阅读说明：本技术 一种集成磁流变液制动结构的轴向磁通永磁电机 (Axial flux permanent magnet motor integrated with magnetorheological fluid braking structure ) 是由 徐炜 胡友康 王激尧 秦岭 张翼骋 于 2021-08-11 设计创作，主要内容包括：本发明公开一种集成磁流变液制动结构的轴向磁通永磁电机,属于轴向磁通永磁电机、磁流变液制动技术领域,包括第一与第二定子、转子盘、磁流变液、第三定子、旋转轴封盖,第一与第二定子沿轴向设置在转子盘的两侧,转子盘的外侧套设有第三定子,磁流变液填充于第三定子与转子盘的外制动壁形成的柱状间隙中,旋转轴封盖设置于第三定子的两侧用于密封磁流变液；本发明克服了传统制动器结构复杂,存在响应迟滞、制动距离长、转矩脉动的问题,同时通过电机集成制动器的设计显著减小电机与制动器组成关节模块时的轴向尺寸,极大地拓宽了关节模块或由关节模块组成的机械臂的安装空间与应用场合。(The invention discloses an axial magnetic flux permanent magnet motor integrated with a magnetorheological fluid braking structure, which belongs to the technical field of axial magnetic flux permanent magnet motors and magnetorheological fluid braking, and comprises a first stator, a second stator, a rotor disc, magnetorheological fluid, a third stator and a rotating shaft sealing cover, wherein the first stator and the second stator are axially arranged at two sides of the rotor disc; the invention overcomes the problems of complex structure, response delay, long braking distance and torque pulsation of the traditional brake, and simultaneously, the axial size of the motor and the brake when forming a joint module is obviously reduced through the design of the motor integrated brake, thereby greatly expanding the installation space and the application occasions of the joint module or a mechanical arm formed by the joint module.)

1. An axial flux permanent magnet motor of integrated magnetorheological suspensions braking structure which characterized in that: the magnetorheological fluid generator comprises a first stator (1), a second stator (2), a rotor disc (3), magnetorheological fluid (4), a third stator (5) and a rotating shaft cover (6);

the first stator (1) comprises a first stator core (11) and a first stator winding (12) arranged on the first stator core (11), the second stator (2) comprises a second stator core (21) and a second stator winding (22) arranged on the second stator core (21), the third stator (5) comprises a third stator core (51) and a third stator winding (52) arranged on the third stator core (51), the third stator core (51) is provided with stator teeth (511), the rotor disc (3) comprises an inner rotor (31), an axially magnetized permanent magnet (32) embedded in the inner rotor (31) and an outer braking wall (33) sleeved outside the inner rotor (31), the outer braking wall (33) and the inner rotor (31) are mechanically connected through a plurality of T-shaped structures (331), and the rotating shaft sealing cover (6) comprises a shaft sealing cover (61), an O-shaped sealing ring (62) is arranged on the shaft sealing cover (61);

the first stator (1) and the second stator (2) are identical in structure, the first stator (1) and the second stator (2) are respectively arranged on two sides of the rotor disc (3) in the axial direction and are coaxial with the rotor disc (3), the third stator (5) is arranged on the outer side of the outer braking wall (33) in the radial direction and coaxially surrounds the outer braking wall (33), the outer braking wall (33) of the rotor disc (3) is made of a material with a mechanical strength and a radial magnetic permeability characteristic, the inner rotor (31) is made of a non-magnetic permeability material with a high mechanical strength, the axially magnetized permanent magnet (32) is embedded into the inner rotor (31) in the axial direction, the arrangement layout mode of the axially magnetized permanent magnet (32) is an 'SNS' layout, the magnetorheological fluid (4) is filled in a columnar gap formed by the third stator (5) and the outer braking wall (33), and the magnetorheological fluid (4) is sealed through rotary shaft sealing covers (6) arranged on two sides of the third stator (5).

2. The axial flux permanent magnet motor of an integrated magnetorheological fluid braking structure according to claim 1, wherein the first stator (1), the second stator (2) and the axially magnetized permanent magnet (32) form an axial magnetic loop and generate an axial rotating magnetic field, the third stator (5), the magnetorheological fluid (4) and the outer braking wall (33) form a radial magnetic loop, and the strength of the radial magnetic field is determined by the excitation current of the third stator core (51).

3. The axial flux permanent magnet motor of an integrated magnetorheological fluid brake structure according to claim 1 or 2, wherein the third stator cores (51) are all in-phase windings, and the third stator cores (51) are wound in a manner that the current directions of adjacent windings are opposite.

4. The axial flux permanent magnet motor with an integrated magnetorheological fluid braking structure according to claim 1, wherein the T-shaped structure (331) is formed by joining a T-shaped convex part of the inner rotor (31) and a T-shaped groove part of the outer braking wall (33), and the T-shaped structure (331) is circumferentially distributed with the inner rotor (31) and the outer braking wall (33) at the same axis and the same included angle.

Technical Field

The invention belongs to the technical field of axial flux permanent magnet motors and magnetorheological fluid braking, and particularly relates to an axial flux permanent magnet motor integrated with a magnetorheological fluid braking structure.

Background

An axial flux permanent magnet motor is also called a disc type permanent magnet motor, an air gap is in a plane shape, and an air gap magnetic field is distributed along the axial direction. Different from the traditional radial flux permanent magnet motor, the axial flux permanent magnet motor has the advantages of short axial size, high efficiency, high power density and the like, and is widely concerned and paid attention to the fields of wind power generation, electric automobiles, aerospace, flywheel energy storage and the like. The magnetorheological fluid is a novel intelligent material, can generate a rheological effect under the action of a magnetic field, and is changed into a solidified body with extremely high viscosity and shear stress from Newtonian fluid through a chaining effect within millisecond time. The magneto-rheological process has the advantages of quick response, reversibility, low energy consumption, strong adaptability and the like.

The brake, also called brake, is an industrial device that can realize speed reduction, brake or brake position maintenance of a working device by generating brake torque, and is widely applied to the fields of mechanical arms, electric vehicles, industrial servo systems and the like. With the recent national arrangement of related industries, the performance requirements for response, stability, and the like of the brake device in the industry are gradually increasing. Under the current demand, the structural design of the traditional braking system is increasingly complex, the defects of response delay, long braking distance, torque pulsation and the like exist, and the actual braking effect is often poor. On the basis, researchers put forward the concept of the magnetorheological fluid brake, and the core concept is to provide braking torque by the principle that the rheological property of the magnetorheological fluid changes along with the rapid change of a magnetic field. The braking torque of the magnetorheological fluid brake can generate a variable external excitation field by adjusting the winding excitation current, so that continuous and real-time control is realized, and the magnetorheological fluid brake has the advantages of simple structure, quick response, convenience in control, high stability and the like.

However, the traditional brake or the magnetorheological fluid brake adopts a structure that the motor and the brake are independent, and the motor and the brake are connected in series to form a joint module for use. The traditional scheme enables the integral axial size of the combined joint module to be remarkably increased, and greatly limits the installation space and application occasions of a single joint module or a mechanical arm formed by the single joint module, so that an integrated design scheme of an axial magnetic flux permanent magnet motor and a magnetorheological fluid brake is necessary.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide an axial flux permanent magnet motor integrated with a magnetorheological fluid braking structure, which overcomes the problems of complicated structure, response delay, long braking distance and torque pulsation of the traditional brake, and simultaneously solves the problems that the whole axial size of a joint module formed by combining a motor and the brake in the traditional scheme is remarkably increased, and the installation space and the application occasion of the joint module or a mechanical arm formed by combining the joint module and the brake are greatly limited.

The purpose of the invention can be realized by the following technical scheme:

an axial flux permanent magnet motor integrated with a magnetorheological fluid braking structure comprises a first stator, a second stator, a rotor disc, magnetorheological fluid, a third stator and a rotating shaft sealing cover;

the rotor disc comprises an inner rotor, an axially magnetized permanent magnet embedded into the inner rotor and an outer braking wall sleeved on the outer side of the inner rotor, the outer braking wall is mechanically connected with the inner rotor through a plurality of T-shaped structures, the rotating shaft sealing cover comprises a shaft sealing cover, and an O-shaped sealing ring is arranged on the shaft sealing cover;

the structure of the first stator is the same as that of the second stator, the first stator and the second stator are respectively arranged on two sides of the rotor disc along the axial direction and are coaxial with the rotor disc, the third stator is arranged on the outer side of the outer braking wall along the radial direction and coaxially surrounds the outer braking wall, the outer braking wall of the rotor is made of a material with the radial magnetic permeability characteristic of mechanical strength, the inner rotor is made of a non-magnetic conductive material with high mechanical strength, the axially magnetized permanent magnets are embedded into the inner rotor along the axial direction, the arrangement layout mode of the axially magnetized permanent magnets is an SNS layout, the magnetorheological fluid is filled in a cylindrical gap formed by the third stator and the outer braking wall, and the rotary shaft sealing covers are arranged on two sides of the third stator and are used for sealing the magnetorheological fluid.

Furthermore, the first stator, the second stator and the axially magnetized permanent magnet form an axial magnetic loop and generate an axial rotating magnetic field, the third stator, the magnetorheological fluid and the outer brake wall form a radial magnetic loop, and the strength of the radial magnetic field is determined by the exciting current of a third stator winding.

Furthermore, the third stator windings are all in-phase windings, and the third stator windings are wound in a mode that current directions of adjacent windings are opposite.

Furthermore, a plurality of T-shaped structures between the inner rotor and the outer braking wall are formed by connecting a T-shaped protruding part of the inner rotor and a T-shaped groove part of the outer braking wall, and the T-shaped structures, the inner rotor and the outer braking wall are coaxial and are distributed in a circumferential mode with equal included angles.

The invention has the beneficial effects that:

1. the invention overcomes the problems of complicated structure, delayed response, long braking distance and torque pulsation of the traditional brake. The invention brakes the motor by the shear stress generated after the rheological property of the magnetorheological fluid is changed sharply under the action of the magnetic field, can realize braking response within millisecond time, accurately adjusts the braking torque of the magnetorheological fluid by controlling the radial exciting current, and has simple control and quick response.

2. Compared with the scheme that a typical motor series brake forms a joint module, the magnetorheological fluid braking structure and the axial flux permanent magnet motor are integrated into a whole, and the motor braking is realized by using a radial magnetic field, so that the whole joint module has smaller axial size, and the installation space and application occasions of a single joint module or a mechanical arm formed by the single joint module are greatly widened.

Drawings

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

FIG. 1 is an exploded view of an axial flux permanent magnet motor incorporating a magnetorheological fluid braking configuration according to the present invention;

FIG. 2 is a schematic view of a T-shaped structure connecting the inner rotor and the outer braking wall of the present invention;

FIG. 3 is a schematic view of a radial magnetic field loop in a magnetorheological fluid braking mode according to the present invention;

fig. 4 is a schematic view of a third stator core according to the present invention;

FIG. 5 is a cross-sectional view of the rotary shaft cover of the present invention;

fig. 6 is an assembly schematic diagram of an axial flux permanent magnet motor integrated with a magnetorheological fluid braking structure according to the present invention.

The reference numbers in the figures illustrate:

1. a first stator; 2. a second stator; 3. a rotor disk; 4. magnetorheological fluid; 5. a third stator; 6. a rotating shaft sealing cover; 11. a first stator core; 12. a first stator winding; 21. a second stator core; 22. a second stator winding; 51. a third stator core; 52. a third stator winding; 31. an inner rotor; 32. an axially magnetized permanent magnet; 33. an outer braking wall; 61. a shaft seal cover; 62. an O-shaped sealing ring; 331. a T-shaped structure; 511. and stator teeth.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "opening," "upper," "lower," "thickness," "top," "middle," "length," "inner," "peripheral," and the like are used in an orientation or positional relationship that is merely for convenience in describing and simplifying the description, and do not indicate or imply that the referenced component or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present invention.

An axial flux permanent magnet motor integrated with a magnetorheological fluid braking structure is shown in fig. 1 and 6 and comprises a first stator 1, a second stator 2, a rotor disc 3, magnetorheological fluid 4, a third stator 5 and a rotating shaft cover 6. The first stator 1 includes a first stator core 11 and a first stator winding 12 disposed on the first stator core 11; the second stator 2 includes a second stator core 21 and a second stator winding 22 provided on the second stator core 21; the third stator 5 includes a third stator core 51 and a third stator winding 52 provided on the third stator core 51; the rotor disc 3 comprises an inner rotor 31, an axially magnetized permanent magnet 32 embedded in the inner rotor 31, and an outer braking wall 33 sleeved outside the inner rotor 31, wherein the outer braking wall 33 and the inner rotor 31 are connected through a plurality of T-shaped structures 331; the rotating shaft sealing cover 6 comprises a shaft sealing cover 61, and an O-shaped sealing ring 62 is arranged on the shaft sealing cover 61; the outer braking wall 33 of the rotor disc 3 is made of a material with mechanical strength and radial magnetic permeability, and various types of silicon steel materials can be selected for a stator iron core part in the design of the motor; the inner rotor 31 is made of a non-magnetic material with high mechanical strength, for example, 40 steel series stainless steel or solid copper with high mechanical strength can be selected, and the axially magnetized permanent magnet 32 is matched with the first stator winding 12 and the second stator winding 22 in pole slots with ten poles and twelve slots.

The first stator 1 and the second stator 2 have the same structure, and the first stator 1 and the second stator 2 are respectively arranged on two sides of the rotor disc 3 along the axial direction and are coaxial with the rotor disc 3; the third stator 5 is arranged radially outside the outer braking wall 33 and coaxially surrounds the outer braking wall 33; the magnetorheological fluid 4 is filled in a columnar gap formed by the third stator 5 and the outer braking wall 33, and the rotating shaft sealing covers 6 are arranged on two sides of the third stator 5 and used for sealing the magnetorheological fluid 4; the arrangement of the permanent magnets 32 which are axially magnetized adopts the arrangement layout of SNS and is embedded into the inner rotor 31 along the axial direction; the first stator 1, the second stator 2 and the axially magnetized permanent magnet 32 form an axial magnetic loop and generate an axial rotating magnetic field, the third stator 5, the magnetorheological fluid 4 and the outer brake wall 33 form a radial magnetic loop, the strength of the radial magnetic field is determined by the exciting current of the third stator winding 52, the magnetorheological fluid 4 generates shear stress to brake the rotor disc 3 through the magnetization of the radial magnetic field, and the brake and the braking of the motor are realized; the third stator windings 52 are all in-phase windings, and the third stator windings 52 are wound in a mode that the current directions of adjacent windings are opposite; the first stator 1, the second stator 2 and the axially magnetized permanent magnet 32 on the rotor disc 3 form an axial magnetic loop to generate an axial rotating magnetic field, and the third stator 5, the magnetorheological fluid 4 and the outer brake wall 33 of the rotor disc 3 form a radial magnetic loop. When the axial flux permanent magnet motor works in a non-braking mode, three-phase current in the same sequence is injected into the first stator winding 12 and the second stator winding 22 to generate an axial rotating magnetic field to rotate the rotor disc 3, correspondingly, the same-phase current is not injected into the third stator winding 52, a radial magnetic field is not generated, the magnetorheological fluid 4 is in a Newtonian fluid state, at the moment, damping hardly exists between the outer braking wall 33 and the magnetorheological fluid 4, when the axial flux permanent magnet motor needs braking, the three-phase current in the same sequence is cancelled from the first stator winding 12 and the second stator winding 22, the axial rotating magnetic field disappears, the rotor disc 3 continues to rotate due to inertia, meanwhile, the single-phase current is injected into the third stator winding 52 to generate a radial magnetic field, the magnetorheological fluid 4 in a radial magnetic field loop is instantaneously (millisecond level) magnetized to be rheological and enter a condensation state, the shear stress is generated by the magnetorheological fluid 4 in the condensation state, and the shear stress is generated on the outer braking wall 33 of the rotor disc 3 in the rotation inertia state And braking, and stopping the axial flux permanent magnet motor from rotating in a short time. After braking is finished, the in-phase current is not injected into the third stator winding 52 any more, the radial magnetic field disappears, the condensed magnetorheological fluid 4 is recovered to the Newtonian fluid, the braking mode is ended, and the axial flux permanent magnet motor can rotate again. In this embodiment, the maximum braking torque of the magnetorheological fluid 4 can be adjusted by controlling the exciting current of the third stator winding 52 to change the radial magnetic field strength.

As shown in fig. 2, the inner rotor 31 of the rotor disc 3 is mechanically connected to the outer braking wall 33 by a number of T-shaped structures 331 to ensure the overall mechanical strength of the rotor disc 3. The T-shaped structure 331 is formed by joining a T-shaped protruding portion of the inner rotor 31 and a T-shaped groove portion of the outer braking wall 33, and is coaxial with the inner rotor 31 and the outer braking wall 33 and circumferentially distributed at equal included angles. During assembly, the inner rotor 31 is inserted into the T-shaped groove of the outer braking wall 33 from top to bottom along the axial direction to form a T-shaped structure 331. Accordingly, the number of the T-shaped structures 331 does not need to be specifically determined, and is determined according to the mechanical strength requirement of the actual axial flux permanent magnet motor under rotation operation, in this embodiment, 10T-shaped structures 331 are selected for connection.

Regarding the operating principle of the radial magnetic field, as shown in fig. 3, the broken line indicates a radial magnetic field loop, and the arrow on one side indicates the direction of the magnetic flux. The third stator windings 52 on the third stator 5 are all in-phase windings, and are wound in a manner that the current directions of adjacent windings are opposite, so that the magnetic field intensity in a single stator tooth 511 can be more concentrated, the exciting current of the third stator windings 52 is not increased, the magnetic field intensity at the position of the magnetorheological fluid 4 in a radial magnetic field loop can be obviously enhanced, the shear stress value after the magnetorheological fluid 4 is magnetized is greatly increased, the radial size of an integrated structure can be effectively reduced, and meanwhile, a larger motor braking torque can be ensured.

As shown in fig. 4, the number of the stator teeth 511 of the third stator core 51 is even and is consistent with the number of the third stator windings 52, which may be 2 to 2N, and each stator tooth 511 is wound with one set of the third stator windings 52. Under the condition that the number of turns of the third stator winding 52 and the current are not changed, the braking torque of the magnetorheological fluid 4 depends on the number of the stator teeth 511, and when the magnetization area occupation ratio of the magnetorheological fluid 4 is close to 100%, the braking torque is not increased any more.

Regarding the sealing process of the magnetorheological fluid 4, as shown in fig. 1 and 5, the rotating shaft cover 6 comprises a shaft cover 61 and an O-ring 62, when assembled, the shorter left vertical wall of the rotating shaft cover 6 is parallel to the inner side wall of the outer braking wall 33 on the rotor disc 3 close to the axial center and keeps a certain distance, the O-ring 62 surrounding the left vertical wall seals the inner side of the outer braking wall 33, and certain lubricating grease is injected; the longer right vertical wall of the rotating shaft cover 6 is tightly sealed against the outer side wall of the third stator core 51, and the magnetorheological fluid 4 is sealed in the cylindrical gap formed by the outer braking wall 33 and the third stator 5 by the rotating shaft covers 6 on the two sides. Under the rotation working state of the axial flux permanent magnet motor, the shaft seal cover 61, the third stator core 51 and the O-shaped seal ring 62 are kept static, and sliding friction with extremely small friction resistance is performed between the O-shaped seal ring 62 and the outer brake wall 33, so that the sealing performance of the magnetorheological fluid 4 under the rotation working state of the axial flux permanent magnet motor is ensured.

Compared with the scheme that a typical motor series brake forms a joint module by the assembling method shown in figure 6, the magnetorheological fluid braking structure and the axial flux permanent magnet motor are integrated into a whole, and the motor braking is realized by using a radial magnetic field, so that the whole joint module has smaller axial size, and the installation space and application occasions of a single joint or a mechanical arm formed by the single joint or the mechanical arm formed by the single joint are greatly widened.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed.