Circuit board for axial end shell of motor and motor

Abstract

The utility model discloses a circuit board used for a motor axial end portion housing and a motor, and relates to the motor technology field, the circuit board used for the motor axial end portion housing comprises a first circuit board, a second circuit board and at least one magnetic isolation layer arranged between the first circuit board and the second circuit board; according to the technical scheme of the utility model, the first circuit board and the second circuit board are laminated, the induction coil is arranged on the first circuit board to induce the magnetic poles on the rotor to generate the induced electromotive force, and the second circuit board is used for collecting the induced electromotive force, so that the position of the rotor or the rotation angle of the rotor is obtained. The angle sensor has the advantages of being free of step loss and small in occupied overall axial space of the motor, and the motor can be conveniently assembled or placed in a limited space.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, and particularly relates to a circuit board and a motor for an axial end housing of a motor. Background Art

[0002] Angle sensors such as optical encoders and resolvers need to be installed at the axial ends of many precision stepping motors or servo motors to track and control the rotation angle of their rotating shafts, resulting in complex peripheral circuits and structures, increasing the corresponding axial dimensions and spatial volumes, and such sensors are also prone to problems such as missing steps and cumulative errors. Summary of the Utility Model

[0003] The main purpose of the utility model is to propose a circuit board and a motor for an axial end housing of a motor, aiming to reduce the axial space occupied by the motor.

[0004] To achieve the above object, the circuit board for an axial end housing of a motor proposed by the utility model includes:

[0005] A first circuit board, on which an induction coil is arranged, and the induction coil is used to induce an electromotive force with the rotor magnetic pole of the motor;

[0006] A second circuit board, electrically connected to the induction coil, the second circuit board is stacked with the first circuit board, and the second circuit board is provided with a drive circuit and a signal acquisition part, and the signal acquisition part is used to receive the electromotive force generated by the induction coil,

[0007] In one embodiment, the drive circuit is used to drive the circuit winding or control the rotation of the rotor.

[0008] In one embodiment, the circuit board for an axial end housing of a motor further includes a magnetic isolation layer, and at least one magnetic isolation layer is arranged between the first circuit board and the second circuit board.

[0009] In one embodiment, the induction coil includes a plurality of independent coil units, and the plurality of coil units are arranged in a divergent shape on the first circuit board.

[0010] In one embodiment, the width of the coil unit gradually increases from the inside to the outside in the radial direction of the induction coil.

[0011] In one embodiment, the coil unit has two wire heads, one of the two wire heads is located inside the coil unit, and the other of the two wire heads is located outside the coil unit, and the coil unit is wound and formed from the inside to the outside.

[0012] In one embodiment, the coil unit includes a plurality of first line segments, a plurality of second line segments, and a plurality of third line segments. The second line segments respectively connect the first line segments and the third line segments. The plurality of first line segments are parallel to each other, the plurality of second line segments are parallel to each other, and the plurality of third line segments are parallel to each other.

[0013] In one embodiment, the number of the coil units is set to N, and N satisfies 6 ≤ N ≤ 20.

[0014] In one embodiment, the induction coil is formed by winding a wire harness, and the induction coil includes a plurality of tooth portions spaced circumferentially.

[0015] In one embodiment, the number of the tooth portions is set to M, and M satisfies 6 ≤ M ≤ 20.

[0016] In one embodiment, the number of the magnetic isolation layers is set to multiple pieces, and the multiple magnetic isolation layers are spaced apart from each other.

[0017] In one embodiment, the circuit board for the axial end housing of the motor further includes a plurality of insulating adhesive layers, and the insulating adhesive layers are disposed on opposite sides of each magnetic isolation layer.

[0018] In one embodiment, the circuit board for the axial end housing of the motor further includes a connecting member, and the connecting member is inserted through and connects the first circuit board, the multiple magnetic isolation layers, the multiple insulating adhesive layers, and the second circuit board.

[0019] In one embodiment, the connecting member includes a middle portion and end portions located at opposite ends of the middle portion. The outer diameter of the middle portion is greater than the outer diameter of the end portions. First placement holes are formed in the middle portions of the induction coil layer and the drive circuit layer, and the two first placement holes are respectively adapted to the two end portions. Second placement holes are formed in the middle portions of the multiple magnetic isolation layers and the multiple insulating adhesive layers, and the middle portion is adapted to the multiple second placement holes.

[0020] In one embodiment, the multiple insulating adhesive layers are provided with a plurality of first through holes, and the multiple magnetic isolation layers are provided with a plurality of second through holes. The aperture of the second through hole is greater than the aperture of the first through hole. The first through holes and the second through holes are plated with copper to electrically connect the first circuit board and the second circuit board.

[0021] In one embodiment, the plurality of first through holes and the plurality of second through holes correspond to each other one by one.

[0022] In one embodiment, the outside of the circuit board for the axial end housing of the motor is wrapped with a metal edging, and the inner side of the metal edging abuts against the magnetic isolation layer.

[0023] In one embodiment, a plurality of through holes are formed in the circuit board for the axial end housing of the motor, a metal ring is disposed in the through hole, and the outer side of the metal ring abuts against the magnetic isolation layer.

[0024] In one embodiment, the magnetic isolation layer is provided with a plurality of openings, and the plurality of openings are arranged in an array.

[0025] In one embodiment, the magnetic isolation layer is arranged in a woven mesh structure.

[0026] In one embodiment, the circuit board for the axial end housing of the motor is formed by hot pressing the first circuit board, a plurality of the insulating adhesive layers, a plurality of the magnetic isolation layers, and the second circuit board.

[0027] The present invention further provides a motor, the motor includes a circuit board for the axial end housing of the motor, the circuit board for the axial end housing of the motor includes a first circuit board, a second circuit board, and a magnetic isolation layer, an induction coil is disposed on the first circuit board, and the induction coil is used to induce an induced electromotive force with the rotor magnetic pole of the motor; the second circuit board is connected to the first circuit board, the second circuit board and the first circuit board are stacked, the second circuit board is provided with a drive circuit and a signal acquisition unit, and the signal acquisition unit is used to collect the induced electromotive force generated by the induction coil; at least one magnetic isolation layer is disposed between the first circuit board and the second circuit board; the motor further includes a motor body, and the first circuit board is closer to the motor body than the second circuit board.

[0028] The technical solution of the present invention adopts a first circuit board and a second circuit board which are stacked. By arranging an induction coil on the first circuit board to induce the magnetic pole on the rotor to generate an induced electromotive force, and a signal acquisition unit is arranged on the second circuit board to collect the induced electromotive force, so as to obtain the position of the rotor or the rotation angle of the rotor, and then replace traditional angle sensors such as photoelectric encoders and resolvers. It has the characteristics of no step loss and small occupation of the overall axial space of the motor, which is convenient for the motor to be assembled or placed in a limited space. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0030] Figure 1 It is a schematic structural diagram of the motor provided by the present invention;

[0031] Figure 2 is Figure 1 a schematic structural diagram of a circuit board for the axial end housing of a motor;

[0032] Figure 3 is Figure 2 an exploded view of a circuit board for the axial end housing of a motor;

[0033] Figure 4 is Figure 2 a schematic structural diagram of an embodiment of a first circuit board;

[0034] Figure 5 is Figure 4 an enlarged view of part A;

[0035] Figure 6 is Figure 2 a schematic structural diagram of another embodiment of a first circuit board;

[0036] Figure 7 is Figure 2 a schematic structural diagram of an embodiment of a magnetic isolation layer;

[0037] Figure 8 is Figure 7 an enlarged view of part B;

[0038] Figure 9 is Figure 2 a schematic structural diagram of another embodiment of a magnetic isolation layer;

[0039] Figure 10 is a schematic diagram of the magnetic field line closure of the motor magnetic pole under three magnetic isolation layers;

[0040] Figure 11 is a schematic diagram of the magnetic force magnitude of the motor magnetic pole within three magnetic isolation layers.

[0041] Explanation of the reference numerals in the drawings:

[0042] 100, motor main body; 200, circuit board for the axial end housing of the motor; 201, first placement hole; 202, second placement hole; 203, through hole; 210, first circuit board; 211, induction coil; 211a, coil unit; 211a1, wire end; 211a2, first line segment; 211a3, second line segment; 211a4, third line segment; 211b, tooth part; 220, second circuit board; 230, magnetic isolation layer; 231, second through hole; 232, opening; 240, insulating adhesive layer; 241, first through hole; 300, connecting piece; 400, metal edge; 410, metal ring.

[0043] The realization of the purpose, functional features and advantages of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation mode

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0045] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention, then the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0046] In addition, if there are descriptions such as "first", "second", etc. in the embodiments of the present invention, then the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B at the same time. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] For many precision stepper motors or servo motors, angle sensors such as optical encoders and resolvers need to be installed at the axial ends to track and control the angle of their rotating shafts, resulting in complex peripheral circuits and structures, increasing the corresponding axial dimensions and space volumes, and such sensors are also prone to problems such as step loss and cumulative errors.

[0048] If an induction coil corresponding to the sensor is arranged in the circuit board by embedding the circuit board at the axial end housing position of the motor, an electromotive force will be induced in the coil due to the movement of the rotor poles. By collecting this electromotive force, the angular position or the number of rotation steps of the motor rotating shaft can be easily obtained. Further, if the acquisition circuit for collecting this induced electromotive force and even the drive circuit of the motor are also integrated into the end housing circuit board, the overall integration of the motor can be further improved, the axial dimensions and space volume of the motor can be reduced, the overall cost of the motor can be reduced at the same time, the control performance can be optimized, and it is more convenient for the flexible use of the motor.

[0049] In view of this, the present utility model provides a circuit board 200 for the axial end housing of a motor. It should be noted that this circuit board is installed at the axial end position of the motor and assembled on the housing of the motor.

[0050] Please refer to Figures 1 to 3 , in an embodiment of the present utility model, the circuit board 200 for the axial end housing of the motor includes a first circuit board 210, a second circuit board 220, and a magnetic isolation layer 230. An induction coil 211 is provided on the first circuit board 210, and the induction coil 211 is used to induce an electromotive force with the rotor poles of the motor; the second circuit board 220 is electrically connected to the induction coil 211. The second circuit board 220 is stacked with the first circuit board 210. The second circuit board 220 is provided with a drive circuit and a signal acquisition part. The signal acquisition part is used to receive the electromotive force generated by the induction coil 211, and the drive circuit can also be used to control the rotation of the rotor of the motor; at least one piece of the magnetic isolation layer 230 is provided between the first circuit board 210 and the second circuit board 220.

[0051] It should be noted that the circuit board 200 for the axial end housing of the motor proposed by the present utility model is installed on the motor body 100. Further, the circuit board 200 for the axial end housing of the motor is installed at one end in the axial direction of the motor housing.

[0052] Specifically, both the first circuit board 210 and the second circuit board 220 are provided as sheet-like board members. An induction coil 211 is provided on the first circuit board 210. The induction coil 211 is used to sense the electromotive force induced by the rotation of the rotor poles to obtain the position of the rotor (i.e., the angle of rotation of the rotor). The induction coil 211 is placed on the innermost circuit board of the circuit board 200 for the axial end housing of the motor, so as to be close to the rotor air-gap magnetic flux, so as to couple the magnetic flux to the maximum extent. Therefore, the first circuit board 210 is closer to the motor body 100 than the second circuit board 220. The induction coil 211 can be provided on the side of the first circuit board 210 close to the motor body 100, or can be provided on the side of the first circuit board 210 far from the motor body 100, and no specific limitation is made here.

[0053] Further, when the induction coil 211 on the first circuit board 210 induces an electromotive force, in order to collect this electromotive force so as to track and control the rotation of the motor shaft, a signal acquisition part is provided on the second circuit board 220. The signal acquisition part collects the signal of the induced electromotive force to judge the rotation angle or the number of turns of the rotor, avoiding the step-loss phenomenon, and then better tracking and controlling the rotor. More importantly, the circuit board 200 for the axial end housing of the motor proposed in this embodiment has the advantage of a relatively small space volume. After being installed on the axial housing of the motor, compared with angle sensors such as photoelectric encoders and resolvers, it has the advantage of reducing the overall axial length of the motor, which is beneficial to the miniaturization design of the motor and facilitates the assembly and placement of the motor in a limited space. Among them, the signal acquisition part can be a signal acquisition circuit on the second circuit board or an electronic device provided on the circuit board.

[0054] Considering that the circuit board 200 for the axial end housing of the motor proposed in the present invention is a new structural design, it is necessary to meet the requirements of motor magnetic circuit closure and magnetic field shielding. Therefore, at least one magnetic isolation layer 230 (in this embodiment, the magnetic isolation layer 230 is arranged in a sheet shape) is provided between the first circuit board 210 and the second circuit board 220 to meet the magnetic shielding performance requirements of the motor. This requirement includes the magnetic circuit closure requirement of the motor itself and the requirements of EMC and EMI. Therefore, the magnetic isolation layer 230 should be placed on the side of the first circuit board 210 close to the outside. The material of the magnetic isolation layer 230 is made of materials with high magnetic permeability such as iron, silicon, and steel. Among them, the number of the magnetic isolation layers 230 is at least one, and is not limited thereto. The number of the magnetic isolation layers 230 can be two, and the number of the magnetic isolation layers 230 can also be multiple, and no specific limitation is made here.

[0055] The technical solution of the present invention adopts the first circuit board 210 and the second circuit board 220 which are stacked. The induction coil 211 is provided on the first circuit board 210 to induce the magnetic poles on the rotor to generate an induced electromotive force. The signal acquisition part is provided on the second circuit board 220 to collect the induced electromotive force, so as to obtain the position of the rotor or the rotation angle of the rotor, and then replace traditional angle sensors such as photoelectric encoders and resolvers. It has the characteristics of no step-loss and small occupation of the overall axial space of the motor, and is convenient for the assembly or placement of the motor in a limited space.

[0056] In one embodiment, please refer to Figure 4 and Figure 5 ., the induction coil 211 includes a plurality of independent coil units 211a, and the plurality of coil units 211a are arranged in a divergent shape on the first circuit board 210.

[0057] It should be noted that the induction coil 211 includes a plurality of independent coil units 211a. The plurality of independent coil units 211a are arranged in a divergent manner on the first circuit board 210, that is, the plurality of coil units 211a have one end close to the center of the first circuit board 210 and the other end far from the center of the first circuit board 210, and the plurality of coil units 211a are circumferentially spaced apart on the first circuit board 210. And the coil unit 211a corresponds to a plurality of iron cores of the rotor. In this way, when the rotor rotates, the plurality of coil units 211a continuously induce the iron cores on the rotor to generate an induced electromotive force. It should be further explained that the plurality of iron cores on the rotor are spaced apart in the circumferential direction of the rotor, so the arrangement of the plurality of coil units 211a corresponds to the plurality of iron cores. During the rotation of the rotor, the magnetic fields passed by the plurality of coil units 211a are different in strength. When the plurality of coil units 211a pass through a place with a stronger magnetic field, the induced electromotive force generated by induction is stronger. Similarly, when the plurality of coil units 211a pass through a place with a weaker magnetic field, the induced electromotive force is weaker. In this way, the position of the rotor can be judged or the angle through which the rotor has turned can be known by the change of the induced electromotive force on the induction coil 211.

[0058] Furthermore, in one embodiment, please refer to Figure 4 , the width of the coil unit gradually increases from the inside to the outside in the radial direction of the induction coil.

[0059] Considering that the coil units are spaced apart from each other, in order to ensure that the distances between the coil units are consistent in the radial direction of the induction coil, so that the induced electromotive force generated by the induction coil is relatively stable, the width of the coil unit gradually increases from the inside to the outside in the radial direction of the coil unit. Among them, the coil unit has a width and a length, and the width is less than the length.

[0060] Furthermore, in one embodiment, please continue to refer to Figure 4 and Figure 5 , the coil unit 211a has two wire ends 211a1. One of the two wire ends 211a1 is located inside the coil unit 211a, and the other of the two wire ends 211a1 is located outside the coil unit 211a. The coil unit 211a is wound and formed from the inside to the outside.

[0061] Specifically, the coil unit 211a is formed by winding a wire harness, so the coil unit 211a has two wire ends 211a1. In this embodiment, one wire end 211a1 of the coil unit 211a is located outside the coil unit 211a, and the other wire end 211a1 is located inside the coil unit 211a. The coil unit 211a can be wound from the inside of the coil unit 211a to the outside of the coil unit 211a, and in other embodiments, it can also be wound from the inside of the coil unit to the outside of the coil unit. By this winding method, the coil unit 211a can have a longer wire harness in a limited space, so that a larger induced electromotive force can be induced and it is convenient for the signal acquisition unit to receive the induced electromotive force.

[0062] In one embodiment, please continue to refer to Figure 4 and Figure 5 , the coil unit includes a plurality of first line segments 211a2, a plurality of second line segments 211a3, and a plurality of third line segments 211a4. The second line segments 211a3 are respectively connected to the first line segments 211a2 and the third line segments 211a4. The plurality of first line segments 211a2 are parallel to each other, the plurality of second line segments 211a3 are parallel to each other, and the plurality of third line segments 211a4 are parallel to each other. With such a setting, it is easier for the coil unit to cut the magnetic induction lines of the rotor poles to generate an induced electromotive force.

[0063] Correspondingly, in another embodiment, please refer to Figure 6 , the induction coil 211 includes a plurality of tooth portions 211b arranged at intervals in the circumferential direction. The number of the tooth portions 211b is set to M, and M satisfies 6 ≤ M ≤ 20.

[0064] It should be noted that the induction coil 211 in this embodiment is different from the induction coil 211 that forms a plurality of coil units 211a. In this embodiment, the induction coil 211 is only formed by winding a single wire harness. The inductive coil includes a plurality of tooth portions 211b arranged at intervals in the circumferential direction. The plurality of tooth portions 211b are respectively used to correspond to a plurality of iron cores of the rotor. The number of the tooth portions 211b can be the same as and correspond one by one to the number of the iron cores, or the number of the tooth portions 211b can be slightly less than the number of the iron cores, or the number of the tooth portions 211b can be slightly greater than the number of the iron cores. No specific limitation is made here. In this embodiment, the number of the tooth portions 211b is limited to be between 6 and 20. Therefore, the number of the tooth portions 211b can be any number among 6, 7, 8... 19, and 20. Within this number range, it can be ensured that the induction coil 211 can generate a larger induced electromotive force, so as to facilitate the signal acquisition unit to receive the induced electromotive force.

[0065] Among them, the tooth part 211b is mainly used to cut the magnetic induction lines generated by the iron core to generate an induced electromotive force. A plurality of tooth parts 211b are spaced apart, so that the induced electromotive force generated by the induction coil 211 changes. During the rotation of the rotor, the induction coil 211 passes through magnetic fields with different strengths. When the induction coil 211 passes through a place with a stronger magnetic field, the generated induced electromotive force is stronger. Similarly, when the induction coil 211 passes through a place with a weaker magnetic field, the generated induced electromotive force is weaker. Thus, through the change of the induced electromotive force on the induction coil 211, the position of the rotor can be judged, or the angle through which the rotor has turned can be known.

[0066] In one embodiment, please continue to refer to Figure 6 , the induction coil 211 is formed by winding a wire harness, and the number of turns of the induction coil 211 is set to S, and S satisfies 2 ≤ S ≤ 12.

[0067] Specifically, in this embodiment, the number of turns of the induction coil 211 is 5 turns. However, it is not limited to this. The number of turns of the induction coil 211 can be set between 2 turns and 12 turns. Therefore, the number of turns of the induction coil 211 can be any one of 2 turns, 3 turns, 4 turns... 9 turns, 10 turns, 11 turns, and 12 turns. Within this range of the number of turns, it can be ensured that the induction coil 211 generates a sufficiently large induced electromotive force so as to be received by the signal acquisition part.

[0068] Preferably, in this embodiment, please refer to Figure 3 , the number of the magnetic isolation layers 230 is set to multiple pieces, and the multiple magnetic isolation layers 230 are spaced apart from each other.

[0069] In the above embodiment, the number of the magnetic isolation layers 230 is limited to at least one piece. In this embodiment, it is further limited that the number of the magnetic isolation layers 230 is set to multiple pieces. Figure 3In this embodiment, the magnetic isolation layer 230 is set as a preferred embodiment in this embodiment, and the number of the magnetic isolation layers 230 is further limited to three. It should be noted that the circuit board 200 for the axial end housing of the motor needs to meet the requirement of magnetic circuit closure, that is, the magnetic force lines will preferentially pass through a good magnetic conductor to close the magnetic circuit. When the magnetic flux in the good magnetic conductor is saturated, the excess magnetic flux will close in the air near the magnetic pole. When the magnetic force lines pass through the first magnetic isolation layer 230, only a part of the magnetic flux will be closed within the first magnetic isolation layer 230, and more magnetic flux will be closed in the air between the iron core of the rotor and the first magnetic isolation layer 230. The remaining magnetic force lines passing through the first magnetic isolation layer 230 will preferentially conduct magnetism in the second magnetic isolation layer 230 to complete the closure of the magnetic circuit, and a small part of the magnetic flux will close the magnetic circuit between the first magnetic isolation layer 230 and the second magnetic isolation layer 230. Furthermore, if three magnetic isolation layers 230 are provided, the number of magnetic force lines that can finally pass through the magnetic isolation layer 230 far from the magnetic pole is very small and can be ignored, and at the same time, the EMI and EMC requirements of the motor are also met.

[0070] In one embodiment, please refer to Figure 3 , and the circuit board 200 for the axial end housing of the motor further includes a plurality of insulating adhesive layers 240, and the insulating adhesive layers 240 are provided on opposite sides of each magnetic isolation layer 230.

[0071] It should be noted that considering that the insulating adhesive layers 240 are provided on opposite sides of each magnetic isolation layer 230, the insulating adhesive layers 240 are used to fix the plurality of magnetic isolation layers 230 together. In addition, the insulating adhesive layers 240 separate the plurality of magnetic isolation layers 230. In this way, part of the magnetic force lines can be closed between the magnetic isolation layers 230, leaving enough space for the magnetic force lines to close.

[0072] In one embodiment, please refer to Figure 3 , the circuit board 200 for the axial end housing of the motor further includes a connector 300, and the connector 300 passes through the first circuit board 210, the plurality of magnetic isolation layers 230, the plurality of insulating adhesive layers 240, and the second circuit board 220 and connects the first circuit board 210, the plurality of magnetic isolation layers 230, the plurality of insulating adhesive layers 240, and the second circuit board 220.

[0073] It should be noted that the connector 300 is located in the middle of the circuit board. In this way, and the connector 300 passes through the first circuit board 210, multiple magnetic isolation layers 230, multiple insulating adhesive layers 240, and the second circuit board 220 respectively. In this way, the connector 300 has the function of connecting the first circuit board 210 and the second circuit board 220. In addition, the magnetic isolation layer 230 is made of metal, and a large amount of heat will be generated during the magnetic isolation process of the magnetic isolation layer 230, and the connector 300 is also made of metal, so the connector 300 helps the magnetic isolation layer 230 dissipate heat.

[0074] In one embodiment, please refer to Figure 3 , the connector 300 includes a middle part and end parts located at opposite ends of the middle part. The outer diameter of the middle part is larger than the outer diameter of the end parts. First placement holes 201 are formed in the middle parts of the induction coil layer 211 and the drive circuit layer. The two first placement holes 201 are respectively adapted to the two end parts. Second placement holes 202 are formed in the middle parts of the multiple magnetic isolation layers 230 and the multiple insulating adhesive layers 240. The middle part is adapted to the multiple second placement holes 202.

[0075] It should be noted that the outer diameter of the middle part of the connector 300 is larger than the outer diameter of the end part, and the middle part is adapted to the second placement hole 202, and the end part is adapted to the first placement hole 201. In this way, the installation relationship between the connector 300 and the first circuit board 210, the second circuit board 220, the multiple magnetic isolation layers 230, and the multiple insulating adhesive layers 240 can be relatively tight, improving the reliability of the assembly of the connector 300.

[0076] In one embodiment, please continue to refer to Figure 3 , multiple first through holes 241 are formed in the multiple insulating adhesive layers 240, multiple second through holes 231 are formed in the multiple magnetic isolation layers 230. The aperture of the second through hole 231 is larger than the aperture of the first through hole 241, and the multiple first through holes 241 and the multiple second through holes 231 correspond one by one. Copper is plated in the first through hole 241 and the second through hole 231 to electrically connect the first circuit board 210 and the second circuit board 220.

[0077] It should be noted that each insulating adhesive layer 240 is provided with a plurality of first vias 241. The number of the first vias 241 can be three, four, or more. In this embodiment, the number of the first vias 241 on each insulating adhesive layer 240 is set to four according to specific requirements. The number of the second vias 231 can be three, four, or more. In this embodiment, the number of the second vias 231 on each magnetic isolation layer 230 is set to four according to specific requirements. The positions of the first vias 241 correspond to the positions of the second vias 231, and the number of the first vias 241 is the same as the number of the second vias 231, which is convenient for copper plating in the first vias 241 and the second vias 231. Among them, a copper layer is electroplated on the inner walls of the plurality of first vias 241, and the aperture of the second via 231 is set to be larger than the aperture of the first via 241 to prevent the magnetic isolation layer 230 from being electrically connected to the copper plating layer passing through the second via 231. It should be noted that the first circuit board 210 and the second circuit board 220 are electrically connected by copper plating in the first vias 241 and the second vias 231.

[0078] In one embodiment, please refer to Figure 2 and Figure 3 , a metal edge 400 is wrapped around the outside of the circuit board 200 for the axial end housing of the motor. The inner side of the metal edge 400 abuts against the magnetic isolation layer 230, and the metal edge 400 is used to dissipate heat from the magnetic isolation layer 230.

[0079] Specifically, the metal edge 400 has the function of strengthening the circuit board 200 for the axial end housing of the motor and has a good protection effect. At the same time, the metal edge 400 abuts against the magnetic isolation layer 230. In this way, the metal edge 400 can also dissipate heat from the magnetic isolation layer 230. The metal edge 400 can be made of a metal material with good hardness such as iron or steel. Among them, the specific edge wrapping method of the metal edge 400 can be electroplated edge wrapping or hardware edge wrapping, which is not specifically limited here.

[0080] In one embodiment, please continue to refer to Figure 2 and Figure 3 , a plurality of through holes 203 are formed in the circuit board 200 for the axial end housing of the motor, and a metal ring 410 is arranged in the through holes 203, and the outer side of the metal ring 410 abuts against the magnetic isolation layer 230.

[0081] It should be noted that in the above embodiment, a connecting member 300 is provided for connecting the rotating shaft of the motor. In addition, a plurality of metal rings 410 are provided to enhance the overall structural strength of the circuit board. The metal rings 410 are arranged in the through holes 203. Considering that a plurality of through holes 203 are formed in the circuit board 200 for the axial end housing of the motor, and a metal ring 410 is installed in each through hole 203, the number of metal rings 410 is the same as the number of through holes 203. In this embodiment, a total of four through holes 203 are formed, so four metal rings 410 are correspondingly provided, and the four through holes 203 are spaced outside the connecting member 300.

[0082] Preferably, in one embodiment, please refer to Figures 7 to 9 , the magnetic isolation layer 230 is arranged in a woven mesh structure, or the magnetic isolation layer 230 is provided with a plurality of mesh holes, or the plurality of mesh holes are arranged in an array.

[0083] Specifically, please refer to Figure 8 and Figure 9 , during the movement of the motor, an attractive force will be generated between the magnetic poles and the magnetic isolation layer 230, and this attractive force is usually also called magnetic pull force. This magnetic pull force will generate a resistance that hinders the movement (rotation) of the magnetic poles. This resistance will consume the efficiency of the motor, manifested as the generation of eddy currents and a large amount of heat in the corresponding metal conductors. The greater the magnetic pull force between the magnetic poles and the magnetic isolation layer 230, the greater the resistance to rotational blockage generated. On the premise that the magnetic poles are certain, the magnitude of the magnetic pull force between the magnetic poles and the magnetic isolation layer 230 only depends on the area and thickness of the corresponding magnetic isolation layer 230. When the area and thickness of the magnetic isolation layer 230 corresponding to the magnetic poles reach a certain value, the magnetic pull force between the magnetic poles and the magnetic isolation layer 230 reaches the maximum. Continuing to increase the area and thickness of the magnetic isolation layer 230, the magnetic pull force between the magnetic poles and the magnetic isolation layer 230 will not increase accordingly. Conversely, reducing the area and thickness of the magnetic isolation layer 230 corresponding to the magnetic poles will correspondingly reduce the magnetic pull force between the magnetic poles and the magnetic isolation layer 230.

[0084] Thus, please refer to Figure 10 and Figure 11 , assuming that the maximum magnetic pull force (mutual attractive force in the completely magnetic isolation state) between the magnetic poles and the magnetic isolation layer 230 is F 0 , the magnetic pull force between the magnetic poles and the first magnetic isolation layer 230 is F 1 , the magnetic pull force between the magnetic poles and the second magnetic isolation layer 230 is F 2 , the magnetic pull force between the magnetic poles and the third magnetic isolation layer 230 is F 3 ……, and so on, the magnetic pull force between the magnetic poles and the nth magnetic isolation layer 230 is F n . By setting the magnetic isolation layer 230 in a mesh woven structure, the area of the magnetic isolation layer 230 is reduced, and at the same time, the thickness of the magnetic isolation layer 230 is greatly reduced, so that the magnetic pull force between the magnetic poles and the first magnetic isolation layer 230 is F1 = 1 / 8F0. Since the magnetic pole and the first magnetic isolation layer 230 have been isolated for the first time, a certain amount of the remaining overflow magnetic flux will decay. The insulating adhesive layer 240 between the first magnetic isolation layer 230 and the second magnetic isolation layer 230 has a magnetic resistance equivalent to air for the magnetic field and has a certain distance, that is, the magnetic pulling force F between the second magnetic isolation layer 230 and the magnetic pole 2 is much smaller than F 1 , and normally does not exceed 1 / 3F 1 , that is, F 2 = 1 / 3F 1 = 1 / 24F 0 . And so on, F 3 = 1 / 3F 2 = 1 / 9F 1 = 1 / 72F 0 ……. The magnetic pulling force between the magnetic pole and the circuit board 200 used for the axial end housing of the motor is F w = F 1 + F 2 + F 3 +……+ F n (n is the number of layers of the magnetic isolation layer 230). After calculation, finally, F w < 20%F 0 .

[0085] Therefore, the magnetic isolation layer 230 is set as a woven mesh structure. Under the conditions of meeting the hardness, strength, EMI, and EMC requirements of the motor operation, the resistance generated by the movement of the magnetic pole is greatly reduced, which can not only improve the working efficiency of the motor, but also directly reduce the heat generation of the circuit board of the motor housing.

[0086] Not limited to the above embodiments, the mesh structure of the magnetic isolation layer 230 itself can block and inhibit the continuity of the end eddy current. Compared with the magnetic isolation layer 230 without a mesh structure, when the eddy current generated by the movement of the magnetic pole in the magnetic isolation layer 230 with a mesh structure encounters the mesh wall, reflection and refraction will occur, resulting in that the eddy current generated by the movement of the magnetic pole cannot be concentrated in a relative local area, and it is not easy to generate situations such as excessive local temperature. The direct heat generation of multiple magnetic isolation layers 230 is also much smaller than the traditional magnetic isolation method (magnetic conductive materials such as iron and silicon steel without a mesh structure).

[0087] Thus, assuming that the maximum heat generation (in a completely magnetic isolation state) corresponding to the magnetic isolation layer 230 induced by the movement of the magnetic pole in the traditional case is Q 0 , the heat generation between the movement of the magnetic pole and the first magnetic isolation layer 230 is Q 1 , the heat generation between the movement of the magnetic pole and the second magnetic isolation layer 230 is Q 2 , and the heat generation between the movement of the magnetic pole and the nth magnetic isolation layer 230 is Q n. The heat generated by the movement of the magnetic poles and the magnetic isolation layer 230 is often proportional to the magnetic field strength or the magnetic pulling force caused thereby. The heat generated by the magnetic poles and the first magnetic isolation layer 230 is Q 1 = 1 / 8Q 0 , Q 2 = 1 / 3Q 1 = 1 / 24Q 0 , the total heat generated by the magnetic poles and the circuit board of the motor housing is Q w = Q 1 + Q 2 + Q 3 +……+ Q n (n is the number of layers of the magnetic isolation layer 230). At the same time, the mesh structure of the magnetic isolation layer 230 itself can block and inhibit the continuity of the end eddy current, so that the eddy current generated by the movement of the magnetic poles cannot be concentrated in a relatively local area. Finally, the temperature of the local test is about 20% of the traditional magnetic isolation method (taking into account uncertain factors such as the environment and heat dissipation).

[0088] Therefore, the magnetic isolation layer 230 is set as a mesh structure, which greatly reduces the resistance generated by the movement of the magnetic poles while meeting the hardness, strength, EMI and EMC requirements of the motor operation, not only improving the working efficiency of the motor, but also directly reducing the heat generated by the circuit board of the motor housing.

[0089] In one embodiment, please refer to Figure 2 and Figure 3 , the circuit board 200 for the axial end housing of the motor is thermally pressed and formed by the first circuit board 210, multiple pieces of the insulating adhesive layer 240, multiple pieces of the magnetic isolation layer 230, and the second circuit board 220.

[0090] It should be noted that pressing is a way of close cooperation between the circuit board and electronic devices. Common circuit board pressing methods include metal pressing, welding pressing, solder ball pressing, and fusion pressing, etc. The pressing method of the circuit board 200 for the axial end housing of the motor in this embodiment can be any of the above pressing methods, and no specific limitation is made here. In the present invention, the specific pressing is to press the first circuit board 210, the second circuit board 220, multiple magnetic isolation layers 230, and multiple insulating adhesive layers 240 into one body. In this way, the overall reliability of the circuit board 200 for the axial end housing of the motor can be better.

[0091] The present invention also proposes a motor, please refer to Figure 1, the motor includes a motor main body 100 and a circuit board 200 for the housing at the axial end of the motor. The specific structure of the circuit board 200 for the housing at the axial end of the motor refers to the above-mentioned embodiments. Since this motor adopts all the technical solutions of the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be elaborated here one by one. Among them, the motor can be a stepper motor, a servo motor, or other types of motors, which are not specifically limited here.

[0092] Among them, please refer to Figure 1 , the outer shell of the motor main body 100 of the present invention is generally prism-shaped, so the circuit board 200 for the housing at the axial end of the motor is correspondingly set as a square plate shape to match the motor main body 100. Among them, considering that the induction coil 211 should have a good induction effect and meet the requirements of magnetic circuit closure, the first circuit board 210 is arranged closer to the motor main body 100 than the second circuit board 220.

[0093] The above is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the technical concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A circuit board (200) for an axial end housing of a motor, used for assembly with the motor, characterized in that: include: A first circuit board (210), wherein an induction coil (211) is arranged on the first circuit board (210), and the induction coil (211) is used to generate an induced electromotive force by induction with the rotor magnetic poles of the motor; A second circuit board (220) is electrically connected to the induction coil (211); the second circuit board (220) and the first circuit board (210) are stacked; the second circuit board (220) is provided with a drive circuit; and the second circuit board (220) is used to receive an induced electromotive force generated by the induction coil (211).

2. The circuit board (200) for the motor axial end housing according to claim 1, characterized in that: The driving circuit is used to drive the circuit winding or control the rotation of the rotor.

3. The circuit board (200) for the motor axial end housing according to claim 2, characterized in that: The circuit board (200) for the motor axial end housing further comprises a magnetic isolation layer (230), and at least one magnetic isolation layer (230) is arranged between the first circuit board (210) and the second circuit board (220).

4. The circuit board (200) for the motor axial end housing according to claim 3, characterized in that: The induction coil (211) comprises a plurality of independent coil units (211a), and the plurality of coil units (211a) are arranged in a divergent manner on the first circuit board (210).

5. The circuit board (200) for the motor axial end housing according to claim 4, characterized in that: The width of the coil unit (211a) gradually increases from the inside to the outside in the radial direction of the induction coil (211).

6. The circuit board (200) for the motor axial end housing according to claim 4, characterized in that: The coil unit (211a) has two thread ends (211a1), one of the two thread ends (211a1) is located on the inner side of the coil unit (211a), and the other of the two thread ends (211a1) is located on the outer side of the coil unit (211a), and the coil unit (211a) is wound from the inside to the outside to form a shape.

7. The circuit board (200) for the motor axial end housing according to claim 6, characterized in that: The coil unit (211a) comprises a plurality of first line segments (211a2), a plurality of second line segments (211a3) and a plurality of third line segments (211a4); the second line segments (211a3) respectively connect the first line segments (211a2) and the third line segments (211a4); the plurality of first line segments (211a2) are parallel to each other; the plurality of second line segments (211a3) are parallel to each other; and the plurality of third line segments (211a4) are parallel to each other.

8. The circuit board (200) for the motor axial end housing according to claim 4, characterized in that: The number of the coil units (211a) is set to N, and N satisfies 6≤N≤20.

9. The circuit board (200) for the motor axial end housing according to claim 3, characterized in that: The induction coil (211) is formed by winding a wire harness, and the induction coil (211) includes a plurality of teeth (211b) arranged at intervals in the circumferential direction.

10. The circuit board (200) for the motor axial end housing according to claim 9, characterized in that: The number of the tooth portions (211b) is set to M, and M satisfies 6≤M≤20.

11. The circuit board (200) for the motor axial end housing according to claim 3, characterized in that: The number of the magnetic isolation layers (230) is set to be multiple, and the multiple magnetic isolation layers (230) are arranged at intervals.

12. The circuit board (200) for the motor axial end housing according to claim 11, characterized in that: The circuit board (200) used for the motor axial end housing also includes a plurality of insulating adhesive layers (240), and the insulating adhesive layers (240) are arranged on opposite sides of each magnetic isolation layer (230).

13. The circuit board (200) for the motor axial end housing according to claim 12, characterized in that: The circuit board (200) for the motor axial end housing further comprises a connector (300), wherein the connector (300) passes through and connects the first circuit board (210), a plurality of magnetic isolation layers (230), a plurality of insulating adhesive layers (240), and the second circuit board (220).

14. The circuit board (200) for the motor axial end housing according to claim 13, characterized in that: The connecting piece (300) comprises a middle portion and ends located at opposite ends of the middle portion, the outer diameter of the middle portion is larger than the outer diameter of the ends, a first placement hole (201) is provided in the middle portions of the induction coil (211) layer and the drive circuit layer, and two of the first placement holes (201) are respectively adapted to the two ends, and second placement holes (202) are provided in the middle portions of the plurality of magnetic isolation layers (230) and the plurality of insulating adhesive layers (240), and the middle portion is adapted to the plurality of the second placement holes (202).

15. The circuit board (200) for the motor axial end housing according to claim 13, characterized in that: A plurality of the insulating adhesive layers (240) are provided with a plurality of first via holes (241), and a plurality of the magnetic isolation layers (230) are provided with a plurality of second via holes (231), wherein the aperture of the second via holes (231) is greater than the aperture of the first via holes (241).

16. The circuit board (200) for the motor axial end housing according to claim 15, wherein the plurality of first via holes (241) and the plurality of second via holes (231) correspond one to one.

17. The circuit board (200) for the motor axial end housing according to claim 13, characterized in that: The outer side of the circuit board (200) used for the motor axial end housing is wrapped with a metal edging (400), and the inner side of the metal edging (400) abuts against the magnetic isolation layer (230).

18. The circuit board (200) for the motor axial end housing according to claim 17, characterized in that: A plurality of through holes (203) are provided on the circuit board (200) used for the motor axial end housing, a metal ring (410) is arranged in the through hole (203), and the outer side of the metal ring (410) abuts against the magnetic isolation layer (230).

19. The circuit board (200) for the motor axial end housing according to claim 3, characterized in that: The magnetic isolation layer (230) is provided with a plurality of openings (232), and the plurality of openings (232) are arranged in an array.

20. The circuit board (200) for the motor axial end housing according to claim 3, characterized in that: The magnetic isolation layer (230) is arranged in a woven mesh structure.

21. The circuit board (200) for the motor axial end housing according to claim 12, characterized in that: The circuit board (200) for the motor axial end housing is formed by hot pressing the first circuit board (210), a plurality of insulating adhesive layers (240), a plurality of magnetic isolation layers (230), and the second circuit board (220).

22. A motor, characterized in that: The invention comprises a circuit board (200) for an axial end housing of a motor according to any one of claims 1 to 21, wherein the motor further comprises a motor body (100), and the first circuit board (210) is closer to the motor body (100) than the second circuit board (220).

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