage inlet 32 ​​is connected to the intake 13 shown in FIG. 2.

[0053] 4 is a cross-sectional view showing the fan casing 15 of the scroll compressor 10. In FIG. 4, the flow of the refrigerant 11 is indicated by dashed arrows.

[0054] The fan casing 15 is made of a metal member configured to cover the fan 17 .

[0055] The fan 17 includes a first fan 28 and a second fan 29. The first fan 28 is disposed upstream of the second fan 29 in the flow of the refrigerant 11.

[0056] The pre-compression chamber 14 is a space formed between the inner wall 27 of the fan casing 15 and the fan 17. The pre-compression chamber 14 is located upstream of the compression space 22 and is a space for performing pre-compression of the refrigerant 11. In other words, the pre-compression chamber 14 is also a space for supercharging the refrigerant 11 to the compression space 22 located downstream.

[0057] The front-stage compression chamber 14 has a first front-stage compression chamber 141 that houses the first fan 28, and a second front-stage compression chamber 142 that houses the second fan 29. The first front-stage compression chamber 141 is a space formed between the inner wall 27 and the first fan 28. The second front-stage compression chamber 142 is a space formed between the inner wall 27 and the second fan 29. The second front-stage compression chamber 142 is located downstream of the first front-stage compression chamber 141. The first front-stage compression chamber 141 and the second front-stage compression chamber 142 are continuous spaces.

[0058] Inside the fan casing 15 , the refrigerant 11 flows through the front-stage inlet 32 ​​, the first front-stage compression chamber 141 , the second front-stage compression chamber 142 , and the front-stage discharge port 33 in this order.

[0059] The first fan 28 has main surface portions, that is, a first upstream main surface portion 281 and a first downstream main surface portion 282, and a first side surface portion 285. The first upstream main surface portion 281 is a main surface facing forward, the first downstream main surface portion 282 is a main surface facing rearward, and the first side surface portion 285 is a surface facing in the radial direction.

[0060] In the first fan 28, the thickness L10 of the gap between the first upstream main surface portion 281 and the inner wall 27, the thickness L11 of the gap between the first downstream main surface portion 282 and the inner wall 27, and the thickness L12 of the gap between the first side surface portion 285 and the inner wall 27 are all substantially the same. For example, when comparing L10, L11, and L12, any one is equal to or less than twice the other two, preferably equal to or less than 1.5 times, and particularly preferably equal to or less than 1.2 times. Furthermore, when comparing L10, L11, and L12, any one is equal to or more than 0.5 times the other two, preferably equal to or more than 0.75 times, and particularly preferably equal to or more than 0.9 times. This allows the refrigerant 11 to flow smoothly through the first pre-stage compression chamber 141, enabling the refrigerant 11 to be effectively compressed.

[0061] The same applies to the second front-stage compression chamber 142 .

[0062] Fig. 5A is an exploded perspective view of the first fan 28 and the second fan 29 of the scroll compressor 10 as seen from the front. Fig. 5B is an exploded perspective view of the first fan 28 and the second fan 29 of the scroll compressor 10 as seen from the rear.

[0063] Referring to FIG. 5A, the fan 17 has, from the front side, a first fan 28 and a second fan 29 .

[0064] 5A and 5B , as described above, the first fan 28 has a first upstream main surface 281, a first downstream main surface 282, and a first side surface 285. The first upstream main surface 281 is a substantially circular surface extending in a direction perpendicular to the axial direction of the shaft 18 and facing upstream in the flow of the refrigerant 11. The first downstream main surface 282 is a substantially circular surface extending in a direction perpendicular to the axial direction of the shaft 18 and facing downstream in the flow of the refrigerant 11. A first insertion hole 286 is formed in the center of the first fan 28, and a first insertion hole 296 is formed in the center of the second fan 29. The shaft 18 described above is inserted into the first insertion hole 286 and the first insertion hole 296.

[0065] As shown in FIG. 5A , a first upstream blowing wall 283 is formed on the first upstream main surface 281. The first upstream blowing wall 283 is a portion of the first upstream main surface 281 that is partially raised forward and extends radially outward in a wall-like shape. An intermediate portion of the first upstream blowing wall 283 has a curved shape that bulges toward the rotation direction of the fan 17. Here, the rotation direction is counterclockwise when viewed from the front of the first fan 28. Furthermore, a plurality of first upstream blowing walls 283 are formed on the first upstream main surface 281, spaced apart at substantially equal angular intervals along the circumferential direction. When the first fan 28 rotates counterclockwise, as shown in FIG. 4 , in the first pre-stage compression chamber 141 surrounded by the first upstream main surface 281 and the inner wall 27, the refrigerant 11 flows radially outward from the center of the first fan 28.

[0066] As shown in Fig. 5B , a first downstream blowing wall 284 is formed on the first downstream main surface 282. The first downstream blowing wall 284 is a portion of the first upstream main surface 281 that is partially raised rearward and extends radially outward in a wall-like shape. An intermediate portion of the first downstream blowing wall 284 has a curved shape that is recessed in the counterclockwise direction, which is the rotation direction of the fan 17. When the first fan 28 rotates counterclockwise, as shown in Fig. 4 , in the first front-stage compression chamber 141 surrounded by the first downstream main surface 282 and the inner wall 27, the refrigerant 11 flows radially inward from the periphery of the first fan 28.

[0067] The second fan 29 has the same configuration as described above. That is, with reference to Figures 5A and 5B, the second fan 29 has a second upstream main surface portion 291, a second downstream main surface portion 292, and a second side surface portion 295. In addition, a second upstream air-blowing wall 293 is formed on the second upstream main surface portion 291, and a second downstream air-blowing wall 294 is formed on the second downstream main surface portion 292.

[0068] Referring again to FIG. 4 , the effects of the walls formed on the first fan 28 and the second fan 29 will be described. First, the refrigerant 11 introduced from the front-stage inlet 32 ​​enters between the inner wall 27 and the first upstream main surface 281. As described above, the first upstream blowing wall 283 is formed on the first upstream main surface 281. Therefore, as the first fan 28 rotates, the first upstream blowing wall 283 blows the refrigerant 11 radially outward. Then, the refrigerant 11 passes between the first side surface 285 and the inner wall 27, and is blown between the first downstream main surface 282 and the inner wall 27. Then, the first downstream blowing wall 284 formed on the first downstream main surface 282 blows the refrigerant 11 radially inward. That is, the first upstream blowing wall 283 blows the refrigerant 11 radially outward, and then the first downstream blowing wall 284 blows the refrigerant 11 radially inward. Therefore, by blowing the refrigerant 11 on both the first upstream main surface 281 side and the first downstream main surface 282 side of the first fan 28, the refrigerant 11 can be compressed more effectively.

[0069] The same applies to the second fan 29. That is, the second upstream blowing wall 293 of the second fan 29 blows the refrigerant 11 radially outward, and the second downstream blowing wall 294 blows the refrigerant 11 radially inward. This further compresses the refrigerant 11, increasing the supercharging effect.

[0070] FIG. 6 is a front view of the first fan 28 of the scroll compressor 10 as seen from the front.

[0071] Here, the first fan 28 is disposed eccentrically downward inside the first front-stage compression chamber 141. In this manner, in the vertical direction, a distance L20 between the lower end of the first fan 28 and the inner wall 27 is shorter than a distance L21 between the upper end of the fan 17 and the inner wall 27. For example, the ratio of L20 to L21 can be 2 / 3 or less, or 1 / 2 or less.

[0072] This configuration prevents lubricating oil from accumulating inside the first pre-stage compression chamber 141. Specifically, as described above, the scroll compressor 10 of this embodiment uses a mist lubrication system. Therefore, when the scroll compressor 10 is operated, the lubricating oil contained in the refrigerant 11 inside the first pre-stage compression chamber 141 may separate from the refrigerant 11, causing the lubricating oil to accumulate at the lower end of the first pre-stage compression chamber 141. In FIG. 6 , the lubricating oil accumulating at the lower end of the first pre-stage compression chamber 141 is indicated by color. If this continues, the refrigerant 11 will not contain a sufficient amount of lubricating oil. Therefore, in a vapor compression refrigeration cycle, equipment having moving parts, such as the scroll compressor 10, may not be sufficiently lubricated, which may shorten the life of the equipment.

[0073] In this embodiment, the first side surface portion 285 is disposed eccentrically downward. Therefore, when the first fan 28 rotates during operation of the scroll compressor 10, the first upstream blowing wall 283 agitates the stored lubricating oil, turning the lubricating oil into a mist again inside the first pre-stage compression chamber 141 and mixing it with the refrigerant 11. Therefore, the lubricating oil in a mist state can be supplied to each device of the vapor compression refrigeration cycle together with the refrigerant 11, thereby extending the life of the devices.

[0074] FIG. 7 is a front view of the first fan 28 of the scroll compressor 10 according to another embodiment, as viewed from the front.

[0075] Here, protrusions 30 that protrude radially outward are formed on a first side surface 285, which is the outer peripheral surface of the first fan 28. The protrusions 30 are arranged at approximately equal intervals along the circumferential direction on the first side surface 285. Here, in the up-down direction, the first fan 28 may be arranged at the center of the first front-stage compression chamber 141, or may be arranged eccentrically downward as shown in FIG. 7. The protrusions 30 are also called slingers.

[0076] The protrusions 30 can turn the lubricating oil accumulated in the lower part of the first pre-stage compression chamber 141 into a mist. Specifically, when the first fan 28 rotates during operation of the scroll compressor 10, the protrusions 30 agitate the accumulated lubricating oil, turning the lubricating oil into a mist again inside the first pre-stage compression chamber 141 and mixing it with the refrigerant 11. As a result, the lubricating oil in a mist state can be supplied to each device of the vapor compression refrigeration cycle together with the refrigerant 11, thereby extending the life of the devices.

[0077] Although the embodiments of the present invention have been described above, the present invention is not limited to these and can be modified within the scope of the present invention. In addition, the above-described embodiments can be combined with each other.

[0078] For example, referring to FIG. 2, the motor 23 does not necessarily have to be housed within the casing 31, and the motor 23 can also be disposed outside the casing 31.

[0079] REFRIGERATION POINTS 10 Scroll compressor 11 Refrigerant 12 Partition wall 13 Inlet 14 Pre-stage compression chamber 141 First pre-stage compression chamber 142 Second pre-stage compression chamber 15 Fan casing 16 Motor housing chamber 17 Fan 18 Shaft 19 Front chamber 20 Orbiting scroll 21 Fixed scroll 22 Compression space 23 Motor 24 Discharge port 25 Rotor 26 Stator 261 Stator core 262 Coil 27 Inner wall 28 First fan 281 First upstream main surface portion 282 First downstream main surface portion 283 First upstream blowing wall 284 First downstream blowing wall 285 First side surface portion 286 First insertion hole 29 Second fan 291 Second upstream main surface portion 292 Second downstream main surface portion 293 Second upstream blowing wall 294 Second downstream blowing wall 295 Second side surface portion 296 First insertion hole 30 Projection portion 31 Casing 32 Former stage inlet 33 Former stage outlet

Claims

1. A scroll compressor that compresses a refrigerant used in a vapor compression refrigeration cycle, comprising: a fixed scroll; a movable scroll arranged to be rotatable relative to the fixed scroll; a compression space formed as a gap between the fixed scroll and the movable scroll; a shaft that provides a driving force to the movable scroll; a fan attached to the shaft; and a front-stage compression chamber in which the fan is housed, wherein the fan and the front-stage compression chamber are arranged upstream of the movable scroll in the flow of the refrigerant.

2. A scroll compressor as described in claim 1, characterized in that the fan comprises a first fan and a second fan arranged downstream of the first fan, and the pre-stage compression chamber comprises a first pre-stage compression chamber in which the first fan is housed, and a second pre-stage compression chamber in which the second fan is housed.

3. The scroll compressor according to claim 1, characterized in that the fan has a main surface portion and a blowing wall, the main surface portion being a substantially circular surface extending in a direction perpendicular to the axial direction of the shaft, and the blowing wall being a partially raised portion of the main surface portion and extending radially outward in a wall-like manner.

4. A scroll compressor as described in claim 3, characterized in that the main surface portion has an upstream main surface portion facing the upstream side in the flow of the refrigerant, and a downstream main surface portion facing the downstream side in the flow of the refrigerant, and the blowing wall has an upstream blowing wall formed on the upstream main surface portion, and a downstream blowing wall formed on the downstream main surface portion.

5. A scroll compressor as claimed in claim 4, characterized in that the intermediate portion of the upstream blowing wall is curved so as to bulge in the direction of rotation of the fan.

6. A scroll compressor as claimed in claim 4 or 5, characterized in that the intermediate portion of the downstream blowing wall has a curved shape that is recessed in the direction of rotation of the fan.

7. A scroll compressor as described in claim 1, further comprising a fan casing configured to cover the fan, the pre-stage compression chamber being a space formed between an inner wall of the fan casing and the fan, the fan having an upstream main surface portion facing upstream in the flow of the refrigerant, a downstream main surface portion facing downstream in the flow of the refrigerant, and a side surface portion facing radially outward, the thickness of the gap between the upstream main surface portion and the inner wall, the thickness of the gap between the downstream main surface portion and the inner wall, and the thickness of the side surface portion and the inner wall being approximately the same.

8. A scroll compressor as claimed in claim 1, characterized in that the distance between the lower end of the fan and the previous-stage compression chamber in the vertical direction is shorter than the distance between the upper end of the fan and the previous-stage compression chamber.

9. The scroll compressor according to claim 1, wherein a protrusion protruding radially outward is formed on a side surface of said fan.

10. A scroll compressor as claimed in claim 1, further comprising a fan casing configured to cover the fan, the front-stage compression chamber being a space formed between an inner wall of the fan casing and the fan, the fan having an upstream main surface portion facing upstream in the flow of the refrigerant, a downstream main surface portion facing downstream in the flow of the refrigerant, and a side portion facing radially outward, wherein, when the thickness of the gap between the upstream main surface portion and the inner wall is L10, the thickness of the gap between the downstream main surface portion and the inner wall is L11, and the thickness of the gap between the side portion and the inner wall is L12, a comparison of L10, L11 and L12 reveals that any one of them is less than twice the other two.

11. A compressor for compressing a refrigerant used in a vapor compression refrigeration cycle, comprising: a fixed scroll; a movable scroll arranged to be rotatable relative to the fixed scroll; a compression space formed as a gap between the fixed scroll and the movable scroll; a shaft for providing a driving force to the movable scroll; a fan attached to the shaft; and a front-stage compression chamber in which the fan is housed; the fan and the front-stage compression chamber are arranged upstream of the movable scroll in the flow of the refrigerant; and the compressor further comprises a fan casing configured to cover the fan, the front-stage compression chamber being a space formed between an inner wall of the fan casing and the fan, the fan having an upstream main surface portion facing the upstream side in the flow of the refrigerant, a downstream main surface portion facing the downstream side in the flow of the refrigerant, and a side surface portion facing radially outward; A scroll compressor characterized in that, when the thickness of the gap between the upstream main surface portion and the inner wall is L10, the thickness of the gap between the downstream main surface portion and the inner wall is L11, and the thickness of the gap between the side surface portion and the inner wall is L12, when L10, L11 and L12 are compared, any one of them is less than twice the other two, and a protrusion that protrudes radially outward is formed on the side surface portion.

12. The scroll compressor according to claim 11, characterized in that, when comparing L10, L11 and L12, any one of them is 1.5 times or less than the other two.

13. The scroll compressor according to claim 11, characterized in that, when comparing L10, L11 and L12, any one of them is 1.2 times or less than the other two.

14. A compressor for compressing a refrigerant used in a vapor compression refrigeration cycle, comprising: a fixed scroll; a movable scroll arranged to be rotatable relative to the fixed scroll; a compression space formed as a gap between the fixed scroll and the movable scroll; a shaft for providing a driving force to the movable scroll; a fan attached to the shaft; and a front-stage compression chamber in which the fan is housed; the fan and the front-stage compression chamber are arranged upstream of the movable scroll in the flow of the refrigerant; and the compressor further comprises a fan casing configured to cover the fan, the front-stage compression chamber being a space formed between an inner wall of the fan casing and the fan, the fan having an upstream main surface portion facing the upstream side in the flow of the refrigerant, a downstream main surface portion facing the downstream side in the flow of the refrigerant, and a side surface portion facing radially outward; a scroll compressor characterized in that, when the thickness of the gap between the upstream main surface portion and the inner wall is L10, the thickness of the gap between the downstream main surface portion and the inner wall is L11, and the thickness of the gap between the side surface portion and the inner wall is L12, a comparison of L10, L11, and L12 reveals that any one of them is less than twice the other two, and a distance between a lower end of the fan and the inner wall in the vertical direction is shorter than a distance between an upper end of the fan and the inner wall.

15. A scroll compressor as claimed in claim 14, characterized in that, when the distance between the lower end of the fan and the inner wall is L20 and the distance between the upper end of the fan and the inner wall is L21, the ratio of L20 to L21 is 2 / 3 or less.

16. A scroll compressor as claimed in claim 14, characterized in that, when the distance between the lower end of the fan and the inner wall is L20 and the distance between the upper end of the fan and the inner wall is L21, the ratio of L20 to L21 is 1 / 2 or less.

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