Tapered bearingless magnetic flux switching motor with five-degree-of-freedom magnetic suspension rotor

Abstract

The invention relates to a rotor five-degree-of-freedom magnetic suspension conical bearingless magnetic flux switching motor, which comprises a rotating shaft, and is characterized in that the rotating shaft is sequentially provided with a front conical bearingless magnetic flux switching motor and a rear conical bearingless magnetic flux switching motor along the axial direction of the rotating shaft from front to back; a machine shell is arranged on the periphery of the front conical bearingless magnetic flux switching motor and the periphery of the rear conical bearingless magnetic flux switching motor, and the front conical bearingless magnetic flux switching motor and the rear conical bearingless magnetic flux switching motor each comprise a conical rotor iron core and a conical stator iron core which are sequentially arranged in the radial direction of the rotating shaft. The conical rotor iron core is installed on the rotating shaft, and the conical stator iron core is installed on the machine shell. The motor is reasonable in structural design, the axial space can be saved, and the power density of the motor is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of motor manufacturing, and in particular to a conical bearingless flux switching motor with a rotor having five degrees of freedom and magnetic suspension. Background Art

[0002] The rotor five-degree-of-freedom active magnetic suspension bearingless flux switching motor realizes the complete suspension of the rotor in space, and has a wide range of applications in air compressors, CNC machine tools, biomedicine and other occasions that require maintenance-free, high-speed, and high-cleanliness. At present, the rotor five-degree-of-freedom active magnetic suspension bearingless flux switching motor faces the following difficulties: the axial suspension requires the additional installation of an axial magnetic bearing device, resulting in excessive axial length, limited power density and maximum speed; the passive design of the air gap bias magnetic field is low, which seriously limits the development of the motor into the large-capacity field. Summary of the invention

[0003] The object of the present invention is to provide a conical bearingless flux switching motor with a five-degree-of-freedom rotor magnetic suspension, the motor has a reasonable structural design, can save axial space, and effectively improve the power density of the motor.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a conical bearingless flux switching motor with a five-degree-of-freedom rotor magnetic suspension, comprising a rotating shaft, wherein a front conical bearingless flux switching motor and a rear conical bearingless flux switching motor are sequentially arranged in the axial direction front and back, and a machine casing is arranged on the outer periphery of the front conical bearingless flux switching motor and the rear conical bearingless flux switching motor, and the front conical bearingless flux switching motor and the rear conical bearingless flux switching motor both comprise a conical rotor core and a conical stator core sequentially arranged in the radial direction of the rotating shaft, the conical rotor core is installed on the rotating shaft, and the conical stator core is installed on the machine casing.

[0005] Furthermore, the front conical bearingless flux switching motor and the rear conical bearingless flux switching motor have the same structure and are symmetrically arranged front to back along the axial direction; the inner radius of the conical stator core of the front conical bearingless flux switching motor gradually decreases from front to back along the axial direction, and the outer radius of the conical rotor core gradually increases from front to back along the axial direction; the inner radius of the conical stator core of the rear conical bearingless flux switching motor gradually increases from front to back along the axial direction, and the outer radius of the conical rotor core gradually decreases from front to back along the axial direction.

[0006] Furthermore, the rotating shaft and the conical rotor core constitute the rotor part of the corresponding conical bearingless flux switching motor, and the conical rotor core is fixedly connected to the rotating shaft; the conical stator core is provided with a power winding, an excitation winding and a high-coercive force permanent magnet, and the conical stator core, the power winding, the excitation winding and the high-coercive force permanent magnet constitute the stator part of the corresponding conical bearingless flux switching motor, and the conical stator core is fixedly connected to the casing.

[0007] Furthermore, the conical stator core is composed of stator core units arranged in a circumferential array, the stator core units are of a U-shaped structure, a core slot is provided in the inner middle of the stator core unit, the core slot of the stator core unit faces the conical rotor core, and permanent magnet slots are provided between adjacent stator core units; high coercive force permanent magnets are embedded between the side walls of adjacent stator core units, that is, in each permanent magnet slot, and adjacent high coercive force permanent magnets are alternately magnetized along the tangential direction; power windings are wound between the core slots of adjacent stator core units; and excitation windings are wound between adjacent permanent magnet slots.

[0008] Furthermore, the power winding and the excitation winding are both concentrated windings.

[0009] Furthermore, the conical stator core is composed of 12 stator core units arranged in a circumferential array, and the stator part is correspondingly provided with 12 high coercive force permanent magnets; the stator part is provided with a six-phase power winding, and two power windings of the same phase are arranged with two power windings of other phases spaced apart.

[0010] Furthermore, the number of teeth of the conical rotor core is 10.

[0011] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides a conical bearingless flux switching motor with a rotor having five degrees of freedom magnetic suspension, the structural design of which is novel and reasonable, and the structural design of the front and rear conical bearingless flux switching motor is adopted to realize the five-degree-of-freedom magnetic suspension of the motor rotor; the stator inner diameter (rotor outer diameter) of the motor changes linearly along the axial direction, and the air gap permanent magnet flux changes linearly along the axial direction. After the control flux generated by the suspension current component is superimposed, the axial flux changes significantly and controllably, and the rotor can obtain a stable and controllable axial suspension force, which can not only replace the function of the axial magnetic bearing in the traditional rotor five-degree-of-freedom active magnetic suspension motor, but also the conical structure can save a lot of axial space and simplify the shaft structure, the excitation winding can realize the active adjustment of the air gap bias magnetic field, and the topology of the conical stator structure combined with the excitation winding can effectively improve the power density of the motor, improve the motor operation mode, and provide an opportunity for the motor to develop into a high-speed and large-capacity field. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 11 is a schematic diagram of an axial cross-sectional structure of a conical bearingless flux switching motor with a rotor having five degrees of freedom and magnetic suspension according to an embodiment of the present invention; Figure 2 1 is a schematic diagram of a radial cross-sectional structure of a conical bearingless flux switching motor with a rotor having five degrees of freedom and magnetic suspension according to an embodiment of the present invention; Figure 3 is a typical winding connection diagram of the stator part in an embodiment of the present invention; Figure 4 1 is a schematic diagram of a disassembled state of a single conical bearingless flux switching motor according to an embodiment of the present invention; Figure 5 It is a schematic diagram of the embedded winding of the power winding and the excitation winding in an embodiment of the present invention.

[0013] In the figure: 1- housing; 2- shaft; 3- conical rotor core; 4- conical stator core; 5- core slot; 6- permanent magnet slot; 7- power winding; 8- excitation winding; 9- high coercive force permanent magnet; 10- front conical bearingless flux switching motor; 11- rear conical bearingless flux switching motor. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0015] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0016] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0017] like Figure 1-5As shown, this embodiment provides a conical bearingless flux switching motor with a five-degree-of-freedom rotor magnetic suspension, including a rotating shaft 2, on which a front conical bearingless flux switching motor 10 and a rear conical bearingless flux switching motor 11 are sequentially arranged front and back along the axial direction thereof, and a casing 1 is arranged on the outer periphery of the front conical bearingless flux switching motor 10 and the rear conical bearingless flux switching motor 11, and the front conical bearingless flux switching motor 10 and the rear conical bearingless flux switching motor 11 both include a conical rotor core 3 and a conical stator core 4 sequentially arranged along the radial direction of the rotating shaft, the conical rotor core 3 is mounted on the rotating shaft 2, and the conical stator core 4 is mounted on the casing 1; the conical stator core 4 is provided with a power winding 7, an excitation winding 8 and a high coercive force permanent magnet 9.

[0018] In this embodiment, the front conical bearingless flux switching motor 10 and the rear conical bearingless flux switching motor 11 are two conical bearingless flux switching motors with completely identical parameters and structures, and the two conical bearingless flux switching motors are symmetrically arranged front and back along the axial direction. Among them, the inner radius of the conical stator core of the front conical bearingless flux switching motor 10 gradually decreases from front to back along the axial direction, and the outer radius of the conical rotor core gradually increases from front to back along the axial direction; the inner radius of the conical stator core of the rear conical bearingless flux switching motor 11 gradually increases from front to back along the axial direction, and the outer radius of the conical rotor core gradually decreases from front to back along the axial direction.

[0019] A rectangular coordinate system is established with the axial direction of the rotating shaft as the z direction. The front conical bearingless flux switching motor 10 has radial degrees of freedom: x1, y1; the rear conical bearingless flux switching motor 11 has radial degrees of freedom: x2, y2; the axial 1 degree of freedom z is decomposed into two parts: 0.5 degrees of freedom z+ along the axial positive direction and 0.5 degrees of freedom z- along the axial negative direction.

[0020] The present invention adopts the structural design of front and rear conical bearingless flux switching motors to realize five-degree-of-freedom magnetic suspension of the rotor, and the five degrees of freedom are: 2.5 degrees of freedom x1, y1, z+ provided by the front conical bearingless flux switching motor 10, and 2.5 degrees of freedom x2, y2, z- provided by the rear conical bearingless flux switching motor 11.

[0021] In this embodiment, the rotating shaft 2 and the conical rotor core 3 constitute the rotor part of the corresponding conical bearingless flux switching motor, and the conical rotor core 3 is fixedly connected to the rotating shaft 2. The conical stator core 4, the power winding 7, the excitation winding 8 and the high coercive force permanent magnet 9 constitute the stator part of the corresponding conical bearingless flux switching motor, and the conical stator core 4 is fixedly connected to the housing 1.

[0022] The conical stator core 4 is composed of stator core units arranged in a circumferential array. The stator core unit is a U-shaped structure. A core slot 5 is provided in the middle of the inner side of the stator core unit. The core slot 5 of the stator core unit faces the conical rotor core 3. There are permanent magnet slots 6 between adjacent stator core units. High coercive force permanent magnets 9 are embedded between the side walls of adjacent stator core units, that is, in each permanent magnet slot 6. Adjacent high coercive force permanent magnets 9 are alternately magnetized along the tangential direction of rotor rotation. Power windings 7 are wound between the core slots 5 of adjacent stator core units. Excitation windings 8 are wound between adjacent permanent magnet slots 6. In this embodiment, the power windings 7 and the excitation windings 8 are both concentrated windings.

[0023] In this embodiment, the conical stator core 4 is composed of 12 stator core units arranged in a circumferential array, and the stator part is correspondingly provided with 12 high coercive force permanent magnets 9. The stator part is provided with a six-phase power winding, and two power windings of the same phase are arranged with two power windings of other phases spaced apart. The number of teeth of the conical rotor core is 10.

[0024] The typical winding connection diagram of the stator part in this embodiment is as follows: Figure 3 As shown. The six-phase power windings are: A phase, B phase, C phase, D phase, E phase, and F phase. The six-phase power winding modulates the air gap magnetic field by injecting a composite power winding current containing a torque current component and a suspension current component, and can output a stable suspension force and electromagnetic torque. The single-phase excitation winding is the L phase. When the L phase is fed with a positive DC current, the total air gap magnetic flux of the motor is enhanced, and the output capacity of the motor is significantly improved.

[0025] In this embodiment, the high coercive force permanent magnet 9 is made of NdFeB material.

[0026] In this embodiment, the housing 1 and the rotating shaft 2 are both made of non-magnetic conductive materials.

[0027] In this embodiment, the front conical bearingless flux switching motor 10 and the rear conical bearingless flux switching motor 11 are connected through the housing 1 .

[0028] In this embodiment, the housing 1 is an axially extending annular structure, and the rotating shaft 2 is an axially extending cylindrical structure.

[0029] The conical bearingless flux switching motor with five-degree-of-freedom rotor magnetic suspension provided by the present invention has a novel structure and a reasonable design. The five-degree-of-freedom magnetic suspension of the motor rotor is realized by arranging the front and rear conical bearingless flux switching motor structures. The stator and rotor conical structures and the arrangement of the excitation windings effectively improve the compactness, power density and maximum speed of the motor, thereby promoting the development of the five-degree-of-freedom rotor magnetic suspension bearingless flux switching motor towards the high-speed and large-capacity fields.

[0030] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by one-piece molding using a casting process) (except when it is obviously impossible to use an one-piece molding process).

[0031] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in the present invention include states or shapes that are approximate, similar, or close to them.

[0032] Any component provided by the present invention may be assembled from a plurality of separate components, or may be a separate component manufactured by an integral forming process.

[0033] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A conical bearingless flux switching motor with a five-degree-of-freedom rotor magnetic suspension, characterized in that: The invention comprises a rotating shaft, wherein a front conical bearingless flux switching motor and a rear conical bearingless flux switching motor are sequentially arranged along the axial direction thereof; a casing is arranged on the outer periphery of the front conical bearingless flux switching motor and the rear conical bearingless flux switching motor; the front conical bearingless flux switching motor and the rear conical bearingless flux switching motor both comprise a conical rotor core and a conical stator core sequentially arranged along the radial direction of the rotating shaft; the conical rotor core is mounted on the rotating shaft, and the conical stator core is mounted on the casing.

2. A conical bearingless flux switching motor with a rotor having five degrees of freedom and magnetic suspension according to claim 1, characterized in that: The front conical bearingless flux switching motor has the same structure as the rear conical bearingless flux switching motor and is symmetrically arranged front to back along the axial direction; the inner radius of the conical stator core of the front conical bearingless flux switching motor gradually decreases from front to back along the axial direction, and the outer radius of the conical rotor core gradually increases from front to back along the axial direction; the inner radius of the conical stator core of the rear conical bearingless flux switching motor gradually increases from front to back along the axial direction, and the outer radius of the conical rotor core gradually decreases from front to back along the axial direction.

3. The conical bearingless flux switching motor with five-degree-of-freedom magnetic suspension of the rotor according to claim 1, characterized in that: The rotating shaft and the conical rotor core constitute the rotor part of the corresponding conical bearingless flux switching motor, and the conical rotor core is fixedly connected to the rotating shaft; the conical stator core is provided with a power winding, an excitation winding and a high-coercive force permanent magnet, and the conical stator core, the power winding, the excitation winding and the high-coercive force permanent magnet constitute the stator part of the corresponding conical bearingless flux switching motor, and the conical stator core is fixedly connected to the casing.

4. A conical bearingless flux switching motor with a rotor having five degrees of freedom and magnetic suspension according to claim 3, characterized in that: The conical stator core is composed of stator core units arranged in a circumferential array. The stator core unit is a U-shaped structure. A core slot is opened in the middle of the inner side of the stator core unit. The core slot of the stator core unit faces the conical rotor core. There are permanent magnet slots between adjacent stator core units. High coercive force permanent magnets are embedded between the side walls of adjacent stator core units, that is, in each permanent magnet slot, and adjacent high coercive force permanent magnets are alternately magnetized along the tangential direction. Power windings are wound between the core slots of adjacent stator core units; and excitation windings are wound between adjacent permanent magnet slots.

5. The conical bearingless flux switching motor with five-degree-of-freedom rotor magnetic suspension according to claim 4, characterized in that: The power winding and the excitation winding both adopt concentrated windings.

6. The conical bearingless flux switching motor with five-degree-of-freedom rotor magnetic suspension according to claim 4, characterized in that: The conical stator core is composed of 12 stator core units arranged in a circumferential array, and the stator part is correspondingly provided with 12 high coercive force permanent magnets; the stator part is provided with a six-phase power winding, and two power windings of the same phase are arranged with two power windings of other phases spaced apart.

7. A conical bearingless flux switching motor with a rotor having five degrees of freedom and magnetic suspension according to claim 6, characterized in that: The number of teeth of the conical rotor core is 10.

Images