Multi-pole magnetic circuit manufacturing method, multi-pole magnetic circuit and stepping motor

Abstract

The invention provides a multi-pole magnetic circuit manufacturing method, a multi-pole magnetic circuit and a stepping motor. The manufacturing method comprises the following steps: S1, providing a plurality of pieces of first magnetic steel, wherein the cross section of the first magnetic steel is in a sector ring shape; s2, splicing and assembling the plurality of pieces of first magnetic steel to obtain a first cylinder; and S3, grinding the side surface of the obtained first cylinder by adopting a grinding process to obtain a second cylinder, and then electroplating the outer surface of the obtained second cylinder to form a coating, thereby obtaining the multi-pole magnetic circuit for the stepping motor. According to the manufacturing method of the multi-pole magnetic circuit, the multiple pieces of first magnetic steel with the large size are prepared at first, then the obtained first magnetic steel is spliced and assembled to obtain the first cylinder with the large outer diameter size, the side face of the obtained first cylinder is ground through the grinding technology to obtain the second cylinder with the small outer diameter size, and therefore the multi-pole magnetic circuit is manufactured. The splicing operation difficulty is reduced, and the roundness and concentricity of the multi-pole magnetic circuit and the reliability of the magnetic circuit are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a method for manufacturing a multi-pole magnetic circuit, a multi-pole magnetic circuit and a stepping motor. Background Art

[0002] A motor is an electromagnetic device that realizes the conversion or transmission of electric energy. The prior art manufacturing process of stepper motors includes the process of splicing and assembling multiple magnetic steels to obtain a multi-pole magnetic circuit. However, due to the small size of the stepper motor magnetic circuit, the size of the magnetic steel used for splicing is even smaller, and the processing and splicing are more difficult. In addition, the roundness and concentricity of the motor magnetic circuit obtained after splicing are poor.

[0003] Therefore, it is necessary to provide a method for manufacturing a multi-pole magnetic circuit, a multi-pole magnetic circuit and a stepping motor. Summary of the invention

[0004] The object of the present invention is to provide a method for manufacturing a multi-pole magnetic circuit, a multi-pole magnetic circuit and a stepping motor; the multi-pole magnetic circuit is used to manufacture a stepping motor. The multi-pole magnetic circuit has better roundness and concentricity.

[0005] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for manufacturing a multi-polar magnetic circuit for a stepper motor, comprising the steps of: S1, providing a plurality of first magnetic steels, wherein the cross-section of the first magnetic steels is fan-shaped; S2, splicing and assembling the plurality of first magnetic steels to obtain a first cylinder; S3, grinding the side of the first cylinder using a grinding process to obtain a second cylinder, and then electroplating the outer surface of the second cylinder to form a coating to obtain a multi-polar magnetic circuit for a stepper motor.

[0006] Optionally, the first magnetic steel is shaped by the grinding process to form a second magnetic steel, and the second magnetic steel is arranged around the central axis of the multi-pole magnetic circuit, and the magnetic properties of one end of two adjacent second magnetic steels close to the central axis of the multi-pole magnetic circuit are opposite, and the magnetic properties of the other ends of two adjacent second magnetic steels are opposite.

[0007] Optionally, in step S3, the grinding process is one or more of longitudinal grinding, plunge grinding, segmented grinding or depth grinding.

[0008] Optionally, in step S3, the coating is a Ni metal coating formed by metal Ni electroplating, or a composite metal coating formed of Zn and Ni.

[0009] Optionally, the first magnetic steel is a sintered magnetic steel; two adjacent first magnetic steels are bonded and fixed to each other via an adhesive layer.

[0010] Optionally, step S2 also includes providing a rotating shaft; step S2 specifically includes the steps of: providing a rotating shaft, splicing and arranging the obtained multiple first magnetic steels circumferentially around the rotating shaft to obtain a first cylinder provided with a rotating shaft.

[0011] In a second aspect, the present invention provides a multi-pole magnetic circuit, which is manufactured using the manufacturing method described above.

[0012] In a third aspect, the present invention provides a stepper motor, comprising the multi-pole magnetic circuit as described above.

[0013] The beneficial effects of the present invention are as follows: the manufacturing method of the multi-pole magnetic circuit of the present invention first prepares a plurality of first magnetic steels with a larger size, then splices and assembles the obtained first magnetic steels to obtain a first cylinder with a larger outer diameter, and then uses a grinding process to grind the side of the obtained first cylinder to obtain a second cylinder with a smaller outer diameter, thereby reducing the difficulty of the splicing operation, improving the roundness and concentricity of the multi-pole magnetic circuit, and ensuring the precise control of the outer diameter tolerance of the magnetic circuit and the reliability of the magnetic circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a process flow chart of the method for manufacturing a multi-pole magnetic circuit.

[0015] Figure 2 This is a schematic structural diagram of the multi-stage magnetic circuit obtained by the present invention.

[0016] Figure 3 Schematic diagram of the magnetic distribution of the second magnetic steel in a multi-pole magnetic circuit.

[0017] Figure 4 It is a structural schematic diagram of the stepping motor of the present invention.

[0018] Figure 5 It is a top view of the stepping motor of the present invention.

[0019] Figure 6 for Figure 5 Section view along AA.

[0020] Figure 7 Schematic diagram of claw pole assembly.

[0021] Figure 8 Schematic diagram of the claw pole structure.

[0022] Fig. 9 Another process flow chart of the method for manufacturing a multi-pole magnetic circuit of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0024] In order to make the technical personnel in the field of the present invention better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all embodiments.

[0025] In the description of the present invention, words such as "first", "second", "third", and "fourth" are only used for the purpose of distinguishing the description and cannot be understood as indicating or implying relative importance or order.

[0026] It should be noted that, in the present invention, the external direction refers to a direction away from the central axis of the multi-pole magnetic circuit, and the internal direction refers to a direction close to the central axis of the multi-pole magnetic circuit.

[0027] Embodiment 1: In a first aspect, the present invention provides a method for manufacturing a multi-pole magnetic circuit, wherein the multi-pole magnetic circuit 110 is used to prepare a stepping motor, see Figure 1 and Figure 2 As shown, it includes the steps of: S1, providing a plurality of first magnetic steels 1, wherein the cross section of the first magnetic steels 1 is fan-shaped; S2, splicing and assembling the plurality of first magnetic steels 1 to obtain a first cylinder 2; S3, grinding the side of the first cylinder 2 by a grinding process to obtain a second cylinder 3, and then electroplating the outer surface of the second cylinder 3 to form a coating 113 to obtain a multi-pole magnetic circuit 110 for a stepper motor.

[0028] The manufacturing method of a multi-pole magnetic circuit 110 described in the present invention is suitable for manufacturing a stepper motor. First, a plurality of first magnetic steels 1 with a larger size are prepared, and then the obtained first magnetic steels 1 are spliced ​​and assembled to obtain a first cylinder 2 with a larger outer diameter. The side of the obtained first cylinder 2 is ground by a grinding process to obtain a second cylinder 3 with a smaller outer diameter. The first magnetic steel 1 with a larger size is not only easy to process but also has a lower difficulty in splicing, which ensures the roundness and concentricity of the first cylinder 2 after splicing, and provides a basis for obtaining a multi-pole magnetic circuit 110 with better roundness and concentricity; then, the outer diameter of the large-sized first cylinder 2 is ground into the required smaller outer diameter of the second cylinder 3 through a grinding process, so as to accurately control the outer diameter tolerance of the magnetic circuit, and the ground second cylinder 3 is electroplated to ensure the reliability of the magnetic circuit; in addition, in step S2, according to actual needs, by controlling the deformation amount of the outer diameter in the grinding process, second cylinders 3 with different outer diameters can be prepared to meet the assembly requirements of stepper motors of different sizes.

[0029] Preferably, the second cylinder 3 includes second magnetic steels 111 spliced ​​together, and the second magnetic steels are formed by the first magnetic steels 1 after being processed by the grinding process; the magnetic properties of one end of two adjacent second magnetic steels 111 close to the central axis of the second cylinder 3 are opposite, and the magnetic properties of the other ends of two adjacent second magnetic steels 111 are opposite.

[0030] The plurality of first magnetic steels 1 may include 2 first magnetic steels 1, 3 first magnetic steels 1, 4 first magnetic steels 1, 5 first magnetic steels 1, 6 first magnetic steels 1, 8 first magnetic steels 1, etc. Correspondingly, the second magnetic steels 111 formed after the grinding process may include 2 second magnetic steels 111, 3 second magnetic steels 111, 4 second magnetic steels 111, 5 second magnetic steels 111, 6 second magnetic steels 111, 8 second magnetic steels 111, etc.

[0031] For example, as an embodiment, when the number of the formed second magnetic steels 111 is 8, the 8 second magnetic steels 111 are spliced ​​together to form the second cylinder 3. The magnetic properties of the end of each second magnetic steel 111 away from the central axis of the second cylinder 3 and the end close to the central axis of the second cylinder 3 are opposite, for example, see Figure 3As shown, the magnetic pole of one end of the second magnetic steel 111 close to the central axis of the second cylinder 3 is an N pole, and the magnetic pole of the other end of the second magnetic steel 111 away from the central axis of the second cylinder 3 is an S pole. And in two adjacent second magnetic steels 111, the magnetic properties of the ends of the two second magnetic steels 111 close to the central axis of the second cylinder 3 are opposite, such as the magnetic pole of one end of the second magnetic steel 111 close to the central axis of the second cylinder 3 is an N pole, and the magnetic pole of the other end of the second magnetic steel 111 adjacent to the second magnetic steel 111 close to the central axis of the second cylinder 3 is an S pole. The magnetic properties of the other ends of the two adjacent second magnetic steels 111 are opposite, such as the magnetic pole of one end of the second magnetic steel 111 away from the central axis of the second cylinder 3 is an S pole, and the magnetic pole of the other end of the second magnetic steel 111 adjacent to the second magnetic steel 111 away from the central axis of the second cylinder 3 is an N pole.

[0032] In step S3, the first cylinder 2 is subjected to a grinding process to obtain the second cylinder 3. The specific outer diameter of the first cylinder 2 and the outer diameter of the formed second cylinder 3 can be set according to actual needs.

[0033] For example, in a specific embodiment of the present invention, the deformation amount of the outer diameter of the first cylinder 2 can be 42.8125%-43.4375%; the outer diameter of the first cylinder 2 can be 3.2 mm, and the outer diameter of the second cylinder 3 can be 1.82±0.01 mm.

[0034] Optionally, in step S3, the grinding process includes one or more of longitudinal grinding, plunge grinding, segmented grinding or depth grinding.

[0035] Optionally, in step S3, the coating 113 is a Ni metal coating formed by electroplating metal Ni, or a composite metal coating formed by Zn and Ni. After the grinding process, the electroplating process is performed to ensure that the outer side of the formed second cylinder 3 can be plated to form a uniform coating, thereby ensuring the stability of the magnetic steel.

[0036] Optionally, the first magnetic steel 1 is a sintered magnetic steel. The first magnetic steel 1 is a sintered magnetic steel, which can effectively improve the torque of the product and improve the magnetic circuit performance. In addition, multiple first magnetic steels 1 can be pre-processed and formed separately and then spliced, which can make the assembly process simpler and meet the assembly requirements of motors of different sizes, thereby improving stability and reliability and helping to improve the driving performance of the motor.

[0037] Two adjacent first magnetic steels 1 are bonded and fixed to each other via an adhesive layer 112 ; the adhesive layer 112 may be made of glue, and the adhesive layer 112 is used to fix two adjacent first magnetic steels 1 , which can improve the stability of multiple first magnetic steels 1 after splicing.

[0038] In a second aspect, the present invention provides a multi-pole magnetic circuit 110, wherein the multi-pole magnetic circuit 110 is manufactured using the manufacturing method described above.

[0039] In a third aspect, the present invention provides a stepping motor, see Figures 4 to 6 As shown, the stepper motor includes a rotor assembly 100 and a stator assembly 200 sleeved on the outer circumference of the rotor assembly 100; the rotor assembly 100 includes a multi-pole magnetic circuit 110 manufactured by the manufacturing method as described above or the multi-pole magnetic circuit 110 as described above.

[0040] The multi-pole magnetic circuit 110 is in the shape of a hollow cylinder as a whole, and includes a plurality of second magnetic steels 111 spliced ​​to each other; the rotor assembly 100 also includes a rotating shaft 120 arranged along the center axis of the multi-pole magnetic circuit 110; that is, the plurality of second magnetic steels 111 are arranged along the circumference of the rotating shaft 120; the magnetic properties of one end of two adjacent second magnetic steels 111 close to the rotating shaft 120 are opposite, and the magnetic properties of the other ends of two adjacent second magnetic steels 111 are opposite.

[0041] Two adjacent second magnetic steels 111 are bonded and fixed to each other via an adhesive layer 112 ; and a coating 113 is provided on the outer surface of the multi-pole magnetic circuit 110 .

[0042] In some embodiments, the stepper motor includes a rotor assembly 100 and a stator assembly 200 ; in other embodiments, the stepper motor includes a rotor assembly 100 and a plurality of stator assemblies 200 sequentially stacked and arranged along the axial direction of the rotor assembly 100 .

[0043] The stator assembly 200 includes a claw pole assembly 210, a plastic part 220, a coil 230 and an outer shell 240 which are sequentially sleeved on the outside of the rotor assembly 100 from the inside to the outside. The claw pole assembly 210 includes two claw poles 211 which are arranged opposite to each other and spaced apart. Figure 8 As shown, the claw pole 211 includes a claw plate 2111, a plurality of claw fingers 2112 vertically distributed on the claw plate 2111 along the circumferential direction, and a limiting portion 2113 extending outward from the claw plate 2111; the claw fingers 2112 are tooth-shaped and the wider end of the claw fingers 2112 is connected to the claw plate 2111, and the outer shell 240 is provided with a limiting groove for the limiting portion 2113 to be placed. The number of claw fingers 2112 is 3 or 4, and the claw fingers 2112 are evenly distributed along the circumference of the claw plate 2111.

[0044] The rotor assembly 100 further includes a flexible circuit board 300 electrically connected to the coil 230, and the flexible circuit board 300 is disposed outside the outer shell 240. The stepper motor further includes an end cover 400, and the end cover 400 is disposed at both ends of the outer shell 240, and both ends of the rotating shaft 120 are respectively disposed through the end cover 400, and both ends of the rotating shaft 120 are respectively connected to the end cover 400 through the bearing 130.

[0045] The number of the stator assemblies 200 may be any integer from 1 to 4.

[0046] As an example, see Figure 6 and Figure 7 As shown, when the stepper motor includes one rotor assembly 100 and four stator assemblies 200 stacked in sequence along the axial direction of the rotor assembly 100; the stator assembly 200 includes a first stator assembly 212, a second stator assembly 213, a third stator assembly 214 and a fourth stator assembly 215 arranged in sequence from one end to the other end of the rotor assembly 100; the end cover 400 includes a first end cover 410 connected to one end of the rotating shaft 120 and a second end cover 420 connected to the other end of the rotating shaft 120.

[0047] The first stator assembly 212 includes a first claw pole assembly 2121, a first plastic part 2122, a first coil 2123 and a first outer shell 2124, which are arranged in sequence from the inside to the outside. The first claw pole assembly 2121 includes a first claw pole 21211 and a second claw pole 21212 which are arranged oppositely and spaced apart; the first claw pole 21211 includes a first claw plate 212111, a first claw finger 212112 and a first limiting portion 212113, and the second claw pole 21212 includes a second claw plate 212121, a second claw finger 212122 and a second limiting portion 212123. The first claw finger 212112 is inserted into the gap of the second claw finger 212122, the outer walls of the first claw plate 212111 and the second claw plate 212121 are connected to the inner wall of the first outer shell 2124, and the first claw plate 212111 is connected to the first end cover 410; the first limiting portion 212113 and the second limiting portion 212123 are staggered along a direction parallel to the central axis of the rotating shaft 120; the first claw plate 212111, the first claw finger 212112, the second claw finger 212122, the second claw plate 212121 and the first outer shell 2124 together form a first installation groove, and the first plastic part 2122 and the first coil 2123 are arranged in the first installation groove from the inside to the outside.

[0048] The second stator assembly 213 includes a second claw pole assembly 2131, a second plastic part 2132, a second coil 2133 and a second outer shell 2134, which are arranged in sequence from the inside to the outside. The second claw pole assembly 2131 includes a third claw pole 21311 and a fourth claw pole 21312 which are arranged oppositely and spaced apart; the third claw pole 21311 includes a third claw plate 213111, a third claw finger 213112 and a third limit portion 213113, the fourth claw pole 21312 includes a fourth claw plate 213121, a fourth claw finger 213122 and a fourth limit portion 213123, the third claw finger 213112 is inserted into the gap of the fourth claw finger 213122, and the outer walls of the third claw plate 213111 and the fourth claw plate 213121 are connected to the second outer shell. The inner wall of 2134, the third claw plate 213111 is connected to the first claw plate 212111, the third limiting portion 213113 is connected to the first limiting portion 212113, and the fourth limiting portion 213123 is staggered with the first limiting portion 212113 and the second limiting portion; the third claw plate 213111, the third claw finger 213112, the fourth claw finger 213122, the fourth claw plate 213121 and the outer shell 240 together form a second installation groove, and the second plastic part 2132 and the second coil 2133 are arranged in the second installation groove from the inside to the outside.

[0049] The third stator assembly 214 includes a third claw pole assembly 2141, a third plastic part 2142, a third coil 2143 and a third outer shell 2144, which are arranged in sequence from the inside to the outside. The third claw pole assembly 2141 includes a fifth claw pole 21411 and a sixth claw pole 21412 which are arranged oppositely and at intervals; the fifth claw pole 21411 includes a fifth claw plate 214111, a fifth claw finger 214112 and a fifth limiting portion 214113, the sixth claw pole 21412 includes a sixth claw plate 214121, a sixth claw finger 214122 and a sixth limiting portion 214123, the fifth claw finger 214112 is inserted into the gap of the sixth claw finger 214122, and the outer walls of the fifth claw plate 214111 and the sixth claw plate 214121 are connected to the third stator assembly 2144. The inner wall of the three outer shells 2144, the fifth claw plate 214111 is connected to the fourth claw plate 213121, the fifth limiting portion 214113 is aligned with the first limiting portion 212113, and the sixth limiting portion 214123 is aligned with the second limiting portion 212123; the fifth claw plate 214111, the fifth claw finger 214112, the sixth claw finger 214122, the sixth claw plate 214121 and the outer shell 240 together form a third installation groove, and the third plastic part 2142 and the third coil 2143 are arranged in the third installation groove from the inside to the outside.

[0050] The fourth stator assembly 215 includes a fourth claw-pole assembly 2151, a fourth plastic part 2152, a fourth coil 2153 and a fourth outer shell 2154 which are sequentially arranged from the inside to the outside. The fourth claw-pole assembly 2151 includes a seventh claw pole 21511 and an eighth claw pole 21512 which are arranged oppositely and at intervals; the seventh claw pole 21511 includes a seventh claw plate 215111, a seventh claw finger 215112 and a seventh limiter 215113, the eighth claw pole 21512 includes an eighth claw plate 215121, an eighth claw finger 215122 and an eighth limiter 215123, the seventh claw finger 215112 is inserted into the gap of the eighth claw finger 215122, the outer walls of the seventh claw plate 215111 and the eighth claw plate 215121 are connected to the inner wall of the fourth outer shell 2154, The seventh claw plate 215111 is connected to the sixth claw plate 214121, the eighth claw plate 215121 is connected to the second end cover 420, the seventh limiting portion 215113 is aligned with the sixth limiting portion 214123, and the eighth limiting portion 215123 is aligned with the fourth limiting portion 213123; the seventh claw plate 215111, the seventh claw finger 215112, the eighth claw finger 215122, the eighth claw plate 215121 and the outer shell 240 together form a fourth mounting groove, and the fourth plastic part 2152 and the fourth coil 2153 are arranged in the fourth mounting groove from the inside to the outside.

[0051] As an option, in some other embodiments, see Fig. 9 As shown, the step S2 also includes providing a rotating shaft 120; step S2 specifically includes the steps of: providing a rotating shaft 120, circumferentially splicing and arranging the obtained multiple first magnetic steels 1 around the rotating shaft 120 to obtain a first cylinder 2 provided with the rotating shaft 120; and obtaining a second cylinder 3 provided with the rotating shaft 120 after the grinding process.

[0052] Comparative Example 1: Compared with Example 1, the outer diameter of the multipole magnetic circuit 110 of Comparative Example 1 is the same as the outer diameter of the multipole magnetic circuit 110 in Example 1, and the number of spliced ​​magnetic steels is the same; the difference is that the multipole magnetic circuit 110 in Comparative Example 1 is directly prepared to obtain a third magnetic steel with the same outer diameter as the second magnetic steel 111, and then the third magnetic steel is spliced ​​to obtain a third cylinder with the same outer diameter as the second cylinder 3, and then the surface of the third cylinder is electroplated to obtain the multipole magnetic circuit 110.

[0053] Compared with comparative example 1, the concentricity of the multi-pole magnetic circuit 110 manufactured by the manufacturing method described in the present invention is improved from ±5s to ±1s, the roundness and concentricity of the multi-pole magnetic circuit 110 manufactured by the manufacturing method described in the present invention are better, and the reliability of the magnetic circuit is better.

[0054] The above description is only an implementation mode of the present invention. It should be pointed out that, for ordinary technicians in this field, improvements can be made without departing from the creative concept of the present invention, but these all belong to the protection scope of the present invention.

Claims

1. A method for manufacturing a multi-pole magnetic circuit, characterized in that: The method comprises the following steps: S1, providing a plurality of first magnetic steels, wherein the cross section of the first magnetic steels is in a fan-shaped ring shape; S2, splicing and assembling the plurality of first magnetic steels to obtain a first cylinder; S3, grinding the side surface of the first cylinder by a grinding process to obtain a second cylinder, and then electroplating the outer surface of the second cylinder to form a coating to obtain a multi-pole magnetic circuit for a stepper motor.

2. The manufacturing method according to claim 1, characterized in that: The first magnetic steel is shaped by the grinding process to form a second magnetic steel, and the second magnetic steel is arranged around the central axis of the multi-pole magnetic circuit. The magnetic properties of one end of two adjacent second magnetic steels close to the central axis of the multi-pole magnetic circuit are opposite, and the magnetic properties of the other ends of two adjacent second magnetic steels are opposite.

3. The manufacturing method according to claim 1, characterized in that: In step S3, the grinding process includes one or more of longitudinal grinding, plunge grinding, segmented grinding or depth grinding.

4. The manufacturing method according to claim 1, characterized in that: In step S3, the coating is a Ni metal coating formed by electroplating metal Ni, or a composite metal coating formed by Zn and Ni.

5. The manufacturing method according to claim 1, characterized in that: The first magnetic steel is a sintered magnetic steel; two adjacent first magnetic steels are bonded and fixed to each other via an adhesive layer.

6. The manufacturing method according to any one of claims 1 to 5, characterized in that: Step S2 also includes providing a rotating shaft; step S2 specifically includes the steps of providing a rotating shaft, splicing and arranging the obtained multiple first magnetic steels circumferentially around the rotating shaft to obtain a first cylinder provided with a rotating shaft.

7. A multi-pole magnetic circuit, characterized in that: The multi-pole magnetic circuit is manufactured using the manufacturing method described in any one of claims 1-6.

8. A stepping motor, characterized in that: The stepper motor comprises the multi-pole magnetic circuit as claimed in claim 7.

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