Electromagnetic bearing rotor system and air compressor

Abstract

The present disclosure relates to an electromagnetic bearing rotor system and an air compressor, the electromagnetic bearing rotor system comprising a rotating shaft, a radial magnetic bearing, an axial magnetic bearing and an auxiliary bearing, the radial magnetic bearing being sleeved on the rotating shaft and used for supporting the radial load of the rotating shaft, the axial magnetic bearing being sleeved on the rotating shaft and used for supporting the axial load of the rotating shaft, the auxiliary bearing being sleeved on the rotating shaft and comprising a bearing outer ring and a bearing inner ring, the bearing inner ring being arranged in the bearing outer ring and being in conical surface cooperation with the bearing outer ring, so that when the radial magnetic bearing and / or the axial magnetic bearing fails, the auxiliary bearing can provide radial and axial support for the rotating shaft, and the inner surface of the bearing outer ring and / or the outer surface of the bearing inner ring is provided with a ceramic metal composite coating, so as to prevent the surface of the bearing outer ring and the bearing inner ring from being seriously abraded and causing impact on the whole electromagnetic bearing rotor system.

Description

Technical Field

[0001] This disclosure relates to the field of magnetic levitation technology, and in particular to an electromagnetic bearing rotor system and an air compressor. Background Technology

[0002] The application of high-speed rotor systems supported by electromagnetic bearings in air compressors for fuel cell vehicles is a growing trend. The principle of a fuel cell vehicle air compressor is that an impeller drives the gas to rotate at high speed, generating centrifugal force. This increases the velocity and pressure of the gas as it passes through the impeller, continuously producing compressed air. Therefore, the centrifugal impeller, as a key component of the air compressor rotor system, has a crucial impact on the compressor's performance.

[0003] In existing air compressors, when the electromagnetic bearing fails or loses power, the auxiliary bearing only plays a supporting role and cannot simultaneously bear the axial and radial forces generated by the rotating shaft during rotation. This causes the high-speed rotating shaft to damage the electromagnetic bearing, or even other equipment installed on the shaft, resulting in an impact on the entire rotor system. Summary of the Invention

[0004] To address the aforementioned technical problems, this disclosure provides a highly safe electromagnetic bearing rotor system and an air compressor.

[0005] The first aspect of this disclosure provides an electromagnetic bearing rotor system, comprising:

[0006] Shaft;

[0007] A radial magnetic bearing is sleeved on the rotating shaft to support the radial load of the rotating shaft;

[0008] An axial magnetic bearing is sleeved on the rotating shaft to support the axial load of the rotating shaft.

[0009] An auxiliary bearing, which is an angular contact sliding bearing, is sleeved on the rotating shaft. The auxiliary bearing includes an outer ring and an inner ring. The inner ring is disposed inside the outer ring and engages with the tapered surface of the outer ring. The inner surface of the outer ring and / or the outer surface of the inner ring are provided with a ceramic-metal composite coating. The auxiliary bearing is used to provide radial and axial support to the rotating shaft when the radial magnetic bearing and / or the axial magnetic bearing fails.

[0010] Optionally, the inner ring of the bearing is fixedly connected to the rotating shaft, and the outer ring of the bearing is fixedly connected to the stationary outer ring, wherein the stationary outer ring includes a stationary component fixedly connected to the housing.

[0011] Optionally, the ceramic-metal composite coating is a Cr3C2-25%NiCr ceramic-metal composite coating.

[0012] Optionally, the thickness of the ceramic-metal composite coating is from 100 μm to 300 μm.

[0013] Optionally, the number of auxiliary bearings is two, and the two auxiliary bearings are respectively located at both ends of the rotating shaft.

[0014] Optionally, the radial magnetic bearing includes a radial stator and a radial rotor, the radial rotor being sleeved on the shaft, and the radial stator having multiple magnetic poles, each of which is wound with a coil winding for adjusting the radial rotor to be in balance by electromagnetic force.

[0015] Optionally, the axial magnetic bearing includes an axial stator and an axial rotor. The axial rotor is sleeved on the rotating shaft. The axial stator includes two annular electromagnets with annular grooves. The annular grooves are provided with annular coil windings for adjusting the axial rotor to be in balance by electromagnetic force. The two annular electromagnets are coaxially arranged on both sides of the axial rotor.

[0016] Optionally, the electromagnetic bearing rotor system further includes a position sensor and a controller;

[0017] The position sensor is coaxially arranged with the rotating shaft and has a gap between them, and is used to determine the axial and radial positions of the rotating shaft. The position sensor is connected to the radial magnetic bearing and the axial magnetic bearing.

[0018] The controller is electrically connected to the position sensor to receive feedback from the position sensor, and the controller is also electrically connected to the radial magnetic bearing and the axial magnetic bearing to control the magnitude of the force applied by the radial magnetic bearing and / or the axial magnetic bearing.

[0019] Optionally, the electromagnetic bearing rotor system further includes a motor, which includes a motor stator and a motor rotor. The motor stator can be fixed to the housing, and the motor rotor is rotatably disposed inside the motor stator and concentrically arranged with the motor stator. A shaft hole is formed in the center of the motor rotor, and the rotating shaft passes through the shaft hole and is fixedly connected to the shaft hole to drive the rotating shaft to rotate.

[0020] A second aspect of this disclosure provides an air compressor, including a housing and an electromagnetic bearing rotor system as described in any of the above embodiments, the electromagnetic bearing rotor system being disposed within the housing.

[0021] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0022] The electromagnetic bearing rotor system and air compressor disclosed herein include a shaft, a radial magnetic bearing, an axial magnetic bearing, and an auxiliary bearing. The radial magnetic bearing is sleeved on the shaft to support the radial load of the shaft; the axial magnetic bearing is sleeved on the shaft to support the axial load of the shaft. By using an angular contact sliding bearing as the auxiliary bearing, which is sleeved on the shaft and includes an outer ring and an inner ring, the inner ring is located inside the outer ring and the inner ring and the outer ring are conically fitted, so that when the radial magnetic bearing and / or the axial magnetic bearing fails, the auxiliary bearing can provide radial and axial support to the shaft. At the same time, the inner surface of the outer ring and / or the outer surface of the inner ring are provided with a ceramic-metal composite coating to prevent severe wear on the surfaces of the outer and inner rings, which would cause impact to the entire electromagnetic bearing rotor system. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0024] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the auxiliary bearing described in an embodiment of the present disclosure;

[0026] Figure 2 This is a schematic diagram of the structure of the auxiliary bearing having a coating as described in an embodiment of the present disclosure;

[0027] Figure 3 This is a schematic diagram of the installation structure of the auxiliary bearing on the electromagnetic bearing rotor system according to an embodiment of this disclosure.

[0028] Among them, 1. Shaft; 2. Radial magnetic bearing; 3. Axial magnetic bearing; 4. Auxiliary bearing; 401. Bearing outer ring; 402. Bearing inner ring; 403. Ceramic-metal composite coating; 5. Position sensor; 6. Controller. Detailed Implementation

[0029] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0030] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0031] Reference Figures 1 to 3 As shown, some embodiments of this disclosure provide an electromagnetic bearing rotor system, including a shaft 1, a radial magnetic bearing 2, an axial magnetic bearing 3, and an auxiliary bearing 4.

[0032] The radial magnetic bearing 2 is sleeved on the rotating shaft 1 to support the radial load of the rotating shaft 1; the axial magnetic bearing 3 is sleeved on the rotating shaft 1 to support the axial load of the rotating shaft 1; the auxiliary bearing 4 is an angular contact sliding bearing, which is sleeved on the rotating shaft 1. The auxiliary bearing 4 includes an outer ring 401 and an inner ring 402. The inner ring 402 is disposed inside the outer ring 401, and the inner ring 402 and the outer ring 401 are in conical contact. The inner surface of the outer ring 401 and / or the outer surface of the inner ring 402 are provided with a ceramic-metal composite coating 403. The auxiliary bearing 4 is used to provide radial and axial support to the rotating shaft 1 when the radial magnetic bearing 2 and / or the axial magnetic bearing 3 fail.

[0033] Specifically, at least one radial magnetic bearing 2 and one axial magnetic bearing 3 are provided. Generally, two radial magnetic bearings 2 and one axial magnetic bearing 3 are provided and sleeved on the rotating shaft 1. Of course, the specific number of radial magnetic bearings 2 and axial magnetic bearings 3 is not specifically limited in this embodiment. Both radial magnetic bearings 2 and axial magnetic bearings 3 rotatably support the rotating shaft 1. When the radial magnetic bearing 2 is energized, it generates a radial magnetic force along the radial direction of the rotating shaft 1. When the axial magnetic bearing 3 is energized, it generates an axial magnetic force along the axial direction of the rotating shaft 1. The radial magnetic force generated by the radial magnetic bearing 2 and the axial magnetic force generated by the axial magnetic bearing 3 suspend and support the rotating shaft 1 in a non-contact manner, so that the rotating shaft 1 has no mechanical contact with the radial magnetic bearings 2 and axial magnetic bearings 3, thereby preventing mechanical wear of the radial magnetic bearings 2 and axial magnetic bearings 3 sleeved on the rotating shaft 1.

[0034] When the radial magnetic bearing 2 and the axial magnetic bearing 3 fail or are de-energized, they cannot withstand the radial and axial forces generated by the rotating shaft 1 during rotation. The high-speed rotation of the shaft 1 will damage the radial magnetic bearing 2 and the axial magnetic bearing 3, and even other equipment mounted on the shaft 1. To avoid the above phenomenon, this embodiment provides an auxiliary bearing 4. The auxiliary bearing 4 provided in this embodiment is an angular contact sliding bearing. The auxiliary bearing 4 is sleeved on the rotating shaft 1 and includes an outer bearing ring 401 and an inner bearing ring 402. The inner bearing ring 402 is disposed inside the outer bearing ring 401, and the inner bearing ring 402 and the outer bearing ring 401 are conically mated, enabling... Simultaneously bearing radial and axial loads, ensuring that the rotating shaft 1 can work continuously and stably under high-speed rotation until the rotating shaft 1 stops rotating. To prevent excessive friction when the inner ring 402 and the outer ring 401 of the bearing are in contact with each other, which could cause impact on the entire electromagnetic bearing rotor system, the inner surface of the outer ring 401 and / or the outer surface of the inner ring 402 of the bearing are provided with a ceramic-metal composite coating 403. This ensures that the outer ring 401 and the inner ring 402 of the bearing do not suffer severe wear during friction. Furthermore, after the outer ring 401 and the inner ring 402 of the bearing generate heat through friction, the ceramic-metal composite coating 403 has a good lubricating effect and will not cause impact on the entire electromagnetic bearing rotor system.

[0035] Furthermore, the inner ring 402 of the bearing is fixedly connected to the rotating shaft 1, and the outer ring 401 of the bearing is fixedly connected to the stationary outer sleeve, wherein the stationary outer sleeve includes a stationary component fixedly connected to the housing. Specifically, the inner ring 402 of the bearing is sleeved on the rotating shaft 1 and rotates together with the rotating shaft 1, while the outer ring 401 of the bearing is connected to the stationary outer sleeve, and the other end of the stationary outer sleeve is connected to the housing, so that the outer ring 401 and the inner ring 402 of the bearing slide relative to each other.

[0036] To ensure the performance requirements of the ceramic-metal composite coating 403, this embodiment employs a Cr3C2-25%NiCr ceramic-metal composite coating. The Cr3C2 in the ceramic-metal composite coating 403 ensures wear resistance, while the Ni and Cr components ensure lubrication under high-temperature conditions. Cr3C2 is a hard material with high hardness and excellent wear resistance, enabling the shaft 1 to rotate. The Ni and Cr components, being metallic, provide lubrication under high-temperature conditions, resulting in a low coefficient of friction for the ceramic-metal composite coating 403. This prevents severe wear on the surfaces of the auxiliary bearing 4, thus ensuring the safety of the entire electromagnetic bearing rotor system.

[0037] Specifically, the thickness of the ceramic-metal composite coating 403 is 100μm to 300μm. The ceramic-metal composite coating 403 is applied using a continuous explosive spraying process, with a coating thickness of 100μm to 300μm, thereby ensuring its good wear resistance and lubricity.

[0038] Furthermore, there are two auxiliary bearings 4, which are respectively located at both ends of the rotating shaft 1. The auxiliary bearings 4 are coaxially arranged with the rotating shaft 1 and are clearance-fitted with the rotating shaft 1. The two auxiliary bearings 4 are respectively located at both ends of the rotating shaft 1 so that when the rotating shaft 1 experiences a large radial displacement, the rotating shaft 1 can be supported by the auxiliary bearings 4 at both ends, thereby achieving the requirement of protecting other equipment on the rotating shaft 1.

[0039] In some embodiments, refer to Figure 3 As shown, the radial magnetic bearing 2 includes a radial stator and a radial rotor. The radial rotor is sleeved on the rotating shaft 1. The radial stator has multiple magnetic poles, each of which is wound with a coil winding for controlling the radial rotor to maintain balance through electromagnetic force. Specifically, the radial rotor is sleeved on the rotating shaft 1 and rotates with the rotating shaft 1. The radial stator has multiple magnetic poles, each of which is wound with a coil winding. Each pair of coil windings is symmetrically arranged radially along the rotating shaft 1. Each coil winding includes a coil, which is formed in a helical winding manner along the radial direction of the rotating shaft 1 and with the radial direction of the rotating shaft 1 as the center. When the radial magnetic bearing 2 is energized, the radial magnetic bearing 2 generates a radial magnetic force along the radial direction of the rotating shaft 1. The generated radial magnetic force can radially support the radial rotor, thereby ensuring the balance of the radial rotor and controlling the movement of the rotating shaft 1 in the radial direction.

[0040] In some embodiments, refer to Figure 3 As shown, the axial magnetic bearing 3 includes an axial stator and an axial rotor. The axial rotor is sleeved on the rotating shaft 1. The axial stator includes two annular electromagnets with annular grooves. Annular coil windings for adjusting the axial rotor to maintain balance via electromagnetic force are provided in the annular grooves. The two annular electromagnets are coaxially arranged on both sides of the axial rotor. The axial rotor of the axial magnetic bearing 3 is sleeved on the rotating shaft 1 and rotates with the rotating shaft 1. The two axial stators are fixed on both axial sides of the rotating shaft 1, and each axial stator includes two annular electromagnets with annular grooves. The annular coil windings are located in the annular grooves. After the two annular electromagnets are energized, the axial force on the axial rotor is changed by adjusting the current passing through the two annular electromagnets, thereby restoring it to a balanced state.

[0041] In some embodiments, refer to Figure 3As shown, the electromagnetic bearing rotor system also includes a position sensor 5 and a controller 6. The position sensor 5 is coaxially arranged with the rotating shaft 1 and has a gap between them, and is used to determine the axial and radial positions of the rotating shaft 1. The position sensor 5 is connected to the radial magnetic bearing 2 and the axial magnetic bearing 3. The controller 6 is electrically connected to the position sensor 5 and is used to receive feedback from the position sensor 5. The controller 6 is also electrically connected to the radial magnetic bearing 2 and the axial magnetic bearing 3 to control the magnitude of the force applied by the radial magnetic bearing 2 and / or the axial magnetic bearing 3. Specifically, the position sensor 5 is used to detect the offset of the rotating shaft 1 in the radial and / or axial directions. When the position sensor 5 detects that the rotating shaft 1 has offset, it sends the offset of the rotating shaft 1 to the controller 6. The controller 6 controls the magnitude of the current in the radial magnetic bearing 2 and / or the axial magnetic bearing 3 to move the rotating shaft 1 in the radial and / or axial directions. The position sensor 5 is coaxially mounted with the rotating shaft 1 and has a clearance fit, but the clearance between the position sensor 5 and the rotating shaft 1 is greater than the clearance between the auxiliary bearing 4 and the rotating shaft 1. This ensures that when the rotating shaft 1 deviates significantly in the radial direction, the rotating shaft 1 will first contact the auxiliary bearing 4, thereby avoiding a collision between the rotating shaft 1 and the position sensor 5 and achieving the purpose of protecting the position sensor 5.

[0042] In some embodiments, the electromagnetic bearing rotor system further includes a motor, which includes a motor stator and a motor rotor. The motor stator can be fixed to a housing, and the motor rotor is rotatably disposed within the motor stator and concentrically arranged with the motor stator. A shaft hole is formed in the center of the motor rotor, and a rotating shaft 1 passes through and is fixedly connected to the shaft hole to drive the rotating shaft 1 to rotate. Specifically, the motor can be a high-speed motor to achieve high-speed driving of the rotating shaft 1. The motor includes a motor stator and a motor rotor. The motor stator is fixedly connected to the housing, and the motor rotor is rotatably disposed within the motor stator and concentrically arranged with the motor stator. A shaft hole is formed in the center of the electromagnetic rotor, allowing the rotating shaft 1 to pass through and be fixed to the shaft hole, thereby enabling the motor to drive the rotating shaft 1 to rotate. Of course, the rotating shaft 1 can also serve as the motor rotor.

[0043] Other embodiments of this disclosure provide an air compressor including a housing and an electromagnetic bearing rotor system as described in any of the above embodiments, the electromagnetic bearing rotor system being disposed within the housing.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An air compressor, comprising a housing and an electromagnetic bearing rotor system disposed within the housing, characterized in that, The electromagnetic bearing rotor system includes: Rotating shaft (1); Radial magnetic bearing (2), the radial magnetic bearing (2) is sleeved on the rotating shaft (1) and is used to support the radial load of the rotating shaft (1); An axial magnetic bearing (3) is sleeved on the rotating shaft (1) to support the axial load of the rotating shaft (1); An auxiliary bearing (4) is an angular contact sliding bearing. The auxiliary bearing (4) is sleeved on the rotating shaft (1). The auxiliary bearing (4) includes an independently set outer bearing ring (401) and an inner bearing ring (402). The inner bearing ring (402) is set inside the inner surface of the outer bearing ring (401), and the outer surface of the inner bearing ring (402) is in conical contact with the inner surface of the outer bearing ring (401). The inner surface of the outer bearing ring (401) and / or the outer surface of the inner bearing ring (402) are provided with a ceramic-metal composite coating (403). The auxiliary bearing (4) is used to provide radial and axial support to the rotating shaft (1) when the radial magnetic bearing (2) and / or the axial magnetic bearing (3) fail. The inner ring (402) of the bearing is fixedly connected to the rotating shaft (1), and the outer ring (401) of the bearing is fixedly connected to the stationary outer sleeve, wherein the stationary outer sleeve includes a stationary component fixedly connected to the housing; there are two auxiliary bearings (4), and the two auxiliary bearings (4) are respectively located at both ends of the rotating shaft (1).

2. The air compressor according to claim 1, characterized in that, The ceramic-metal composite coating (403) is a Cr3C2-25%NiCr ceramic-metal composite coating.

3. The air compressor according to claim 1, characterized in that, The thickness of the ceramic-metal composite coating (403) is 100 μm to 300 μm.

4. The air compressor according to any one of claims 1 to 3, characterized in that, The radial magnetic bearing (2) includes a radial stator and a radial rotor. The radial rotor is sleeved on the shaft (1). The radial stator has multiple magnetic poles, and each magnetic pole is wound with a coil winding for adjusting the radial rotor to be in balance by electromagnetic force.

5. The air compressor according to any one of claims 1 to 3, characterized in that, The axial magnetic bearing (3) includes an axial stator and an axial rotor. The axial rotor is sleeved on the rotating shaft (1). The axial stator includes two annular electromagnets with annular grooves. The annular grooves are provided with annular coil windings for adjusting the axial rotor to be in balance by electromagnetic force. The two annular electromagnets are coaxially arranged on both sides of the axial rotor.

6. The air compressor according to any one of claims 1 to 3, characterized in that, It also includes a position sensor (5) and a controller (6); The position sensor (5) is coaxially arranged with the rotating shaft (1) and has a gap between them, and is used to determine the axial and radial positions of the rotating shaft (1). The position sensor (5) is connected to the radial magnetic bearing (2) and the axial magnetic bearing (3). The controller (6) is electrically connected to the position sensor (5) to receive feedback from the position sensor (5), and the controller (6) is electrically connected to the radial magnetic bearing (2) and the axial magnetic bearing (3) to control the magnitude of the force applied by the radial magnetic bearing (2) and / or the axial magnetic bearing (3).

7. The air compressor according to any one of claims 1 to 3, characterized in that, It also includes a motor, which includes a motor stator and a motor rotor. The motor stator can be fixed on the housing. The motor rotor is rotatably disposed inside the motor stator and is concentrically disposed with the motor stator. A shaft hole is formed in the center of the motor rotor. The rotating shaft (1) passes through the shaft hole and is fixedly connected to the shaft hole to drive the rotating shaft (1) to rotate.

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