Centrifugal air compressor and fuel cell system

Abstract

Embodiments of the present application provide a centrifugal air compressor and a fuel cell system. The centrifugal air compressor comprises a base, a motor body, and a bearing assembly; the motor body is arranged in a cavity formed in the base and comprises a motor stator, a motor rotor and a rotating shaft, the motor rotor is arranged on the rotating shaft, and the rotating shaft is rotatably mounted in the base by means of the bearing assembly; the bearing assembly comprises a first bearing base comprising a first air cooling channel, a second air cooling channel and a bearing accommodating space, a first radial bearing, and a thrust bearing assembly, the first radial bearing and the thrust bearing assembly are arranged on the first bearing base, at least part of the structure of the thrust bearing assembly is located in the bearing accommodating space, the first air cooling channel is communicated with the cavity at least through the first radial bearing, and the second air cooling channel is at least communicated with the bearing accommodating space. The centrifugal air compressor in the embodiments of the present application has a good cooling effect.

Description

A centrifugal air compressor and fuel cell system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 2023116099143 and application date of November 29, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present application relates to the field of fuel cells, and in particular to a centrifugal air compressor and a fuel cell system. Background Art

[0004] The performance of the air compressor for fuel cells is directly related to the performance of the fuel cell system. A high-efficiency, high-pressure ratio centrifugal air compressor can provide high-pressure air for the fuel cell, thereby improving the power density and performance of the fuel cell.

[0005] When a centrifugal air compressor is working, a large amount of heat will be generated inside the air compressor. Excessive temperature will cause the internal components of the air compressor to be damaged due to overheating. Therefore, the internal components of the air compressor need to be cooled and dissipated.

[0006] However, in the related art, the cooling scheme for the air compressor mainly focuses on cooling the stator and rotor in the inner cavity of the air compressor, while less consideration is given to the cooling of the internal bearings. Since the air compressor will also cause the bearings to generate a large amount of heat when running at high speed, the cooling scheme in the related art is difficult to achieve a good cooling effect for the air compressor as a whole.

[0007] Summary of the Invention

[0008] In view of this, the embodiments of the present application hope to provide a centrifugal air compressor and fuel cell system with better cooling effect.

[0009] To achieve the above objectives, an embodiment of the present application provides a centrifugal air compressor, comprising:

[0010] A machine base, wherein the machine base is formed with a cavity;

[0011] a motor body, the motor body comprising a motor stator, a motor rotor and a rotating shaft, the motor stator being arranged in the cavity, the motor rotor being arranged on the rotating shaft and located in the cavity;

[0012] A bearing assembly, wherein the rotating shaft is rotatably mounted in the machine base through the bearing assembly, wherein the bearing assembly includes a first bearing seat, a first radial bearing and a thrust bearing assembly; the first bearing seat has a first gas cooling channel, a second gas cooling channel and a bearing accommodating space, the first bearing seat is arranged at one end of the machine base along the axial direction of the rotating shaft, the first radial bearing and the thrust bearing assembly are arranged on the first bearing seat, and at least part of the structure of the thrust bearing assembly is located in the bearing accommodating space, the first gas cooling channel is connected to the cavity at least through the first radial bearing, and the second gas cooling channel is connected to at least the bearing accommodating space.

[0013] In one embodiment, the first radial bearing is sleeved on the motor rotor, and a first gap is defined between the first radial bearing and the motor rotor, and the first gas cooling channel is connected to the cavity at least through the first gap.

[0014] In one embodiment, the bearing seat has an air hole, the air hole is located on a side of the first radial bearing away from the rotating shaft, and the first gas cooling channel is connected to the cavity through the air hole.

[0015] In one embodiment, the bearing seat has at least one bearing exhaust hole, and the bearing exhaust hole is connected to the bearing accommodating space; and / or,

[0016] The machine base has a machine base exhaust hole communicated with the inner cavity, and the machine base exhaust hole is located on a side of the air gap between the motor stator and the motor rotor away from the first bearing seat.

[0017] In one embodiment, the thrust bearing assembly includes a thrust bearing and a thrust plate, the thrust bearing includes a first thrust bearing and a second thrust bearing, the thrust plate is sleeved on the rotating shaft, and at least part of the structure of the thrust plate is located in the bearing accommodating space, the first thrust bearing and the second thrust bearing are respectively arranged on opposite sides of the thrust plate along the axial direction of the rotating shaft, and are located in the bearing accommodating space.

[0018] In one embodiment, the first bearing seat includes a first sub-bearing seat having a first gas cooling channel and a second sub-bearing seat having a second gas cooling channel. The second sub-bearing seat is located on the side of the first sub-bearing seat away from the cavity, and the first sub-bearing seat and the second sub-bearing seat jointly define the bearing accommodating space.

[0019] In one embodiment, the first sub-bearing seat has a first axial hole communicating with the bearing accommodating space, and the first sub-bearing seat has at least one first cooling groove on a side close to the bearing accommodating space, the first cooling groove is located on a circumferential side of the first axial hole, and the first gas cooling channel is communicated with the first cooling groove through the first axial hole; and / or,

[0020] The second sub-bearing seat has a second axial hole connected to the bearing accommodating space, and the second sub-bearing seat has at least one second cooling groove on the side close to the bearing accommodating space. The second cooling groove is located on the circumferential side of the first axial hole, and the second gas cooling channel is connected to the second cooling groove through the second axial hole.

[0021] In one embodiment, a first annular boss having a first exhaust port is provided on one side of the first sub-bearing seat, and a second annular boss having a second exhaust port is provided on one side of the second sub-bearing seat, and one of the first annular boss and the second annular boss extends into the other to define the bearing accommodating space, and the first exhaust groove is connected to the bearing exhaust hole to jointly form a bearing exhaust hole.

[0022] In one embodiment, the first sub-bearing seat further has an air intake hole, and the air intake hole is connected to the second cooling channel.

[0023] In one embodiment, the bearing seat has a second sealing member, and the second sealing member is sandwiched between the first sub-bearing seat and the second sub-bearing seat.

[0024] In one embodiment, the bearing assembly further comprises a first seal, which is sandwiched between the bearing seat and the machine base.

[0025] In one embodiment, the machine base has a third gas cooling channel and at least one machine base air outlet, the third gas cooling channel is spirally arranged along the circumference of the cavity, and the third gas cooling channel is connected to the first gas cooling channel and the second gas cooling channel through the machine base air outlet.

[0026] In one embodiment, the machine base further has a water cooling channel, which is located between the third gas cooling channel and the motor stator and is spirally arranged along the circumference of the cavity.

[0027] In one embodiment, the base includes a casing and an inner cylinder disposed in the casing, the motor stator is disposed in the inner cylinder, the casing has the third gas cooling channel, and the inner cylinder and the casing jointly define the water cooling channel.

[0028] In one embodiment, the machine base has an inner cylinder seal, and the inner cylinder seal is sandwiched between the machine housing and the inner cylinder.

[0029] In one embodiment, the outlet of the water cooling channel and the inlet of the water cooling channel pass through the third gas cooling channel arranged in a spiral, and the third gas cooling channel is arranged in a spiral with unequal pitches, and the pitch of the opposite ends of the third gas cooling channel along the axial direction of the rotating shaft is greater than the pitch of the third gas channel between the outlet and the inlet.

[0030] In one embodiment, the machine base has two machine base air outlets, one of the two machine base air outlets is communicated with the first gas cooling channel, and the other of the two machine base air outlets is communicated with the second gas cooling channel.

[0031] In one embodiment, the centrifugal air compressor includes a second sealing component, and the bearing assembly also includes a second radial bearing and a second bearing seat, the second bearing seat is arranged on the side of the machine base away from the first bearing seat along the axial direction, the second radial bearing is arranged on the second radial bearing seat and is sleeved on the motor rotor, the second sealing component is arranged on the side of the second bearing seat away from the cavity, the second bearing seat and the second sealing component jointly define a fourth gas cooling channel, and the fourth gas cooling channel is connected to the cavity at least through the second radial bearing.

[0032] In one embodiment, the second sealing component has an air inlet, and the air inlet is communicated with the fourth gas cooling channel.

[0033] In one embodiment, the centrifugal air compressor has a connecting pipe, a first volute and a second volute, the first volute and the second volute are respectively arranged on opposite sides of the machine base along the axial direction, and the inlet of the first volute is connected to the outlet of the second volute through the connecting pipe, and the first gas cooling channel and the second gas cooling channel are both connected to the connecting pipe.

[0034] Another embodiment of the present application provides a fuel cell system, including any one of the centrifugal air compressors described above.

[0035] The present invention provides a centrifugal air compressor and fuel cell system. The centrifugal air compressor includes a first bearing seat having a first cooling channel, a second cooling channel, and a bearing accommodating space. A first radial bearing is disposed on the first bearing seat. The first cooling channel is connected to a cavity at least through the first radial bearing, thereby cooling the first radial bearing. At least a portion of the thrust bearing assembly is located in the bearing accommodating space, and the second cooling channel is connected to at least the bearing accommodating space. During operation of the centrifugal air compressor, cooling gas in the first cooling channel can enter the cavity from the first radial bearing, thereby cooling both the first radial bearing and components such as the motor stator and motor rotor within the cavity. Cooling gas in the second cooling channel can enter the bearing accommodating space to cool the thrust bearing assembly. Because the centrifugal air compressor of the present invention can not only cool components such as the motor stator and motor rotor within the cavity, but also effectively cool the first radial bearing and thrust bearing assembly, the centrifugal air compressor of the present invention has a good cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a cross-sectional view of a centrifugal air compressor according to an embodiment of the present application;

[0037] FIG2 is a schematic diagram of the base structure of the centrifugal air compressor shown in FIG1 ;

[0038] FIG3 is a perspective view of the centrifugal air compressor shown in FIG1 ;

[0039] FIG4 is a partial enlarged view of point A in FIG1 , wherein the dotted arrows in the figure indicate the direction of air flow;

[0040] FIG5 is a partial enlarged view of point B in FIG1 , wherein the dotted arrows in the figure indicate the direction of air flow;

[0041] FIG6 is a perspective view of the first bearing seat shown in FIG1 ;

[0042] FIG7 is a front view of the first bearing seat shown in FIG1 ;

[0043] FIG8 is a cross-sectional view of CC in FIG7;

[0044] FIG9 is a cross-sectional view at DD in FIG7 ;

[0045] FIG10 is a cross-sectional view of a point EE in FIG7 ;

[0046] FIG11 is a schematic structural diagram of the first sub-bearing seat shown in FIG6 ;

[0047] FIG12 is a schematic structural diagram of the first sub-bearing seat shown in FIG11 at another angle;

[0048] FIG13 is a schematic structural diagram of the second sub-bearing seat shown in FIG6 . DETAILED DESCRIPTION

[0049] An embodiment of the present application provides a centrifugal air compressor. Please refer to FIG1 . The centrifugal air compressor includes a base 10 , a motor body 20 and a bearing assembly 30 .

[0050] The base 10 is formed with a cavity 10 a , and the motor body 20 is disposed in the cavity 10 a .

[0051] The motor body 20 includes a motor stator 21 , a motor rotor 22 and a rotating shaft 23 . The motor stator 21 is disposed in the cavity 10 a . The motor rotor 22 is disposed on the rotating shaft 23 and is located in the cavity 10 a . The rotating shaft 23 is rotatably mounted in the base 10 through a bearing assembly 30 .

[0052] The bearing assembly 30 includes a first bearing seat 31, a first radial bearing 33 and a thrust bearing assembly 35. The first bearing seat 31 has a first gas cooling channel 311a, a second gas cooling channel 312a and a bearing accommodating space 31c. The first bearing seat 31 is arranged at one end of the machine base 10 along the axial direction of the rotating shaft 23. The first radial bearing 33 and the thrust bearing assembly 35 are arranged on the first bearing seat 31, and at least part of the structure of the thrust bearing assembly 35 is located in the bearing accommodating space 31c.

[0053] The first gas cooling channel 311 a and the second gas cooling channel 312 a are used for cooling gas to pass through.

[0054] The thrust bearing assembly 35 may have only a portion of its structure located in the bearing accommodating space 31 c , or may have its entire structure located in the bearing accommodating space 31 c .

[0055] Referring to Figure 4 , the first gas cooling channel 311a communicates with the cavity 10a at least through the first radial bearing 33. In other words, the cooling gas in the first gas cooling channel 311a flows through at least the first radial bearing 33. The cooling gas in the first gas cooling channel 311a cools the first radial bearing 33 as it flows through it. After entering the cavity 10a, the cooling gas continues to cool components such as the motor stator 21 and rotor 22 within the cavity 10a.

[0056] The path of the cooling gas flowing through the first radial bearing 33 is not limited. For example, please refer to Figure 4. The first radial bearing 33 is mounted on the motor rotor 22, and a first gap 33a is defined between the first radial bearing 33 and the motor rotor 22. The first gas cooling channel 311a is connected to the cavity 10a at least through the first gap 33a. The cooling gas cools the first radial bearing 33 when flowing through the first gap 33a.

[0057] In some embodiments, a gap (not shown) may be provided between the first radial bearing 33 and the first bearing seat 31. The first cooling channel may communicate with the cavity 10a through the gap, and the cooling gas may cool the first radial bearing 33 when flowing through the gap. In other embodiments, the first radial bearing 33 may also have one or more holes (not shown) for the cooling gas to flow through.

[0058] The second gas cooling channel 312 a is in communication with at least the bearing accommodating space 31 c . The cooling gas in the second gas cooling channel 312 a can at least enter the bearing accommodating space 31 c , thereby cooling the thrust bearing assembly 35 .

[0059] An embodiment of the present application also provides a fuel cell system, which includes the centrifugal air compressor provided by any embodiment of the present application.

[0060] It should be noted that the fuel cell system of the embodiment of the present application includes but is not limited to a hydrogen fuel cell system.

[0061] The centrifugal air compressor of the embodiment of the present application is provided with a bearing assembly 30 having a first bearing seat 31, a first radial bearing 33 and a thrust bearing assembly 35. The first bearing seat 31 has a first gas cooling channel 311a, a second gas cooling channel 312a and a bearing accommodating space 31c. The first bearing seat 31 is provided at one end of the machine base 10 along the axial direction of the rotating shaft 23. The first radial bearing 33 and the thrust bearing assembly 35 are provided on the first bearing seat 31, and at least part of the structure of the thrust bearing assembly 35 is located in the bearing accommodating space 31c. The first gas cooling channel 311a is at least axially spaced from the first radial bearing 33 to the second radial bearing assembly 35. The first radial bearing 33 is in communication with the cavity 10a, and the second gas cooling channel 312a is in communication with at least the bearing accommodating space 31c. During operation of the centrifugal air compressor, cooling gas in the first gas cooling channel 311a can enter the cavity 10a from the first radial bearing 33, thereby cooling both the first radial bearing 33 and components such as the motor stator 21 and the motor rotor 22 within the cavity 10a. Meanwhile, cooling gas in the second gas cooling channel 312a can enter the bearing accommodating space 31c to cool the thrust bearing assembly 35. Because the centrifugal air compressor of the present embodiment can not only cool components such as the motor stator 21 and the motor rotor 22 within the cavity 10a, but also effectively cool the first radial bearing 33 and the thrust bearing assembly 35, the centrifugal air compressor of the present embodiment has a good cooling effect.

[0062] In one embodiment, referring to FIG. 9 , the first bearing seat 31 may have an air hole 31a located on a side of the first bearing seat 31 facing away from the rotating shaft 23. The first gas cooling channel 311a may communicate with the cavity 10a through the air hole 31a. The cooling gas in the first gas cooling channel 311a may directly communicate with the cavity 10a through the air hole 31a. In other words, the cooling gas passing through the air hole 31a does not pass through the first radial bearing seat 33. The cooling gas flowing out of the air hole 31a can cool the motor rotor 22 and the motor stator 21 together with the cooling gas flowing through the first radial bearing 33. This can increase the flow rate of the cooling gas entering the cavity 10a, thereby enhancing the cooling effect.

[0063] Furthermore, referring to FIG. 1 , the base 10 may have a base exhaust hole 10 b communicating with the inner cavity. The base exhaust hole 10 b is used to discharge the cooling gas in the cavity 10 a to the outside of the base 10 .

[0064] For example, referring to Figure 1, the base exhaust hole 10b can be located on the side of the air gap between the motor stator 21 and the motor rotor 22 that is away from the first bearing seat 31. That is to say, the cooling gas entering the cavity 10a from the first bearing seat 31 can pass through the air gap between the motor stator 21 and the motor rotor 22, and then be discharged from the base exhaust hole 10b, thereby ensuring that the cooling gas can fully cool the motor stator 21 and the motor rotor 22.

[0065] In some embodiments, the base exhaust hole 10 b may also be provided on a side of the air gap between the motor stator 21 and the motor rotor 22 close to the first bearing seat 31 .

[0066] In one embodiment, referring to Figures 8 and 10, the first bearing seat 31 may have a bearing exhaust hole 31b, which is connected to the bearing accommodating space 31c. When the cooling gas enters the bearing accommodating space 31c from the second gas cooling channel 312a, it can flow out of the centrifugal air compressor from the bearing exhaust hole 31b, thereby bringing out the high-temperature gas in the bearing accommodating space 31c to ensure the cooling effect.

[0067] It is understandable that the first bearing seat 31 may have one bearing exhaust hole 31 b or may have multiple bearing exhaust holes 31 b.

[0068] In one embodiment, referring to Figures 1 and 4, the thrust bearing assembly 35 includes a thrust bearing and a thrust plate 353. The thrust bearing includes a first thrust bearing 351 and a second thrust bearing 352. The thrust plate 353 is sleeved on the rotating shaft 23, and at least part of the structure of the thrust plate 353 is located in the bearing accommodating space 31c. The first thrust bearing 351 and the second thrust bearing 352 are respectively arranged on opposite sides of the thrust plate 353 along the axial direction of the rotating shaft 23 and are located in the bearing accommodating space 31c.

[0069] Further, referring to Figures 8 to 10, the first bearing seat 31 can be a split type, for example, including a first sub-bearing seat 311 and a second sub-bearing seat 312, the second sub-bearing seat 312 is located on the side of the first sub-bearing seat 311 away from the cavity 10a, and the first sub-bearing seat 311 and the second sub-bearing seat 312 jointly define a bearing accommodating space 31c, so as to facilitate the installation of the thrust bearing assembly 35 in the bearing accommodating space 31c.

[0070] Exemplarily, referring to FIG8 and FIG9 , the first sub-bearing seat 311 has a first gas cooling channel 311 a , the first radial bearing 33 can be mounted on the first sub-bearing seat 311 , and the second sub-bearing seat 312 has a second gas cooling channel 312 a .

[0071] Further, referring to Figures 4, 11 and 12, the first sub-bearing seat 311 may have a first axial hole 311b connected to the bearing accommodating space 31c, and the first sub-bearing seat 311 has a first cooling groove 311c on the side close to the bearing accommodating space 31c. The first cooling groove 311c may be located on the circumferential side of the first axial hole 311b, and the first gas cooling channel 311a is connected to the first cooling groove 311c through the first axial hole 311b. That is, the first gas cooling channel 311a can introduce cooling gas from the first axial hole 311b into the first cooling groove 311c to cool the first thrust bearing 351, thereby improving the cooling effect of the first thrust bearing 351.

[0072] The first sub-bearing seat 311 may have one first cooling groove 311c or multiple first cooling grooves 311c. For example, the first sub-bearing seat 311 shown in Figure 11 has six first cooling grooves 311c. Providing multiple first cooling grooves 311c allows cooling of the first thrust bearing 351 at multiple locations along the circumference of the first axial hole 311b, thereby further enhancing the cooling effect of the cooling air on the first thrust bearing 351.

[0073] For example, referring to Figures 1 and 4 , when the cooling gas passes through the first gas cooling channel 311a and reaches the vicinity of the first axial hole 311b, the cooling gas can be divided into two branches. The first branch enters the first cooling groove 311c. Since the first thrust bearing 351 is disposed on the side of the bearing accommodating space 31c near the first cooling groove 311c, the cooling gas entering the first cooling groove 311c can cool the side of the first thrust bearing 351 near the first cooling groove 311c. The cooling gas in the second branch can then pass through the first radial bearing 33 to cool the first radial bearing 33.

[0074] In addition, please refer to Figure 4. A third gap 35a can be provided between the first thrust bearing 351 and the thrust plate 353. Part of the gas in the first branch can pass through the third gap 35a to cool the side of the first thrust bearing 351 away from the first cooling groove 311c and the side of the thrust plate 353 close to the first cooling groove 311c. The cooling gas in the first branch can thereby complete the cooling of the first thrust bearing 351 and the thrust plate 353 from the inside out.

[0075] In one embodiment, please refer to Figures 4, 8 and 13, the second sub-bearing seat 312 has a second axial hole 312b connected to the bearing accommodating space 31c, and the second sub-bearing seat 312 may have a second cooling groove 312c on the side close to the bearing accommodating space 31c. The second cooling groove 312c is located on the circumferential side of the second axial hole 312b, and the second gas cooling channel 312a is connected to the second cooling groove 312c through the second axial hole 312b. That is, the second gas cooling channel 312a can introduce cooling gas from the second axial hole 312b into the second cooling groove 312c to cool the second thrust bearing 352, thereby improving the cooling effect of the second thrust bearing 352.

[0076] The second sub-bearing seat 312 may have one or more second cooling grooves 312c. For example, the second sub-bearing seat 312 shown in FIG13 has six second cooling grooves 312c. Providing multiple second cooling grooves 312c allows cooling of the second thrust bearing 352 at multiple locations along the circumference of the second axial hole 312b, thereby further enhancing the cooling effect of the cooling air on the second thrust bearing 352.

[0077] The cooling gas passes through the first gas cooling channel 311a to the vicinity of the first axial hole 311b and enters the second cooling groove 312c. Since the second thrust bearing 352 is arranged on the side of the bearing accommodating space 31c close to the second cooling groove 312c, the cooling gas entering the second cooling groove 312c can cool the side of the second thrust bearing 352 close to the second cooling groove 312c.

[0078] In addition, please refer to Figure 4. There can be a fourth gap 35b between the second thrust bearing 352 and the thrust plate 353. Part of the gas in the first branch can pass through the fourth gap 35b to cool the side of the first thrust bearing 351 away from the second cooling groove 312c and the side of the thrust plate 353 close to the second cooling groove 312c. The cooling gas in the first branch can thus complete the cooling of the second thrust bearing 352 and the thrust plate 353 from the inside out.

[0079] In one embodiment, referring to Figures 9, 11 and 13, a first annular boss 3111 having a first exhaust port 3111a may be provided on one side of the first sub-bearing seat 311, and a second annular boss 3121 having a second exhaust port 3121a may be provided on one side of the second sub-bearing seat 312, and one of the first annular boss 3111 and the second annular boss 3121 extends into the other, that is, the first annular boss 3111 as shown in Figure 10 may extend into the second annular boss 3121, or the second annular boss 3121 may extend into the first annular boss 3111. The first annular boss 3111 and the second annular boss 3121 define a bearing accommodating space 31c, and the first exhaust port 3111a and the second exhaust port 3121a are connected to jointly form a bearing exhaust hole 31b. After the cooling gas after cooling the thrust bearing assembly 35 enters the bearing accommodating space 31c, it can flow out of the centrifugal air compressor through the first exhaust port 3111a and the second exhaust port 3121a.

[0080] It is understandable that the first annular boss 3111 may be provided with one first exhaust port 3111 a or multiple first exhaust ports 3111 a , and the second annular boss 3121 may be provided with corresponding second exhaust ports 3121 a .

[0081] In one embodiment, referring to FIG. 8 and FIG. 10 , the first sub-bearing seat 311 may further have an air intake hole 311 d , which is connected to the second cooling channel, and the cooling gas may enter the second cooling channel from the first sub-bearing seat 311 through the air intake channel.

[0082] In one embodiment, referring to FIG. 4 , the first bearing seat 31 may have a second seal 313 , which is sandwiched between the first sub-bearing seat 311 and the second sub-bearing seat 312 to prevent leakage of cooling gas caused by vibration during operation of the centrifugal air compressor and loose fit between the end faces of the first sub-bearing seat 311 and the second sub-bearing seat 312 , thereby affecting the cooling effect of the bearing assembly 30 .

[0083] For example, referring to FIG. 13 , a second sealing groove 312d may be provided on the second sub-bearing seat 312 , and the second sealing member 313 is provided in the second sealing groove 312d . In other embodiments, the second sealing groove 312d may also be provided on the first sub-bearing seat 311 .

[0084] Similarly, referring to FIG. 4 , the bearing assembly 30 may include a first seal 36 . The first seal 36 is disposed between the first bearing seat 31 and the machine base 10 to prevent leakage of cooling gas.

[0085] In one embodiment, referring to Figures 1 and 2, the machine base 10 may have a third gas cooling channel 10c and at least one machine base air outlet 10d. The third gas cooling channel 10c may be spirally arranged along the circumference of the cavity 10a. The third gas cooling channel 10c is connected to the first gas cooling channel 311a and the second gas cooling channel 312a through the machine base air outlet 10d. The third gas cooling channel 10c is spirally arranged along the bearing of the cavity 10a, which can increase wind resistance and reduce the flow rate of the cooling gas entering the first cooling channel and the second gas cooling channel 312a, which is beneficial to the stable operation of the motor stator 21 and the motor rotor 22 and the bearing assembly 30 in the centrifugal air compressor cavity 10a, while increasing the heat exchange time of the cooling gas, reducing the temperature of the cooling gas, and improving the cooling efficiency.

[0086] For example, referring to Figures 2, 4, 8 and 9, the machine base 10 can have two machine base air outlets 10d, one of the two machine base air outlets 10d is communicated with the first gas cooling channel 311a, and the other of the two machine base air outlets 10d is communicated with the second gas cooling channel 312a. A partition can be set between the two machine base air outlets 10d to pre-divide the cooling gas.

[0087] It can be understood that since the internal components of the centrifugal air compressor generate different amounts of heat when working, the components have different demands for cooling gas. Specifically, the cooling gas flow rate required by the motor rotor 22 is the largest, followed by the stressed side of the thrust bearing assembly 35, and finally the unstressed side of the radial bearing thrust bearing assembly 35. By targetedly changing the size and number of the base air outlet 10d on the base 10 and the area, number and distribution of the cooling grooves on the first bearing seat 31, the cooling gas flow in the first cooling gas channel and the second gas cooling channel 312a can be adjusted to improve the cooling efficiency.

[0088] In other embodiments, the machine base 10 may have only one machine base air outlet 10d, and the machine base air outlet 10d is communicated with both the first gas cooling channel 311a and the second gas cooling channel 312a.

[0089] Furthermore, referring to FIG1 , the base 10 may also have a water cooling channel 10e, which may be located between the third gas cooling channel 10c and the motor stator 21 and arranged in a spiral shape along the circumference of the cavity 10a. A cooling medium with a large specific heat capacity may be introduced into the water cooling channel 10e. The cooling medium may not only cool the motor stator 21 through the water cooling channel 10e, but may also further cool the cooling gas in the third gas cooling channel 10c, thereby further improving the cooling efficiency of the motor stator 21, the motor rotor 22 and the bearing assembly 30.

[0090] For example, referring to FIG1 , the base 10 may include a casing 11 and an inner cylinder 12 disposed in the casing 11 , the motor stator 21 may be disposed in the inner cylinder 12 , the casing 11 has a third gas cooling channel 10 c , and the inner cylinder 12 and the casing 11 jointly define a water cooling channel 10 e.

[0091] Please refer to FIG. 1 . A spiral groove may be provided on the circumference of the inner cylinder 12 . The spiral groove and the inner wall of the casing 11 together define a water cooling channel 10 e , so that the water cooling channel 10 e can be disassembled and maintained.

[0092] In one embodiment, referring to FIG1 , the base 10 may further include an inner cylinder seal 13 , which is sandwiched between the casing 11 and the inner cylinder 12 to prevent the inner cylinder 12 and the casing 11 from fitting loosely, thereby preventing leakage of the cooling medium and damaging the function of the centrifugal air compressor.

[0093] In one embodiment, please refer to Figure 1. The outlet and the inlet of the water cooling channel 10e pass through the third gas cooling channel arranged in a spiral. The third gas cooling channel is arranged in an unequal pitch spiral. The pitch of the third gas cooling channel 10c at the opposite ends along the axial direction of the rotating shaft 23 is greater than the pitch between the outlet and the inlet of the third gas channel. The pitch of the third gas cooling channel 10c at the opposite ends along the axial direction of the rotating shaft 23 is larger, so that the outlet and the inlet of the water cooling channel 10e can effectively avoid the third gas cooling channel 10c, and the pitch of the third gas channel between the outlet and the inlet is smaller, which can further increase the contact area and heat exchange time between the cooling gas and the third gas cooling channel 10c, effectively reduce the temperature of the cooling gas, and improve the cooling efficiency of the cooling system.

[0094] In one embodiment, referring to Figures 1 and 5, the centrifugal air compressor may include a second sealing component 50, the bearing assembly 30 may also include a second radial bearing 34 and a second bearing seat 32, the second bearing seat 32 is arranged on the side of the machine base 10 axially away from the first bearing seat 31, the second radial bearing 34 is arranged on the second radial bearing seat 34 and is sleeved on the motor rotor 22, the second sealing component 50 is arranged on the side of the second bearing seat 32 away from the cavity 10a, the second bearing seat 32 and the second sealing component 50 can jointly define a fourth gas cooling channel 32a, the fourth gas cooling channel 32a can be connected to the cavity 10a through the second radial bearing 34, the second sealing component 50 can prevent the cooling air in the fourth gas cooling channel 32a from leaking, so that the cooling air can better cool the second radial bearing 34.

[0095] Further, referring to FIG. 5 , the second sealing portion may have an air inlet 50 a , and the air inlet 50 a may be in communication with the fourth gas cooling channel.

[0096] For example, please refer to Figure 5, there is a second gap 34a between the second radial bearing 34 and the motor rotor 22, and the fourth gas cooling channel can be connected to the cavity 10a through the second gap 34a. When the cooling air in the fourth gas cooling channel flows through the second gap 34a and enters the cavity 10a, the second radial bearing 34 can be cooled.

[0097] In one embodiment, referring to Figures 1 and 3, the centrifugal air compressor has a connecting pipe 60, a first volute 70 and a second volute 80. The first volute 70 and the second volute 80 are respectively arranged on opposite sides of the machine base 10 along the axial direction of the rotating shaft 23, and the inlet of the first volute 70 and the outlet of the second volute 80 are connected through the connecting pipe 60. The first gas cooling channel 311a and the second gas cooling channel 312a are both connected to the connecting pipe 60. That is to say, the cooling gas can be the compressed gas in the first volute 70 and the second volute 80 of the centrifugal air compressor itself, without the need to additionally set up other equipment for providing cooling gas. As a result, the installation space of the centrifugal air compressor system can be saved and the system integration can be improved.

[0098] Further, referring to Figure 3, a flow control valve 61 is provided on the connecting pipe 60, which can control the pressure and flow of the cooling gas entering the first gas cooling channel 311a and the second gas cooling channel 312a. The optimal gas flow rate can be selected to meet the cooling requirements of the bearing assembly 30 and the motor body 20 without reducing the output pressure ratio of the centrifugal air compressor too much.

[0099] In the description of this application, the descriptions with reference to the terms "in one embodiment", "in some embodiments", "in other embodiments", "in yet other embodiments", or "exemplary" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this application, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine different embodiments or examples described in this application and features of different embodiments or examples, unless they are mutually inconsistent.

[0100] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application are intended to be within the scope of protection of the present application.

Claims

1. A centrifugal air compressor, comprising: A machine base, wherein the machine base is formed with a cavity; A motor body, the motor body comprising a motor stator, a motor rotor and a rotating shaft, the motor stator is arranged in the cavity, the motor rotor is arranged on the rotating shaft and is located in the cavity; A bearing assembly, wherein the rotating shaft is rotatably mounted in the machine base through the bearing assembly, wherein the bearing assembly comprises a first bearing seat, a first radial bearing and a thrust bearing assembly; the first bearing seat has a first gas cooling channel, a second gas cooling channel and a bearing accommodating space, the first bearing seat is arranged at one end of the machine base along the axial direction of the rotating shaft, the first radial bearing and the thrust bearing assembly are arranged on the first bearing seat, and at least part of the structure of the thrust bearing assembly is located in the bearing accommodating space, the first gas cooling channel is connected to the cavity at least through the first radial bearing, and the second gas cooling channel is connected to at least the bearing accommodating space.

2. According to the centrifugal air compressor of claim 1, the first radial bearing is sleeved on the motor rotor, and there is a first gap between the first radial bearing and the motor rotor, and the first gas cooling channel is connected to the cavity at least through the first gap.

3. According to the centrifugal air compressor of claim 2, the first bearing seat has an air hole, the air hole is located on the side of the first bearing seat away from the rotating shaft, and the first gas cooling channel is connected to the cavity through the air hole.

4. The centrifugal air compressor according to any one of claims 1 to 3, wherein the first bearing seat has at least one bearing exhaust hole, and the bearing exhaust hole is connected to the bearing accommodating space; and / or, The machine base has a machine base exhaust hole communicated with the inner cavity, and the machine base exhaust hole is located on a side of the air gap between the motor stator and the motor rotor away from the first bearing seat.

5. According to the centrifugal air compressor according to any one of claims 1-3, the thrust bearing assembly includes a thrust bearing and a thrust plate, the thrust bearing includes a first thrust bearing and a second thrust bearing, the thrust plate is sleeved on the rotating shaft, and at least part of the structure of the thrust plate is located in the bearing accommodating space, the first thrust bearing and the second thrust bearing are respectively arranged on opposite sides of the thrust plate along the axial direction of the rotating shaft, and are located in the bearing accommodating space.

6. In the centrifugal air compressor according to claim 5, the first bearing seat includes a first sub-bearing seat having a first gas cooling channel and a second sub-bearing seat having a second gas cooling channel, the second sub-bearing seat is located on the side of the first sub-bearing seat away from the cavity, and the first sub-bearing seat and the second sub-bearing seat jointly define the bearing accommodating space.

7. The centrifugal air compressor according to claim 6, wherein the first sub-bearing seat has a first axial hole connected to the bearing accommodating space, and the first sub-bearing seat has at least one first cooling groove on a side close to the bearing accommodating space, the first cooling groove is located on a peripheral side of the first axial hole, and the first gas cooling channel is connected to the first cooling groove through the first axial hole; and / or, The second sub-bearing seat has a second axial hole connected to the bearing accommodating space, and the second sub-bearing seat has at least one second cooling groove on a side close to the bearing accommodating space. The second cooling groove is located on the circumferential side of the second axial hole, and the second gas cooling channel is connected to the second cooling groove through the second axial hole.

8. According to the centrifugal air compressor of claim 6, a first annular boss having a first exhaust port is provided on one side of the first sub-bearing seat, and a second annular boss having a second exhaust port is provided on one side of the second sub-bearing seat, one of the first annular boss and the second annular boss extends into the other to define the bearing accommodating space, and the first exhaust port is connected to the second exhaust port to jointly form a bearing exhaust hole.

9. The centrifugal air compressor according to claim 6, wherein the first sub-bearing seat further has an air intake hole, and the air intake hole is connected to the second cooling channel.

10. The centrifugal air compressor according to claim 6, wherein the first bearing seat has a second seal, and the second seal is sandwiched between the first sub-bearing seat and the second sub-bearing seat.

11. The centrifugal air compressor according to claim 1, wherein the bearing assembly further comprises a first seal, and the first seal is sandwiched between the first bearing seat and the machine seat.

12. The centrifugal air compressor according to any one of claims 1-3, wherein the machine base has a third gas cooling channel and at least one machine base air outlet, the third gas cooling channel is spirally arranged along the circumference of the cavity, and the third gas cooling channel is connected to the first gas cooling channel and the second gas cooling channel through the machine base air outlet.

13. The centrifugal air compressor according to claim 12, wherein the base further comprises a water cooling channel, wherein the water cooling channel is located between the third gas cooling channel and the motor stator and is spirally arranged along the circumference of the cavity.

14. The centrifugal air compressor according to claim 13, wherein the base comprises a casing and an inner cylinder disposed in the casing, the motor stator is disposed in the inner cylinder, the casing has the third gas cooling channel, and the inner cylinder and the casing jointly define the water cooling channel. 15 . The centrifugal air compressor according to claim 14 , wherein the base has an inner cylinder seal, and the inner cylinder seal is sandwiched between the casing and the inner cylinder.

16. The centrifugal air compressor according to claim 13, wherein the outlet of the water cooling channel and the inlet of the water cooling channel pass through the third gas cooling channel which is spirally arranged, the third gas cooling channel is spirally arranged with unequal pitches, and the pitch of the opposite ends of the third gas cooling channel along the axial direction of the rotating shaft is greater than the pitch of the third gas channel between the outlet and the inlet.

17. The centrifugal air compressor according to claim 12, wherein the base has two base air outlets, one of the two base air outlets is communicated with the first gas cooling channel, and the other of the two base air outlets is communicated with the second gas cooling channel.

18. The centrifugal air compressor according to any one of claims 1-3, wherein the centrifugal air compressor includes a second sealing component, and the bearing assembly also includes a second radial bearing and a second bearing seat, the second bearing seat is arranged on the side of the machine base away from the first bearing seat along the axial direction, the second radial bearing is arranged on the second radial bearing seat and is sleeved on the motor rotor, the second sealing component is arranged on the side of the second bearing seat away from the cavity, the second bearing seat and the second sealing component jointly define a fourth gas cooling channel, and the fourth gas cooling channel is connected to the cavity at least through the second radial bearing. 19 . The centrifugal air compressor according to claim 18 , wherein the second sealing member has an air inlet, and the air inlet is communicated with a fourth gas cooling passage.

20. According to any one of claims 1-3, the centrifugal air compressor comprises a connecting pipe, a first volute and a second volute, the first volute and the second volute are respectively arranged on opposite sides of the machine base along the axial direction, and the inlet of the first volute is connected with the outlet of the second volute through the connecting pipe, and the first gas cooling channel and the second gas cooling channel are both connected with the connecting pipe.

21. A fuel cell system, comprising the centrifugal air compressor according to any one of claims 1 to 20.

Images