Air compressor, axial force adjusting method thereof, fuel cell system and vehicle

Abstract

The invention discloses an air compressor and an axial force adjusting method thereof, a fuel cell system and a vehicle, the air compressor comprises a machine body, a pressurization mechanism and a sealing mechanism, the sealing mechanism comprises a first sealing assembly and a second sealing assembly which are both installed on a rotating shaft, the first sealing assembly is connected with the side, close to a second impeller, of a first impeller, and the second sealing assembly is connected with a second impeller. A first sealing channel communicating with the first volute is arranged between the first sealing assembly and the first impeller. The second sealing assembly is connected with the side, close to the first impeller, of the second impeller, and a second sealing channel communicating with the second volute is arranged between the second sealing assembly and the first impeller. The second sealing assembly is provided with a bypass sealing channel communicating with the second sealing channel and an adjusting assembly used for adjusting the opening degree of a communicating opening between the bypass sealing channel and the second sealing channel. The opening degree of the communicating opening is adjusted through the adjusting assembly, axial force balance of the air compressor within the full rotating speed range is achieved, and the safety performance and efficiency of the thrust bearing are improved.

Description

Technical Field

[0001] This invention relates to the field of air compressor technology, and more particularly to an air compressor and its axial force adjustment method, a fuel cell system, and a vehicle. Background Technology

[0002] Currently, the impeller of an air compressor generates axial force along the axial direction due to the pressure difference between the impeller back plate and the hub surface, as well as the airflow force on the blade surface during high-speed rotation. The main component bearing the axial force is the thrust bearing assembly. Therefore, controlling the magnitude of the axial force of the air compressor is of great significance for improving bearing efficiency and rotor stability. In actual operation of an air compressor, the axial force borne by the thrust bearing is a constantly changing dynamic load. However, the thrust bearing can usually only balance the axial force within a small speed range. Beyond this range, the axial force cannot be balanced. At this point, the large axial force will cause the thrust bearing to become inefficient, affecting the overall efficiency of the air compressor, and may even damage the thrust bearing. Therefore, existing technologies usually change the impeller diameter or redesign the thrust bearing to give it a greater load-bearing capacity in order to balance the axial force and ensure the safety of the thrust bearing. The shortcomings of the above solutions are: changing the impeller diameter often affects the aerodynamic efficiency of the impeller, and redesigning the thrust bearing increases the design cost. Furthermore, the thrust bearing's ability to balance the axial force is always limited by the speed range and cannot achieve axial force balance across the entire speed range. Summary of the Invention

[0003] This invention provides an air compressor and its axial force adjustment method, a fuel cell system, and a vehicle to solve the problem that air compressors in the prior art cannot balance axial force across the entire speed range.

[0004] This invention provides an air compressor, comprising: The machine body includes a housing and a rotating shaft and a thrust bearing assembly both installed within the housing; the thrust bearing assembly is connected between the rotating shaft and the housing. The booster mechanism includes a first volute, a second volute communicating with the first volute, a first impeller mounted on the rotating shaft and located inside the first volute, and a second impeller mounted on the rotating shaft and located inside the second volute; the first volute and the second volute are respectively mounted at opposite ends of the housing; The sealing mechanism includes a first sealing assembly and a second sealing assembly, both mounted on the rotating shaft. The first sealing assembly is connected to the side of the first impeller closest to the second impeller, and a first sealing channel communicating with the first volute is provided between the first sealing assembly and the first impeller. The second sealing assembly is connected to the side of the second impeller closest to the first impeller, and a second sealing channel communicating with the second volute is provided between the second sealing assembly and the first impeller. The second sealing assembly is provided with a bypass sealing channel communicating with the second sealing channel, and an adjusting assembly for adjusting the opening of the connection between the bypass sealing channel and the second sealing channel.

[0005] This invention also provides a method for adjusting the axial force of an air compressor, applied to the aforementioned air compressor, the method comprising: The axial thrust requirement of the second impeller is determined based on the boost pressure information of the air compressor, and the adjustment state of the second sealing assembly is determined based on the axial thrust requirement. The opening of the connection between the bypass sealing channel and the second sealing channel is adjusted by the adjusting component according to the state to be adjusted.

[0006] This invention also provides a fuel cell system, including the aforementioned air compressor.

[0007] This invention also provides a vehicle including the aforementioned fuel cell system.

[0008] In the air compressor, axial force adjustment method, fuel cell system, and vehicle of the present invention, a first sealing channel is provided on the back side of the first impeller (i.e., the side of the first impeller closer to the second impeller); a second sealing channel and a bypass sealing channel are provided on the back side of the second impeller, and a connecting port is provided between the second sealing channel and the bypass sealing channel. The opening of the connecting port can be adjusted by an adjustment component, thereby matching the opening of the connecting port with the current boost pressure information. Under the boost pressure information, the second impeller can meet the axial thrust requirement, thereby achieving controllable adjustment of the axial force of the air compressor, realizing axial force balance of the air compressor across the entire speed range, thereby reducing the magnitude of the axial force borne by the thrust bearing across the entire speed range, improving the safety performance of the thrust bearing, and improving the efficiency of the thrust bearing. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the structure of an air compressor in one embodiment of the present invention.

[0011] Figure 2 This is a partial structural diagram of an air compressor with its connection port fully open in one embodiment of the present invention.

[0012] Figure 3 This is a schematic diagram of the forces acting on the second impeller when the communication port of the air compressor is fully open in one embodiment of the present invention.

[0013] Figure 4 This is a partial structural diagram of the air compressor when its connection port is closed, according to one embodiment of the present invention.

[0014] Figure 5 This is a schematic diagram of the forces acting on the second impeller when the connection port of the air compressor is closed in one embodiment of the present invention.

[0015] Figure 6 This is a partial structural schematic diagram of the air compressor's connection port at the target opening degree in one embodiment of the present invention.

[0016] Figure 7 This is a schematic diagram of the forces acting on the second impeller when the connection port of the air compressor is at the target opening degree in one embodiment of the present invention.

[0017] Figure 8 This is a schematic diagram of the structure of the regulating component of an air compressor in one embodiment of the present invention.

[0018] Figure 9 This is a flowchart of an air compressor axial force adjustment method in one embodiment of the present invention.

[0019] Figure 10 This is a schematic diagram of the change in axial force after adjusting the axial force of an air compressor in one embodiment of the prior art.

[0020] Figure 11 This is a schematic diagram of the change in axial force after adjusting the axial force using the air compressor axial force adjustment method in one embodiment of the present invention.

[0021] The reference numerals in the accompanying drawings are as follows: 1. Body; 11. Housing; 12. Shaft; 13. Thrust bearing assembly; 14. Flange protrusion; 15. Motor stator; 16. First radial bearing assembly; 161. First bearing housing; 162. First radial foil gas hydrodynamic bearing; 17. Second radial bearing assembly; 171. Second bearing housing; 172. Second radial foil gas hydrodynamic bearing; 2. Pressurizing mechanism; 21. First volute; 22. Second volute; 23. First impeller; 24. Second impeller; 3. Sealing mechanism; 31. A sealing assembly; 311, first sealing plate; 312, first shaft seal; 313, first piston ring; 32, second sealing assembly; 321, second sealing plate; 322, second shaft seal; 323, second piston ring; 324, third piston ring; 325, receiving groove; 33, first sealing channel; 34, second sealing channel; 35, bypass sealing channel; 36, adjusting assembly; 361, spring; 362, sealing element; 3621, annular body; 3622, mounting post; 37, connecting port. Detailed Implementation

[0022] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] In the description of this invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] like Figures 1 to 7 As shown, the present invention provides an air compressor, comprising: The machine body 1 includes a housing 11 and a rotating shaft 12 and a thrust bearing assembly 13, both installed within the housing 11. The thrust bearing assembly 13 connects the rotating shaft 12 and the housing 11. The rotating shaft 12 can be a split structure, with a magnet embedded in its middle position and a protective sleeve securing the magnet to its outer side. The machine body 1 also includes a motor stator 15 and a motor rotor installed within the housing 11. The motor rotor is connected to the rotating shaft 12, and the motor stator 15 is fixed to the housing 11. The motor stator 15 and the motor rotor cooperate to provide the torque to drive the rotating shaft 12. The type of motor stator 15 can be set according to requirements. Preferably, the motor stator 15 uses round wire windings, which can reduce AC losses in ultra-high-speed motors. The thrust bearing assembly 13 is installed inside the housing 11. In one embodiment, the rotating shaft 12 is provided with a flange protrusion 14 that mates with the thrust bearing assembly 13. The thrust bearing assembly 13 and the flange protrusion 14 mate with each other to provide axial support for the rotating shaft 12.

[0026] Furthermore, the body 1 also includes a radial bearing assembly, which includes a first radial bearing assembly 16 and a second radial bearing assembly 17. The first radial bearing assembly 16 is installed on the side of the housing 11 near the first impeller 23 and includes a first bearing seat 161 and a first radial foil gas dynamic bearing 162. The second radial bearing assembly 17 is installed on the side of the housing 11 near the second impeller 24 and includes a second bearing seat 171 and a second radial foil gas dynamic bearing 172. The rotating shaft 12 is installed in the hollow shaft hole formed by the first radial foil gas dynamic bearing 162 and the second radial foil gas dynamic bearing 172. The rotating shaft 12 is supported by the foil gas dynamic bearing, which improves the stability and efficiency of the rotating shaft 12 during high-speed rotation and reduces friction loss.

[0027] Furthermore, the housing 11 is provided with a cooling ring groove (not shown in the figure), through which a cooling medium such as coolant is circulated to remove the heat generated by the motor and other components of the housing 1 during operation.

[0028] The booster mechanism 2 includes a first volute 21, a second volute 22 communicating with the first volute 21, a first impeller 23 mounted on the rotating shaft 12 and located inside the first volute 21, and a second impeller 24 mounted on the rotating shaft 12 and located inside the second volute 22; the first volute 21 and the second volute 22 are respectively mounted at opposite ends of the housing 11; wherein, the first impeller 23 and the second impeller 24 are both centrifugal impellers. Furthermore, the first volute 21 and the second volute 22 are asymmetrical structures. The first volute 21 is connected to the second volute 22 through an interstage tube. The first impeller 23 can rotate with the shaft 12, thereby continuously drawing gas into the inlet of the first volute 21 and, after pressurizing the gas, discharging it through the exhaust port, thus compressing the gas. The second impeller 24 can also rotate with the shaft 12, and the compressed gas discharged from the exhaust port of the first volute 21 will be transmitted into the second volute 22 through the interstage tube. The second impeller 24 will further pressurize the compressed gas entering the second volute 22 to obtain a higher pressure ratio. The gas after final pressurization is collected through the second volute 22 and can be used to increase the inlet pressure of the fuel cell stack.

[0029] The sealing mechanism 3 includes a first sealing component 31 and a second sealing component 32, both mounted on the rotating shaft 12. The first sealing component 31 is connected to the side of the first impeller 23 near the second impeller 24, and a first sealing channel 33 communicating with the first volute 21 is provided between the first sealing component 31 and the first impeller 23. The second sealing component 32 is connected to the side of the second impeller 24 near the first impeller 23, and a second sealing channel 34 communicating with the second volute 22 is provided between the second sealing component 32 and the first impeller 23. The second sealing component 32 is provided with a bypass sealing channel 35 communicating with the second sealing channel 34, and an adjusting component 36 for adjusting the opening of the communication port 37 between the bypass sealing channel 35 and the second sealing channel 34.

[0030] A first sealing channel 33 is formed between the first sealing assembly 31 and the first impeller 23. Understandably, a portion of the pressurized gas from the first impeller 23 will inevitably enter the first sealing channel 33, thus exerting a certain thrust on the first impeller 23. Since the first impeller 23 is fixed to the shaft 12, the back of the first impeller 23 (i.e., the...) Figure 1 The pressure on the right side of the first impeller 23 and the front side of the first impeller 23 (i.e., Figure 1The pressure difference on the left side of the first impeller 23 creates a first axial thrust. Typically, the pressure on the back of the first impeller 23 is higher than the pressure on its front side. Therefore, the first axial thrust of the first impeller 23 points towards its inlet. Gas entering the first sealing channel 33 is sealed by the first sealing assembly 31 to prevent leakage of useful pressurized gas.

[0031] Similarly, a second sealing channel 34 is formed between the second sealing assembly 32 and the second impeller 24. Simultaneously, the second sealing assembly 32 also has a bypass sealing channel. Understandably, a portion of the pressurized gas from the second impeller 24 will inevitably enter the second sealing channel 34, thus generating a certain thrust on the second impeller 24. Since the second impeller 24 is fixed to the shaft 12, the back of the second impeller 24 (i.e., the...) Figure 1 The pressure on the left side of the second impeller 24 and the front side of the second impeller 24 (i.e., Figure 1 The pressure difference on the right side of the second impeller 24 will generate a second axial thrust. Usually, the pressure on the back of the first impeller 23 is higher than the pressure on the front of the first impeller 23. Therefore, the second sealing channel 34 will also generate a second axial thrust pointing towards the inlet of the second impeller 24. It should be noted that the gas temperature after two-stage pressurization is very high when it comes into contact with the second impeller 24. Therefore, it must be sealed by the second sealing assembly 32 to strictly limit this part of high-temperature gas from entering the bearing and motor axially.

[0032] As described above, the first and second axial thrusts are typically in opposite directions, allowing them to cancel each other out at least partially, resulting in the resultant force, which is the axial force of the air compressor. This axial force needs to be balanced by a thrust bearing mounted axially. In the actual use of air compressors in fuel cell systems, gas bearings are typically used to prevent oil leakage from the oil bearings from contaminating the fuel cell stack. Gas bearings generally have a much lower load-bearing capacity than oil bearings, therefore, the magnitude of the axial force needs to be strictly limited.

[0033] In the above embodiments of the present invention, a bypass sealing channel 35 is provided on the second sealing assembly 32 for adjusting the force on the back of the second impeller 24.

[0034] Specifically, when the air compressor receives a boosting command, it acquires boosting pressure information. This boosting pressure information indicates that the air compressor's boosting demand is low. At this time, the first axial thrust generated by the first impeller 23 is relatively small. In order to maintain the resultant force between the first axial force and the second axial force, that is, the balance of axial forces, the second impeller 24 also needs a relatively small second axial thrust to balance it. At this time, it can be determined that the axial thrust demand of the second impeller 24 is at a low demand level. Therefore, the second sealing channel 34 can be kept open, while the bypass sealing channel 35 only needs to be kept closed (the connection port 37 between the second sealing channel 34 and the bypass sealing channel 35 is closed, and the two cannot be connected). At this time, the compressed gas generated by the second impeller 24 only enters the second sealing channel 34, and thus can only act on the back part of the second impeller 24 corresponding to the second sealing channel 34, so that the generated second axial thrust is relatively small, and then the smaller second axial thrust is balanced with the smaller first axial thrust generated by the first impeller 23.

[0035] When the boost pressure information indicates that the air compressor has a high boost pressure demand, the first impeller 23 generates a large first axial thrust. To maintain axial force balance, the second impeller 24 also needs to generate a large second axial thrust to balance it. At this time, it can be determined that the axial thrust demand of the second impeller 24 is a high demand level. Therefore, the second sealing channel 34 and the bypass sealing channel 35 can be fully opened, that is, the connection port 37 between the second sealing channel 34 and the bypass sealing channel 35 is fully opened, and the second sealing channel 34 is connected to the bypass sealing channel 35. At this time, the compressed gas generated by the second impeller 24 enters the second sealing channel 34 and the bypass sealing channel 35 at the same time, so that it can act on the back of the entire second impeller 24 corresponding to the second sealing channel 34 and the bypass sealing channel 35, so that the generated second axial thrust is large, thereby meeting the axial thrust demand of the high demand level. In this way, the large second axial thrust is balanced with the large first axial thrust generated by the first impeller 23.

[0036] When the boost pressure information indicates that the air compressor's boost pressure demand is between the two states mentioned above (low boost pressure demand and high boost pressure demand), the bypass sealing channel 35 of the second sealing assembly 32 will be in a partially open state. At this time, the compressed gas generated by the second impeller 24 enters both the second sealing channel 34 and the bypass sealing channel 35. However, the gas pressure entering the bypass sealing channel 35 will decrease. Therefore, the main axial thrust acting on the first back part of the second impeller 24 corresponding to the second sealing channel 34 is larger, while the bypass axial thrust acting on the second back part of the second impeller 24 corresponding to the bypass sealing channel 35 is relatively smaller. Thus, the second axial thrust generated at this time is the sum of the main axial thrust and the bypass axial thrust, and its magnitude is between the second axial thrust corresponding to the two states mentioned above (low boost pressure demand and high boost pressure demand). At this time, the second axial thrust can be balanced with the axial thrust generated by the first impeller 23.

[0037] In the above embodiments of the present invention, a first sealing channel 33 is provided on the back side of the first impeller 23 of the air compressor (that is, on the side of the first impeller 23 near the second impeller 24); a second sealing channel 34 and a bypass sealing channel 35 are provided on the back side of the second impeller 24, and a connecting port 37 is provided between the second sealing channel 34 and the bypass sealing channel 35. The opening of the connecting port 37 can be adjusted by the adjusting component 36, so that the opening of the connecting port 37 matches the current boost pressure information, so that under the boost pressure information, the second impeller 24 can meet the axial thrust requirement, thereby realizing the controllable adjustment of the axial force of the air compressor, realizing the axial force balance of the air compressor in the full speed range, thereby reducing the magnitude of the axial force borne by the thrust bearing in the full speed range, improving the safety performance of the thrust bearing, and improving the efficiency of the thrust bearing.

[0038] In one embodiment, such as Figures 1 to 3As shown, the first sealing assembly 31 includes a first sealing plate 311, a first shaft seal 312 sleeved on the rotating shaft 12, and a first piston ring 313 sleeved on the first shaft seal 312; one end of the first sealing plate 311 is sealed to the first shaft seal 312 through the first piston ring 313, and the other end of the first sealing plate 311 is connected to the first volute 21; the first sealing channel 33 is disposed between the first impeller 23 and the first sealing plate 311, and the first piston ring 313 is used to seal the end of the first sealing channel 33 away from the first volute 21. Understandably, a thrust bearing is installed between the first sealing plate 311 and the first radial bearing assembly 16, and the thrust bearing is a foil gas bearing installed on the rotating shaft 12. The first sealing assembly 31 can be a single piston ring seal, that is, the first shaft seal 312 has a first annular groove in the middle for installing the first piston ring 313. The gas entering the first sealing channel 33 needs to be sealed by the first shaft seal 312 installed on the rotating shaft 12 in the first sealing assembly 31, and the first piston ring 313 installed on the first shaft seal 312 is used to prevent useful pressurized gas from leaking out.

[0039] In one embodiment, such as Figures 1 to 3As shown, the second sealing assembly 32 includes a second sealing plate 321, a second shaft seal 322 sleeved on the rotating shaft 12, and a second piston ring 323 and a third piston ring 324 both sleeved on the second shaft seal 322. One end of the second sealing plate 321 is sealed to the second shaft seal 322 through the second piston ring 323 and the third piston ring 324, and the other end of the second sealing plate 321 is connected to the second volute 22. The second sealing channel 34 is disposed between the second impeller 24 and the second sealing plate 321. The second piston ring 323 is used to seal the end of the second sealing channel 34 away from the second volute 22. The third piston ring 324 is used to seal the end of the bypass sealing channel 35 away from the second passage. The second piston ring 323 is located between the third piston ring 324 and the second impeller 24. Understandably, the end of the second sealing channel 34 away from the second impeller 24 is individually sealed by the second piston ring 323 to control the leakage of high-temperature gas. The bypass sealing channel 35, located away from the second impeller 24, is individually sealed with a third piston ring 324 to control the leakage of high-temperature gas. The second shaft seal 322 has a second annular groove and a third annular groove for mounting the second piston ring 323 and the third piston ring 324, respectively. The diameters of the second and third annular grooves are unequal to accommodate piston rings 323 and 324 of different diameters. In this embodiment, the high-temperature gas entering the second sealing channel 34 or the bypass sealing channel 35 is sealed by the second piston ring 323 and the third piston ring 324 mounted on the second shaft seal 322, thus strictly limiting the axial entry of this high-temperature gas into the bearing and motor.

[0040] Furthermore, the second sealing plate 321 may also be provided with one or more other bypass channels that connect to the second sealing channel 34 or the bypass sealing channel 35, and a fourth piston ring may be provided at the end of each other bypass channel away from the second sealing channel 34 or the bypass sealing channel 35 for sealing. The design structure of the other bypass channels can refer to the specific design of the bypass sealing channel 35 described above. In this way, near-continuously adjustable axial force control can be achieved, which can further ensure that the axial force is adjustable across the entire speed range.

[0041] In one embodiment, such as Figures 1 to 8As shown, the second sealing plate 321 is further provided with a receiving groove 325 communicating with the second sealing channel 34 at a position opposite to the communication port 37. The receiving groove 325 and the first sealing channel 33 are located on opposite sides of the communication port 37. The adjusting assembly 36 includes a spring 361 and a sealing member 362 installed in the receiving groove 325. The sealing member 362 is used to extend out of the receiving groove 325 and abut against the edge of the communication port 37 under the elastic force of the spring 361. Further, as Figure 8 As shown, the sealing member 362 includes an annular body 3621 and a plurality of mounting posts 3622 spaced apart on the end face of the annular body 3621 away from the first impeller 23. A plurality of springs 361 can be fitted one-to-one onto the mounting posts 3622. A plurality of insertion holes are also provided one-to-one on the bottom surface of the receiving groove 325. After the mounting posts 3622 of the sealing member 362 are inserted into the insertion holes, the springs 361 are compressed and pressed against the bottom surface of the receiving groove 325 and the annular body 3621. When the end face of the annular body 3621 away from the springs 361 abuts against the edge of the connecting port 37, the connecting port 37 can be sealed and closed. When the end face of the annular body 3621 away from the springs 361 leaves the edge of the connecting port 37, the connecting port 37 is partially or completely opened. At this time, the second sealing channel 34 and the bypass sealing channel 35 are connected. In some embodiments, the action of the sealing member 362 moving closer to or away from the connection port 37 can be achieved by the compressed gas flowing from the second sealing channel 34 to the connection port 37. In other embodiments, a control device can also be provided to control the transmission assembly to actively control the movement of the sealing member 362 to perform the action of the sealing member 362 moving closer to or away from the connection port 37. This is not limited here.

[0042] This invention also provides a method for adjusting the axial force of an air compressor, applicable to the aforementioned air compressor. The specific limitations of this air compressor are detailed above and will not be repeated here. Figure 9 As shown, the method for adjusting the axial force of the air compressor includes: S10, the axial thrust requirement of the second impeller 24 is determined based on the boost pressure information of the air compressor, and the adjustment state of the second sealing assembly 32 is determined based on the axial thrust requirement. The boost pressure information characterizes the level of boost pressure required by the air compressor to compress and boost the gas. The axial thrust requirement of the second impeller 24 is related to the boost pressure information; specifically, if the boost pressure information indicates a higher boost pressure requirement, the axial thrust requirement of the second impeller 24 will also be relatively high, and vice versa. The adjustment state of the second sealing assembly 32 refers to the open state of the second sealing channel 34 and the bypass sealing channel 35. In this invention, the second sealing channel 34 will remain continuously connected to the second volute 22 and thus remain open, while the bypass sealing channel 35 will switch between fully open, partially open, and closed states according to the actual axial thrust requirement of the second impeller 24.

[0043] S20, the opening degree of the connection port 37 between the bypass sealing channel 35 and the second sealing channel 34 is adjusted by the adjusting component 36 according to the state to be adjusted. Understandably, in this embodiment, a fully open bypass sealing channel 35 represents a 100% opening degree of the connection port 37 between the second sealing channel 34 and the bypass sealing channel 35; a closed bypass sealing channel 35 represents a 0% opening degree of the connection port 37 between the second sealing channel 34 and the bypass sealing channel 35; and a partially open bypass sealing channel 35 represents an opening degree greater than 0 and less than 100% of the connection port 37 between the second sealing channel 34 and the bypass sealing channel 35. Since, with constant power, as the compressor speed increases, its flow rate (i.e., the volume of gas discharged per unit time) also increases, and its compression capacity improves, resulting in a corresponding increase in output pressure. In other words, the higher the compressor speed, the greater the pressure. In this embodiment, regardless of the compressor's boost pressure information state—that is, regardless of whether the compressor's corresponding speed is high or low (i.e., regardless of whether the compressor's boost pressure demand is high or low)—the axial force of the compressor can be balanced by adjusting the opening of the connection port 37. This embodiment can achieve axial force balance across the entire speed range, thereby reducing the axial force borne by the thrust bearing across the entire speed range, improving the thrust bearing's safety performance, and increasing its efficiency. Understandably, the opening of the connection port 37 can be adjusted by adjusting the adjustment component 36. The specific adjustment process can be referred to in the above embodiment of the air compressor, and will not be repeated here.

[0044] In the above embodiments of the present invention, a first sealing channel 33 is provided on the back side of the first impeller 23 of the air compressor (that is, on the side of the first impeller 23 near the second impeller 24); a second sealing channel 34 and a bypass sealing channel 35 are provided on the back side of the second impeller 24, and a connecting port 37 is provided between the second sealing channel 34 and the bypass sealing channel 35. The opening of the connecting port 37 can be adjusted by the adjusting component 36, so that the opening of the connecting port 37 matches the current boost pressure information, so that under the boost pressure information, the second impeller 24 can meet the axial thrust requirement, thereby realizing the controllable adjustment of the axial force of the air compressor, realizing the axial force balance of the air compressor in the full speed range, thereby reducing the magnitude of the axial force borne by the thrust bearing in the full speed range, improving the safety performance of the thrust bearing, and improving the efficiency of the thrust bearing.

[0045] In one embodiment, such as Figure 1 , Figure 4 and Figure 5 As shown, determining the axial thrust requirement of the second impeller 24 based on the boost pressure information of the air compressor, and determining the adjustment state of the second sealing assembly 32 based on the axial thrust requirement, includes: When the axial thrust requirement of the second impeller is determined to be at a low demand level based on the boost pressure information, the adjustment state of the second sealing assembly 32 is determined to be the first state. The first state includes: keeping the second sealing channel 34 fully open and closing the bypass sealing channel 35.

[0046] In some embodiments, a control device is provided to control the transmission assembly to actively control the movement of the sealing member 362. When the sealing member 362 moves closer to or further away from the communication port 37, a first preset pressure threshold can be obtained first. Then, when the pressure information is less than or equal to the first preset pressure threshold, the axial thrust requirement of the second impeller 24 is determined to be at a low demand level. Subsequently, the adjustment state of the second sealing assembly 32 is determined to be the first state based on the low demand level. Understandably, due to the wheel back of the first impeller 23 (i.e., Figure 1 The pressure on the right side of the first impeller 23 and the front side of the first impeller 23 (i.e., Figure 1 The pressure difference on the left side of the first impeller 23 will generate the first axial thrust; the back of the second impeller 24 (i.e., Figure 1 The pressure on the left side of the second impeller 24 and the front side of the second impeller 24 (i.e., Figure 1The pressure difference on the right side of the second impeller 24 will generate a second axial thrust. In this embodiment, the first preset boosting threshold can be set according to requirements. As long as the boosting pressure information is less than or equal to the first preset boosting threshold, it is only necessary to open the second sealing channel 34 to achieve the balance of the axial force of the air compressor. The determination process of the first preset boosting threshold can be determined according to the following experiment: Set the test boost pressure P, and pressurize the back of the first impeller 23 (i.e., Figure 1 The pressure on the right side of the first impeller 23 and the front side of the first impeller 23 (i.e., Figure 1 The pressure difference experienced by the left side of the first impeller 23 is recorded as the first pressure difference ΔFX.

[0047] When the bypass sealing channel 35 is completely closed, the compressed gas generated by the second impeller 24 only enters the second sealing channel 34, thus acting only on the back side of the second impeller 24 corresponding to the second sealing channel 34. This separates the pressure on the back side of the second impeller 24 corresponding to the second sealing channel 34 from the pressure on the front side of the second impeller 24 (i.e., the pressure on the front side). Figure 1 The pressure difference experienced by the right side of the second impeller 24 is recorded as the second pressure difference ΔFY1.

[0048] By gradually opening the bypass sealing channel 35, the second sealing channel 34 connects with the bypass sealing channel 35. At this time, the compressed gas generated by the second impeller 24 simultaneously enters the second sealing channel 34 and the bypass sealing channel 35, thus acting on the entire back side of the second impeller 24 corresponding to the second sealing channel 34 and the bypass sealing channel 35, causing the generated second axial thrust to gradually increase. At this time, the pressure on the entire back side of the second impeller 24 corresponding to the second sealing channel 34 and the bypass sealing channel 35 is compared with the front side of the second impeller 24 (i.e., the pressure on the front side of the second impeller 24). Figure 1 The pressure difference experienced by the right side of the second impeller 24 is recorded as the second pressure difference ΔFY2.

[0049] If we set ΔFY1-ΔFX=ΔF1; ΔFY2-ΔFX=ΔF2; then, if ΔF2 corresponding to the test boost pressure P is greater than ΔF1, it can be considered that the test boost pressure P is less than the first preset boost threshold. If ΔF2 corresponding to the test boost pressure P is less than ΔF1, it can be considered that the test boost pressure P is greater than the first preset boost threshold. If ΔF2 corresponding to the test boost pressure P is approximately equal to ΔF1, it can be considered that the test boost pressure P is the first preset boost threshold. Furthermore, by conducting tests on different test boost pressures P, different test results are obtained. Based on these test results, the first preset boost threshold can be determined. Understandably, the first preset boost threshold can be adjusted according to actual test results or actual needs. When the actual boost pressure information is less than or equal to the first preset boost threshold, the axial thrust requirement of the second impeller 24 is determined to be at a low requirement level, that is, the requirement for the second axial force is relatively small.

[0050] In this embodiment, when the axial thrust requirement of the second impeller 24 is at a low level, the second sealing channel 34 needs to be kept fully open, and the bypass sealing channel 35 needs to be closed. Specifically, when the air compressor receives a boosting command, it acquires boosting pressure information. This boosting pressure information indicates that the air compressor's boosting demand is low. At this time, the first axial thrust generated by the first impeller 23 is relatively small. To maintain the resultant force between the first axial force and the second axial force, that is, the balance of axial forces, the second impeller 24 also needs a smaller second axial thrust to balance it. At this time, it can be determined that the axial thrust requirement of the second impeller 24 is at a low level; therefore, if Figure 4 As shown, the second sealing channel 34 can remain open at this time, while the bypass sealing channel 35 only needs to remain closed (the connection port 37 between the second sealing channel 34 and the bypass sealing channel 35 is closed, and the two cannot connect). At this time, as... Figure 5 As shown, the compressed gas generated by the second impeller 24 only enters the second sealing channel 34, and thus can only act on the back part of the second impeller 24 corresponding to the second sealing channel 34, so that the generated second axial thrust is relatively small, and thus the smaller second axial thrust is balanced with the smaller first axial thrust generated by the first impeller 23.

[0051] In one embodiment, such as Figure 1 , Figure 4 and Figure 5 As shown, adjusting the opening of the communication port 37 between the bypass sealing channel 35 and the second sealing channel 34 according to the state to be adjusted by the adjusting component 36 includes: When the adjustment state is the first state, the adjustment component 36 is controlled to close the connection port 37 between the bypass sealing channel 35 and the second sealing channel 34. In one embodiment, the second sealing plate 321 of the second sealing component 32 is further provided with a receiving groove 325 communicating with the second sealing channel 34 at a position opposite to the connection port 37. The receiving groove 325 and the first sealing channel 33 are located on opposite sides of the connection port 37. The adjustment component 36 includes a spring 361 and a sealing member 362 installed in the receiving groove 325. The sealing member 362 is used to extend out of the receiving groove 325 and abut against the edge of the connection port 37 under the elastic force of the spring 361. Furthermore, in some embodiments, a control device is provided to control the transmission component to actively control the movement of the sealing member 362 to execute the action of the sealing member 362 moving closer to or away from the connection port 37; while in other embodiments, the automatic adjustment of the connection port opening can be achieved by relying solely on the elastic force of the spring.

[0052] In this embodiment, when the adjustment state is the first state, the connection port 37 needs to be closed. At this time, since the boost pressure information indicates that the air compressor's boost pressure demand is low, the axial thrust demand of the second impeller 24 is also at a low demand level, and the boost pressure corresponding to the second impeller 24 is also relatively small. Thus, as... Figure 4 As shown, the spring 361 installed on the second sealing plate 321 will press against the sealing member 362 so that the sealing member 362 blocks the connection port 37, preventing the bypass sealing channel 35 from opening. In this way, the high-pressure gas can only enter the second sealing channel 34, forming a small second axial thrust on the back plate part of the second impeller 24 corresponding to the second sealing channel 34, which balances the small first axial thrust formed by the first impeller 23.

[0053] In one embodiment, such as Figure 1 , Figure 6 and Figure 7 As shown, determining the axial thrust requirement of the second impeller 24 based on the boost pressure information of the air compressor, and determining the adjustment state of the second sealing assembly 32 based on the axial thrust requirement, includes: When the axial thrust requirement of the second impeller 24 is determined to be at the medium demand level based on the boost pressure information, the adjustment state of the second sealing assembly 32 is determined to be the second state. The second state includes: keeping the second sealing channel 34 fully open and keeping the bypass sealing channel 35 partially open; the second preset boost pressure threshold is greater than the first preset boost pressure threshold.

[0054] In some embodiments, a control device is provided to control the transmission assembly to actively control the movement of the sealing member 362. When the sealing member 362 moves closer to or away from the connection port 37, a first preset pressure threshold and a second preset pressure threshold can be obtained first. Then, when the pressure information is greater than the first preset pressure threshold and less than the second preset pressure threshold, the axial thrust requirement of the second impeller 24 is determined to be at a medium demand level. Based on the medium demand level, the adjustment state of the second sealing assembly 32 is determined to be a second state. Understandably, the method for determining the first preset pressure threshold is the same as described in the above embodiments, and the second preset pressure threshold can also be set according to demand, as long as the second sealing channel 34 and the bypass sealing channel 35 need to be fully opened when the pressure information is greater than the second preset pressure threshold to achieve the balance of the axial force of the air compressor. The process for determining the second preset pressure threshold can be determined according to the following experiment: Set the test boost pressure P, and pressurize the back of the first impeller 23 (i.e., Figure 1 The pressure on the right side of the first impeller 23 and the front side of the first impeller 23 (i.e., Figure 1 The pressure difference experienced by the left side of the first impeller 23 is recorded as the first pressure difference ΔFX.

[0055] When the bypass sealing channel 35 gradually opens but is not fully open, the second sealing channel 34 connects with the bypass sealing channel 35. At this time, the compressed gas generated by the second impeller 24 simultaneously enters the second sealing channel 34 and the bypass sealing channel 35, thus acting on the entire back side of the second impeller 24 corresponding to the second sealing channel 34 and the bypass sealing channel 35, causing the generated second axial thrust to gradually increase. At this time, the pressure on the entire back side of the second impeller 24 corresponding to the second sealing channel 34 and the bypass sealing channel 35 is compared with the pressure on the front side of the second impeller 24 (i.e., the pressure on the front side of the second impeller 24). Figure 1 The pressure difference experienced by the right side of the second impeller 24 is recorded as the second pressure difference ΔFY2.

[0056] After the bypass sealing channel 35 is fully opened, the pressure on the back side of the entire second impeller 24, corresponding to the second sealing channel 34 and the bypass sealing channel 35, will be equal to the pressure on the front side of the second impeller 24 (i.e., Figure 1 The pressure difference experienced by the right side of the second impeller 24 is recorded as the third pressure difference ΔFY3.

[0057] If we set ΔFY3-ΔFX=ΔF3; ΔFY2-ΔFX=ΔF2; then, if ΔF3 corresponding to the test boost pressure P is greater than ΔF2, it can be considered that the test boost pressure P is less than the second preset boost threshold. If ΔF3 corresponding to the test boost pressure P is less than ΔF2, it can be considered that the test boost pressure P is greater than the second preset boost threshold. If ΔF3 corresponding to the test boost pressure P is approximately equal to ΔF2, it can be considered that the test boost pressure P is the second preset boost threshold. Therefore, based on the above test results, the second preset boost threshold can be determined. Understandably, the above second preset boost threshold can be adjusted according to actual test results or actual needs. When the actual boost pressure information is greater than the first preset boost threshold and less than the second preset boost threshold, the axial thrust requirement of the second impeller 24 is determined to be at a medium demand level, that is, the requirement for the second axial force is also medium.

[0058] In this embodiment, when the air compressor receives a boosting command, it acquires boosting pressure information. This boosting pressure information indicates that the air compressor's boosting demand is between two states: low boosting demand and high boosting demand. Figure 6 As shown, the bypass sealing channel 35 of the second sealing assembly 32 will be in a partially open state. At this time, the compressed gas generated by the second impeller 24 enters both the second sealing channel 34 and the bypass sealing channel 35. However, the gas pressure entering the bypass sealing channel 35 will decrease. Therefore, as... Figure 7 As shown, at this time, the main axial thrust acting on the first back part of the second impeller 24 corresponding to the second sealing channel 34 is relatively large, while the bypass axial thrust acting on the second back part of the second impeller 24 corresponding to the bypass sealing channel 35 is relatively small. Therefore, the second axial thrust generated at this time is the sum of the main axial thrust and the bypass axial thrust, and its magnitude is between the second axial thrust corresponding to the above two states (low boosting demand and high boosting demand). At this time, the second axial thrust can be balanced with the axial thrust generated by the first impeller 23.

[0059] In one embodiment, such as Figure 1 , Figure 6 and Figure 7 As shown, adjusting the opening of the communication port 37 between the bypass sealing channel 35 and the second sealing channel 34 according to the state to be adjusted by the adjusting component 36 includes: When the adjustment state is the second state, the adjustment component 36 is controlled to open the communication port 37 between the bypass sealing channel 35 and the second sealing channel 34, and adjust the current opening degree of the communication port 37 to the target opening degree corresponding to the pressurization pressure information, wherein the target opening degree is greater than 0 and less than 100%. In one embodiment, the second sealing plate 321 of the second sealing component 32 is further provided with a receiving groove 325 communicating with the second sealing channel 34 at a position opposite to the communication port 37, wherein the receiving groove 325 and the first sealing channel 33 are located on opposite sides of the communication port 37; the adjustment component 36 includes a spring 361 and a sealing member 362 installed in the receiving groove 325, wherein the sealing member 362 is used to extend out of the receiving groove 325 and abut against the edge of the communication port 37 under the elastic force of the spring 361. Furthermore, in some embodiments, a control device is provided to control the transmission assembly to actively control the movement of the blocking member 362, so as to execute the action of the blocking member 362 moving closer to or away from the connection port 37; while in other embodiments, the automatic adjustment of the opening of the connection port can be achieved simply by relying on the elastic force of the spring.

[0060] In this embodiment, when the state to be adjusted is the second state, the connecting port 37 needs to be partially opened, that is, the opening degree of the connecting port 37 needs to be adjusted to the target opening degree (greater than 0 and less than 100%). At this time, the bypass sealing channel 35 on the second sealing plate 321 of the second sealing assembly 32 is in a half-open state, and the boost pressure information indicates that the boost pressure demand of the air compressor is between two states: low boost pressure demand and high boost pressure demand. Therefore, the axial thrust demand of the second impeller 24 is also at the medium demand level, and the boost pressure corresponding to the second impeller 24 is also medium. Thus, as Figure 6As shown, the spring 361 installed on the second sealing plate 321 will press against the sealing member 362. However, under the thrust of the high-pressure gas at the connecting port 37 in the second sealing channel 34, the sealing member 362 will also be partially pushed open, so that the sealing member 362 will not completely block the connecting port 37. Thus, after the high-pressure gas enters the second sealing channel 34, a portion of it will enter the bypass sealing channel 35 through the half-open connecting port 37. However, since the boosted pressure is not particularly high, the pressure of the high-pressure gas in the second sealing channel 34 will drop significantly after the action of pushing the sealing member 362 before entering the bypass sealing channel 35. As the gas enters the bypass sealing channel 35, the gas pressure inside the bypass sealing channel 35 decreases. At this time, the main axial thrust acting on the first back part of the second impeller 24 corresponding to the second sealing channel 34 is relatively large, while the bypass axial thrust acting on the second back part of the second impeller 24 corresponding to the bypass sealing channel 35 is relatively small. Therefore, the second axial thrust generated at this time is the sum of the main axial thrust and the bypass axial thrust, and its magnitude is between the second axial thrust corresponding to the two states of low pressurization demand and high pressurization demand. At this time, the second axial thrust can be balanced with the axial thrust generated by the first impeller 23.

[0061] In one embodiment, such as Figure 1 , Figure 2 and Figure 3 As shown, determining the axial thrust requirement of the second impeller 24 based on the boost pressure information of the air compressor, and determining the adjustment state of the second sealing assembly 32 based on the axial thrust requirement, includes: When the axial thrust requirement of the second impeller 24 is determined to be at a high demand level based on the boost pressure information, the adjustment state of the second sealing assembly 32 is determined to be the third state. The third state includes: keeping the second sealing channel 34 and the bypass sealing channel 35 fully open.

[0062] In some embodiments, a control device is provided to control the transmission assembly to actively control the movement of the sealing member 362. When the sealing member 362 moves closer to or further away from the connection port 37, a second preset pressure threshold can be obtained first. Then, when the pressure information is greater than or equal to the second preset pressure threshold, the axial thrust requirement of the second impeller 24 is determined to be at a high demand level; at this time, the second axial thrust requirement of the second impeller 24 is large. Understandably, the method for determining the first preset pressure threshold is the same as described in the above embodiments, and will not be repeated here.

[0063] In this embodiment, when the boost pressure information indicates a high boost pressure demand from the air compressor, the first impeller 23 generates a large first axial thrust. To maintain axial force balance, the second impeller 24 also needs to generate a correspondingly large second axial thrust to balance it. At this time, it can be determined that the axial thrust demand of the second impeller 24 is at a high demand level. Therefore, both the second sealing channel 34 and the bypass sealing channel 35 can be fully opened, that is, as... Figure 2 As shown, the connection port 37 between the second sealing channel 34 and the bypass sealing channel 35 is fully opened, connecting the second sealing channel 34 and the bypass sealing channel 35. At this time, the compressed gas generated by the second impeller 24 simultaneously enters the second sealing channel 34 and the bypass sealing channel 35, thus, as... Figure 3 As shown, compressed gas can act on the back side of the entire second impeller 24 corresponding to the second sealing channel 34 and the bypass sealing channel 35, resulting in a larger second axial thrust, thereby meeting the axial thrust requirements of high demand levels. In this way, the larger second axial thrust is balanced with the larger first axial thrust generated by the first impeller 23.

[0064] In one embodiment, such as Figure 1 , Figure 2 and Figure 3 As shown, adjusting the opening of the communication port 37 between the bypass sealing channel 35 and the second sealing channel 34 according to the state to be adjusted by the adjusting component 36 includes: When the adjustment state is the third state, the adjustment component 36 is controlled to fully open the communication port 37 between the bypass sealing channel 35 and the second sealing channel 34. In one embodiment, the second sealing plate 321 of the second sealing component 32 is further provided with a receiving groove 325 communicating with the second sealing channel 34 at a position opposite to the communication port 37. The receiving groove 325 and the first sealing channel 33 are located on opposite sides of the communication port 37. The adjustment component 36 includes a spring 361 and a sealing member 362 installed in the receiving groove 325. The sealing member 362 is used to extend out of the receiving groove 325 and abut against the edge of the communication port 37 under the elastic force of the spring 361. Furthermore, in some embodiments, a control device is provided to control the transmission component to actively control the movement of the sealing member 362 to execute the action of the sealing member 362 moving closer to or away from the communication port 37; while in other embodiments, the automatic adjustment of the opening degree of the communication port can be achieved by relying solely on the elastic force of the spring.

[0065] In this embodiment, when the adjustment state is the third state, the connection port 37 needs to be fully opened. At this time, since the boost pressure information indicates that the air compressor's boost pressure demand is high, the axial thrust demand of the second impeller 24 is also at a high demand level, and the boost pressure corresponding to the second impeller 24 is also relatively large. Thus, as... Figure 2 As shown, the sealing member 362 installed on the second sealing plate 321 will be completely pushed open by the high-pressure gas entering the second sealing channel 34, thereby completely opening the bypass sealing channel 35 and completely connecting the second sealing channel 34 and the bypass sealing channel 35. Furthermore, due to the large boost pressure information, the pressure of the high-pressure gas entering the second sealing channel 34 is very high. Therefore, even after the action of pushing the sealing member 362, the pressure of the high-pressure gas in the second sealing channel 34 will not drop significantly. Thus, the gas pressure entering the bypass sealing channel 35 is still very high. At this time, the main axial thrust acting on the first back part of the second impeller 24 corresponding to the second sealing channel 34 is large, and the bypass axial thrust acting on the second back part of the second impeller 24 corresponding to the bypass sealing channel 35 is also large. Therefore, the second axial thrust generated at this time is large, which can balance the large first axial thrust generated by the first impeller 23.

[0066] like Figure 10 and Figure 11 As shown, Figure 10 The image shows the axial force change state of an air compressor after adjusting the axial force in an embodiment of the prior art, where F0 is the axial force and P0 is the boost pressure. Figure 10 In the process, as the booster pressure of the air compressor increases, that is, as the rotational speed of the air compressor shaft 12 increases, the axial force will become unbalanced and increase rapidly, which will eventually lead to problems with the thrust bearing, etc. Figure 11 The figure shows the axial force change state after adjusting the axial force of an air compressor according to an embodiment of the present invention. The axial force can be controlled to fluctuate within a certain small range and will not increase to an uncontrollable state. Therefore, the present invention can achieve axial force balance regardless of the axial force speed, that is, it can achieve axial force balance across the entire speed range.

[0067] This invention also provides a fuel cell system, including the aforementioned air compressor. The air compressor is as described in the embodiments above and will not be repeated here. In the fuel cell system of the above embodiments of this invention, a first sealing channel 33 is provided on the back side of the first impeller 23 of the air compressor (i.e., the side of the first impeller 23 near the second impeller 24); a second sealing channel 34 and a bypass sealing channel 35 are provided on the back side of the second impeller 24, and a connecting port 37 is provided between the second sealing channel 34 and the bypass sealing channel 35. The opening of the connecting port 37 can be adjusted by the adjusting component 36, thereby matching the opening of the connecting port 37 with the current boost pressure information. Under this boost pressure information, the second impeller 24 can meet the axial thrust requirement, thus achieving controllable adjustment of the axial force of the air compressor, realizing axial force balance of the air compressor across the entire speed range, thereby reducing the magnitude of the axial force borne by the thrust bearing across the entire speed range, improving the safety performance of the thrust bearing, and increasing the efficiency of the thrust bearing.

[0068] This invention also provides a vehicle including the aforementioned fuel cell system. In the vehicle of the above-described embodiment of the invention, a first sealing channel 33 is provided on the back side of the first impeller 23 of the air compressor of the fuel cell system (i.e., the side of the first impeller 23 closest to the second impeller 24); a second sealing channel 34 and a bypass sealing channel 35 are provided on the back side of the second impeller 24, and a connecting port 37 is provided between the second sealing channel 34 and the bypass sealing channel 35. The opening of the connecting port 37 can be adjusted by the adjusting component 36, thereby matching the opening of the connecting port 37 with the current boost pressure information. Under this boost pressure information, the second impeller 24 can meet the axial thrust requirement, thus achieving controllable adjustment of the axial force of the air compressor, realizing axial force balance of the air compressor across the entire speed range, thereby reducing the magnitude of the axial force borne by the thrust bearing across the entire speed range, improving the safety performance of the thrust bearing, and increasing the efficiency of the thrust bearing.

[0069] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An air compressor characterized by, include: The machine body includes a housing and a rotating shaft and a thrust bearing assembly both installed within the housing; the thrust bearing assembly is connected between the rotating shaft and the housing. The booster mechanism includes a first volute, a second volute communicating with the first volute, a first impeller mounted on the rotating shaft and located inside the first volute, and a second impeller mounted on the rotating shaft and located inside the second volute; the first volute and the second volute are respectively mounted at opposite ends of the housing; The sealing mechanism includes a first sealing assembly and a second sealing assembly, both mounted on the rotating shaft. The first sealing assembly is connected to the side of the first impeller closest to the second impeller, and a first sealing channel communicating with the first volute is provided between the first sealing assembly and the first impeller. The second sealing assembly is connected to the side of the second impeller closest to the first impeller, and a second sealing channel communicating with the second volute is provided between the second sealing assembly and the first impeller. The second sealing assembly is provided with a bypass sealing channel communicating with the second sealing channel, and an adjusting assembly for adjusting the opening of the connection between the bypass sealing channel and the second sealing channel.

2. The air compressor of claim 1, wherein, The first sealing assembly includes a first sealing plate, a first shaft seal fitted on the rotating shaft, and a first piston ring fitted on the first shaft seal; one end of the first sealing plate is sealed to the first shaft seal through the first piston ring, and the other end of the first sealing plate is connected to the first volute; the first sealing channel is disposed between the first impeller and the first sealing plate, and the first piston ring is used to seal the end of the first sealing channel away from the first volute.

3. The air compressor of claim 1, wherein, The second sealing assembly includes a second sealing plate, a second shaft seal fitted onto the rotating shaft, and a second piston ring and a third piston ring both fitted onto the second shaft seal; one end of the second sealing plate is sealed to the second shaft seal via the second piston ring and the third piston ring, and the other end of the second sealing plate is connected to the second volute; the second sealing channel is disposed between the second impeller and the second sealing plate; the second piston ring is used to seal the end of the second sealing channel away from the second volute; the third piston ring is used to seal the end of the bypass sealing channel away from the second passage; the second piston ring is located between the third piston ring and the second impeller.

4. The air compressor according to claim 3, characterized in that, The second sealing plate is also provided with a receiving groove for communicating with the second sealing channel at a position opposite to the communication port. The receiving groove and the first sealing channel are located on opposite sides of the communication port. The adjusting assembly includes a spring and a sealing member installed in the receiving groove. The sealing member is used to extend out of the receiving groove and abut against the edge of the communication port under the elastic force of the spring.

5. A method for adjusting the axial force of an air compressor, applied to the air compressor as described in any one of claims 1 to 4, characterized in that, The method for adjusting the axial force of the air compressor includes: The axial thrust requirement of the second impeller is determined based on the boost pressure information of the air compressor, and the adjustment state of the second sealing assembly is determined based on the axial thrust requirement. The opening of the connection between the bypass sealing channel and the second sealing channel is adjusted by the adjusting component according to the state to be adjusted.

6. The method for adjusting the axial force of an air compressor according to claim 5, characterized in that, The step of determining the axial thrust requirement of the second impeller based on the boost pressure information of the air compressor, and determining the adjustment state of the second sealing assembly based on the axial thrust requirement, includes: When the axial thrust requirement of the second impeller is determined to be at a low requirement level based on the boost pressure information, the adjustment state of the second sealing assembly is determined to be the first state, which includes: keeping the second sealing channel fully open and closing the bypass sealing channel.

7. The method for adjusting the axial force of an air compressor according to claim 6, characterized in that, The step of adjusting the opening degree of the communication port between the bypass sealing channel and the second sealing channel according to the state to be adjusted by the adjusting component includes: When the state to be adjusted is the first state, the adjustment component is controlled to close the connection between the bypass sealing channel and the second sealing channel.

8. The method for adjusting the axial force of an air compressor according to claim 5, characterized in that, The step of determining the axial thrust requirement of the second impeller based on the boost pressure information of the air compressor, and determining the adjustment state of the second sealing assembly based on the axial thrust requirement, includes: When the axial thrust requirement of the second impeller is determined to be at the medium demand level based on the boost pressure information, the adjustment state of the second sealing assembly is determined to be the second state. The second state includes: keeping the second sealing channel fully open and keeping the bypass sealing channel partially open; the second preset boost pressure threshold is greater than the first preset boost pressure threshold.

9. The method for adjusting the axial force of an air compressor according to claim 8, characterized in that, The step of adjusting the opening degree of the communication port between the bypass sealing channel and the second sealing channel according to the state to be adjusted by the adjusting component includes: When the state to be adjusted is the second state, the adjustment component is controlled to open the connection between the bypass sealing channel and the second sealing channel, and the current opening of the connection is adjusted to the target opening corresponding to the boost pressure information, wherein the target opening is greater than 0 and less than 100%.

10. The method for adjusting the axial force of an air compressor according to claim 5, characterized in that, The step of determining the axial thrust requirement of the second impeller based on the boost pressure information of the air compressor, and determining the adjustment state of the second sealing assembly based on the axial thrust requirement, includes: When the axial thrust requirement of the second impeller is determined to be at a high demand level based on the boost pressure information, the adjustment state of the second sealing assembly is determined to be the third state, which includes: keeping the second sealing channel and the bypass sealing channel fully open.

11. The method for adjusting the axial force of an air compressor according to claim 10, characterized in that, The step of adjusting the opening degree of the communication port between the bypass sealing channel and the second sealing channel according to the state to be adjusted by the adjusting component includes: When the state to be adjusted is the third state, the adjustment component is controlled to fully open the connection between the bypass sealing channel and the second sealing channel.

12. A fuel cell system, characterized in that, Includes the air compressor as described in any one of claims 1-4.

13. A vehicle, characterized in that, Includes the fuel cell system as described in claim 12.

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