Air compressor, fuel cell system and vehicle

Abstract

The utility model discloses an air compressor, fuel cell system and vehicle, said air compressor includes, machine body, pressurization mechanism and sealing mechanism, sealing mechanism includes first sealing subassembly and second sealing subassembly both installed on the rotating shaft, first sealing subassembly is connected with first impeller close to the one side of second impeller, and second sealing subassembly is connected with second impeller close to the one side of 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] The utility model relates to the technical field of air compressors, and in particular to an air compressor, a fuel cell system and a vehicle. Background Art

[0002] At present, the impeller of an air compressor will generate 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 bearing component of the axial force is the thrust bearing assembly. Therefore, controlling the axial force of the air compressor is of great significance for improving bearing efficiency and shaft rotor stability. However, in the actual operating conditions of the air compressor, the axial force borne by the thrust bearing is a constantly changing dynamic load, but the thrust bearing can usually only balance the axial force within a relatively small speed range. Beyond this range, the axial force cannot be balanced. At this time, the large axial force will cause the thrust bearing to be inefficient, affecting the overall efficiency of the air compressor and may even damage the thrust bearing. Therefore, in the prior art, the diameter of the impeller is usually changed or the thrust bearing is redesigned to have a larger load-bearing capacity to balance the axial force and ensure the safety of the thrust bearing. The shortcomings of the above scheme are: changing the impeller diameter often affects the aerodynamic efficiency of the impeller, and redesigning the thrust bearing increases the design cost. In addition, the thrust bearing's ability to balance the axial force is always limited by the speed range, and it cannot achieve axial force balance within the full speed range. Summary of the Invention

[0003] The embodiments of the present invention provide an air compressor, a fuel cell system, and a vehicle to solve the problem in the prior art that the air compressor cannot balance the axial force within the full speed range.

[0004] The present invention provides an air compressor, comprising:

[0005] The machine body comprises a housing, a rotating shaft and a thrust bearing assembly both mounted in the housing; the thrust bearing assembly is connected between the rotating shaft and the housing;

[0006] a supercharging mechanism comprising a first volute, a second volute communicating with the first volute, a first impeller mounted on the rotating shaft and located within the first volute, and a second impeller mounted on the rotating shaft and located within the second volute; the first volute and the second volute being mounted at opposite ends of the casing, respectively;

[0007] The sealing mechanism includes a first sealing assembly and a second sealing assembly, both of which are installed on the rotating shaft, the first sealing assembly is connected to the side of the first impeller close to the second impeller, and a first sealing channel connected to 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 close to the first impeller, and a second sealing channel connected to 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 connected to the second sealing channel, and an adjustment assembly for adjusting the opening of the connecting port between the bypass sealing channel and the second sealing channel.

[0008] Furthermore, the first sealing assembly includes a first sealing plate, a first shaft seal sleeved on the rotating shaft, and a first piston ring sleeved on the first shaft seal; one end of the first sealing plate is sealed and connected 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 arranged 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.

[0009] Furthermore, the second sealing assembly includes a second sealing plate, a second shaft seal sleeved on the rotating shaft, and a second piston ring and a third piston ring both sleeved on the second shaft seal; one end of the second sealing plate is sealed and connected to the second shaft seal through 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 arranged 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 sealing channel; the second piston ring is located between the third piston ring and the second impeller.

[0010] Furthermore, a accommodating groove communicating with the second sealing channel is provided on the second sealing plate at a position opposite to the communicating port, and the accommodating groove and the first sealing channel are located on opposite sides of the communicating port; the adjusting assembly includes a spring and a sealing member installed in the accommodating groove, and the sealing member is used to extend out of the accommodating groove and abut against the edge of the communicating port under the elastic force of the spring.

[0011] Furthermore, the sealing member includes an annular body and a plurality of mounting posts spaced apart on the end surface of the annular body away from the first impeller; the adjusting assembly includes a plurality of springs, and a plurality of plug holes are provided on the bottom surface of the accommodating groove; the plurality of springs are respectively sleeved on the plurality of mounting posts, and the mounting posts are respectively plugged into the plug holes, and the springs abut between the bottom surface of the accommodating groove and the annular body.

[0012] Furthermore, the machine body further includes a motor stator and a motor rotor installed in the housing, the motor rotor is connected to the rotating shaft, and the motor stator is fixed on the housing.

[0013] Furthermore, the machine body further includes a radial bearing assembly, the radial bearing assembly including a first radial bearing assembly and a second radial bearing assembly, the first radial bearing assembly being mounted on a side of the casing close to the first impeller, the first radial bearing assembly including a first bearing seat and a first radial foil gas dynamic pressure bearing;

[0014] The second radial bearing assembly is installed on the side of the casing close to the second impeller, and the second radial bearing assembly includes a second bearing seat and a second radial foil gas dynamic pressure bearing; the rotating shaft is installed in the hollow shaft hole formed by the first radial foil gas dynamic pressure bearing and the second radial foil gas dynamic pressure bearing.

[0015] Furthermore, the housing is provided with a cooling ring groove for dissipating heat from the body components.

[0016] Furthermore, the air compressor further includes an interstage pipe, and the first volute is connected to the second volute through the interstage pipe.

[0017] Furthermore, the second sealing assembly also includes a fourth piston ring sleeved on the second shaft seal and at least one other bypass channel arranged on the second sealing plate, the other bypass channel is connected to the second sealing channel or the bypass sealing channel, and the fourth piston ring is arranged one by one at one end of each of the other bypass channels away from the second sealing channel or the bypass sealing channel connected thereto.

[0018] An embodiment of the present invention further provides a fuel cell system, comprising the above-mentioned air compressor.

[0019] An embodiment of the present invention further provides a vehicle, comprising the fuel cell system.

[0020] In the air compressor, fuel cell system and vehicle of the present invention, a first sealing channel is provided on the back side of the first impeller (that is, the side of the first impeller close 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 adjusting component, so that the opening of the connecting port is matched with the current boost pressure information, so that under the boost pressure information, the second impeller can meet the axial thrust requirement and thus realize controllable adjustment of the axial force of the air compressor, realize the axial force balance of the air compressor within the full speed range, and thus reduce the axial force borne by the thrust bearing within the full speed range, improve the safety performance of the thrust bearing, and improve the efficiency of the thrust bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. 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 these drawings without paying any creative labor.

[0022] Figure 1 It is a structural schematic diagram of an air compressor in one embodiment of the present utility model.

[0023] Figure 2 It is a partial structural diagram of an embodiment of the present invention when the communication port of the air compressor is fully opened.

[0024] Figure 3 It is a schematic diagram of the force on the second impeller when the communication port of the air compressor is fully opened in one embodiment of the utility model.

[0025] Figure 4 It is a partial structural diagram of an air compressor when the communication port is closed in one embodiment of the utility model.

[0026] Figure 5 It is a schematic diagram of the force on the second impeller when the communication port of the air compressor is closed in one embodiment of the utility model.

[0027] Figure 6 It is a partial structural diagram of an embodiment of the present invention when the communication port of the air compressor is at a target opening.

[0028] Figure 7 It is a schematic diagram of the force on the second impeller when the communication port of the air compressor is at a target opening in one embodiment of the present utility model.

[0029] Figure 8 It is a structural schematic diagram of an adjustment component of an air compressor in one embodiment of the present utility model.

[0030] Figure 9 This is a flow chart of an air compressor axial force adjustment method in one embodiment of the present invention.

[0031] Figure 10 This is a schematic diagram of the change in axial force after the air compressor in one embodiment of the prior art adjusts the axial force.

[0032] Figure 11 This is a schematic diagram of the change in axial force after the axial force is adjusted by the air compressor axial force adjustment method in one embodiment of the present utility model.

[0033] The reference numerals in the specification are as follows:

[0034] 1. Machine body; 11. Machine housing; 12. Rotating shaft; 13. Thrust bearing assembly; 14. Flange protrusion; 15. Motor stator; 16. First radial bearing assembly; 161. First bearing seat; 162. First radial foil gas dynamic pressure bearing; 17. Second radial bearing assembly; 171. Second bearing seat; 172. Second radial foil gas dynamic pressure bearing; 2. Pressurizing mechanism; 21. First volute; 22. Second volute; 23. First impeller; 24. Second impeller; 3. Sealing mechanism; 31. First A sealing assembly; 311, a first sealing plate; 312, a first shaft seal; 313, a first piston ring; 32, a second sealing assembly; 321, a second sealing plate; 322, a second shaft seal; 323, a second piston ring; 324, a third piston ring; 325, a receiving groove; 33, a first sealing channel; 34, a second sealing channel; 35, a bypass sealing channel; 36, an adjusting assembly; 361, a spring; 362, a sealing member; 3621, an annular body; 3622, a mounting column; 37, a connecting port. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] In the description of the present invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0037] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0038] like Figures 1 to 7 As shown, the utility model provides an air compressor, comprising:

[0039] The body 1 includes a housing 11, a rotating shaft 12 and a thrust bearing assembly 13, both mounted within the housing 11; the thrust bearing assembly 13 is connected between the rotating shaft 12 and the housing 11; the rotating shaft 12 may be a split structure, wherein a magnet is embedded in the middle of the rotating shaft 12 and the magnet is fixed on the outside with a protective sleeve; the body 1 also includes a motor stator 15 and a motor rotor mounted within the housing 11, the motor rotor being connected to the rotating shaft 12, and the motor stator 15 being fixed to the housing 11; the motor stator 15 and the motor rotor cooperate with each other to provide torque for driving the rotating shaft 12 to rotate. The type of the motor stator 15 can be set as required. Preferably, the motor stator 15 uses a round wire winding that can reduce AC loss in ultra-high-speed motors. The thrust bearing assembly 13 is installed in the housing 11. In one embodiment, a flange protrusion 14 is provided on the rotating shaft 12 to cooperate with the thrust bearing assembly 13. The thrust bearing assembly 13 and the flange protrusion 14 cooperate with each other to provide axial support for the rotating shaft 12.

[0040] 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 mounted on the side of the casing 11 near the first impeller 23, and includes a first bearing seat 161 and a first radial foil gas dynamic pressure bearing 162. The second radial bearing assembly 17 is mounted on the side of the casing 11 near the second impeller 24, and includes a second bearing seat 171 and a second radial foil gas dynamic pressure bearing 172. The rotating shaft 12 is mounted in a hollow shaft hole formed by the first radial foil gas dynamic pressure bearing 162 and the second radial foil gas dynamic pressure bearing 172. The rotating shaft 12 is supported by the foil gas dynamic pressure bearing, which improves the stability and efficiency of the rotating shaft 12 during high-speed rotation and reduces friction loss.

[0041] Furthermore, the housing 11 is provided with a cooling ring groove (not shown) for dissipating heat from the body components. The cooling ring groove is used for circulating a cooling medium such as a coolant to remove heat generated by the motor and other body 1 components during operation.

[0042] The boost mechanism 2 includes a first volute 21, a second volute 22 connected to the first volute 21, a first impeller 23 mounted on the rotating shaft 12 and located within the first volute 21, and a second impeller 24 mounted on the rotating shaft 12 and located within the second volute 22. The first volute 21 and the second volute 22 are mounted at opposite ends of the casing 11. The first impeller 23 and the second impeller 24 are both centrifugal impellers. The first volute 21 and the second volute 22 have an asymmetric structure. Furthermore, the air compressor includes an interstage pipe, through which the first volute 21 connects to the second volute 22. The first impeller 23 can rotate along with the rotating shaft 12, and then continuously suck in the gas from the air inlet of the first volute 21, and after pressurizing the gas, discharge the gas wall through the exhaust port to achieve gas compression; the second impeller 24 can also rotate along with the rotating 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 pipe, and the second impeller 24 will further pressurize the compressed gas entering the second volute 22 to obtain a higher pressure ratio. After the final pressurization, the gas is collected by the second volute 22 and can be used to increase the intake pressure of the fuel cell system stack.

[0043] The sealing mechanism 3 includes a first sealing component 31 and a second sealing component 32, both of which are installed on the rotating shaft 12. The first sealing component 31 is connected to the side of the first impeller 23 close to the second impeller 24, and a first sealing channel 33 connected to 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 close to the first impeller 23, and a second sealing channel 34 connected to 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 connected to the second sealing channel 34, and an adjustment component 36 for adjusting the opening of the connecting port 37 between the bypass sealing channel 35 and the second sealing channel 34.

[0044] Among them, a first sealing channel 33 is formed between the first sealing assembly 31 and the first impeller 23; it is understandable that a portion of the gas pressurized by the first impeller 23 will inevitably enter the first sealing channel 33, thereby generating a certain thrust on the first impeller 23, and the first impeller 23 and the rotating shaft 12 are fixed, so the wheel back of the first impeller 23 (that is, Figure 1 The pressure on the right side of the first impeller 23) is the same as the pressure on the front side of the first impeller 23 (i.e. Figure 1 The pressure difference on the left side of the first impeller 23 generates a first axial thrust. Generally, 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 first axial thrust of the first impeller 23 is directed toward the inlet of the first impeller 23. The gas entering the first sealing channel 33 is sealed by the first sealing assembly 31 to prevent leakage of useful pressurized gas.

[0045] Similarly, a second sealing channel 34 is formed between the second sealing assembly 32 and the second impeller 24. At the same time, a bypass sealing channel is also provided on the second sealing assembly 32. It is understandable that a portion of the gas pressurized by the second impeller 24 will inevitably enter the second sealing channel 34, thereby generating a certain thrust on the second impeller 24. The second impeller 24 is fixed to the rotating shaft 12, so the wheel back of the second impeller 24 (that is, Figure 1 The pressure on the left side of the second impeller 24) is the same as the pressure on the front side of the second impeller 24 (i.e. Figure 1 The pressure difference on the right side of the second impeller 24 in the middle will generate a second axial thrust, and 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 directed to the inlet of the second impeller 24. It should be noted that the temperature of the gas after two-stage pressurization that the second impeller 24 contacts is very high. Therefore, it must be sealed by the second sealing assembly 32 to strictly limit this part of the high-temperature gas from entering the bearing and motor through the axial direction.

[0046] As described above, the first and second axial thrusts are generally directed in opposite directions, allowing them to at least partially offset each other, resulting in a resultant force between the first and second axial thrusts, which is the axial force of the air compressor. This axial force is balanced by a thrust bearing mounted axially. In the actual use of the air compressor in a fuel cell system, gas bearings are typically used to prevent oil leakage from the oil bearings and contamination of the fuel cell stack. Gas bearings generally have a much lower load-bearing capacity than oil bearings, so the magnitude of the axial force needs to be strictly limited.

[0047] In the above embodiment of the present invention, a bypass sealing channel 35 is provided on the second sealing assembly 32 to adjust the force on the wheel back of the second impeller 24 .

[0048] Specifically, when the air compressor receives a boost command, it obtains boost pressure information. The boost pressure information indicates that the boost demand of the air compressor is low. At this time, the first axial thrust generated by the first impeller 23 is small. In order to maintain the resultant force between the first axial force and the second axial force, that is, the balance of the axial forces, the second impeller 24 also requires a smaller 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 low demand level; therefore, the second sealing channel 34 can be kept open at this time, and the bypass sealing channel 35 only needs to be kept closed (the connecting 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 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 balanced by the smaller second axial thrust and the smaller first axial thrust generated by the first impeller 23.

[0049] When the boost pressure information indicates that the boost demand of the air compressor is high, the first impeller 23 generates a larger first axial thrust. In order to maintain the axial force balance, the second impeller 24 also needs to generate a corresponding larger 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. Then, at this time, the second sealing channel 34 and the bypass sealing channel 35 can be fully opened, that is, the connecting 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 side 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 larger, thereby meeting the axial thrust demand of the high demand level. In this way, the larger second axial thrust is balanced with the larger first axial thrust generated by the first impeller 23.

[0050] When the boost pressure information indicates that the boost demand of the air compressor is between the above two states (low boost demand and high boost 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 the second sealing channel 34 and the bypass sealing channel 35 at the same time, but the gas pressure entering the bypass sealing channel 35 will be reduced. Therefore, at this time, the main axial thrust corresponding to the first back part of the second impeller 24 corresponding to the second sealing channel 34 is larger, and the bypass axial thrust corresponding to 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 thrusts corresponding to the above two states (low boost demand and high boost demand). At this time, the second axial thrust can be balanced with the axial thrust generated by the first impeller 23.

[0051] In the above embodiment 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, the side of the first impeller 23 close 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, 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 and thus realize controllable adjustment of the axial force of the air compressor, realize axial force balance of the air compressor within the full speed range, and thereby reduce the axial force borne by the thrust bearing within the full speed range, improve the safety performance of the thrust bearing, and improve the efficiency of the thrust bearing.

[0052] In one embodiment, if Figures 1 to 3 As 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 via 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 provided 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. It is understood that a thrust bearing is installed between the first sealing plate 311 and the first radial bearing assembly 16, and the thrust bearing is installed on the rotating shaft 12 using a foil gas bearing. Among them, the first sealing assembly 31 can adopt a single piston ring seal, that is, a first annular groove is opened in the middle of the first shaft seal 312 for installing the first piston ring 313. The gas entering the first sealing channel 33 needs to be sealed through 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.

[0053] In one embodiment, if 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 sealedly connected to the second shaft seal 322 via 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 provided 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 sealing channel. The second piston ring 323 is located between the third piston ring 324 and the second impeller 24. It is understood that the second piston ring 323 is provided at the end of the second sealing channel 34 away from the second impeller 24 to provide a separate seal thereto to control leakage of high-temperature gas. A third piston ring 324 is installed at the end of the bypass seal channel 35 away from the second impeller 24 for separate sealing to control the leakage of high-temperature gas. The second shaft seal 322 is provided with a second annular groove and a third annular groove for mounting the second piston ring 323 and the third piston ring 324, respectively. The second and third annular grooves have unequal diameters to accommodate second and third piston rings 323 and 324 of different diameters. In this embodiment, high-temperature gas entering the second seal channel 34 or the bypass seal channel 35 is sealed by the second piston ring 323 and the third piston ring 324 installed on the second shaft seal 322, thereby strictly limiting the axial entry of this high-temperature gas into the bearings and motor.

[0054] Furthermore, the second sealing assembly 32 also includes a fourth piston ring (not shown) sleeved on the second shaft seal 322 and at least one other bypass channel (not shown) provided on the second sealing plate 321. The other bypass channel is connected to the second sealing channel 34 or the bypass sealing channel 35. The fourth piston ring is provided in a one-to-one correspondence at the end of each other bypass channel remote from the second sealing channel 34 or the bypass sealing channel 35 connected thereto. That is, the second sealing plate 321 may also be provided with one or more other bypass channels connected to the second sealing channel 34 or the bypass sealing channel 35, and each other bypass channel may be provided with a fourth piston ring at the end remote 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, nearly continuously adjustable axial force control can be achieved, further ensuring that the axial force is adjustable over the entire speed range.

[0055] In one embodiment, if Figures 1 to 8As shown, a receiving groove 325 communicating with the second sealing channel 34 is further provided on the second sealing plate 321 at a position opposite to the communication opening 37. The receiving groove 325 and the first sealing channel 33 are located on opposite sides of the communication opening 37. The adjustment assembly 36 includes a spring 361 and a blocking member 362 installed in the receiving groove 325. The blocking member 362 is used to extend out of the receiving groove 325 under the elastic force of the spring 361 and abut against the edge of the communication opening 37. Figure 8 As shown, the blocking member 362 includes an annular body 3621 and a plurality of mounting posts 3622 spaced apart on the end surface of the annular body 3621 away from the first impeller 23. The adjustment assembly 36 includes a plurality of springs 361. The bottom surface of the accommodating groove 325 is provided with a plurality of insertion holes. The plurality of springs 361 are sleeved one-to-one on the plurality of mounting posts 3622, and the mounting posts 3622 are inserted one-to-one into the insertion holes. The springs 361 are compressed and abutted between the bottom surface of the accommodating groove 325 and the annular body 3621. In this embodiment, when the end surface of the annular body 3621 away from the springs 361 abuts against the edge of the communication port 37, the communication port 37 can be blocked and closed. When the end surface of the annular body 3621 away from the springs 361 moves away from the edge of the communication port 37, the communication port 37 is partially or fully opened, and the second sealing channel 34 and the bypass sealing channel 35 are now connected. In some embodiments, the movement of the blocking member 362 approaching or moving away from the connecting port 37 can be achieved by the compressed gas flowing from the second sealing channel 34 to the connecting port 37. In other embodiments, a control device can also be provided to control the transmission assembly to actively control the movement of the blocking member 362 to execute the movement of the blocking member 362 approaching or moving away from the connecting port 37. This is not limited here.

[0056] The present invention also provides an air compressor axial force adjustment method, which is applied to the above-mentioned air compressor. The air compressor can refer to the definition in the above embodiment and will not be described in detail here. Figure 9 As shown, the air compressor axial force adjustment method includes:

[0057] S10, determining the axial thrust requirement of the second impeller 24 based on the boost pressure information of the air compressor, and determining the state to be adjusted of the second sealing assembly 32 based on the axial thrust requirement; wherein the boost pressure information is used to represent the level of the boost demand corresponding to the current need of the air compressor to compress and boost the gas; the axial thrust requirement of the second impeller 24 is associated with the boost pressure information. Specifically, if the boost pressure information represents a high boost demand, the axial thrust requirement of the second impeller 24 will also be relatively high; if the boost pressure information represents a low boost demand, the axial thrust requirement of the second impeller 24 will also be relatively low. The state to be adjusted of the second sealing assembly 32 refers to the open state of the second sealing channel 34 and the bypass sealing channel 35. In the present utility model, the second sealing channel 34 will continue to communicate with the second volute 22 and remain in an open state, while the bypass sealing channel 35 will switch between three states: fully open, partially open, and closed according to the actual axial thrust demand of the second impeller 24.

[0058] S20: Adjusting the opening of the communication port 37 between the bypass sealed channel 35 and the second sealed channel 34 based on the state to be adjusted via the adjustment assembly 36. It is understood that in this embodiment, a fully open bypass sealed channel 35 indicates that the opening of the communication port 37 between the second sealed channel 34 and the bypass sealed channel 35 is 100%; a closed bypass sealed channel 35 indicates that the opening of the communication port 37 between the second sealed channel 34 and the bypass sealed channel 35 is 0%; and a partially open bypass sealed channel 35 indicates that the opening of the communication port 37 between the second sealed channel 34 and the bypass sealed channel 35 is greater than 0% and less than 100%. Since, when the air compressor speed increases while the power remains constant, its flow rate (i.e., the volume of gas discharged per unit time) also increases, and its compression capacity improves, thereby correspondingly increasing the output pressure. That is, the higher the air compressor speed, the greater the pressure. In this embodiment, regardless of the state of the air compressor boost pressure information, that is, regardless of whether the corresponding air compressor speed is high or low (i.e., regardless of whether the air compressor boost demand is high or low), the air compressor axial force can be balanced by adjusting the opening of the connecting port 37. That is, 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 safety performance of the thrust bearing, and increasing the efficiency of the thrust bearing. It is understandable that the opening of the connecting port 37 can be achieved by adjusting the adjustment assembly 36. The specific adjustment process can be referred to as described in the above-mentioned air compressor embodiment and will not be repeated here.

[0059] In the above embodiment 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, the side of the first impeller 23 close 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, 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 and thus realize controllable adjustment of the axial force of the air compressor, realize axial force balance of the air compressor within the full speed range, and thereby reduce the axial force borne by the thrust bearing within the full speed range, improve the safety performance of the thrust bearing, and improve the efficiency of the thrust bearing.

[0060] In one embodiment, if Figure 1 、 Figure 4 and Figure 5 As shown, the method of determining the axial thrust requirement of the second impeller 24 according to the boost pressure information of the air compressor and determining the state to be adjusted of the second sealing assembly 32 according to the axial thrust requirement includes:

[0061] When the axial thrust requirement of the second impeller is determined to be a low demand level according to the boost pressure information, the state to be adjusted of the second sealing assembly 32 is determined to be a first state, and the first state includes: keeping the second sealing channel 34 fully open and closing the bypass sealing channel 35.

[0062] In some embodiments, a control device is provided to control the transmission assembly to actively control the movement of the blocking member 362. When the blocking member 362 moves closer to or away from the communication port 37, a first preset boost threshold value can be first obtained. Then, when the boost pressure information is less than or equal to the first preset boost threshold value, the axial thrust demand of the second impeller 24 is determined to be a low demand level. Then, based on the low demand level, the state to be adjusted of the second sealing assembly 32 is determined to be the first state. It is understandable that due to the wheel back (i.e. Figure 1 The pressure on the right side of the first impeller 23) is the same as the pressure on 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 form a first axial thrust; the wheel back of the second impeller 24 (i.e. Figure 1 The pressure on the left side of the second impeller 24) is the same as the pressure on the front side of the second impeller 24 (i.e. Figure 1The pressure difference on the right side of the second impeller 24 in the compressor generates a second axial thrust. In this embodiment, the first preset boost threshold can be set as needed. As long as the boost pressure information is less than or equal to the first preset boost threshold, the second sealing channel 34 only needs to be opened to achieve balancing of the compressor axial force. The first preset boost threshold can be determined based on the following test:

[0063] Set the test boost pressure P, and move the wheel back (i.e. Figure 1 The pressure on the right side of the first impeller 23) is the same as the pressure on the front side of the first impeller 23 (i.e. Figure 1 The pressure difference between the left side of the first impeller 23 and the left side of the first impeller 23 is recorded as the first pressure difference ΔFX.

[0064] The bypass sealing channel 35 is completely closed. 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 portion of the second impeller 24 corresponding to the second sealing channel 34, and the pressure on the back portion of the second impeller 24 corresponding to the second sealing channel 34 is combined with the pressure on the front portion of the second impeller 24 (i.e. Figure 1 The pressure difference between the right side of the second impeller 24 and the left side of the second impeller 24 is recorded as the second pressure difference ΔFY1.

[0065] The bypass sealing channel 35 is gradually 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 gradually increases. At this time, the pressure on the back of the entire second impeller 24 corresponding to the second sealing channel 34 and the bypass sealing channel 35 is combined with the pressure on the front of the second impeller 24 (that is, Figure 1 The pressure difference between the right side of the second impeller 24 and the left side of the second impeller 24 is recorded as the second pressure difference ΔFY2.

[0066] If ΔFY1-ΔFX=ΔF1 and ΔFY2-ΔFX=ΔF2, then if ΔF2 corresponding to the test boost pressure P is greater than ΔF1, the test boost pressure P can be considered less than the first preset boost threshold. If ΔF2 corresponding to the test boost pressure P is less than ΔF1, the test boost pressure P can be considered greater than the first preset boost threshold. If ΔF2 corresponding to the test boost pressure P is substantially equal to ΔF1, the test boost pressure P can be considered to be the first preset boost threshold. Furthermore, by testing different test boost pressures P, different test results are obtained, and the first preset boost threshold can be determined based on the test results. It is understood that the first preset boost threshold can be adjusted based on 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 demand of the second impeller 24 is determined to be a low demand level, i.e., the second axial force demand is relatively small.

[0067] In this embodiment, when the axial thrust demand of the second impeller 24 is at a low demand level, it is necessary to keep the second sealing channel 34 fully open and close the bypass sealing channel 35. Specifically, when the air compressor receives a boost command, it obtains boost pressure information. The boost pressure information indicates that the boost demand of the air compressor 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 the axial forces, the second impeller 24 also requires a smaller 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, if Figure 4 As shown, the second sealing channel 34 can be kept open, and the bypass sealing channel 35 only needs to be kept closed (the communication port 37 between the second sealing channel 34 and the bypass sealing channel 35 is closed and the two cannot communicate). At this time, as shown in FIG. Figure 5 As shown, the compressed gas generated by the second impeller 24 only enters the second sealed channel 34, and can thus only act on the back portion of the second impeller 24 corresponding to the second sealed channel 34, so that the second axial thrust generated is relatively small, and then the smaller second axial thrust is balanced with the smaller first axial thrust generated by the first impeller 23.

[0068] In one embodiment, if Figure 1 、 Figure 4 and Figure 5 As shown, the adjusting component 36 adjusts 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, including:

[0069] When the adjustment state is the first state, the adjustment assembly 36 is controlled to close the communication port 37 between the bypass sealing channel 35 and the second sealing channel 34. In one embodiment, a receiving groove 325 communicating with the second sealing channel 34 is provided on the second sealing plate 321 of the second sealing assembly 32 at a position opposite 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 assembly 36 includes a spring 361 mounted in the receiving groove 325 and a blocking member 362. The blocking member 362 is configured 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, thereby causing the blocking member 362 to move closer to or further from the communication port 37. In other embodiments, the automatic adjustment of the communication port opening can be achieved solely through the elastic force of the spring.

[0070] In this embodiment, when the state to be adjusted is the first state, the communication port 37 needs to be closed. At this time, since the boost pressure information indicates that the boost demand of the air compressor 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 small. 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 connecting 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 smaller second axial thrust on the back plate portion of the second impeller 24 corresponding to the second sealing channel 34, which is balanced with the smaller first axial thrust formed by the first impeller 23.

[0071] In one embodiment, if Figure 1 、 Figure 6 and Figure 7 As shown, the method of determining the axial thrust requirement of the second impeller 24 according to the boost pressure information of the air compressor and determining the state to be adjusted of the second sealing assembly 32 according to the axial thrust requirement includes:

[0072] When it is determined that the axial thrust requirement of the second impeller 24 is a medium demand level according to the boost pressure information, the adjusted state of the second sealing assembly 32 is determined to be the second state, and 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 threshold is greater than the first preset boost threshold.

[0073] In some embodiments, a control device is provided to control the transmission assembly to actively control the movement of the blocking member 362, so that when the blocking member 362 moves closer to or away from the connecting port 37, the first preset boost threshold and the second preset boost threshold can be first obtained, and then when the boost pressure information is greater than the first preset boost threshold and less than the second preset boost threshold, the axial thrust demand of the second impeller 24 is determined to be a medium demand level; and the state to be adjusted of the second sealing assembly 32 is determined to be the second state according to the medium demand level. It can be understood that the determination method of the first preset boost threshold refers to that described in the above embodiment, and the second preset boost threshold can also be set according to demand, as long as the boost pressure information is greater than the second preset boost threshold, the second sealing channel 34 and the bypass sealing channel 35 need to be fully opened to achieve the balance of the axial force of the air compressor. The determination process of the second preset boost threshold can be determined according to the following test:

[0074] Set the test boost pressure P, and move the wheel back (i.e. Figure 1 The pressure on the right side of the first impeller 23) is the same as the pressure on the front side of the first impeller 23 (i.e. Figure 1 The pressure difference between the left side of the first impeller 23 and the left side of the first impeller 23 is recorded as the first pressure difference ΔFX.

[0075] When the bypass sealing channel 35 is gradually opened but not fully opened, 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 gradually increases. At this time, the pressure on the back of the entire second impeller 24 corresponding to the second sealing channel 34 and the bypass sealing channel 35 is combined with the pressure on the front of the second impeller 24 (that is, Figure 1 The pressure difference between the right side of the second impeller 24 and the left side of the second impeller 24 is recorded as the second pressure difference ΔFY2.

[0076] 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 is combined with the pressure on the front side of the second impeller 24 (i.e. Figure 1 The pressure difference between the right side of the second impeller 24 and the left side of the second impeller 24 is recorded as the third pressure difference ΔFY3.

[0077] If ΔFY3-ΔFX=ΔF3 and ΔFY2-ΔFX=ΔF2, then if ΔF3 corresponding to the test boost pressure P is greater than ΔF2, the test boost pressure P can be considered less than the second preset boost threshold. If ΔF3 corresponding to the test boost pressure P is less than ΔF2, the test boost pressure P can be considered greater than the second preset boost threshold. If ΔF3 corresponding to the test boost pressure P is substantially equal to ΔF2, the test boost pressure P can be considered equal to the second preset boost threshold. Furthermore, based on the above test results, the second preset boost threshold can be determined. It is understood that the above second preset boost threshold can be adjusted based on 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 demand of the second impeller 24 is determined to be a medium demand level, i.e., the second axial force demand is also medium.

[0078] In this embodiment, when the air compressor receives a boost command, it obtains boost pressure information, and the boost pressure information indicates that the boost demand of the air compressor is between the low boost demand and the high boost demand. Figure 6 As shown, the bypass sealing channel 35 of the second sealing assembly 32 is in a partially open state. 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, but the pressure of the gas entering the bypass sealing channel 35 is reduced. Therefore, as shown in FIG. Figure 7 As shown, at this time, the main axial thrust corresponding to the first back portion of the second impeller 24 corresponding to the second sealing channel 34 is larger, and the bypass axial thrust corresponding to the second back portion 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 thrusts corresponding to the above two states (low boost demand and high boost demand). At this time, the second axial thrust can be balanced with the axial thrust generated by the first impeller 23.

[0079] In one embodiment, if Figure 1 、 Figure 6 and Figure 7 As shown, the adjusting component 36 adjusts 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, including:

[0080] When the adjustment state is the second state, the adjustment assembly 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 of the communication port 37 to a target opening corresponding to the boost pressure information, wherein the target opening is greater than 0 and less than 100%. In one embodiment, a receiving groove 325 for communicating with the second sealing channel 34 is provided on the second sealing plate 321 of the second sealing assembly 32 at a position opposite 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 assembly 36 includes a spring 361 and a blocking member 362 installed in the receiving groove 325. The blocking member 362 is configured to extend out of the receiving groove 325 under the elastic force of the spring 361 and abut against the edge of the communication port 37. Moreover, 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 move the blocking member 362 closer to or away from the connecting port 37; in other embodiments, the automatic adjustment of the opening of the connecting port can be achieved by relying solely on the elastic force of the spring.

[0081] In this embodiment, when the state to be adjusted is the second state, the communication port 37 needs to be partially opened, that is, the opening of the communication port 37 is adjusted to the target opening (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 demand of the air compressor is between the low boost demand and the high boost demand. Therefore, the axial thrust demand of the second impeller 24 is also a medium demand level, and the boost pressure corresponding to the second impeller 24 is also medium. Figure 6As shown, the spring 361 installed on the second sealing plate 321 will press the blocking member 362, but the blocking member 362 will be partially pushed open under the thrust of the high-pressure gas at the connecting port 37 in the second sealing channel 34, so that the blocking member 362 will not completely block the connecting port 37. In this way, after the high-pressure gas enters the second sealing channel 34, a part of it will enter the bypass sealing channel 35 through the half-open connecting port 37. However, at this time, since the boost pressure information is not particularly large, the high-pressure gas in the second sealing channel 34 will significantly reduce its pressure after pushing the blocking member 362 before entering. Entering the bypass sealing channel 35, therefore, the gas pressure entering the bypass sealing channel 35 will be reduced. At this time, the main axial thrust corresponding to the first back part of the second impeller 24 corresponding to the second sealing channel 34 is larger, and the bypass axial thrust corresponding to 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 size is between the second axial thrusts corresponding to the two states of low boost demand and high boost demand. At this time, the second axial thrust can be balanced with the axial thrust generated by the first impeller 23.

[0082] In one embodiment, if Figure 1 、 Figure 2 and Figure 3 As shown, the method of determining the axial thrust requirement of the second impeller 24 according to the boost pressure information of the air compressor and determining the state to be adjusted of the second sealing assembly 32 according to the axial thrust requirement includes:

[0083] When it is determined that the axial thrust demand of the second impeller 24 is a high demand level according to the boost pressure information, the adjustment state of the second sealing assembly 32 is determined to be the third state, and the third state includes: keeping the second sealing channel 34 and the first level of the bypass sealing channel 35 fully open.

[0084] In some embodiments, a control device is provided to control the transmission assembly to actively control the movement of the blocking member 362. When the blocking member 362 moves toward or away from the communication port 37, a second preset boost threshold value may be first obtained. Then, when the boost pressure information is greater than or equal to the second preset boost threshold value, the axial thrust demand of the second impeller 24 is determined to be high. In this case, the second axial thrust demand of the second impeller 24 is high. It is understood that the method for determining the first preset boost threshold value is similar to that described in the above embodiment and will not be repeated here.

[0085] In this embodiment, when the boost pressure information indicates that the boost demand of the air compressor is high, the first impeller 23 generates a large first axial thrust. In order to maintain the axial force balance, the second impeller 24 also needs to generate a corresponding 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. Then, at this time, the second sealing channel 34 and the bypass sealing channel 35 can be fully opened, that is, as shown in FIG. Figure 2 As shown, the communication port 37 between the second sealed channel 34 and the bypass sealed channel 35 is fully opened, and the second sealed channel 34 is connected to the bypass sealed channel 35. At this time, the compressed gas generated by the second impeller 24 enters the second sealed channel 34 and the bypass sealed channel 35 at the same time, so that Figure 3 As shown, the 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, so that the second axial thrust generated is larger, thereby meeting the axial thrust demand of the high demand level. In this way, the larger second axial thrust is balanced with the larger first axial thrust generated by the first impeller 23.

[0086] In one embodiment, if Figure 1 、 Figure 2 and Figure 3 As shown, the adjusting component 36 adjusts 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, including:

[0087] When the adjustment state is the third state, the adjustment assembly 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, a receiving groove 325 for communicating with the second sealing channel 34 is provided on the second sealing plate 321 of the second sealing assembly 32 at a position opposite 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 assembly 36 includes a spring 361 mounted in the receiving groove 325 and a blocking member 362. The blocking member 362 is configured 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, thereby causing the blocking member 362 to move closer to or further from the communication port 37. In other embodiments, the automatic adjustment of the communication port opening can be achieved solely through the elastic force of the spring.

[0088] In this embodiment, when the state to be adjusted is the third state, the communication port 37 needs to be fully opened. At this time, since the boost pressure information indicates that the boost demand of the air compressor 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. 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 sealed bypass sealing channel 35. Moreover, 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 high-pressure gas in the second sealing channel 34 pushes the sealing member 362, the pressure will not drop significantly. Therefore, the gas pressure entering the bypass sealing channel 35 is still very high. At this time, the main axial thrust corresponding to the first back part of the second impeller 24 corresponding to the second sealing channel 34 is large, and the bypass axial thrust corresponding to 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 be balanced with the large first axial thrust generated by the first impeller 23.

[0089] like Figure 10 and Figure 11 As shown, Figure 10 FIG. 1 shows the axial force change state of the air compressor after adjusting the axial force in an embodiment of the prior art, wherein F0 is the axial force, P0 is the boost pressure, and Figure 10 In the process, as the boost pressure of the air compressor increases, that is, the speed of the air compressor shaft 12 increases, the axial force will not be balanced and will increase rapidly, which will uniformly lead to the thrust bearing, etc. Figure 11 The figure shows the change state of the axial force after the axial force is adjusted by the axial force adjustment method of the air compressor according to one embodiment of the present invention. The axial force can be controlled to fluctuate within a relatively 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 height, that is, it can achieve axial force balance within the full speed range.

[0090] An embodiment of the present invention further provides a fuel cell system including the above-mentioned air compressor. The air compressor can be described in detail in the above-mentioned embodiments and will not be further described here. In the fuel cell system of the above-mentioned embodiment of the present 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 adjacent 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 communication port 37 is provided between the second sealing channel 34 and the bypass sealing channel 35. The opening of the communication port 37 can be adjusted by an adjustment assembly 36 to match the opening of the communication port 37 with the current boost pressure information. Under this boost pressure information, the second impeller 24 can meet the axial thrust requirement, thereby achieving controllable adjustment of the axial force of the air compressor, achieving axial force balance across the entire speed range of the air compressor, and thereby reducing the axial force borne by the thrust bearing across the entire speed range, thereby improving the safety performance and efficiency of the thrust bearing.

[0091] An embodiment of the present invention further provides a vehicle including the aforementioned fuel cell system. In the vehicle of the aforementioned embodiment of the present 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 adjacent 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 communication port 37 is provided between the second sealing channel 34 and the bypass sealing channel 35. The opening of the communication port 37 can be adjusted by an adjustment assembly 36 to match the opening of the communication port 37 with current boost pressure information. Under this boost pressure information, the second impeller 24 can meet the axial thrust requirement, thereby achieving controllable adjustment of the axial force of the air compressor, achieving axial force balance within the full speed range of the air compressor, and thereby reducing the axial force borne by the thrust bearing within the full speed range, thereby improving the safety performance and efficiency of the thrust bearing.

[0092] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. An air compressor, characterized in that: include: The body comprises a housing, a rotating shaft and a thrust bearing assembly both mounted in the housing; the thrust bearing assembly is connected between the rotating shaft and the housing; a supercharging mechanism comprising a first volute, a second volute communicating with the first volute, a first impeller mounted on the rotating shaft and located within the first volute, and a second impeller mounted on the rotating shaft and located within the second volute; the first volute and the second volute being mounted at opposite ends of the casing, respectively; The sealing mechanism includes a first sealing assembly and a second sealing assembly, both of which are installed on the rotating shaft, the first sealing assembly is connected to the side of the first impeller close to the second impeller, and a first sealing channel connected to 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 close to the first impeller, and a second sealing channel connected to 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 connected to the second sealing channel, and an adjustment assembly for adjusting the opening of the connecting port between the bypass sealing channel and the second sealing channel.

2. The air compressor according to claim 1, characterized in that The first sealing assembly includes a first sealing plate, a first shaft seal sleeved on the rotating shaft, and a first piston ring sleeved 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 arranged 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 according to claim 1, characterized in that The second sealing assembly includes a second sealing plate, a second shaft seal sleeved on the rotating shaft, and a second piston ring and a third piston ring both sleeved on the second shaft seal; one end of the second sealing plate is sealed and connected to the second shaft seal through 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 arranged 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 sealing channel; 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: A accommodating groove communicating with the second sealing channel is also provided on the second sealing plate at a position opposite to the communicating port, and the accommodating groove and the first sealing channel are located on opposite sides of the communicating port; the adjusting assembly includes a spring and a sealing member installed in the accommodating groove, and the sealing member is used to extend out of the accommodating groove and abut against the edge of the communicating port under the elastic force of the spring.

5. The air compressor according to claim 4, characterized in that: The sealing member includes an annular body and a plurality of mounting posts spaced apart on the end surface of the annular body away from the first impeller; the adjusting assembly includes a plurality of springs, and a plurality of plug holes are provided on the bottom surface of the accommodating groove; the plurality of springs are respectively sleeved on the plurality of mounting posts, and the mounting posts are respectively inserted into the plug holes, and the springs abut between the bottom surface of the accommodating groove and the annular body.

6. The air compressor according to claim 1, characterized in that The machine body further comprises a motor stator and a motor rotor installed in the housing. The motor rotor is connected to the rotating shaft, and the motor stator is fixed on the housing.

7. The air compressor according to claim 1, characterized in that The machine body further includes a radial bearing assembly, the radial bearing assembly including a first radial bearing assembly and a second radial bearing assembly, the first radial bearing assembly being mounted on a side of the housing close to the first impeller, the first radial bearing assembly including a first bearing seat and a first radial foil gas dynamic pressure bearing; The second radial bearing assembly is installed on the side of the casing close to the second impeller, and the second radial bearing assembly includes a second bearing seat and a second radial foil gas dynamic pressure bearing; the rotating shaft is installed in the hollow shaft hole formed by the first radial foil gas dynamic pressure bearing and the second radial foil gas dynamic pressure bearing.

8. The air compressor according to claim 1, characterized in that The housing is provided with a cooling ring groove for dissipating heat from the body components; and / or The air compressor further includes an interstage pipe, through which the first volute is connected to the second volute; and / or The second sealing assembly also includes a fourth piston ring sleeved on the second shaft seal and at least one other bypass channel arranged on the second sealing plate, the other bypass channel is connected to the second sealing channel or the bypass sealing channel, and the fourth piston ring is arranged one by one at one end of each of the other bypass channels away from the second sealing channel or the bypass sealing channel connected thereto.

9. A fuel cell system, characterized in that: Including the air compressor according to any one of claims 1-8.

10. A vehicle, characterized in that: A fuel cell system comprising the fuel cell system according to claim 9.

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