A bearingless motor
By designing independent drive and control windings in bearingless motors and adopting radial and L-shaped iron core structures, the complex winding design and magnetic field interference are solved, and more efficient heat dissipation and more stable control are achieved, which improves the motor reliability and rotor suspension performance.
Patent Information
- Application Number
- CN202411324541.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2044-09-23
AI Technical Summary
The existing bearingless motor winding design has problems such as high winding difficulty, large core length, small air gap space, high magnetic field interference and high control difficulty, which affects the motor's heat dissipation efficiency and fault tolerance.
Design independent drive windings and control windings, adopt radial core and L-shaped iron core structures, with different winding directions, and the magnetic field distribution is at an angle of 90° to reduce magnetic field interference, and stabilize the static bias electromagnetic force of the control winding. In the rotor, the air gap space is expanded, and the heat dissipation and control accuracy are improved.
It reduces the difficulty of winding processing, shortens the core length, expands the air gap space, improves heat dissipation efficiency and control error tolerance, reduces the risk of magnetic field failure and rotor drop, and improves the reliability and control accuracy of the motor.
Smart Images
Figure CN118868475B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of magnetic levitation motors, and in particular relates to a bearingless motor. Background Art
[0002] The bearingless motor is a new type of motor designed based on the magnetic levitation motor. Since the structure, support principle and control principle of the radial active magnetic bearing are similar to those of the permanent magnet synchronous motor, based on this similarity, the winding of the radial magnetic bearing can be installed on the motor stator to achieve independent control of the motor torque and radial suspension force through decoupling control, and ultimately eliminate the radial magnetic bearing of the motor, shorten the axial dimension, reduce the weight of the machine body, and make the whole machine compact and lightweight, thereby further improving the speed and efficiency.
[0003] At present, most of the windings of bearingless motors mainly adopt the superimposed winding design, that is, a pair of drive windings and control windings are coaxially wound and connected in series on the same iron core. This design increases the difficulty of winding and increases the length of the iron core, making the bearingless motor have a higher diameter length and radial space occupancy rate. At the same time, there is magnetic field interference between the drive winding and the control winding, which increases the risk of magnetic field failure and rotor falling. The increase in winding density reduces the air gap space between the rotor and the stator, affecting the heat dissipation efficiency of the motor, reducing the air gap distance between the motor rotor and the stator, reducing the fault tolerance of the motor control, and increasing the control difficulty. Summary of the invention
[0004] The main technical problem to be solved by the present invention is to provide a bearingless motor, in which the drive winding and the control winding of the motor have independent iron cores, and the winding processing difficulty is relatively low. It also avoids the problems of large iron core length and small air gap space of the traditional bearingless motor structure to a certain extent, improves the heat dissipation efficiency and control fault tolerance. At the same time, the magnetic field direction and electromagnetic force generated by the winding have different ranges of action on the rotor, which avoids mutual interference between the magnetic fields and improves the reliability of the motor.
[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:
[0006] A bearingless motor comprises a housing, a motor stator is fixedly mounted in the housing, end covers are fixedly mounted at both ends of the housing, the end covers seal and protect the internal structure of the housing, a rotor is movably arranged in the middle of the motor stator, the two ends of the rotor respectively penetrate the corresponding end covers, and the two ends of the rotor are rotatably connected to the end covers;
[0007] The motor stator comprises a driving winding and a control winding, and the iron cores of the driving winding and the control winding are fixedly connected as a whole.
[0008] The following is a further optimization of the above technical solution by the present invention:
[0009] The driving winding comprises a plurality of radial iron cores, which are arranged in a ring shape and at intervals. The plurality of radial iron cores are respectively provided with driving windings, which are wound and arranged with the radial iron cores as axes, and the winding direction of the driving windings is the radial direction of the motor.
[0010] Further optimization: the control winding mainly includes multiple groups of control iron cores, which are arranged in a ring shape and at intervals along the outer surface of the rotor, and each group of control iron cores includes two symmetrically arranged L-shaped iron cores, and the two L-shaped iron cores are fixedly connected at one end close to each other; the two L-shaped iron cores are respectively arranged along the axial direction of the motor, and the other ends of the two L-shaped iron cores are bent 90° toward the direction close to the rotor.
[0011] Further optimization: control windings are installed at the connection points of the two L-shaped iron cores, the control windings are wound and arranged with the long axis of the L-shaped iron core as the axis, and the winding direction of the control windings is the axial direction of the motor.
[0012] Further optimization: the rotor includes a rotor shaft, and a plurality of driving permanent magnet patches are arranged at the axial middle position of the rotor shaft, and the plurality of driving permanent magnet patches are arranged in a ring shape and at equal intervals along the outer surface of the rotor shaft, and the driving permanent magnet patches are arranged at the inner position of the driving winding.
[0013] Further optimization: control permanent magnetic patches are respectively arranged on both sides of the driving permanent magnetic patch on the rotor shaft, there are multiple control permanent magnetic patches, and the multiple control permanent magnetic patches are respectively arranged in a ring shape and at equal intervals along the outer surface of the rotor shaft.
[0014] Further optimization: The magnetic polarities of the control permanent magnetic patches on both sides of the driving permanent magnetic patch are opposite and are 180° flipped symmetrically.
[0015] Further optimization: the materials of the driving permanent magnetic patch and the control permanent magnetic patch are both permanent magnets.
[0016] Further optimization: the driving permanent magnet patch is fixedly installed on the rotor shaft by using a surface mount or embedded structure; the control permanent magnet patch is fixedly installed on the rotor shaft by using a surface mount or embedded structure.
[0017] Further optimization: A sensor is fixedly installed on the short axis of the L-shaped core at the center of a side surface close to the rotor, and the sensor is used to detect the position of the rotor.
[0018] The present invention adopts the above technical scheme, which is ingenious in conception and reasonable in structure. The bearingless motor decomposes the integrated drive and control windings of the traditional bearingless motor into independent drive windings and control windings, reduces the difficulty of winding processing, shortens the radial length of the iron core, reduces the radial space occupancy of the bearingless motor, expands the air gap space between the rotor and the stator, and improves the heat dissipation efficiency and control fault tolerance of the bearingless motor.
[0019] Compared with the superimposed winding structure of the traditional bearingless motor, the bearingless motor in the present invention has a drive winding and a control winding with different winding axes, and the main distribution directions of the magnetic fields of the two are at an angle of 90°, so the interference between the magnetic fields is relatively small. At the same time, the L-shaped iron core of the control winding further guides the magnetic field of the control winding to the control permanent magnet patch part at both ends of the bearing, forming a spatial separation from the action position of the electromagnetic force of the drive winding, further reducing the magnetic field interference between the drive winding and the control winding, and reducing the risk of magnetic field failure and rotor falling.
[0020] Compared with the superimposed winding structure of the traditional bearingless motor, the bearingless motor in the present invention has a static bias electromagnetic force of the control winding that acts symmetrically on both ends of the rotor, so the electromagnetic force is more stable and has a better control effect on the rotor.
[0021] The winding structure of the bearingless motor in the present invention can also be set to multiple groups. By increasing the windings, the close angle of the control winding can be reduced, thereby improving the control accuracy.
[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;
[0024] Figure 2 A schematic diagram of the structure of a rotor in an embodiment of the present invention;
[0025] Figure 3 Schematic diagram of the stator structure of the motor in an embodiment of the present invention;
[0026] Figure 4 It is a transverse cross-sectional view of the overall structure in an embodiment of the present invention.
[0027] In the figure: 1-housing; 2-rotor; 21-rotor shaft; 22-driving permanent magnetic patch; 23-controlling permanent magnetic patch; 3-driving winding; 31-radial iron core; 32-driving winding; 4-control winding; 41-L-shaped iron core; 42-control winding; 5-protective bearing; 6-sensor; 7-end cover. DETAILED DESCRIPTION
[0028] like Figure 1-4 As shown: a bearingless motor comprises a housing 1, in which a motor stator is fixedly installed, end covers 7 are fixedly installed at both ends of the housing 1, and the end covers 7 seal and protect the internal structure of the housing 1, a rotor 2 is movably arranged in the middle of the motor stator, and both ends of the rotor 2 pass through the corresponding end covers 7, and the two ends of the rotor 2 are rotatably connected to the end covers 7.
[0029] The motor stator includes a drive winding 3 and a control winding 4. The iron cores of the drive winding 3 and the control winding 4 are structurally fixedly connected as one by welding, riveting, etc.
[0030] The driving winding 3 includes a plurality of radial cores 31, which are annular and arranged at intervals. Driving windings 32 are respectively installed on the plurality of radial cores 31. The driving windings 32 are wound and arranged with the radial cores 31 as the axis, and the winding direction of the driving windings 32 is the radial direction of the motor.
[0031] The control winding 4 mainly includes multiple groups of control cores, which are arranged in a ring shape and at intervals along the outer surface of the rotor 2. Each group of control cores includes two symmetrically arranged L-shaped cores 41, and the two L-shaped cores 41 are fixedly connected at one end close to each other.
[0032] The two L-shaped iron cores 41 are arranged along the axial direction of the motor, and the other ends of the two L-shaped iron cores 41 are bent at 90 degrees toward the direction close to the rotor 2 .
[0033] A control winding 42 is installed at the connection of the two L-shaped cores 41 . The control winding 42 is wound around the long axis of the L-shaped core 41 , and the winding direction of the control winding 42 is the axial direction of the motor.
[0034] In this embodiment, the two L-shaped cores 41 of each group of control cores are fixedly connected to the corresponding radial cores 31 by welding, riveting or the like.
[0035] The rotor 2 includes a rotor shaft 21 , and a plurality of driving permanent magnetic patches 22 are arranged at the axial middle position of the rotor shaft 21 . The plurality of driving permanent magnetic patches 22 are arranged in a ring shape and at equal intervals along the outer surface of the rotor shaft 21 , and the driving permanent magnetic patches 22 are arranged at the inner side position of the driving winding 3 .
[0036] In this embodiment, the driving permanent magnet patch 22 is fixedly mounted on the rotor shaft 21 by using a surface-mounted or embedded structure, which is convenient for assembly and installation.
[0037] The driving permanent magnetic patch 22 is used in conjunction with the driving winding 3. The driving winding 3 generates electromagnetic force and acts on the driving permanent magnetic patch 22. At this time, the driving permanent magnetic patch 22 generates torque and drives the rotor 2 to rotate.
[0038] Control permanent magnetic patches 23 are respectively arranged on both sides of the driving permanent magnetic patch 22 on the rotor shaft 21 . There are multiple control permanent magnetic patches 23 , and the multiple control permanent magnetic patches 23 are arranged in a ring shape and at equal intervals along the outer surface of the rotor shaft 21 .
[0039] In this embodiment, the plurality of control permanent magnetic patches 23 are fixedly mounted on the rotor shaft 21 in a surface-mounted or embedded structure, which is convenient for assembly and installation.
[0040] The control permanent magnetic patch 23 is used in conjunction with the control winding 4 , and the control permanent magnetic patch 23 is subjected to a static bias electromagnetic force applied by the control winding 4 , thereby controlling the displacement of the rotor 2 .
[0041] In this embodiment, due to the limitation of the structure of the control winding 4, the magnetic polarities of the control permanent magnetic patches 23 located on both sides of the driving permanent magnetic patches 22 are opposite and 180° flipped and symmetrical.
[0042] In this embodiment, the materials of the driving permanent magnetic patch 22 and the control permanent magnetic patch 23 are both permanent magnets.
[0043] In this embodiment, a sensor 6 is fixedly mounted on the short axis of the L-shaped core 41 at the center of a side surface close to the rotor 2 , and the sensor 6 is used to detect the position of the rotor 2 .
[0044] The rotor 2 is provided with protective bearings 5 near both ends thereof, and the protective bearings 5 are fixed on corresponding end covers 7 .
[0045] In this embodiment, when the rotor 2 is suspended and rotated normally, there is an air gap between the rotor 2 and the protective bearing 5, and the protective bearing 5 does not play a supporting role; the main function of the protective bearing 5 is to protect the motor structure. After the rotor 2 fails and falls, the rotor 2 contacts the protective bearing 5, and the protective bearing 5 absorbs the impact force and stops the rotation of the rotor 2 by friction, thereby preventing the impact force from damaging the motor structure.
[0046] The driving winding 3 and the control winding 4 are respectively arranged in the motor housing 1 , and the radial iron core 31 of the driving winding 3 and the L-shaped iron core 41 of the control winding 4 are respectively fixedly mounted on the inner wall of the housing 1 .
[0047] In this embodiment, the end covers 7 are arranged at both ends of the motor housing 1. The end covers 7 are used to place and fix the protective bearings 5 and to seal and protect the internal structure of the motor.
[0048] The operating principle of the bearingless motor is as follows: after the bearingless motor is powered on, the driving winding 3 generates a magnetic field mainly distributed along the radial direction of the motor. The direction of the current in the driving winding 3 changes, which changes the polarity of the magnetic field of the driving winding 3, generates a dynamic electromagnetic force acting on the driving permanent magnet patch 22 of the rotor 2, generates an electromagnetic torque, and drives the rotor 2 to rotate.
[0049] The control principle is as follows: after the bearingless motor is powered on, the control winding 4 generates a magnetic field distributed along the axial direction of the motor, and is transmitted by the L-shaped iron core 41 to the vicinity of the control permanent magnet patches 23 at both ends of the rotor 2, generating a static bias electromagnetic force for controlling the radial and axial displacements of the rotor 2; when the sensor 6 senses that the position of the rotor 2 is offset, the control winding 4 increases the current intensity, thereby enhancing the static bias electromagnetic force, and generates an electromagnetic force of a certain intensity between the control winding 4 and the control permanent magnet patches 23 on the rotor 2, thereby correcting the position of the rotor 2.
[0050] Since the control winding 4 is responsible for the radial and axial displacement control of the rotor 2 at the same time, the static bias electromagnetic force it generates mainly acts on the control permanent magnet patches 23 at both ends of the rotor 2 in the form of electromagnetic attraction. When the rotor 2 produces a radial offset to one side, the control winding 4 on the opposite side of the offset direction generates a radial pulling effect by enhancing the electromagnetic attraction, thereby correcting the radial position of the rotor 2.
[0051] When the rotor 2 produces axial displacement, all its control windings 4 generate axial pulling effect by enhancing electromagnetic attraction to correct the axial position of the rotor 2; for more complex rotor displacement situations, the rotor 2 can be controlled and the position corrected through the combined action of multiple control windings 4.
[0052] When the rotor 2 is suspended and rotating, there is an air gap between the rotor 2 and the protective bearing 5, and the protective bearing 5 does not play a supporting role; the main function of the protective bearing 5 is to protect the motor structure. After the rotor 2 fails and falls, the rotor 2 contacts the protective bearing 5, and the protective bearing 5 absorbs the impact force and stops the rotation of the rotor 2 by friction, thereby preventing the impact force from damaging the motor structure.
[0053] For those skilled in the art, according to the teachings of the present invention, without departing from the principles and spirit of the present invention, changes, modifications, substitutions and variations made to the implementation methods are still within the protection scope of the present invention.
Claims
1. A bearingless motor, comprising a housing (1), characterized in that: The motor stator is fixedly mounted in the housing (1), and end covers (7) are fixedly mounted at both ends of the housing (1), the end covers (7) seal and protect the internal structure of the housing (1), and a rotor (2) is movably mounted in the middle of the motor stator, and both ends of the rotor (2) respectively penetrate the corresponding end covers (7), and the two ends of the rotor (2) are rotatably connected to the end covers (7); The motor stator comprises a drive winding (3) and a control winding (4), and the iron cores of the drive winding (3) and the control winding (4) are fixedly connected as one body; The driving winding (3) comprises a plurality of radial iron cores (31), the plurality of radial iron cores (31) are annularly arranged and spaced apart, driving windings (32) are respectively mounted on the plurality of radial iron cores (31), the driving windings (32) are wound around the radial iron cores (31) as axes, and the winding direction of the driving windings (32) is the radial direction of the motor; The control winding (4) mainly comprises a plurality of groups of control iron cores, which are arranged in a ring shape and at intervals along the outer surface of the rotor (2), each group of control iron cores comprising two symmetrically arranged L-shaped iron cores (41), and the two L-shaped iron cores (41) are fixedly connected at one end close to each other; the two L-shaped iron cores (41) are arranged along the axial direction of the motor, and the other ends of the two L-shaped iron cores (41) are bent at 90 degrees in a direction close to the rotor (2); A control winding (42) is installed at the connection of the two L-shaped iron cores (41), and the control winding (42) is wound and arranged with the long axis of the L-shaped iron core (41) as an axis, and the winding direction of the control winding (42) is the axial direction of the motor.
2. A bearingless motor according to claim 1, characterized in that: The rotor (2) comprises a rotor shaft (21), a plurality of driving permanent magnetic patches (22) are arranged at an axial middle position of the rotor shaft (21), and the plurality of driving permanent magnetic patches (22) are arranged in a ring shape and at equal intervals along the outer surface of the rotor shaft (21), and the driving permanent magnetic patches (22) are arranged at an inner position of the driving winding (3).
3. A bearingless motor according to claim 2, characterized in that: Control permanent magnetic patches (23) are respectively arranged on both sides of the driving permanent magnetic patch (22) on the rotor shaft (21), there are a plurality of control permanent magnetic patches (23), and the plurality of control permanent magnetic patches (23) are respectively arranged in a ring shape and at equal intervals along the outer surface of the rotor shaft (21).
4. A bearingless motor according to claim 3, characterized in that: The control permanent magnetic patches (23) on both sides of the driving permanent magnetic patch (22) have opposite magnetic polarities and are 180° flipped and symmetrical.
5. A bearingless motor according to claim 4, characterized in that: The materials of the driving permanent magnetic patch (22) and the controlling permanent magnetic patch (23) are both permanent magnets.
6. A bearingless motor according to claim 5, characterized in that: The driving permanent magnetic patch (22) is fixedly mounted on the rotor shaft (21) by using a surface mount or embedded structure; and the control permanent magnetic patch (23) is fixedly mounted on the rotor shaft (21) by using a surface mount or embedded structure.
7. A bearingless motor according to claim 6, characterized in that: A sensor (6) is fixedly mounted on the short axis of the L-shaped iron core (41) at the center of a side surface close to the rotor (2), and the sensor (6) is used to detect the position of the rotor (2).