Fuel cell air compressor

Abstract

The invention provides a fuel cell air compressor which comprises an air compressor body, a turbine assembly and an air compression assembly, the air compressor body comprises a shell, a rotating shaft, a motor stator, a radial bearing seat, a first air foil bearing and a second air foil bearing, and the turbine assembly comprises a first-stage volute, a first-stage impeller, a second-stage volute, a second-stage impeller and an interstage pipeline. The shell is provided with an air channel outlet, the air compression assembly is provided with an air flow channel used for air circulation, and the air compression assembly is connected between the first air foil bearing and the first-stage impeller. In this way, the back-to-back design mode of the two stages of impellers is adopted, axial thrust can be counteracted, and therefore the axial force applied by aerodynamic loads in the axial direction is reduced, and the service life of the thrust bearing can be prolonged; and the air foil bearing structure is adopted, so that the friction between the bearing and the rotor can be reduced, the mechanical loss is reduced, meanwhile, the oil-free requirement of the operating environment of the cell stack is met, and the air foil bearing has the advantages of large bearing capacity, good stability and the like.

Description

Technical Field

[0001] The invention relates to the technical field of air compressors, in particular to a fuel cell air compressor. Background Art

[0002] As the most important component in the fuel cell air supply system, the fuel cell air compressor is mainly used to pressurize the air in the atmospheric environment to the optimal operating pressure of the fuel cell reactor and provide the required air mass flow. Due to the particularity of the electrode reaction of the fuel cell system and its importance as a core component of the automobile, the air compressor as an air supply system needs to meet the characteristics of oil-free, low power consumption, high power density, low cost, low noise, high reliability and good dynamic performance. To meet these requirements, the mainstream technical route of fuel cell air compressors is a centrifugal air compressor supported by a dynamic pressure foil air bearing driven by an ultra-high-speed permanent magnet motor.

[0003] At present, the existing fuel cell air compressor occupies a large space and is heavy, and generates relatively large noise during operation, which is one of the main noise sources of the fuel cell system. The fuel cell air compressor has a high parasitic efficiency, accounting for about 20% of the power of the fuel cell system, and the air compressor is the second largest cost source in the fuel cell system cost, accounting for 20% of the total cost. In addition, during the operation of the air compressor, due to frequent friction, large mechanical losses, large vibration response, and many start and stop times, the service life of the air compressor is affected.

[0004] In view of this, it is necessary to propose a fuel cell air compressor to solve or at least alleviate the above-mentioned defects. Summary of the invention

[0005] The main purpose of the present invention is to provide a fuel cell air compressor to solve the problem in the prior art that the fuel cell air compressor frequently vibrates due to friction, thereby affecting the service life.

[0006] To achieve the above-mentioned object, the present invention provides a fuel cell air compressor, comprising an air compressor body, a turbine assembly and a compressor assembly; wherein:

[0007] The air compressor body includes a housing, a rotating shaft built in the housing, a motor stator, a radial bearing seat, and a first air foil bearing and a second air foil bearing arranged opposite to each other along the axial direction of the rotating shaft. The turbine assembly includes a first-stage volute, a first-stage impeller, a second-stage volute, a second-stage impeller, and an interstage pipeline; wherein,

[0008] The shell has an airway outlet, the shell includes a first-stage air compression end and a second-stage air compression end, the first-stage volute is connected to the first-stage air compression end, the second-stage volute is connected to the second-stage air compression end, and the two ends of the interstage pipeline are connected to the first-stage volute and the second-stage volute respectively;

[0009] The rotating shaft passes through the motor stator, and the two ends of the rotating shaft rotatably pass through the first air foil bearing and the second air foil bearing respectively, the radial bearing seat is connected to the first-stage air compression end, the first air foil bearing is connected to the radial bearing seat, the first-stage impeller is connected to one end of the rotating shaft located at the first-stage air compression end, and the second-stage impeller is connected to one end of the rotating shaft located at the second-stage air compression end;

[0010] The air compression assembly has an air flow channel for gas circulation, and the air compression assembly is connected between the first air foil bearing and the first-stage impeller.

[0011] Preferably, the compressed air assembly includes a thrust bearing seat, a thrust plate, and two first and second air foil thrust bearings that are axially opposite to each other. The thrust bearing seat is connected between the radial bearing seat and the first-stage impeller. The thrust bearing seat has the air flow channel, and the inner side of the thrust bearing seat is recessed to form an installation space. The thrust plate has a through hole for the rotating shaft to pass through. The thrust plate, the first air foil thrust bearing and the second air foil thrust bearing are all arranged in the installation space and sleeved on the rotating shaft, and the thrust plate is attached to the shoulder of the rotating shaft. The first air foil thrust bearing and the second air foil thrust bearing are respectively connected to both sides of the thrust plate.

[0012] Preferably, it also includes a first limiting assembly, which includes a first bearing retaining ring and a first positioning pin for limiting the circumferential rotation of the first air foil bearing, the first bearing retaining ring is abutted against the outer side of the first air foil bearing, the first positioning pin is extended axially, and the first positioning pin passes through the first bearing retaining ring and extends into the first air foil bearing.

[0013] Preferably, it also includes a second limiting assembly, which includes a second bearing retaining ring and a second positioning pin for limiting the circumferential rotation of the second air foil bearing, the second bearing retaining ring is abutted against the outer side of the second air foil bearing, the second positioning pin is extended axially, and the second positioning pin passes through the second bearing retaining ring and extends into the second air foil bearing.

[0014] Preferably, the inner side of the thrust bearing seat is convexly provided with a plurality of arc-shaped bosses arranged at intervals along its own circumference, a ventilation gap is formed between each two adjacent arc-shaped bosses, a groove is formed between the arc-shaped bosses and the outer periphery of the thrust bearing seat, an oblique through hole is provided on the thrust bearing seat, one end of the oblique through hole extends to the outside of the thrust bearing seat, and the other end of the oblique through hole extends to communicate with the groove, and the thrust bearing seat is also provided with a plurality of radial air passages arranged at intervals along its own circumference.

[0015] Preferably, the radial bearing seat is provided with a plurality of dispersed ventilation holes, and the ventilation holes are extended in the axial direction.

[0016] Preferably, it further comprises a sealing disk, wherein the sealing disk has an axial hole for the rotating shaft to pass through, and the sealing disk is sleeved on the rotating shaft and arranged between the secondary impeller and the second bearing retaining ring.

[0017] Preferably, it further comprises a first spacer sleeve, wherein the first spacer sleeve is sleeved on one end of the rotating shaft located at the first-stage air compression end, and the thrust bearing seat is sleeved on the first spacer sleeve.

[0018] Preferably, it further comprises a second spacer sleeve, wherein the second spacer sleeve is sleeved on one end of the rotating shaft located at the secondary air compression end, and the sealing disc is sleeved on the second spacer sleeve.

[0019] Preferably, a spiral water channel is provided in the shell, and a water cooling inlet and a water cooling outlet are also provided on the shell, and two ends of the spiral water channel are connected to the water cooling inlet and the water cooling outlet respectively.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] A fuel cell air compressor provided by the present invention comprises an air compressor body, a turbine assembly and a compressor assembly, wherein the air compressor body comprises a housing, a rotating shaft all built into the housing, a motor stator, a radial bearing seat and a first air foil bearing and a second air foil bearing arranged opposite to each other along the axial direction of the rotating shaft, the turbine assembly comprises a first-stage volute, a first-stage impeller, a second-stage volute, a second-stage impeller and an interstage pipeline, the housing is provided with an airway outlet, the housing comprises a first-stage compressor end and a second-stage compressor end, the first-stage volute is connected to the first-stage compressor end, and the second-stage volute is connected to the second-stage compressor end The two ends of the interstage pipeline are connected to the first-stage volute and the second-stage volute respectively, the rotating shaft passes through the motor stator, and the two ends of the rotating shaft can rotatably pass through the first air foil bearing and the second air foil bearing respectively, the radial bearing seat is connected to the first-stage compression end, the first air foil bearing is connected to the radial bearing seat, the first-stage impeller is connected to one end of the rotating shaft located at the first-stage compression end, the second-stage impeller is connected to one end of the rotating shaft located at the second-stage compression end, the compression assembly has an air flow channel for gas circulation, and the compression assembly is connected between the first air foil bearing and the first-stage impeller. In this way, the two-stage impeller back-to-back design can achieve mutual offset of axial thrust, thereby reducing the axial force applied by the aerodynamic load in the axial direction, and can increase the service life of the thrust bearing; and the structure of the air foil bearing can reduce the friction between the bearing and the rotor, reduce mechanical loss, and meet the oil-free requirements of the battery stack operating environment at the same time. The air foil bearing has the advantages of large bearing capacity and good stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1 It is a three-dimensional schematic diagram of the overall structure of one embodiment of the present invention;

[0024] Figure 2 A three-dimensional schematic diagram of the overall structure of an embodiment of the present invention from another viewing angle;

[0025] Figure 3 A cross-sectional schematic diagram of the overall structure of an embodiment of the present invention;

[0026] Figure 4 It is an enlarged cross-sectional schematic diagram of a compressed air component part in one embodiment of the present invention;

[0027] Figure 5 is a three-dimensional schematic diagram of a thrust bearing seat in one embodiment of the present invention;

[0028] Figure 6 is a three-dimensional schematic diagram of the back side of a thrust bearing seat in one embodiment of the present invention;

[0029] Figure 7 is a three-dimensional schematic diagram of a radial bearing seat in one embodiment of the present invention;

[0030] Figure 8 is an exploded schematic diagram of various components inside a housing in one embodiment of the present invention;

[0031] Fig. 9 It is a cross-sectional schematic diagram of a shell in one embodiment of the present invention.

[0032] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

[0033] Description of Figure Numbers:

[0034] 10. Air compressor body; 110. Shell; 111. Airway outlet; 112. First-stage air compressor end; 113. Second-stage air compressor end; 114. Spiral waterway; 115. Water cooling inlet; 116. Water cooling outlet; 117. Inner wall channel; 118. Oblique channel; 120. Rotating shaft; 130. Motor stator; 140. Radial bearing seat; 141. Air vent; 150. First air foil bearing; 160. Second air foil bearing; 170. First stop assembly; 171. First bearing retaining ring; 172. First positioning pin; 180. Second stop assembly; 1 81. Second bearing retaining ring; 182. Second locating pin; 190. Sealing disk; 191. Second spacer; 20. Turbine assembly; 210. First-stage volute; 220. First-stage impeller; 230. Second-stage volute; 240. Second-stage impeller; 250. Interstage duct; 30. Compressor assembly; 310. Thrust bearing seat; 311. Arc boss; 312. Ventilation gap; 313. Groove; 314. Oblique through hole; 315. Radial air duct; 316. First spacer; 320. Thrust disk; 330. First air foil thrust bearing; 340. Second air foil thrust bearing. DETAILED DESCRIPTION

[0035] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] Please refer to the attached Figure 1-9 In one embodiment of the present invention, a fuel cell air compressor is provided, comprising an air compressor body 10, a turbine assembly 20 and a compressor assembly 30. First of all, it should be noted that the axial direction in the present application refers to the axial extension direction along the rotating shaft 120; which is different from the fuel cell air compressor in the prior art, which occupies a large space and is heavy, and during operation, due to frequent friction, leads to large mechanical losses, large vibration response, and many start and stop times, which affects the service life of the air compressor. The present application solves the above-mentioned defects in the prior art by providing a fuel cell air compressor, as follows:

[0040] The air compressor body 10 includes a shell 110, a rotating shaft 120, a motor stator 130, a radial bearing seat 140, and a first air foil bearing 150 and a second air foil bearing 160 arranged axially opposite to each other along the rotating shaft 120. The turbine assembly 20 includes a first-stage volute 210, a first-stage impeller 220, a second-stage volute 230, a second-stage impeller 240, and an interstage pipe 250; wherein, the shell 110 has an airway outlet 111, the shell 110 includes a first-stage compression end 112 and a second-stage compression end 113, the first-stage volute 210 is connected to the first-stage compression end 112, the second-stage volute 230 is connected to the second-stage compression end 113, and both ends of the interstage pipe 250 are connected to the first-stage volute 210, respectively. 0 is connected to the secondary volute 230; the rotating shaft 120 passes through the motor stator 130, and the two ends of the rotating shaft 120 respectively rotatably pass through the first air foil bearing 150 and the second air foil bearing 160, the radial bearing seat 140 is connected to the first-stage compression end 112, the first air foil bearing 150 is connected to the radial bearing seat 140, the first-stage impeller 220 is connected to one end of the rotating shaft 120 located at the first-stage compression end 112, and the second-stage impeller 240 is connected to one end of the rotating shaft 120 located at the second-stage compression end 113; the compression assembly 30 has an air flow channel for gas circulation, and the compression assembly 30 is connected between the first air foil bearing 150 and the first-stage impeller 220.

[0041] Specifically, the fuel cell air compressor in the present application includes an air compressor body 10, a turbine assembly 20 and a compressor assembly 30. The air compressor body 10 is an existing component of the entire fuel cell air compressor, which includes a shell 110, a rotating shaft 120, a motor stator 130, a radial bearing seat 140, and a first air foil bearing 150 and a second air foil bearing 160 arranged axially opposite to each other along the rotating shaft 120. The shell 110 is used for other components to be installed and built-in, and the bearings connected at both ends of the rotating shaft 120 in the present application adopt an air foil bearing structure, which has the advantages of large bearing capacity and good stability, and can ensure that the air compressor can operate stably at a maximum speed of 120000r / min. Therefore, the two ends of the rotating shaft 120 can rotatably penetrate the first air foil bearing 150 and the second air foil bearing 160 respectively, and the first air foil bearing 150 at one end is installed on the radial bearing seat 140, and the second air foil bearing 160 at the other end is installed in the groove space formed in the shell 110.

[0042] The turbine assembly 20 is used for pressurizing and compressing air, and includes a first-stage volute 210, a first-stage impeller 220, a second-stage volute 230, a second-stage impeller 240, and an interstage duct 250, which are arranged at both ends of the housing 110 to perform two-stage pressurization. Therefore, it can be understood that the housing 110 has a first-stage compression end 112 and a second-stage compression end 113, and the first-stage compression end 112 is used for the installation and connection of the first-stage volute 210, and the first-stage impeller 220 is installed at The first-stage volute 210 is connected to one end of the rotating shaft 120 located at the first-stage compression end 112. Similarly, the second-stage compression end 113 is used for the installation and connection of the second-stage volute 230, and the second-stage impeller 240 is installed in the second-stage volute 230 and connected to one end of the rotating shaft 120 located at the second-stage compression end 113. At the same time, the first-stage volute 210 and the second-stage volute 230 are connected through the interstage pipe 250, and the interstage pipe 250 is in the form of surrounding the outside of the shell 110.

[0043] Furthermore, the compressed air component 30 is used to provide an air source for the air foil bearing after compressing the air to form a dynamic pressure air film, thereby taking away the heat. Therefore, the compressed air component 30 is provided with an air flow channel for gas circulation, and the shell 110 is provided with an air duct outlet 111 to allow the gas taking away the heat to flow out from the air duct outlet 111. Therefore, the compressed air component 30 is arranged between the first air foil bearing 150 and the first-stage impeller 220, so that the high-pressure gas generated by the rotation of the first-stage impeller 220 flows to the first air foil bearing 150 through the compressed air component 30.

[0044] As a preferred embodiment of the present invention, the compressed air assembly 30 includes a thrust bearing seat 310, a thrust plate 320, and two first air foil thrust bearings 330 and second air foil thrust bearings 340 arranged opposite to each other in the axial direction. The thrust bearing seat 310 is connected between the radial bearing seat 140 and the first-stage impeller 220. The thrust bearing seat 310 has the air flow channel, and the inner side of the thrust bearing seat 310 is recessed to form an installation space. The thrust plate 320 has a through hole for the rotating shaft 120 to pass through. The thrust plate 320, the first air foil thrust bearing 330 and the second air foil thrust bearing 340 are all arranged in the installation space and sleeved on the rotating shaft 120, and the thrust plate 320 is attached to the shoulder of the rotating shaft 120. The first air foil thrust bearing 330 and the second air foil thrust bearing 340 are respectively connected to the two sides of the thrust plate 320.

[0045] It should be noted that the thrust bearing seat 310, the thrust plate 320 and each air foil thrust bearing are used to prevent the axial movement of the rotating shaft 120 and bear the axial thrust. Since the thrust bearing seat 310 is connected between the radial bearing seat 140 and the first-stage impeller 220, the air flow channel is arranged on the thrust bearing seat 310 to facilitate the inflow of the high-pressure gas generated at the first-stage impeller 220; and the installation space formed by the inner recess of the thrust bearing seat 310 is used for the installation of other components, so that the thrust plate 320 The first air foil thrust bearing 330 and the second air foil thrust bearing 340 are both arranged in the installation space and are installed by being sleeved on the rotating shaft 120. The first air foil thrust bearing 330 has a clockwise thrust effect, and bears the axial thrust generated by the rotor when it rotates clockwise to prevent axial movement; while the second air foil thrust bearing 340 has a counterclockwise thrust effect, and bears the axial thrust generated by the rotor when it rotates counterclockwise to prevent axial movement. Both of them cooperate with the thrust plate 320 to bear the axial force.

[0046] As a preferred embodiment of the present invention, the first limiting assembly 170 includes a first bearing retaining ring 171 and a first positioning pin 172 for limiting the circumferential rotation of the first air foil bearing 150. The first bearing retaining ring 171 is abutted against the outer side of the first air foil bearing 150, and the first positioning pin 172 is extended axially. The first positioning pin 172 passes through the first bearing retaining ring 171 and extends into the first air foil bearing 150.

[0047] It should be noted that the first bearing retaining ring 171 is used to fix the position of the rotating shaft 120 close to the first-stage compressor end 112 to avoid swinging and shaking due to unstable position. At the same time, it can cooperate with the first positioning pin 172 to limit the circumferential rotation of the first air foil bearing 150, thereby fixing the first air foil bearing 150. The first bearing retaining ring 171 is abutted against the outer side of the first air foil bearing 150 and connected to the shell 110. The outer side here refers to the side away from the center (towards the first-stage compressor end 112). After the first positioning pin 172 penetrates the first bearing retaining ring 171 and extends into the first air foil bearing 150, the circumferential rotation of the first air foil bearing 150 is limited.

[0048] As a preferred embodiment of the present invention, the second limiting assembly 180 includes a second bearing retaining ring 181 and a second positioning pin 182 for limiting the circumferential rotation of the second air foil bearing 160. The second bearing retaining ring 181 is abutted against the outer side of the second air foil bearing 160, and the second positioning pin 182 is extended axially. The second positioning pin 182 passes through the second bearing retaining ring 181 and extends into the second air foil bearing 160.

[0049] It is worth noting that, similar to the first bearing retaining ring 171, the second bearing retaining ring 181 is used to fix the position of the rotating shaft 120 close to the secondary air compressor end 113 to avoid swinging and shaking due to unstable position. At the same time, it can cooperate with the second positioning pin 182 to limit the circumferential rotation of the second air foil bearing 160, thereby fixing the second air foil bearing 160. The second bearing retaining ring 181 is abutted against the outer side of the second air foil bearing 160 and connected to the shell 110. The outer side here refers to the side away from the center (towards the secondary air compressor end 113). After the second positioning pin 182 penetrates the second bearing retaining ring 181 and extends into the second air foil bearing 160, the circumferential rotation of the second air foil bearing 160 is limited.

[0050] As a preferred embodiment of the present invention, the inner side of the thrust bearing seat 310 is convexly provided with a plurality of arc-shaped bosses 311 arranged at intervals along its own circumference, and a ventilation gap 312 is formed between each adjacent two of the arc-shaped bosses 311, and a groove 313 is formed between the arc-shaped bosses 311 and the outer periphery of the thrust bearing seat 310, and the thrust bearing seat 310 is provided with an oblique through hole 314, one end of the oblique through hole 314 extends to the outside of the thrust bearing seat 310, and the other end of the oblique through hole 314 extends to communicate with the groove 313, and the thrust bearing seat 310 is also provided with a plurality of radial air channels 315 arranged at intervals along its own circumference.

[0051] It is worth noting that the ventilation gaps 312 formed between the arc-shaped bosses 311 are used for air circulation, and since the arc-shaped bosses 311 are arranged in the recessed installation space of the thrust bearing seat 310, the arc-shaped bosses 311 are spaced apart from the outer periphery (i.e., the non-recessed portion) of the thrust bearing seat 310 to form a groove 313, which is also used for air circulation, and the oblique through hole 314 provided on the thrust bearing seat 310 extends obliquely from the outer side surface. The groove 313 extends to the inner side surface so that the high-pressure airflow at the first-stage impeller 220 can enter the groove 313 from the outer side surface through the inclined through hole 314, and then the airflow circulates. The airflow that takes away the heat flows out from the multiple radial air channels 315 on the thrust bearing seat 310 and flows out from the air channel outlet 111; therefore, it can be understood that the ventilation gap 312, the groove 313, the inclined through hole 314 and the radial air channel 315 are all part of the airflow channel.

[0052] It is worth mentioning that the inner wall of the housing 110 itself also has an inner wall channel 117 and an oblique channel 118 extending along the axial direction, which are interconnected to facilitate gas circulation. For details, please refer to the attached Fig. 9 .

[0053] Furthermore, the radial bearing seat 140 is provided with a plurality of dispersed ventilation holes 141 , and the ventilation holes 141 are extended in the axial direction.

[0054] It should be noted that the vent holes 141 are used for allowing airflow that takes away heat to flow out from the airway outlet 111 after passing through the vent holes 141 .

[0055] Furthermore, it also includes a sealing disk 190 , which has an axial hole for the rotating shaft 120 to pass through. The sealing disk 190 is sleeved on the rotating shaft 120 and is arranged between the secondary impeller 240 and the second bearing retaining ring 181 .

[0056] It should be understood that the sealing disk 190 plays an axial sealing role, but there is a gap between it and the inner side (wheel back) of the secondary impeller 240 to facilitate the high-pressure gas generated by the secondary impeller 240 to flow to the second air foil bearing 160 through this gap. Therefore, it is arranged between the secondary impeller 240 and the second bearing retaining ring 181.

[0057] Furthermore, it also includes a first spacer sleeve 316 , which is sleeved on one end of the rotating shaft 120 located at the first-stage air compression end 112 , and the thrust bearing seat 310 is sleeved on the first spacer sleeve 316 .

[0058] It should be noted that the first spacer sleeve 316 is used to reduce the wear of the rotating shaft 120 at the first-stage air compression end 112, and can also be used to adjust the assembly clearance of the thrust bearing seat 310 sleeve; and the second spacer sleeve 191 is similar to the first spacer sleeve 316, and is used to reduce the wear of the rotating shaft 120 at the second-stage air compression end 113, and can also be used to adjust the assembly clearance of the sealing disk 190.

[0059] Furthermore, the shell 110 has a spiral water channel 114 therein, and the shell 110 is also provided with a water cooling inlet 115 and a water cooling outlet 116 , and two ends of the spiral water channel 114 are connected to the water cooling inlet 115 and the water cooling outlet 116 respectively.

[0060] It is understandable that the spiral water channel 114 is used for cooling water to circulate, thereby performing surrounding cooling on the motor stator 130 , and therefore a water cooling inlet 115 and a water cooling outlet 116 are also provided on the housing 110 for cooling water to flow in and out.

[0061] To facilitate understanding by those skilled in the art, several cooling methods in this application are briefly described as follows:

[0062] The first air cooling method: at the first-stage compression end 112, the first-stage impeller 220 rotates at a high speed, and the high-pressure gas generated passes through the oblique through hole 314 and the groove 313 of the thrust bearing seat 310, and flows to the first air foil thrust bearing 330 and the second air foil thrust bearing 340 in turn to provide an air source for the dynamic pressure air film formed thereon, and takes away the heat generated by the relatively high-speed rotation between the thrust plate 320 and the first air foil thrust bearing 330 and the second air foil thrust bearing 340. The high-pressure gas passes through the radial air channel 315 of the thrust bearing seat 310, flows to the air vent 141 on the radial bearing seat 140, and then flows out from the air channel outlet 111.

[0063] The second air cooling method: at the first-stage compression end 112, the first-stage impeller 220 rotates at a high speed, and the high-pressure gas generated passes through the inclined through hole 314 of the thrust bearing seat 310. The high-pressure gas passes through the ventilation gap 312 between the arc-shaped bosses 311 on the thrust bearing seat 310, flows to the first air foil bearing 150 to provide an air source for the dynamic pressure air film formed therein, and takes away the heat generated by the relative high-speed rotation of the first air foil bearing 150 and the rotating shaft 120, and then flows out from the air duct outlet 111.

[0064] The third air cooling method: the air source is divided into two parts. The first part is the high-speed rotation of the first-stage impeller 220 of the first-stage compressor end 112, and the high-pressure gas generated passes through the oblique through hole 314 on the thrust bearing seat 310. The high-pressure gas passes through the ventilation gap 312 between the arc-shaped bosses 311 on the thrust bearing seat 310, flows to the ventilation hole 141 of the radial bearing seat 140, and passes through the inner wall channel 117 and the oblique channel 118 of the shell 110 to flow to the first radial air foil bearing; the second part is the secondary compressor end 112. The secondary impeller 240 of the gas end 113 rotates at a high speed, and the generated high-pressure gas flows along the gap between the wheel back of the secondary impeller 240 and the sealing disk 190 to the second air foil bearing 160; the two parts of gas jointly provide an air source to the air foil bearing to form a dynamic pressure air film, and take away the heat generated by the relatively high-speed rotation between the two air foil bearings and the rotating shaft 120, cool the motor stator 130 through the gap between the rotating shaft 120 and the motor stator 130, and finally flow out from the air duct outlet 111.

[0065] Water channel cooling: cooling water is connected to the outer surface of the shell 110 through the water cooling inlet 115, and the motor stator 130 is cooled by the spiral water channel 114 on the wall of the shell 110. The cooling water then flows out through the water cooling outlet 116, thereby realizing a water cooling cycle. In this way, the service life of the air compressor is further improved by combining air channel cooling with water cooling, making the overall structure of the air compressor simpler, more compact and more efficient.

[0066] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fuel cell air compressor, characterized in that: It includes an air compressor body, a turbine assembly and a compressor assembly; wherein, The air compressor body includes a housing, a rotating shaft built in the housing, a motor stator, a radial bearing seat, and a first air foil bearing and a second air foil bearing arranged opposite to each other along the axial direction of the rotating shaft. The turbine assembly includes a first-stage volute, a first-stage impeller, a second-stage volute, a second-stage impeller, and an interstage pipeline; wherein, The shell has an airway outlet, the shell includes a first-stage air compression end and a second-stage air compression end, the first-stage volute is connected to the first-stage air compression end, the second-stage volute is connected to the second-stage air compression end, and the two ends of the interstage pipeline are connected to the first-stage volute and the second-stage volute respectively; The rotating shaft passes through the motor stator, and the two ends of the rotating shaft rotatably pass through the first air foil bearing and the second air foil bearing respectively, the radial bearing seat is connected to the first-stage air compression end, the first air foil bearing is connected to the radial bearing seat, the first-stage impeller is connected to one end of the rotating shaft located at the first-stage air compression end, and the second-stage impeller is connected to one end of the rotating shaft located at the second-stage air compression end; The air compression assembly has an air flow channel for gas circulation, and the air compression assembly is connected between the first air foil bearing and the first-stage impeller.

2. The fuel cell air compressor according to claim 1, characterized in that: The compressed air assembly includes a thrust bearing seat, a thrust plate, and two first air foil thrust bearings and a second air foil thrust bearing that are axially opposite to each other. The thrust bearing seat is connected between the radial bearing seat and the first-stage impeller. The thrust bearing seat has the air flow channel, and the inner side of the thrust bearing seat is recessed to form an installation space. The thrust plate has a through hole for the rotating shaft to pass through. The thrust plate, the first air foil thrust bearing, and the second air foil thrust bearing are all arranged in the installation space and sleeved on the rotating shaft. The thrust plate is attached to the shoulder of the rotating shaft. The first air foil thrust bearing and the second air foil thrust bearing are respectively connected to both sides of the thrust plate.

3. The fuel cell air compressor according to claim 1, characterized in that: It also includes a first limiting assembly, which includes a first bearing retaining ring and a first positioning pin for limiting the circumferential rotation of the first air foil bearing, the first bearing retaining ring is abutted against the outer side of the first air foil bearing, the first positioning pin is extended axially, and the first positioning pin passes through the first bearing retaining ring and extends into the first air foil bearing.

4. The fuel cell air compressor according to claim 1, characterized in that: It also includes a second limiting assembly, which includes a second bearing retaining ring and a second positioning pin for limiting the circumferential rotation of the second air foil bearing, the second bearing retaining ring is abutted against the outer side of the second air foil bearing, the second positioning pin is extended axially, and the second positioning pin passes through the second bearing retaining ring and extends into the second air foil bearing.

5. The fuel cell air compressor according to claim 2, characterized in that: The inner side of the thrust bearing seat is convexly provided with a plurality of arc-shaped bosses arranged at intervals along its own circumference, a ventilation gap is formed between each two adjacent arc-shaped bosses, a groove is formed between the arc-shaped bosses and the outer periphery of the thrust bearing seat, an oblique through hole is provided on the thrust bearing seat, one end of the oblique through hole extends to the outside of the thrust bearing seat, and the other end of the oblique through hole extends to communicate with the groove, and the thrust bearing seat is also provided with a plurality of radial air passages arranged at intervals along its own circumference.

6. The fuel cell air compressor according to claim 5, characterized in that: The radial bearing seat is provided with a plurality of dispersed ventilation holes, and the ventilation holes are extended in the axial direction.

7. The fuel cell air compressor according to claim 4, characterized in that: It also includes a sealing disk, which has an axial hole for the rotating shaft to pass through, and the sealing disk is sleeved on the rotating shaft and arranged between the secondary impeller and the second bearing retaining ring.

8. The fuel cell air compressor according to claim 2, characterized in that: It also includes a first spacer sleeve, which is sleeved on one end of the rotating shaft located at the first-stage air compression end, and the thrust bearing seat is sleeved on the first spacer sleeve.

9. The fuel cell air compressor according to claim 7, characterized in that: It also includes a second spacer sleeve, which is sleeved on one end of the rotating shaft located at the secondary air compression end, and the sealing disk is sleeved on the second spacer sleeve.

10. The fuel cell air compressor according to claim 1, characterized in that: The shell has a spiral water channel inside, and a water cooling inlet and a water cooling outlet are also provided on the shell. Two ends of the spiral water channel are connected to the water cooling inlet and the water cooling outlet respectively.

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