Bearingless motor magnetic suspension combination and bearingless motor magnetic suspension turbo molecular pump
By integrating the motor stator as the core of the magnetic levitation bearing into a bearingless motor magnetic levitation assembly, the problems of large size, high cost and high energy consumption of magnetic levitation turbomolecular pumps have been solved, achieving magnetic levitation operation with higher speed and lower energy consumption.
Patent Information
- Application Number
- CN202520924582.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-12
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-05-12
AI Technical Summary
Existing magnetic levitation turbomolecular pumps suffer from problems such as large size, high cost, difficulty in increasing power and critical speed, and high energy consumption.
The bearingless motor magnetic levitation combination is adopted, with the motor stator as the core of the magnetic levitation bearing, integrating the functions of the motor and the magnetic levitation bearing. The radial electromagnetic force generated by the motor winding is used to achieve bearingless operation.
The size and weight of the motor have been reduced, the critical speed and output power have been increased, energy consumption has been reduced, and more compact and efficient magnetic levitation operation has been achieved.
Smart Images
Figure CN223781718U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a bearingless motor magnetic suspension assembly and a bearingless motor magnetic suspension turbomolecular pump. Background Technology
[0002] A turbomolecular pump is a momentum transfer vacuum pump that uses a high-speed rotating impeller to transfer momentum to gas molecules, causing the gas to flow in a directional manner, thus creating a vacuum. It can operate at speeds up to 10... -3 Up to 10 -10 It generates clean vacuum within the hPa range. Due to its stable and reliable operation and excellent pumping efficiency in molecular flow, it has become the mainstream equipment for obtaining clean high vacuum and ultra-high vacuum applications and is widely used in scientific instruments and industrial production equipment.
[0003] Magnetic levitation turbomolecular pumps, as a type of turbomolecular pump, are turbomolecular pumps that achieve contactless rotation using magnetic levitation technology through a structure combining a traditional electric motor and magnetic bearings (i.e., two radial magnetic bearings plus one traditional electric motor plus one axial magnetic bearing). This type of magnetic levitation turbomolecular pump has the following advantages:
[0004] a) No mechanical friction: Since there is no physical contact between the rotor and the stator, there is no mechanical friction, resulting in smoother operation.
[0005] b) No lubricant: Reduces the use of lubricant and lowers the risk of contamination.
[0006] c) High cleanliness: The rotor operates in suspension, which reduces wear and impurity generation, making it suitable for applications requiring high cleanliness.
[0007] d) High reliability: The magnetic levitation design reduces bearing friction loss and extends service life.
[0008] e) Low noise and low vibration: The noise and vibration are very low during operation, making it suitable for places that require a quiet environment.
[0009] However, the levitation function of this type of magnetic levitation turbomolecular pump mainly relies on electromagnetic bearings. These electromagnetic bearings still have the following shortcomings or drawbacks:
[0010] (1) Large size and high cost. Because the torque magnetic circuit and the suspension magnetic circuit are separated, the magnetic bearing occupies a certain axial length, resulting in a relatively long and large motor. The magnetic bearing itself requires a high-quality controller, a high-performance power amplifier, and multiple expensive displacement sensors, thus increasing the cost.
[0011] (2) It is difficult to significantly increase both power and critical speed. The large axial length limits the further increase of the critical speed of the magnetic bearing motor; to increase the output power of the motor while avoiding the critical speed, the only way is to increase the radial dimension of the motor. However, the increase of the radial dimension of the motor is limited by the mechanical strength of the electromagnet and other components, and the margin for expansion is limited.
[0012] (3) Magnetic levitation consumes a large amount of energy. Magnetic levitation bearings require a direct current to establish a DC bias magnetic field, resulting in relatively high power consumption for levitation control. Furthermore, providing the additional DC bias magnetic field requires a dedicated excitation device. These drawbacks mean that electromagnetic bearings still cannot fully meet the requirements for high-performance, ultra-high-speed levitation operation.
[0013] In order to further improve the performance of magnetic levitation turbomolecular pumps and address the shortcomings and deficiencies of the current magnetic levitation technology using a traditional motor plus magnetic bearing structure, it is necessary to adopt a new type of magnetic levitation technology. Utility Model Content
[0014] Therefore, in view of the shortcomings of the prior art, the purpose of this utility model is to provide a bearingless motor magnetic suspension combination that can overcome the limitations of conventional magnetic bearing motors and has better performance, as well as a bearingless motor magnetic levitation turbomolecular pump with the bearingless motor magnetic suspension combination.
[0015] One aspect of this utility model is to provide a bearingless motor magnetic suspension assembly, which includes at least one bearingless motor and at least one magnetic suspension bearing. The bearingless motor includes a motor stator, a motor rotor, and motor windings disposed on the motor stator. The motor stator of the bearingless motor also serves as the core of the magnetic suspension bearing, and the motor windings of the bearingless motor also serve as the windings of the magnetic suspension bearing that generate radial electromagnetic force.
[0016] Preferably, in the bearingless motor magnetic suspension assembly described above, the bearingless motor magnetic suspension assembly includes a radial-axial magnetic suspension bearing for realizing two radial degrees of freedom control and axial control, and a bearingless motor for realizing two radial degrees of freedom control.
[0017] Preferably, in the bearingless motor magnetic suspension assembly described above, the radial-axial magnetic suspension bearing includes rotor laminations disposed on a rotating shaft and an axial stator disposed radially outward relative to the rotor laminations; the axial stator is a hollow annular structure with an opening, the rotor laminations are inserted into the opening of the axial stator, and the two form an axial magnetic bearing air gap in the axial direction; an annular permanent magnet and a radial magnetic bearing stator are disposed in the hollow structure of the axial stator, an axial control coil is wound on the annular permanent magnet and the radial magnetic bearing stator, a radial control coil is wound on the radial magnetic bearing stator, and a radial magnetic bearing air gap is formed between the rotor laminations and the radial magnetic bearing stator.
[0018] Preferably, in the bearingless motor magnetic suspension assembly described above, the radial bearing stator and rotor laminations of the radial-axial magnetic suspension bearing include stacked silicon steel sheets with a thickness of 0.1mm-0.5mm; the half-air gap values of the radial magnetic bearing air gap and the axial magnetic bearing air gap are between 0.2mm-1mm.
[0019] Preferably, in the bearingless motor magnetic suspension assembly described above, the bearingless motor magnetic suspension assembly includes an axial magnetic suspension bearing for axial control and two bearingless motors for radial degree of freedom control.
[0020] Preferably, in the bearingless motor magnetic levitation assembly described above, the two bearingless motors are respectively disposed on both sides of the axial magnetic levitation bearing in the axial direction.
[0021] Preferably, in the bearingless motor magnetic levitation assembly described above, in the axial direction, the two bearingless motors are disposed on one side of the axial magnetic levitation bearing.
[0022] Preferably, in the bearingless motor magnetic suspension assembly described above, the bearingless motor magnetic suspension assembly includes a bearingless motor arranged along the axial direction for realizing two radial degrees of freedom control, a radial magnetic suspension bearing for realizing two radial degrees of freedom control, and an axial magnetic suspension bearing for realizing axial control.
[0023] Preferably, in the bearingless motor magnetic suspension assembly described above, the wire diameter of the motor winding of the bearingless motor ranges from 0.05 to 2 mm; the motor stator of the bearingless motor includes stacked silicon steel sheets with a thickness of 0.1 mm to 0.5 mm; and the motor rotor of the bearingless motor is a permanent magnet.
[0024] Another aspect of this utility model is to provide a bearingless motor magnetic levitation turbomolecular pump, which includes the bearingless motor magnetic levitation assembly as described above.
[0025] According to this utility model, the bearingless motor magnetic suspension assembly integrates the motor and the magnetic levitation bearing into one unit on the magnetic circuit, with the motor's iron core also serving as the core of the magnetic levitation bearing. This is a novel motor system that integrates the functions of a motor and a magnetic bearing. The bearingless motor magnetic suspension assembly utilizes the similarity between the magnetic bearing structure and the motor stator structure, superimposing the windings that generate radial electromagnetic force in the magnetic bearing onto the conventional motor stator windings. This integrates the magnetic circuit of the levitation magnetic field and the conventional motor magnetic circuit into a single unit, independently controlling the motor's rotation and the stable levitation of the shaft, thereby achieving bearingless operation of the motor. Compared to existing "magnetic bearing motors" with a conventional motor and magnetic levitation bearing structure, the bearingless motor magnetic suspension assembly not only possesses all the advantages of magnetic bearing motors but also overcomes their limitations, thus exhibiting superior performance. Compared to traditional mechanical bearing plus levitation bearing turbomolecular pumps, the bearingless motor magnetic levitation turbomolecular pump with the bearingless motor magnetic suspension assembly according to this utility model has the following advantages:
[0026] (1) High axial utilization, more compact structure, small size, and easy miniaturization. The stator of the bearingless motor also serves as the core of the magnetic bearing. The radial force winding is wound on the stator core of the motor, which does not occupy additional axial space. Under the same power conditions, the motor size is smaller; the radial magnetic levitation bearings at both ends are eliminated, and the motor cost is relatively low. Under the same conditions, because the motor is smaller, the molecular pump is relatively smaller and lighter.
[0027] (2) By making full use of the axial space of the motor and reducing the shaft length, the critical speed of the motor can be greatly increased and can reach extremely high speed. Under the same conditions, the bearingless motor magnetic levitation turbomolecular pump can achieve higher speed.
[0028] (3) Because it makes full use of the axial space of the motor, its output power is relatively high under the condition that the axial length of the motor is constant. Under the same conditions, the bearingless motor magnetic levitation turbomolecular pump can meet the greater aerodynamic load requirements.
[0029] (4) Magnetic levitation consumes less energy. Eliminating the DC bias magnetic field of the magnetic bearing reduces the electrical energy required to generate magnetic levitation force, thus improving system efficiency. Under the same conditions, the bearingless motor magnetic levitation turbomolecular pump consumes less electricity and is more environmentally friendly.
[0030] (5) Magnetic levitation force can be generated along the entire length of the rotor, resulting in a large electromagnetic levitation force. Under the same conditions, the size of a bearingless motor magnetic levitation turbomolecular pump can be larger. Attached Figure Description
[0031] Figure 1 This is a simplified cross-sectional view of a bearingless motor magnetic levitation turbomolecular pump according to the present invention, which includes a bearingless motor magnetic levitation assembly according to the first embodiment of the present invention.
[0032] Figure 2 This is a simplified cross-sectional schematic diagram of the radial-axial magnetic levitation bearing according to the present invention.
[0033] Figure 3 This is a simplified cross-sectional schematic diagram of the bearingless motor according to the present invention.
[0034] Figure 4 This is a schematic diagram of a bearingless motor magnetic suspension assembly according to the second embodiment of the present invention.
[0035] Figure 5 This is a schematic diagram of a bearingless motor magnetic suspension assembly according to the third embodiment of the present invention.
[0036] Figure 6 This is a schematic diagram of a bearingless motor magnetic suspension assembly according to the fourth embodiment of the present invention. Detailed Implementation
[0037] Figure 1 This is a simplified cross-sectional schematic diagram of the bearingless motor magnetic levitation turbomolecular pump according to this utility model. Figure 1 As shown, the bearingless motor magnetic levitation turbomolecular pump includes components such as a housing 1, an integrated rotor 2, an inner casing 3, stator blades 4, a base 5, a high-precision displacement sensor 6, a rear end cover 7, a safety bearing 8, a radial-axial magnetic levitation bearing 9, a bearingless motor 10, and a pressure ring 11. Figure 1 In the bearingless motor magnetic levitation turbomolecular pump shown, the radial-axial magnetic levitation bearing 9 and the bearingless motor 10 together constitute the bearingless motor magnetic levitation assembly according to the first embodiment of this utility model.
[0038] exist Figure 1 In the bearingless motor magnetic levitation turbomolecular pump shown, the base 5 is connected to the housing 1, and the rear end cover 7 is connected to the base 5. The housing 1, base 5, and rear end cover 7 together constitute the enclosure structure of the bearingless motor magnetic levitation turbomolecular pump, used to accommodate and encapsulate the other parts of the bearingless motor magnetic levitation turbomolecular pump. The stator blades 4 extend axially inward from the housing 1 and correspond to the integrated rotor 2. A bearingless motor magnetic levitation assembly according to the first embodiment of this utility model, namely a radial-axial magnetic levitation bearing 9 and a bearingless motor 10, is coaxially arranged with the integrated rotor 2. In addition, multiple high-precision displacement sensors 6 are provided to detect displacement and perform axial and / or radial adjustments based on the detection results.
[0039] After assembly, the integrated rotor 2 of this high-performance turbomolecular pump can rotate freely around the rotor shaft center. Under energized conditions, the radial-axial magnetic levitation bearing 9 generates radial and axial levitation forces, achieving three degrees of freedom (two radial and one axial). The bearingless motor 10, when energized, generates levitation forces in at least two degrees of freedom (two radial). Under the magnetic levitation forces of the radial-axial magnetic levitation bearing and the bearingless motor, 5-axis magnetic levitation control of the turbomolecular pump is achieved through PID algorithm control.
[0040] Figure 2 This is a simplified cross-sectional schematic diagram of the radial-axial magnetic levitation bearing according to this utility model. Figure 2 As shown, the radial-axial magnetic levitation bearing 9 according to this utility model mainly consists of an axial stator 12, an axial control coil 13, a radial magnetic bearing air gap 14, an axial magnetic bearing air gap 15, a radial control coil 16, an annular permanent magnet 17, a radial magnetic bearing stator 18, rotor laminations 19, and a rotating shaft 20. The radial bearing stator 18 and the rotor laminations 19 are made of silicon steel sheets, with a thickness of 0.1mm-0.5mm; the half-air gap values of the radial magnetic bearing air gap 14 and the axial magnetic bearing air gap 15 are between 0.2mm-1mm. The annular permanent magnet 17 is made of rare earth materials, such as neodymium iron boron (NdFeB) and samarium cobalt (SmCo).
[0041] The rotor laminations 19 are mounted on the rotating shaft 20 and can rotate with the rotating shaft 20. The axial stator 12 is positioned radially outward relative to the rotor laminations 19. The axial stator 12 is a hollow annular structure with a roughly rectangular cross-section and an opening near the rotating shaft 20, which communicates with the hollow portion of the axial stator 12. The rotor laminations 19 are inserted into the opening of the axial stator 12, and there is a certain air gap between them in the axial direction, namely the axial magnetic bearing air gap 15. The axial control coil 13, the radial control coil 16, the annular permanent magnet 17, and the radial magnetic bearing stator 18 are disposed within the hollow structure of the axial stator 12. The annular permanent magnet 17 and the radial magnetic bearing stator 18 are disposed within the hollow structure of the axial stator 12 and are located away from the opening of the axial stator 12. Axial control coil 13 is wound around the end of annular permanent magnet 17 and radial magnetic bearing stator 18 closest to annular permanent magnet 17, while radial control coil 16 is wound around the end of radial magnetic bearing stator 18 furthest from annular permanent magnet 17. In the radial direction, a radial magnetic bearing air gap 14 is formed between rotor laminations 19 and radial magnetic bearing stator 18.
[0042] Figure 3 This is a simplified cross-sectional schematic diagram of the bearingless motor according to this utility model. Figure 3As shown, the bearingless motor according to this utility model mainly consists of a motor winding 21, a motor stator 22, a rotating shaft 23, and a motor rotor 24. The motor rotor 24 is mounted on the rotating shaft 23 and can rotate with the rotation of the rotating shaft 23. The motor stator 22 is mounted radially outward relative to the motor rotor 24, and the motor winding 21 is mounted on the motor stator 22. The wire diameter of the motor winding 21 ranges from 0.05 to 2 mm, and the winding material includes, but is not limited to, copper and aluminum; the motor stator 22 is made of laminated silicon steel sheets with a thickness of 0.1 mm to 0.5 mm; the motor rotor 24 is a permanent magnet, and the material includes, but is not limited to, rare earth permanent magnets such as neodymium iron boron and samarium cobalt.
[0043] In the bearingless motor magnetic suspension assembly according to the first embodiment of the present invention, which is composed of a radial-axial magnetic levitation bearing 9 and a bearingless motor 10, the motor stator 22 of the bearingless motor 10 also serves as the core of the radial-axial magnetic levitation bearing 9, and the motor winding 21 of the bearingless motor 10 also serves as the winding of the radial-axial magnetic levitation bearing 9 that generates radial electromagnetic force.
[0044] In the first embodiment of this utility model, the control of the bearingless motor magnetic levitation turbomolecular pump includes... Figure 2 radial-axial magnetic levitation bearings and Figure 3 Bearingless motor control. Its control strategy is as follows:
[0045] 1) Radial-Axial Magnetic Suspension Bearing Control. This radial-axial magnetic suspension bearing can achieve three degrees of freedom of motion and control. The axial control method is as follows: After detecting the rotor's axial offset position using a high-precision displacement sensor 6, the displacement signal is fed back to the DSP controller. After PID adjustment by the digital controller, a control current signal is output to the DC power amplifier to control the control current of the axial control coil, thereby controlling the magnetic flux at the axial air gap and ensuring the rotor is in an axially balanced position. The radial control method is as follows: After detecting the rotor's radial offset position using a high-precision displacement sensor 6, the position signal is fed back to the DSP controller. After PID adjustment, it is converted into a force control signal, which is then converted into a reference control current signal. This signal is tracked and compared with the real-time current in the radial three-phase winding detected by the current transformer. By controlling the switching devices of the three-phase inverter, the magnitude of the control current in the radial three-phase winding is changed, thereby changing the control magnetic flux and generating a magnetic attraction force to return the rotor to the radial balance position.
[0046] 2) Bearingless Motor Control. The stator windings of a bearingless motor contain multiple three-phase modules, the number of which can be increased or decreased according to actual needs. To achieve the levitation effect, at least two modules are required in the motor windings. For fault redundancy, three or more modules can achieve better fault redundancy. The bearingless motor uses rotor field-oriented control, enabling at least two degrees of freedom of motion. In a bearingless motor, the basic conditions for the stable and controllable Maxwell radial electromagnetic resultant force generated by the modulation of the levitation magnetic field are as follows:
[0047] a) The relationship between the number of pole pairs P1 of the torque winding and the number of pole pairs P2 of the suspension winding is: P1=P2±1;
[0048] b) The angular frequency ω1 of the current in the motor torque winding is equal to the angular frequency ω2 of the current in the suspension control winding, i.e., ω1=ω2.
[0049] c) In multiple winding modules, the introduction of the levitation magnetic field breaks the balance of the original motor's rotating air gap magnetic field, which strengthens the magnetic field in some areas of the air gap and weakens the magnetic field in the areas where the space is piled up, thereby generating a Maxwell electromagnetic resultant force pointing towards the area of enhanced magnetic field. By controlling the magnitude and phase of the levitation control current, a magnetic levitation force with controllable magnitude and direction can be generated on the rotor to counteract the unstable unilateral magnetic pull and external radial load caused by rotor eccentricity, thereby realizing the levitation operation of the bearingless rotor.
[0050] 3) By combining radial-axial magnetic levitation bearing control and bearingless motor control, the 5-axis magnetic levitation control of the bearingless motor magnetic levitation turbomolecular pump can be realized.
[0051] Figure 4 This is a schematic diagram of a bearingless motor magnetic suspension assembly according to the second embodiment of the present invention. The bearingless motor magnetic suspension assembly according to the second embodiment of the present invention includes two bearingless motors 25 and an axial magnetic levitation bearing 26. Along the axial direction, a bearingless motor 25 is respectively arranged on both sides of the axial magnetic levitation bearing 26. Figure 4 In the second embodiment shown, each of the upper and lower bearingless motors 25 can achieve control of two radial degrees of freedom, while axial control can be achieved through the axial magnetic levitation bearing 26. The bearingless motor magnetic levitation assembly according to the second embodiment of this invention can achieve the same functionality as the first embodiment (i.e.,... Figure 2 Radial-axial magnetic levitation bearings Figure 3 With the same function as a bearingless motor, five-axis magnetic levitation control of a magnetic levitation turbomolecular pump can be achieved.
[0052] Figure 5This is a schematic diagram of a bearingless motor magnetic suspension assembly according to a third embodiment of the present invention. The bearingless motor magnetic suspension assembly according to the third embodiment of the present invention includes a bearingless motor 27 and an axial magnetic suspension bearing 28. The bearingless motor 27, the bearingless motor 27, and the axial magnetic suspension bearing 28 are arranged sequentially along the axial direction. Both bearingless motors 27 can achieve control of two radial degrees of freedom, and axial control can be achieved through the axial magnetic suspension bearing 28. The bearingless motor magnetic suspension assembly according to the third embodiment of the present invention can achieve the same functionality as the first embodiment (i.e.,...). Figure 2 Radial-axial magnetic levitation bearings Figure 3 With the same function as a bearingless motor, five-axis magnetic levitation control of a magnetic levitation turbomolecular pump can be achieved.
[0053] Figure 6 This is a schematic diagram of a bearingless motor magnetic suspension assembly according to the fourth embodiment of the present invention. The bearingless motor magnetic suspension assembly according to the fourth embodiment of the present invention includes a bearingless motor 29, a radial magnetic suspension bearing 30, and an axial magnetic suspension bearing 31. The bearingless motor 29 enables control of two radial degrees of freedom, the radial magnetic suspension bearing 30 enables control of two radial degrees of freedom, and the axial magnetic suspension bearing 31 enables axial control. Therefore, the bearingless motor magnetic suspension assembly according to the fourth embodiment of the present invention can achieve the same control as the first embodiment (i.e.,...). Figure 2 Radial-axial magnetic levitation bearings Figure 3 With the same function as a bearingless motor, five-axis magnetic levitation control of a magnetic levitation turbomolecular pump can be achieved.
[0054] like Figure 4-6 The bearingless motor magnetic suspension combination shown can be applied to, for example... Figure 1 In the bearingless motor magnetic levitation turbomolecular pump shown, the radial-axial magnetic levitation bearing 9 and the bearingless motor 10 together constitute the bearingless motor magnetic levitation assembly according to the first embodiment of this utility model.
[0055] According to this utility model, the bearingless motor magnetic suspension assembly integrates the motor and the magnetic levitation bearing into one unit on the magnetic circuit, with the motor's iron core also serving as the core of the magnetic levitation bearing. This is a novel motor system that integrates the functions of a motor and a magnetic bearing. The bearingless motor magnetic suspension assembly utilizes the similarity between the magnetic bearing structure and the motor stator structure, superimposing the windings that generate radial electromagnetic force in the magnetic bearing onto the conventional motor stator windings. This integrates the magnetic circuit of the levitation magnetic field and the conventional motor magnetic circuit into a single unit, independently controlling the motor's rotation and the stable levitation of the shaft, thereby achieving bearingless operation of the motor. Compared to existing "magnetic bearing motors" with a conventional motor and magnetic levitation bearing structure, the bearingless motor magnetic suspension assembly not only possesses all the advantages of magnetic bearing motors but also overcomes their limitations, thus exhibiting superior performance. Compared to traditional mechanical bearing plus levitation bearing turbomolecular pumps, the bearingless motor magnetic levitation turbomolecular pump with the bearingless motor magnetic suspension assembly according to this utility model has the following advantages:
[0056] (1) High axial utilization, more compact structure, small size, and easy miniaturization. The stator of the bearingless motor also serves as the core of the magnetic bearing. The radial force winding is wound on the stator core of the motor, which does not occupy additional axial space. Under the same power conditions, the motor size is smaller; the radial magnetic levitation bearings at both ends are eliminated, and the motor cost is relatively low. Under the same conditions, because the motor is smaller, the molecular pump is relatively smaller and lighter.
[0057] (2) By making full use of the axial space of the motor and reducing the shaft length, the critical speed of the motor can be greatly increased and can reach extremely high speed. Under the same conditions, the bearingless motor magnetic levitation turbomolecular pump can achieve higher speed.
[0058] (3) Because it makes full use of the axial space of the motor, its output power is relatively high under the condition that the axial length of the motor is constant. Under the same conditions, the bearingless motor magnetic levitation turbomolecular pump can meet the greater aerodynamic load requirements.
[0059] (4) Magnetic levitation consumes less energy. Eliminating the DC bias magnetic field of the magnetic bearing reduces the electrical energy required to generate magnetic levitation force, thus improving system efficiency. Under the same conditions, the bearingless motor magnetic levitation turbomolecular pump consumes less electricity and is more environmentally friendly.
[0060] (5) Magnetic levitation force can be generated along the entire length of the rotor, resulting in a large electromagnetic levitation force. Under the same conditions, the size of a bearingless motor magnetic levitation turbomolecular pump can be larger.
[0061] In this specification, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples.
[0062] The above description is merely an implementation example of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A bearingless motor magnetic suspension assembly, characterized in that... It includes at least one bearingless motor and at least one magnetic levitation bearing. The bearingless motor includes a motor stator, a motor rotor, and motor windings disposed on the motor stator. The motor stator of the bearingless motor also serves as the core of the magnetic levitation bearing, and the motor windings of the bearingless motor also serve as the windings of the magnetic levitation bearing that generate radial electromagnetic force.
2. The bearingless motor magnetic suspension assembly as described in claim 1, characterized in that: The bearingless motor magnetic suspension assembly includes a radial-axial magnetic suspension bearing for achieving two radial degrees of freedom control and axial control, and a bearingless motor for achieving two radial degrees of freedom control.
3. The bearingless motor magnetic suspension assembly as described in claim 2, characterized in that: The radial-axial magnetic levitation bearing includes rotor laminations disposed on a rotating shaft and an axial stator disposed radially outward relative to the rotor laminations. The axial stator is a hollow annular structure with an opening. The rotor laminations are inserted into the opening of the axial stator, and the two form an axial magnetic bearing air gap in the axial direction. An annular permanent magnet and a radial magnetic bearing stator are disposed in the hollow structure of the axial stator. An axial control coil is wound on the annular permanent magnet and the radial magnetic bearing stator, and a radial control coil is wound on the radial magnetic bearing stator. A radial magnetic bearing air gap is formed between the rotor laminations and the radial magnetic bearing stator.
4. The bearingless motor magnetic suspension assembly as described in claim 3, characterized in that: The radial bearing stator and rotor laminations of the radial-axial magnetic levitation bearing include stacked silicon steel sheets with a thickness of 0.1mm-0.5mm; the half-air gap values of the radial magnetic bearing air gap and the axial magnetic bearing air gap are between 0.2mm-1mm.
5. The bearingless motor magnetic suspension assembly as described in claim 1, characterized in that: The bearingless motor magnetic suspension assembly includes an axial magnetic suspension bearing for axial control and two bearingless motors for two radial degrees of freedom control.
6. The bearingless motor magnetic suspension assembly as described in claim 5, characterized in that: In the axial direction, the two bearingless motors are respectively located on both sides of the axial magnetic levitation bearing.
7. The bearingless motor magnetic suspension assembly as described in claim 5, characterized in that: In the axial direction, the two bearingless motors are positioned on one side of the axial magnetic levitation bearing.
8. The bearingless motor magnetic suspension assembly as described in claim 1, characterized in that: The bearingless motor magnetic suspension assembly includes a bearingless motor arranged along the axial direction for achieving two radial degrees of freedom control, a radial magnetic suspension bearing for achieving two radial degrees of freedom control, and an axial magnetic suspension bearing for achieving axial control.
9. The bearingless motor magnetic suspension assembly as described in any one of claims 1-8, characterized in that: The wire diameter of the motor windings in a bearingless motor ranges from 0.05 to 2 mm; the stator of a bearingless motor consists of stacked silicon steel sheets with a thickness of 0.1 mm to 0.5 mm; and the rotor of a bearingless motor is a permanent magnet.
10. A bearingless motor magnetic levitation turbomolecular pump, characterized in that... Including the bearingless motor magnetic suspension assembly as described in any one of claims 1-9.