CN113595286A

CN113595286A - Car hub motor

Info

Publication number: CN113595286A
Application number: CN202110959507.XA
Authority: CN
Inventors: 李林; 姚学诗; 张兴华; 杨志勇; 李彦霞; 吕偿; 钟小华
Original assignee: Guangdong Baiyun University
Current assignee: Guangdong Baiyun University
Priority date: 2021-08-20
Filing date: 2021-08-20
Publication date: 2021-11-02

Abstract

The application relates to a car hub motor, include: a motor shaft; a bearing; the stator comprises a radial stator part and an axial stator part, the radial stator part is excited along the radial direction, the axial stator part is excited along the axial direction, the stator is fixedly connected with a motor shaft, and a stator core adopts a composite material structure of steel fiber reinforced epoxy resin; and the rotor comprises a radial rotor part and an axial rotor part, the radial rotor part and the radial stator part form a closed magnetic circuit, the axial rotor part and the axial stator part form a closed magnetic circuit, permanent magnets of the radial rotor part and the axial rotor part are distributed according to a Halbach array and are arranged as an outer rotor, and the outer rotor is connected with the motor shaft by a bearing. The hub motor has a bidirectional closed magnetic circuit, and is high in output torque density and power density.

Description

Car hub motor

Technical Field

The application relates to the technical field of driving motors, in particular to a car hub motor.

Background

The motor is an electromagnetic device for realizing electric energy conversion, and the driving torque generated by the motor can be used as a power source of an electric car or various machines.

With the development of motors in the directions of high efficiency, high speed, high power density, large torque density and miniaturization, the traditional motor also shows certain limitation, and has the problems of high heating effect and low driving efficiency.

Disclosure of Invention

Based on this, aiming at the problem that the traditional motor has high heating effect and low driving efficiency, the sedan hub motor with high torque density and high power density is needed to be provided.

The application provides a car wheel hub motor includes: a motor shaft, a bearing, a stator and a rotor; the stator comprises a radial stator part and an axial stator part, the radial stator part is excited along the radial direction, the axial stator part is excited along the axial direction, the stator is fixedly connected with a motor shaft, and a stator core adopts a composite material structure of steel fiber reinforced epoxy resin; the rotor comprises a radial rotor part and an axial rotor part, wherein the radial rotor part and the radial stator part form a closed magnetic circuit, the axial rotor part and the axial stator part form a closed magnetic circuit, permanent magnets of the radial rotor part and the axial rotor part are distributed according to a Halbach array and are arranged as outer rotors, and the outer rotors are connected with a motor shaft through bearings.

In one embodiment, the radial rotor part comprises two groups of radial permanent magnet groups, the two groups of radial permanent magnet groups are respectively positioned at the upper side and the lower side of the radial stator part, and each group of radial permanent magnets are distributed according to a Halbach array; the axial rotor part comprises two groups of axial permanent magnet groups, the two groups of axial permanent magnet groups are respectively positioned on the left side and the right side of the axial stator part, and the axial permanent magnets of each group are distributed according to a Halbach array.

In one embodiment, the magnetizing angle of each permanent magnet is changed by 45 degrees in sequence.

In one embodiment, the radial stator part comprises a radial iron core and an excitation winding, the axial stator part comprises an axial iron core and an excitation winding, and the axial iron core and the radial iron core are both made of steel fiber reinforced epoxy resin composite materials or steel fiber reinforced ceramic composite materials; wherein the volume percentage of the steel fiber is 40-80%.

In one embodiment, the surface of the steel fiber is coated with a copper plating layer.

In one embodiment, the permanent magnets on the radial rotor part and the axial rotor part of the rotor adopt Halbach arrays, and bidirectional magnetic fluxes are distributed in a sine mode respectively.

In one embodiment, the radial stator part further comprises a radial excitation winding, the axial stator part further comprises an axial excitation winding, the radial excitation winding and the axial excitation winding are independent coils wound by enameled wires and are formed by EPT904 epoxy glue or PUT120 polyurethane glue, the radial stator and the axial stator are formed by the excitation winding, a composite material iron core and resin, and the stator coil is externally connected with a three-phase alternating current power supply by using a hollow core shaft.

Above-mentioned car wheel hub motor through radial stator portion, axial stator portion, radial rotor portion and axial rotor portion whole, has constituted the two-way closed magnetic circuit that has radial magnetic circuit and axial magnetic circuit, and this motor has concentrated the advantage of axial magnetic circuit and radial magnetic circuit motor, and the permanent magnet of its radial rotor portion and axial rotor portion sets up to Halbach array and arranges, and it is big to set up this wheel hub motor output torque density above, and power density is high.

Drawings

Fig. 1 is a schematic cross-sectional structure diagram of an in-wheel motor in the embodiment of the present application.

100. A hub motor; 10. a motor shaft; 30. a stator; 31. an axial stator portion; 311. an axial core; 313. an axial excitation winding; 33. a radial stator portion; 331. a radial core; 333. a radial excitation winding; 50. a rotor; 52. an axial rotor portion; 522. an axial yoke; 524. an axial permanent magnet group; 54. a radial rotor portion; 542. a radial yoke; 544. radial permanent magnet groups.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

The hub motor and the vehicle of the present application will be described with reference to the accompanying drawings.

Fig. 1 is a schematic cross-sectional structure diagram of an in-wheel motor according to an embodiment of the present application. For the purpose of illustration, only the structures described in connection with the present application are illustrated in the drawings.

The in-wheel motor 100 disclosed in at least one embodiment of the present application includes a motor shaft 10, a bearing, a stator 30, and a rotor 50, and the motor generates a driving torque and can be used as a power source for a car or various machines. The stator 30 is fixed on the motor shaft 10, and the rotor 50 is rotatably connected to the motor shaft 10 by a bearing.

In some embodiments, the stator 30 includes an axial stator portion 31 and a radial stator portion 33, the axial stator portion 31 extending in an axial direction and having one end connected to the motor shaft 10, the axial stator portion 31 having the other end connected to the radial stator portion 33, and the radial stator portion 33 extending in a radial direction.

Further, the rotor 50 includes an axial rotor portion 52 and a radial rotor portion 54, one end of the axial rotor portion 52 is rotatably connected to the motor shaft 10, the axial rotor portion 52 is located on the left and right sides of the axial stator portion 31 along the axial direction of the motor shaft 10, the other end of the axial rotor portion 52 is connected to the radial rotor portion 54, and the radial rotor portion 54 is located on the upper and lower sides of the radial stator portion 33.

In this way, in the in-wheel motor 100, the axial stator portion 31, the radial stator portion 33, the axial rotor portion 52, and the radial rotor portion 54 form a bidirectional closed magnetic circuit having a radial magnetic circuit and an axial magnetic circuit as a whole, so that the advantages of the axial magnetic circuit and the radial magnetic circuit motor are integrated, and the torque density and the power density are high.

In some embodiments, axial rotor portion 52 includes an axial yoke iron 522 and radial rotor portion 54 includes a radial yoke iron 542. Further, one end of the axial yoke 522 is connected to the radial yoke 542, and the end of the axial yoke 522 away from the radial yoke 542 is rotatably connected to the motor shaft 10 by a bearing. In this way, the axial rotor portion 52 and the radial rotor portion 54 constitute the rotor 50, and the rotor 50 is rotatable with respect to the motor shaft 10.

Further, axial rotor portion 52 and radial rotor portion 54 all include a plurality of permanent magnets, and axial rotor portion 52's permanent magnet is installed on axial yoke 522, and radial rotor portion 54's permanent magnet is installed on radial yoke 542, and all arranges according to the Halbach array.

Specifically, in some embodiments, the axial rotor portion 52 includes two sets of axial permanent magnet sets 524, the two sets of axial permanent magnet sets 524 are respectively located on the left and right sides of the axial stator portion 31 along the axial direction of the motor shaft 10, and each axial permanent magnet set 524 includes a plurality of permanent magnets arranged in a Halbach array; the radial rotor portion 54 includes two sets of radial permanent magnet sets 544, the two sets of radial permanent magnet sets 544 are respectively located on the upper and lower sides of the radial stator portion 33 along the radial direction of the motor shaft 10, and each radial permanent magnet set 544 includes a plurality of permanent magnets arranged according to a Halbach array. Therefore, the magnetic field intensity can be improved, a sine-distributed air gap magnetic field can be obtained, the power density is high, and the torque density and the power density of the in-wheel motor 100 can be increased due to the increase of the air gap magnetic density.

Further, the magnetizing angle of each permanent magnet is changed by 45 degrees in turn. In this way, the electromagnetic torque and the output efficiency of the in-wheel motor 100 can be further improved by quantitative calculation.

In some embodiments, axial stator portion 31 includes an axial core 311, radial stator portion 33 includes a radial core 331, and both radial core 331 and axial core 311 are made of a steel fiber reinforced epoxy composite or a steel fiber reinforced ceramic composite. In this way, hysteresis loss, eddy current loss, and weight of the radial core 331 and the axial core 311 can be reduced, and further, heat generation effect can be reduced, output torque can be increased, and driving efficiency can be improved.

Furthermore, the volume ratio of the steel fibers in the radial iron core 331 and the axial iron core 311 is 40-80% so as to ensure the requirements of magnetic field intensity, heating effect, power density and torque density of the radial iron core 331 and the axial iron core 311. Further, the surface of the steel fiber is coated with the copper plating layer, which can further reduce hysteresis loss and eddy current loss of the stator 30.

In some embodiments, the flux of radial core 331 and axial core 311 are each distributed sinusoidally. So as to improve the magnetic field intensity of the closed magnetic circuit, increase the output power, improve the driving efficiency and enhance the control precision.

In some embodiments, the radial stator portion 33 further comprises a radial excitation winding 333, the radial excitation winding 333 wound on the radial core 331, and the axial stator portion 31 further comprises an axial excitation winding 313, the axial excitation winding 313 wound axially on the core 311. The radial excitation winding 333 and the axial excitation winding 313 are independent coils wound by enameled wires, and are formed by EPT904 epoxy glue sealing or PUT120 polyurethane glue sealing in an encapsulating way.

Further, the radial stator portion 33 and the axial stator portion 31 are formed by resin sealing of the field winding and the composite core.

In some embodiments, the motor shaft 10 has a hollow structure, and the stator coil may externally connect a three-phase ac power source using the hollow structure of the motor shaft 10.

Further, the resin potting layer may be an epoxy potting adhesive or a polyurethane potting adhesive. Specifically, in some embodiments, the resin encapsulation layer may be an EPT904 epoxy encapsulant, a PUT120 polyurethane encapsulant, or a ceramic matrix composite molding to reduce the heating effect, hysteresis loss, and eddy current loss of the stator 30. It is to be understood that the above description is intended to be illustrative only and is not intended to be limiting.

In some embodiments, the in-wheel motor 100 further includes a transformer disposed at an end of the motor shaft 10 and an encoder disposed at an end of the transformer away from the motor shaft 10 and connected to the transformer. Specifically, in practical applications, the encoder changes the rotating magnetic field of the stator 30 through the control transformer, so as to achieve the axial braking, acceleration, and deceleration functions of the rotor 50.

As the same concept of the present application, there is also provided a car including the in-wheel motor 100 and a wheel as described above, the in-wheel motor 100 driving the wheel. In practical application, the outer shell of the outer rotor 50 is mounted on the tire of a vehicle, and the car has the advantages of large output torque, strong and stable power, low heating effect, light weight and simple assembly.

The stator 30 of the in-wheel motor 100 has a radial magnetic circuit and a bidirectional closed magnetic circuit of an axial magnetic circuit, and the permanent magnets of the axial rotor part 52 and the radial rotor part 54 of the rotor 50 are arranged according to a Halbach array, so that the in-wheel motor 100 has the advantages of large torque density, high power density and high output efficiency.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A car hub motor, comprising: a motor shaft, a bearing, a stator and a rotor; the stator comprises a radial stator part and an axial stator part, the radial stator part is excited along the radial direction, the axial stator part is excited along the axial direction, the stator is fixedly connected with a motor shaft, and a stator core adopts a composite material structure of steel fiber reinforced epoxy resin; the rotor comprises a radial rotor part and an axial rotor part, wherein the radial rotor part and the radial stator part form a closed magnetic circuit, the axial rotor part and the axial stator part form a closed magnetic circuit, permanent magnets of the radial rotor part and the axial rotor part are distributed according to a Halbach array and are arranged as outer rotors, and the outer rotors are connected with a motor shaft through bearings.

2. The car hub motor of claim 1, wherein the radial rotor portion comprises two groups of radial permanent magnet sets, the two groups of radial permanent magnet sets are respectively positioned at the upper side and the lower side of the radial stator portion, and each group of radial permanent magnets are distributed according to a Halbach array; the axial rotor part comprises two groups of axial permanent magnet groups, the two groups of axial permanent magnet groups are respectively positioned on the left side and the right side of the axial stator part, and the axial permanent magnets of each group are distributed according to a Halbach array.

3. The car hub motor of claim 2, wherein the magnetizing angle of each permanent magnet is changed by 45 degrees in turn.

4. The car hub motor of claim 1, wherein the radial stator portion comprises a radial core and an excitation winding, the axial stator portion comprises an axial core and an excitation winding, and the axial core and the radial core are both made of a steel fiber reinforced epoxy resin composite material or a steel fiber reinforced ceramic composite material; wherein the volume percentage of the steel fiber is 40-80%.

5. The car hub motor of claim 4, wherein the surface of the steel fibers is coated with a copper plating layer.

6. The car hub motor of claim 1, wherein the permanent magnets on the radial rotor part and the axial rotor part of the rotor are Halbach arrays, and the bidirectional magnetic flux is distributed sinusoidally.

7. The car hub motor of claim 1, wherein the radial stator portion further comprises a radial winding, the axial stator portion further comprises an axial winding, the radial winding and the axial winding are independent coils wound by enameled wires, the coils are formed by EPT904 epoxy glue or PUT120 polyurethane glue, the radial stator and the axial stator are formed by an excitation winding, a composite material iron core and resin, and the stator coil is externally connected with a three-phase alternating current power supply by using a hollow core shaft.