Motor with built-in hysteresis device

Abstract

A motor with a built-in hysteresis device comprises a motor cover assembly, a stator assembly, a rotor assembly and the hysteresis device, the rotor assembly is installed in the stator assembly, and the motor cover assembly is installed on the stator assembly. The stator assembly and the machine cover assembly are respectively provided with a bearing, the bearing is in rotating fit with the two ends of a motor shaft arranged on the rotor assembly and supports the motor shaft, the rotor assembly can rotate in the circumferential direction, and the hysteresis device is arranged on one side of the rotor assembly in a machine shell of the stator assembly and comprises a fixing ring, an annular frame, an inner magnetic ring and an outer magnetic ring. The outer magnetic ring is fixed inside the machine shell and provided with a plurality of N magnetic poles and S magnetic poles which are distributed alternately, an air gap is formed between the outer circle face of the inner magnetic ring and the inner circle face of the outer magnetic ring, the inner magnetic ring and the N magnetic poles and the S magnetic poles which are distributed alternately with the outer magnetic ring form a magnetic field loop, the inner magnetic ring is fixed on the annular frame, and the outer magnetic ring is fixed on the annular frame. The annular frame is connected with a fixing ring, and the fixing ring is fixed on a motor shaft.

Description

Technical Field

[0001] The invention relates to a motor with a built-in hysteresis device Background Art

[0002] As a special type of motor, the hysteresis motor generates damping torque through the hysteresis principle. It has the advantages of simple structure, stable torque, good linearity, high-precision positioning control, long service life and low noise. These characteristics make the hysteresis motor widely used in various occasions that require high-precision positioning control and precise operation control, such as automobiles, robots, precision instruments and automation equipment. It can not only reduce the vibration and impact generated during the operation, but also ensure reliability and safety. During the operation of the motor, the rotor assembly drives the inner magnetic ring to rotate, and a hysteresis damping torque is generated between the inner magnetic ring and the outer magnetic ring, which can reduce the inertial load of the motor, thereby reducing impact, vibration and noise, improving the stability and service life of the motor, and can also reduce the displacement fluctuation of the motor drive mechanism after it stops at the specified working position point, and realize position locking to improve the positioning control accuracy and operation control accuracy.

[0003] In the existing hysteresis motor, the external permanent magnet of the hysteresis device arranged inside is not independently arranged, but shares the permanent magnet of the motor, which has the following problems: 1. The axial length of the external permanent magnet is relatively large, the precision is not easy to guarantee, and the processing performance is not good; 2. The price of magnetic materials is relatively high, and the external permanent magnet will have an extra connected part outside the effective permanent magnet required by the motor and the effective permanent magnet required by the hysteresis device, which will increase the cost of the motor; 3. The magnetic properties of the external permanent magnet are mainly designed according to the performance of the motor. Therefore, it is difficult to adjust the hysteresis damping torque generated by the hysteresis device according to different usage requirements; 4. The number of poles of the external permanent magnet is also designed according to the performance of the motor, so the stability of the hysteresis damping torque cannot be adjusted by changing the number of poles of the external permanent magnet of the hysteresis device. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a motor with a built-in hysteresis device in view of the existing technical situation, so that the motor can be effectively reduced in size and better meet the needs of the motor.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: A motor with a built-in hysteresis device comprises a cover assembly, a stator assembly, a rotor assembly and a hysteresis device, wherein the rotor assembly is mounted in the stator assembly, the cover assembly is mounted on the stator assembly, the stator assembly and the cover assembly are respectively provided with bearings which are rotatably matched with and support two ends of a motor shaft provided with the rotor assembly, the rotor assembly can rotate along a circumferential direction, the hysteresis device is arranged on one side of the rotor assembly in a casing of the stator assembly, and comprises a fixing ring, an annular frame, an inner magnetic ring and an outer magnetic ring, the outer magnetic ring is fixed inside the casing, a plurality of alternately distributed N magnetic poles and S magnetic poles are arranged on the outer magnetic ring, an air gap is formed between the outer circumferential surface of the inner magnetic ring and the inner circumferential surface of the outer magnetic ring, the inner magnetic ring and the casing and the alternately distributed N magnetic poles and S magnetic poles of the outer magnetic ring form a magnetic field loop, the inner magnetic ring is fixed on the annular frame, the annular frame is connected with the fixing ring, and the fixing ring is fixed on the motor shaft.

[0006] Preferably, the fixing ring is interference mounted on the motor shaft.

[0007] Preferably, the fixing ring and the annular frame are integrally formed by injection molding.

[0008] Preferably, the stator assembly includes a casing, a cylindrical bearing, an N-pole permanent magnet, an S-pole permanent magnet and a wave spring, a plurality of positioning bosses and a plurality of positioning bayonet holes are arranged in the casing to position a plurality of alternatingly distributed N-pole permanent magnets and S-pole permanent magnets arranged on its inner circular surface, and a wave spring is arranged to support the N-pole permanent magnet and the S-pole permanent magnet.

[0009] Preferably, a bearing chamber is provided in the center of the housing to fix the cylindrical bearing.

[0010] Preferably, the outer magnetic ring is axially positioned on both sides of the outer magnetic ring in the housing, so that the installation and fixing position of the outer magnetic ring in the housing is more accurate and the matching accuracy with the inner magnetic ring is improved.

[0011] Preferably, the outer magnetic ring is interference fit with the housing, and adhesive can be applied to the outer circumferential surface of the outer magnetic ring during assembly to assist in fixing the outer magnetic ring, making its fixation to the housing more firm and reliable.

[0012] Preferably, the fixing ring is provided with an annular boss along the axial middle position, a plurality of straight surfaces are sequentially provided on the outer circumferential surface of the annular boss, and an arc surface transition is provided between adjacent straight surfaces; the annular frame is provided with an annular groove along the axial middle position, a plurality of straight surfaces are sequentially provided on the outer circumferential surface of the annular groove, and an arc surface transition is provided between adjacent straight surfaces; the annular boss of the fixing ring cooperates with the annular groove of the annular frame to prevent axial looseness and relative rotation between the fixing ring and the annular frame.

[0013] Preferably, the annular frame includes an inner ring and an outer ring, which are connected by a plurality of left arc spokes and right arc spokes, so that there is a certain elasticity between the inner ring and the outer ring, which can effectively prevent the inner magnetic ring from cracking and the annular frame from breaking, causing the hysteresis device to fail.

[0014] Preferably, an annular groove is provided on the outer ring of the annular frame, and a plurality of interconnected straight surfaces are provided in sequence on the outer circular surface of the bottom of the annular groove, which cooperate with the plurality of interconnected straight surfaces provided in sequence on the inner circle of the inner magnetic ring, thereby preventing axial looseness and relative rotation between the inner magnetic ring and the annular frame.

[0015] Compared with the prior art, the advantages of the present invention are: the external permanent magnet shared by the existing motor and the hysteresis device is designed as a split permanent magnet, which can reduce the length of the external permanent magnet and thus reduce the cost of the motor; and because the axial length of the N-pole permanent magnet and the S-pole permanent magnet of the motor is reduced, the processing performance is better and the accuracy is easier to ensure.

[0016] Since the external permanent magnet of the hysteresis device is an independent external magnetic ring and is not affected by the external permanent magnet of the motor, different hysteresis damping torque requirements required for the use of the motor can be obtained by setting different magnetic properties of the external permanent magnet; the hysteresis damping torque generated by the hysteresis device can also be made smoother by increasing the number of magnetic poles of the external magnetic ring, thereby further improving the operation accuracy and control accuracy of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of a motor with a built-in hysteresis device according to an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 An enlarged view of the AA section view.

[0019] Figure 3 It is a schematic diagram of an exploded view of a stator assembly of a motor with a built-in hysteresis device according to an embodiment of the present invention.

[0020] Figure 4 It is a schematic diagram of the decomposition of a hysteresis device of a motor with a built-in hysteresis device according to an embodiment of the present invention.

[0021] Figure 5 It is a schematic diagram of a fixing ring of a motor with a built-in hysteresis device according to an embodiment of the present invention.

[0022] Figure 6 It is a schematic diagram of a ring frame of a motor with a built-in hysteresis device according to an embodiment of the present invention.

[0023] Figure 7 It is a schematic diagram of an inner magnetic ring of a motor with a built-in hysteresis device according to an embodiment of the present invention.

[0024] Figure 8It is a schematic diagram of the outer magnetic ring of a motor with a built-in hysteresis device according to an embodiment of the present invention.

[0025] Explanation of the reference numerals in the figure: 1, cover assembly; 11, spherical bearing; 2, stator assembly; 21, housing; 211, inner cylindrical surface; 212, positioning boss; 213, bearing chamber; 214, positioning bayonet; 22, cylindrical bearing; 23, N-pole permanent magnet; 24, S-pole permanent magnet; 25, wave spring; 3, rotor assembly; 31, motor shaft; 4, hysteresis device; 41, fixing ring; 411, inner hole; 412, annular boss; 413, straight surface; 414, arc surface; 42, annular frame, 421 , annular groove; 422, straight face; 423, outer ring; 424, inner ring; 425, annular groove; 426, right arc-shaped spoke; 427, left arc-shaped spoke; 428, straight face; 429, arc surface; 43, inner magnetic ring; 431, upper end face; 432, lower end face; 433, outer cylindrical surface; 434, straight face; 44, outer magnetic ring; 441, outer cylindrical surface; 442, inner cylindrical surface; 443, N-pole magnetic pole; 444, S-pole magnetic pole; 445, upper end face; 446, lower end face. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] like Figure 1-8 As shown, a motor with a built-in hysteresis device includes a cover assembly 1, a stator assembly 2, a rotor assembly 3 and a hysteresis device 4.

[0028] A spherical bearing 11 is arranged at the center of the left end of the cover assembly 1, and a cylindrical bearing 22 is arranged at the center of the right end of the stator assembly 2. The spherical bearing 11 and the cylindrical bearing 22 respectively cooperate with the two ends of the motor shaft 31 arranged on the rotor assembly 3 and support the motor shaft 31, so that the rotor assembly 3 can rotate in a circumferential direction around the motor shaft 31.

[0029] The stator assembly 2 includes a housing 21 , a cylindrical bearing 22 , an N-pole permanent magnet 23 , an S-pole permanent magnet 24 , and a wave spring 25 .

[0030] A plurality of positioning bosses 212 and a plurality of positioning bayonet sockets 214 are provided in the housing 21, which can be used to position a plurality of alternatingly distributed N-pole permanent magnets 23 and S-pole permanent magnets 24 provided on its inner circular surface 211, and a wave spring 25 is provided to support the N-pole permanent magnet 23 and the S-pole permanent magnet 24, and a bearing chamber 213 is provided at the center of the right end of the housing 21 to fix the cylindrical bearing 22.

[0031] Adhesive glue may also be applied to the outer circumferential surfaces of the N-pole permanent magnet 23 and the S-pole permanent magnet 24 to make them more reliably fixed in the housing 21 .

[0032] The hysteresis device 4 includes a fixing ring 41 , an annular frame 42 , an inner magnetic ring 43 and an outer magnetic ring 44 .

[0033] The inner hole 411 of the fixing ring 41 and the motor shaft 31 are interference fit to fix the fixing ring 41 on the motor shaft 31 .

[0034] The fixing ring 41 and the annular frame 42 are integrally formed by injection molding, which can simplify assembly.

[0035] The fixing ring 41 is provided with an annular boss 412 in the middle of the axial direction, a plurality of straight surfaces 413 are sequentially provided on the outer circumferential surface of the annular boss 412 , and arc surfaces 414 are provided between adjacent straight surfaces 413 for transition.

[0036] The annular frame 42 is provided with an annular groove 421 along the axial middle position, a plurality of straight surfaces 428 are sequentially provided on the outer circumferential surface of the annular groove 421, and an arc surface 429 is provided between adjacent straight surfaces 428 for transition. The annular boss 412 of the fixing ring 41 cooperates with the annular groove 421 of the annular frame 42 to fix the annular frame 42 on the fixing ring 41, and can prevent axial looseness and relative rotation between the fixing ring 41 and the annular frame 42.

[0037] An annular groove 421 is arranged on the outer ring 423 of the annular frame 42, and a plurality of interconnected straight surfaces 422 are arranged in sequence on the outer circumferential surface at the bottom of the annular groove 421, which cooperate with a plurality of interconnected straight surfaces 434 arranged in sequence on the inner circumference of the inner magnetic ring 43 to be fixed.

[0038] The inner magnetic ring 43 and the annular frame 42 are integrally formed by injection molding, which can simplify assembly.

[0039] The upper end surface 431 and the lower end surface 432 of the inner magnetic ring 43 respectively cooperate with the two side surfaces of the annular groove 421 provided on the annular frame 42 to prevent axial looseness and relative rotation between the inner magnetic ring 43 and the annular frame 42.

[0040] The outer circumferential surface 441 of the outer magnetic ring 44 is interference-fitted with the inner circumferential surface 211 of the housing 21 to fix the outer magnetic ring 44 in the housing 21 .

[0041] An air gap is formed between the inner circumferential surface 442 of the outer magnetic ring 44 and the outer circumferential surface 433 of the inner magnetic ring 43 .

[0042] The upper end surface 445 of the outer magnetic ring 44 is limited by the positioning boss 212 provided on the housing 21 , and the lower end surface 446 of the outer magnetic ring 44 is limited by the positioning bayonet 214 provided on the housing 21 , thereby axially positioning the outer magnetic ring 44 .

[0043] The annular frame 42 has a plurality of evenly disposed left arc-shaped spokes 427 and right arc-shaped spokes 426 on the inner ring 424 to connect the inner ring 424 with the outer ring 423 , so that there is a certain elasticity between the inner ring 424 and the outer ring 423 .

[0044] Since the operating temperature range of the motor is usually between -40°C and +125°C, the temperature difference is particularly large, and due to the different materials used for the inner magnetic ring 43 of magnetic material, the fixing ring 41 of metal material and the annular frame 42 of plastic material, during the operation of the motor, the inner magnetic ring 43 is rapidly and repeatedly magnetized by the N-pole magnetic poles 443 and the S-pole magnetic poles 444 evenly arranged and alternately distributed by the outer magnetic ring 44, the temperatures of the inner magnetic ring 43, the annular frame 42 and the fixing ring 41 will increase significantly, the thermal expansion coefficients of the magnetic material, the metal material and the plastic material are different, there is stress that damages the parts, resulting in cracking of the inner magnetic ring 43 and breaking of the annular frame 42, causing the hysteresis device 4 to fail in function, therefore, the inner ring 424 and the outer ring 423 of the annular frame 42 are connected by the left arc spoke 427 and the right arc spoke 426, which can effectively reduce the risk of breakage.

[0045] During the operation of the motor, since the alternatingly distributed N-pole magnetic poles 443 and S-pole magnetic poles 444 are evenly arranged on the casing 21 and the inner magnetic ring 43 and the outer magnetic ring 44 to form a magnetic field loop, the rotor assembly 3 drives the inner magnetic ring 43 to rotate, and generates a hysteresis damping torque between the inner magnetic ring 43 and the outer magnetic ring 44, which can reduce the inertial load of the motor, thereby reducing impact, vibration and noise, improving the stability and service life of the motor, and can also reduce the displacement fluctuation of the motor drive mechanism after it stops at the specified working position point, and realize position locking to improve the positioning control accuracy and operation control accuracy.

[0046] It should be noted that the directional characters such as inside, outside, left, right, up, and down and words containing the directional characters mentioned in this embodiment and this application document that indicate directions are only used for the convenience of explanation. They only refer to specific directions determined during the description and do not constitute a limitation on the content and protection scope of the present invention.

Claims

1. A motor with a built-in hysteresis device, comprising a cover assembly, a stator assembly, a rotor assembly and a hysteresis device, characterized in that: The rotor assembly is installed in the stator assembly, and the cover assembly is installed on the stator assembly. The stator assembly and the cover assembly are respectively provided with bearings that are rotatably matched with and support the two ends of the motor shaft provided by the rotor assembly. The rotor assembly can rotate in a circumferential direction. The hysteresis device is arranged on one side of the rotor assembly in the casing of the stator assembly, and includes a fixed ring, an annular frame, an inner magnetic ring and an outer magnetic ring. The outer magnetic ring is fixed inside the casing. The outer magnetic ring is provided with a plurality of alternately distributed N magnetic poles and S magnetic poles. An air gap is formed between the outer cylindrical surface of the inner magnetic ring and the inner cylindrical surface of the outer magnetic ring. The inner magnetic ring, the casing, and the alternately distributed N poles and S poles of the outer magnetic ring form a magnetic field loop. The inner magnetic ring is fixed on the annular frame, the annular frame is connected to the fixed ring, and the fixed ring is fixed on the motor shaft.

2. The motor with built-in hysteresis device according to claim 1, characterized in that: The fixing ring is interference mounted on the motor shaft.

3. The motor with built-in hysteresis device according to claim 1, characterized in that: The fixing ring and the annular frame are integrally formed by injection molding.

4. The motor with built-in hysteresis device according to claim 1, characterized in that: The stator assembly includes a housing, a cylindrical bearing, an N-pole permanent magnet, an S-pole permanent magnet and a wave spring. A plurality of positioning bosses and a plurality of positioning bayonet holes are arranged in the housing to position a plurality of alternately distributed N-pole permanent magnets and S-pole permanent magnets arranged on its inner circular surface, and a wave spring is arranged to support the N-pole permanent magnet and the S-pole permanent magnet.

5. The motor with built-in hysteresis device according to claim 4, characterized in that: A bearing chamber is arranged at the center of the casing to fix the cylindrical bearing.

6. The motor with built-in hysteresis device according to claim 4, characterized in that: The outer magnetic ring is axially positioned on two sides of the outer magnetic ring in the casing.

7. The motor with built-in hysteresis device according to claim 4, characterized in that: The outer magnetic ring is interference fit with the casing.

8. The motor with built-in hysteresis device according to claim 4, characterized in that: The fixing ring is provided with an annular boss along the axial middle position, a plurality of straight surfaces are sequentially provided on the outer circumferential surface of the annular boss, and an arc surface transition is provided between adjacent straight surfaces; the annular frame is provided with an annular groove along the axial middle position, a plurality of straight surfaces are sequentially provided on the outer circumferential surface of the annular groove, and an arc surface transition is provided between adjacent straight surfaces; the annular boss of the fixing ring cooperates with the annular groove of the annular frame, which can prevent axial looseness and relative rotation between the fixing ring and the annular frame.

9. The motor with built-in hysteresis device according to claim 4, characterized in that: The annular frame comprises an inner ring and an outer ring, and the inner ring and the outer ring are connected by a plurality of left arc spokes and right arc spokes.

10. The motor with built-in hysteresis device according to claim 4, characterized in that: An annular groove is arranged on the outer ring of the annular frame, and a plurality of mutually connected straight surfaces are arranged in sequence on the outer circumferential surface of the bottom of the annular groove to cooperate with a plurality of mutually connected straight surfaces arranged in sequence on the inner circumference of the inner magnetic ring.

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