Passive compensation type magnetic suspension rotor supporting system and application thereof

Abstract

The invention discloses a passive compensation type magnetic suspension rotor supporting system and application thereof.The passive compensation type magnetic suspension rotor supporting system comprises a rotor shaft, the rotor shaft is rotatably installed in a machine shell through a magnetic suspension bearing assembly, the magnetic suspension bearing assembly comprises a radial magnetic suspension bearing and an axial magnetic suspension bearing, the radial magnetic suspension bearing is fixed in the machine shell, and the axial magnetic suspension bearing is fixed in the machine shell; a thrust disc is fixedly installed on the rotor shaft, the axial magnetic suspension bearing is adjacent to the thrust disc, the axial magnetic suspension bearing can be installed in the machine shell in an axial moving mode, and the passive axial position compensation device can generate corresponding amount of deformation under different temperature conditions. And then the axial magnetic suspension bearing is driven to move in the axial direction so as to realize compensation. The passive axial position compensation device is additionally arranged, so that the position of the axial magnetic suspension bearing can be adjusted and compensated in different temperature fields, and the stability of the relative position of the axial magnetic suspension bearing and the rotor shaft is ensured.

Description

Technical Field

[0001] The present invention relates to a magnetic levitation rotor support system, and in particular to a passive compensation type magnetic levitation rotor support system and its application. Background Art

[0002] The magnetic levitation rotor support system is an electromagnetic levitation technology. Through magnetic force, the rotor and the stator are suspended without contact, thereby greatly reducing the friction when the rotor shaft rotates, reducing the loss of mechanical energy due to friction, and having a higher energy conversion rate.

[0003] Chinese Patent Publication No. CN118499254A discloses a magnetic levitation air compressor, including: a compressor housing, a motor stator, a rotor, a first impeller assembly and a second impeller assembly that can be subjected to axial magnetic force, and a control module. The compressor housing, the motor stator and the rotor are sleeved in sequence. Both ends of the rotor are rotatably connected to the inside of the compressor housing through magnetic levitation bearing groups. The first impeller assembly and the second impeller assembly are respectively fixedly installed at both ends of the rotor relatively; the magnetic levitation bearing groups include: a first thrust bearing member that generates a first axial magnetic force on the first impeller assembly, and a second thrust bearing member that generates a second axial magnetic force on the second impeller assembly. The vector sum of the first axial magnetic force and the second axial magnetic force is used to offset the axial force received by the rotor.

[0004] The above patent realizes the suspension of the rotor without physical contact with bearings or other components, greatly improving the energy conversion rate. However, since magnetic hysteresis eddy current losses will occur when the rotor shaft changes from the stationary standby state to different rotational speed states, copper losses will occur in the stator assembly, and airflow friction losses will occur in the impeller. These losses will cause corresponding changes in temperature. The length of the rotor shaft will change due to changes in thermal stress and mechanical stress. After the length of the rotor shaft changes, the position of the thrust disc on the rotor shaft will also change accordingly. However, due to the settings of the first thrust bearing member and the second thrust bearing member, the axial displacement of the thrust disc is restricted, resulting in the rotor shaft telescoping to the left and right from the thrust disc, which will cause the radial magnetic levitation bearing to be misaligned with the rotor shaft, thereby affecting and weakening the electromagnetic bearing capacity of the magnetic levitation bearing. At the same time, if the rotor shaft expands forward from the thrust disc after being heated, it will cause a change in the gap between the impeller and the volute, thereby affecting the work efficiency of the impeller, and seriously, there will be rubbing between the impeller and the volute; thus, it is urgently needed to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a passive compensation type magnetic levitation rotor support system and its application in view of the above problems, so as to solve the problems raised in the above background art.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A passive compensation type magnetic levitation rotor support system includes a rotor shaft, the rotor shaft is rotatably installed in a housing through a magnetic levitation bearing assembly, the magnetic levitation bearing assembly includes a radial magnetic levitation bearing and an axial magnetic levitation bearing, the radial magnetic levitation bearing is fixed in the housing, the rotor shaft passes through the radial magnetic levitation bearing and the axial magnetic levitation bearing, and a thrust disc is fixedly installed on the rotor shaft, the axial magnetic levitation bearing is adjacent to the thrust disc, and further includes a passive axial position compensation device, the axial magnetic levitation bearing is axially movably installed in the housing, and the passive axial position compensation device can generate corresponding amounts of deformation under different temperature conditions, thereby driving the axial magnetic levitation bearing to move in the axial direction to achieve compensation.

[0008] As a preferred embodiment of the present invention, the axial magnetic levitation bearing includes a first axial magnetic levitation bearing and a second axial magnetic levitation bearing, and the first axial magnetic levitation bearing and the second axial magnetic levitation bearing are symmetrically arranged at both axial ends of the thrust disc.

[0009] As a preferred embodiment of the present invention, the passive axial position compensation device includes a first compensation component and a second compensation component, the first axial magnetic levitation bearing is located at the first axial end of the thrust disc, the first compensation component is located at the first axial end of the first axial magnetic levitation bearing and is adjacent to the first axial magnetic levitation bearing, the second axial magnetic levitation bearing is located at the second axial end of the thrust disc, and the second compensation component is located at the second axial end of the second axial magnetic levitation bearing and is adjacent to the second axial magnetic levitation bearing.

[0010] As a preferred embodiment of the present invention, the first compensation component and the second compensation component have the same structure, and specifically include a first metal sheet and a second metal sheet, both the first metal sheet and the second metal sheet are made of shape memory alloy, and the thermal expansion coefficient of the first metal sheet is greater than that of the second metal sheet.

[0011] As a preferred embodiment of the present invention, the increase amount / decrease amount of the axial length of the first compensation component is equal to the decrease amount / increase amount of the axial length of the second compensation component.

[0012] As a preferred embodiment of the present invention, the passive axial position compensation device further includes a limiting component, the limiting component is fixed in the housing, and the limiting component is located at the second axial end of the second compensation component.

[0013] As a preferred embodiment of the present invention, guide rails are provided on the inner wall of the housing, the guide rails are arranged in the axial direction, and the axial magnetic levitation bearing is slidably connected to the guide rails.

[0014] A rotor support system for a magnetic levitation centrifugal blower, comprising a passive compensation type magnetic levitation rotor support system as described above.

[0015] A rotor support system for a magnetic levitation centrifugal compressor, comprising a passive compensation type magnetic levitation rotor support system as described above.

[0016] A rotor support system for a magnetic levitation centripetal turbine generator, comprising a passive compensation type magnetic levitation rotor support system as described above.

[0017] The beneficial effects of the present invention are as follows. Compared with the prior art, by adding a passive axial position compensation device, the present invention can adjust and compensate the position of the axial magnetic levitation bearing under different temperature fields, ensure the stability of the relative position between the axial magnetic levitation bearing and the rotor shaft, reduce the influence of the expansion and contraction amount of the rotor shaft under different temperature fields on the electromagnetic force of the axial magnetic levitation bearing, and also reduce the influence on the gap between the impeller and the volute, so as to ensure the system efficiency and reliability of the magnetic levitation impeller machinery under different working conditions. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a passive compensation type magnetic levitation rotor support system of the present invention;

[0019] Figure 2 It is a schematic structural diagram of a passive axial position compensation device of the present invention.

[0020] In the figure:

[0021] 101, housing; 102, rotor shaft; 103, thrust disk; 104, front radial magnetic levitation bearing; 105, rear radial magnetic levitation bearing; 106, volute; 107, front end cover; 108, rear end cover; 109, impeller; 110, first axial magnetic levitation bearing; 111, second axial magnetic levitation bearing; 112, stator assembly; 113, permanent magnet core; 114, first metal sheet; 115, second metal sheet; 116, limiting component; 117, guide rail. Detailed Embodiment

[0022] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar components or components with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, a mechanical connection, an electrical connection, or an indirect connection through an intermediate medium. It may also be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the description of the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first feature and the second feature, or may include the situation where the first feature and the second feature are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature. The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0025] Please refer to Figure 1 and Figure 2 as shown Figure 1 which is a schematic structural diagram of a passive compensation type magnetic levitation rotor support system of the present invention; Figure 2 which is a schematic structural diagram of a passive axial position compensation device of the present invention.

[0026] In this embodiment, a passive compensation type magnetic levitation rotor support system is applied to a magnetic levitation centrifugal compressor. The magnetic levitation centrifugal compressor includes a casing 101, a volute 106, a front end cover 107, a rear end cover 108, a stator assembly 112, an impeller 109, and a rotor shaft 102. The rotor shaft 102 is rotatably installed in the casing 101 through a magnetic levitation bearing assembly. The magnetic levitation bearing assembly includes a radial magnetic levitation bearing and an axial magnetic levitation bearing. The radial magnetic levitation bearing is fixed in the casing 101. The rotor shaft 102 passes through the radial magnetic levitation bearing and the axial magnetic levitation bearing, and a thrust disk 103 is fixedly installed on the rotor shaft 102. The axial magnetic levitation bearing is adjacent to the thrust disk 103. A passive axial position compensation device is further included. The axial magnetic levitation bearing is axially movably installed in the casing 101. The passive axial position compensation device can generate corresponding deformations under different temperature conditions, and then drive the axial magnetic levitation bearing to move in the axial direction to achieve compensation.

[0027] Specifically, in this embodiment, the radial magnetic suspension bearing includes a front radial magnetic suspension bearing 104 and a rear radial magnetic suspension bearing 105. The front radial magnetic suspension bearing 104 is arranged on the housing 101, and the front end of the rotor shaft 102 passes through the front radial magnetic suspension bearing 104. When an alternating current passes through the front radial magnetic suspension bearing 104, an electromagnetic force is formed with the rotor shaft 102. Collaborating with the electromagnetic force formed by the rear radial magnetic suspension bearing 105 and the rotor shaft 102, the rotor shaft 102 is supported, so that the rotor shaft 102 is suspended without physical contact with the bearing or other components, greatly reducing the friction when the rotor shaft 102 rotates, reducing the loss of mechanical energy due to friction, and having a higher energy conversion rate.

[0028] Specifically, in this embodiment, the axial magnetic suspension bearing includes a first axial magnetic suspension bearing 110 and a second axial magnetic suspension bearing 111. The first axial magnetic suspension bearing 110 and the second axial magnetic suspension bearing 111 are symmetrically arranged at both axial ends of the thrust disk 103.

[0029] Specifically, in this embodiment, the passive axial position compensation device includes a first compensation component and a second compensation component. The first axial magnetic suspension bearing 110 is located at the first axial end of the thrust disk 103, and the first compensation component is located at the first axial end of the first axial magnetic suspension bearing 110 and is adjacent to the first axial magnetic suspension bearing 110. The second axial magnetic suspension bearing 111 is located at the second axial end of the thrust disk 103, and the second compensation component is located at the second axial end of the second axial magnetic suspension bearing 111 and is adjacent to the second axial magnetic suspension bearing 111.

[0030] Specifically, in this embodiment, the first compensation component and the second compensation component have the same structure and specifically include a first metal sheet 114 and a second metal sheet 115. The first metal sheet 114 and the second metal sheet 115 are laminated and connected. The first metal sheet 114 and the second metal sheet 115 are both made of shape memory alloy, and the thermal expansion coefficient of the first metal sheet 114 is greater than that of the second metal sheet 115; further, the first metal sheet 114 is the active layer and the second metal sheet 115 is the passive layer; the materials of the active layer are mainly manganese-nickel-copper alloy, nickel-chromium-iron alloy, and nickel-manganese-iron alloy; the material of the passive layer is mainly nickel-iron alloy with a nickel content of 34% - 50%. Due to the difference in thermal expansion coefficients, when the temperature changes, the deformation of the active layer is greater than that of the passive layer, so that the first compensation component and the second compensation component will bend towards the passive layer side and generate deformation. Therefore, in different temperature fields, the first compensation component and the second compensation component will have different amplitudes of structural bending changes corresponding to the temperature.

[0031] Specifically, in this embodiment, at the same temperature, the increase amount / decrease amount of the axial length of the first compensation component is equal to the decrease amount / increase amount of the axial length of the second compensation component.

[0032] Specifically, in this embodiment, the passive axial position compensation device further includes a limiting component 116. The limiting component 116 is fixed inside the housing 101, and the limiting component 116 is located at the second axial end of the second compensation component. Both the first compensation component and the second compensation component are installed on the inner wall of the limiting component 116.

[0033] Specifically, in this embodiment, a guide rail 117 is provided on the inner wall of the housing 101. The guide rail 117 is arranged along the axial direction. The first axial magnetic suspension bearing 110 and the second axial magnetic suspension bearing 111 are slidably connected to the guide rail 117; thus, the circumferential rotation of the first axial magnetic suspension bearing 110 and the second axial magnetic suspension bearing 111 on the inner wall of the housing 101 can be restricted.

[0034] Specifically, in this embodiment, the impeller 109 is arranged at the front end of the rotor shaft 102. The gaseous working medium enters the impeller working chamber from the air inlet passage and is discharged after being compressed and doing work by the impeller 109.

[0035] Specifically, in this embodiment, the stator assembly 112 is arranged on the inner wall of the housing 101. The stator assembly 112 includes a stator core and a stator coil. The stator coil is wound around the stator core. A permanent magnet core 113 is embedded in the rotor shaft 102, and the permanent magnet core 113 faces the stator assembly 112; when an alternating current passes through the stator assembly 112, a rotating magnetic field is generated, forming an electromagnetic force with the permanent magnet core 113 of the rotor shaft 102, thereby converting electrical energy into mechanical energy.

[0036] Specifically, in this embodiment, the thrust disk 103 is fixed on the rotor shaft 102. The first axial magnetic suspension bearing 110 is arranged at the front end of the thrust disk 103, and the second axial magnetic suspension bearing 111 is arranged at the rear end of the thrust disk 103. When the impeller 109 compresses and does work, an axial force is generated. The axial force acts on the thrust disk 103. When an alternating current passes through the first axial magnetic suspension bearing 110, the formed electromagnetic force acts on the thrust disk 103. When an alternating current passes through the second axial magnetic suspension bearing 111, the formed electromagnetic force also acts on the thrust disk 103. Thus, acting forces are formed on the front and rear sides of the thrust disk 103, thereby limiting the axial displacement of the rotor shaft 102.

[0037] When the temperature changes and there is a tendency for the position of the thrust disk 103 on the rotor shaft 102 to change, the first compensation component and the second compensation component of the passive axial position compensation device will also deform, pushing the first axial magnetic levitation bearing 110 and the second axial magnetic levitation bearing 111 to move axially, basically ensuring that the first magnetic levitation bearing 110 and the second axial magnetic levitation bearing 111 are facing the thrust disk 103, and the increase in the axial length of the first compensation component is equal to the decrease in the axial length of the second compensation component, thereby being able to maintain structural stability; for example, please refer to Figure 2 As shown, when the temperature rises, the first compensation component bends, and its center bulges to the right, thereby pushing the first axial magnetic levitation bearing 110 to move to the right. At the same time, the second compensation component bends, and its center bulges to the right. The first compensation component pushes the first axial magnetic levitation bearing 110 to move, thereby driving the thrust disk 103 to move. Since there is a repulsive force between the thrust disk 103 and the second axial magnetic levitation bearing 111, it will drive the second axial magnetic levitation bearing 111 to move. The movement amount of the first axial magnetic levitation bearing 110 is equal to the extended amount of the thrust disk 103 after being heated. Thus, while ensuring the relative position stability of the first axial magnetic levitation bearing 110, the second axial magnetic levitation bearing 111 and the thrust disk 103, it is possible to prevent the rotor shaft 102 from elongating towards both ends from the thrust disk 103; when the temperature drops, the first compensation component and the second compensation component slowly return to their original shapes. The second compensation component will push the second axial magnetic levitation bearing 111 to move leftward to reset. Under the action of the repulsive force, it drives the thrust disk 103 to reset, and the thrust disk 103 drives the first axial magnetic levitation bearing 110 to reset, still maintaining the relative position between the first axial magnetic levitation bearing 110, the second axial magnetic levitation bearing 111 and the thrust disk 103.

[0038] It is worth mentioning that although only the application of the passive compensation type magnetic levitation rotor support system to a magnetic levitation centrifugal compressor is described in this embodiment, the present invention is not limited thereto. The passive compensation type magnetic levitation rotor support system can also be applied to a magnetic levitation centrifugal blower and a magnetic levitation centripetal turbo generator.

[0039] The above embodiments only illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, there are various changes and modifications to the present invention, and these changes and modifications all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims.

Claims

1. A passive compensation type magnetic levitation rotor support system, comprising a rotor shaft, the rotor shaft is rotatably installed in a casing through a magnetic levitation bearing assembly, the magnetic levitation bearing assembly includes a radial magnetic levitation bearing and an axial magnetic levitation bearing, the radial magnetic levitation bearing is fixed in the casing, the rotor shaft passes through the radial magnetic levitation bearing and the axial magnetic levitation bearing, and a thrust disc is fixedly installed on the rotor shaft, the axial magnetic levitation bearing is adjacent to the thrust disc, and it is characterized in that: It further includes a passive axial position compensation device. The axial magnetic suspension bearing is axially movably installed in the housing. The passive axial position compensation device can generate corresponding amounts of deformation under different temperature conditions, and then drive the axial magnetic suspension bearing to move in the axial direction to achieve compensation.

2. A passive compensation type magnetic suspension rotor support system according to claim 1, characterized in that: The axial magnetic suspension bearing includes a first axial magnetic suspension bearing and a second axial magnetic suspension bearing. The first axial magnetic suspension bearing and the second axial magnetic suspension bearing are symmetrically arranged at both axial ends of the thrust disk.

3. The passive compensation type magnetic suspension rotor support system according to claim 2, characterized in that: The passive axial position compensation device includes a first compensation component and a second compensation component. The first axial magnetic suspension bearing is located at the first axial end of the thrust disk. The first compensation component is located at the first axial end of the first axial magnetic suspension bearing and is adjacent to the first axial magnetic suspension bearing. The second axial magnetic suspension bearing is located at the second axial end of the thrust disk. The second compensation component is located at the second axial end of the second axial magnetic suspension bearing and is adjacent to the second axial magnetic suspension bearing.

4. A passive compensation type magnetic levitation rotor support system according to claim 3, characterized in that: The first compensation component and the second compensation component have the same structure and specifically include a first metal sheet and a second metal sheet. Both the first metal sheet and the second metal sheet are made of shape memory alloy, and the thermal expansion coefficient of the first metal sheet is greater than that of the second metal sheet.

5. A passive compensation type magnetic suspension rotor support system according to claim 4, characterized in that: The increase amount / decrease amount of the axial length of the first compensation component is equal to the decrease amount / increase amount of the axial length of the second compensation component.

6. A passive compensation type magnetic levitation rotor support system according to claim 5, characterized in that: The passive axial position compensation device further includes a limiting component. The limiting component is fixed in the housing, and the limiting component is located at the second axial end of the second compensation component.

7. A passive compensation type magnetic suspension rotor support system according to any one of claims 1 to 6, characterized in that: The inner wall of the housing is provided with a guide rail. The guide rail is arranged along the axial direction. The axial magnetic suspension bearing is slidably connected to the guide rail.

8. A rotor support system for a magnetic levitation centrifugal blower, characterized in that: A passive compensation type magnetic suspension rotor support system comprising any one of claims 1 to 7.

9. A rotor support system for a magnetic levitation centrifugal compressor, characterized in that: A passive compensation type magnetic suspension rotor support system comprising any one of claims 1 to 7.

10. A rotor support system for a magnetically levitated centripetal turbine generator, characterized in that: A passive compensation type magnetic suspension rotor support system comprising any one of claims 1 to 7.

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