Stator structure and AC motor

Abstract

The present invention discloses a stator structure and an AC motor, and relates to the technical field of AC motors, wherein the stator structure includes a stator yoke and a stator winding; a cavity with two ends passing through is formed inside the stator yoke; the stator winding includes a flexible circuit board formed by winding and having the same shape as the cavity, one end of the flexible circuit board is provided with a terminal, the terminal is used to connect an external AC power supply, the flexible circuit board includes at least two conductive layers, and the conductive layers are provided with a plurality of groups of coils arranged at intervals along the circumference of the stator yoke, and are all electrically connected to the terminal; the flexible circuit board is attached to the inner wall of the stator yoke, and the current passes through the coil, and a radial magnetic field perpendicular to the stator yoke is generated in the air gap of the motor, and the magnetic field forms a magnetic field loop using the yoke. The present application adopts the method of arranging a coil on the flexible circuit board and attaching it to the inner wall of the stator yoke. Since the radial precision of the winding is high, it is not necessary to arrange a stator slot on the stator yoke, and the processing and assembly of the stator structure of the motor are simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a stator structure and an AC motor. Background Art

[0002] With the continuous advancement of science and technology, high-performance motors are playing an increasingly important role in many fields such as robots and medical equipment. Three-phase AC motors, especially three-phase permanent magnet AC motors, are widely used in robots, medical equipment and other fields due to their high torque density and good reliability. This type of motor generates a driving torque by the interaction between the magnetic field generated by the current in the stator winding and the magnetic field generated by the permanent magnet material on the rotor.

[0003] However, the stator structure of this motor is relatively complex, including a stator core and a stator armature winding, the stator core is provided with stator slots, and the armature winding is formed according to the structure of the stator core and embedded in the stator core. This structure is easy to implement in large-sized motors, but in small motors, due to the presence of stator slots and armature windings, the stator structure of the motor is difficult to process and assemble. Summary of the invention

[0004] The main purpose of the present invention is to provide a stator structure and an AC motor, aiming to solve the problem that the existing stator structure is difficult to process and assemble in a small motor.

[0005] In order to achieve the above-mentioned object, the present invention proposes a stator structure, which comprises:

[0006] a stator yoke, wherein a cavity with two ends penetrating therein is formed; and

[0007] A stator winding, wherein the stator winding comprises a flexible circuit board formed by winding and having the same shape as the cavity, wherein one end of the flexible circuit board is provided with a terminal, wherein the terminal is used to connect to an external AC power source, wherein the flexible circuit board comprises at least two conductive layers, wherein a plurality of coils are arranged at intervals along the circumference of the stator yoke and are all electrically connected to the terminal;

[0008] The flexible circuit board is attached to the inner wall of the stator yoke. Current passes through the coil and generates a radial magnetic field perpendicular to the stator yoke in the air gap of the motor. The magnetic field forms a magnetic field loop using the stator yoke.

[0009] In one embodiment of the present invention, the flexible circuit board includes two conductive layers arranged in sequence along the radial direction of the stator yoke, and multiple groups of coils are arranged in each conductive layer. The number of coils in the two conductive layers is the same, and they are overlapped in pairs along the radial direction of the stator yoke. The magnetic field directions generated by the currents of the two coils overlapped with each other in the two conductive layers are the same.

[0010] In one embodiment of the present invention, the conductive layer is provided with a conductive through hole in the middle of each of the coils, the conductive through holes of the two conductive layers overlap, and one end of the coil in one conductive layer is electrically connected to the coil in the other conductive layer through the conductive through hole; the two coils overlapped with each other allow current to pass through the coil of one conductive layer and flow to the overlapping coil of the other conductive layer through the conductive through hole, and the rotation direction of the two coils can ensure that the magnetic fields generated by the current passing through the two conductive layers are superimposed in the same direction.

[0011] In one embodiment of the present invention, three coils are provided in the conductive layer, and the flexible circuit board is wound along the circumferential direction of the stator yoke to form a three-phase stator winding with an electrical angle width of 120 electrical degrees.

[0012] In one embodiment of the present invention, the flexible circuit board has a first section and a second section, and the first section and the second section are both provided with the same number of coils;

[0013] The second section is connected to one side of the first section and folded toward the first section so that the second section is located above the first section and partially overlaps with the first section;

[0014] The first section and the second section are wound to form two layers of the stator winding which are sequentially arranged along the radial direction of the stator yoke.

[0015] In one embodiment of the present invention, three coils are provided in the conductive layer of the first section and the second section, the electrical angle width of the three coils in each conductive layer is 120 degrees, and the electrical angles of the two layers of stator windings differ by 120 degrees or 240 degrees.

[0016] In one embodiment of the present invention, the flexible circuit board has a first section, a second section and a third section, and the first section and the third section are respectively connected to the same side or two opposite sides of the second section;

[0017] The first section, the second section and the third section are all provided with the same number of coils, the second section is folded toward the first section to partially overlap the first section, and the third section is folded toward the second section to partially overlap the second section;

[0018] The first section, the second section and the third section are wound to form three layers of the stator winding which are sequentially arranged along the radial direction of the stator yoke.

[0019] In one embodiment of the present invention, two coils are provided in the conductive layers of the first section, the second section and the third section, the electrical angle width of the two coils in each conductive layer is 180 degrees, and the electrical angles of the three layers of stator windings differ by 120 degrees or 240 degrees.

[0020] In one embodiment of the present invention, the stator structure further includes a magnetic field detection component, and the magnetic field detection component includes a circuit control board and a Hall sensor;

[0021] The Hall sensor is arranged on the circuit control board, and the circuit control board is connected to a side of the flexible circuit board where the terminal is arranged. The flexible circuit board is wound to form the cylindrical stator winding, and the circuit control board is in the shape of a circular ring. After the flexible circuit board is wound to form the cylindrical stator winding, the circuit control board is arranged at the opening of the stator winding in a cover shape. A positioning groove is provided on the outer periphery of the circuit control board, and a positioning tooth is provided at the opening of the stator winding, and the positioning tooth is limited to the positioning groove; the Hall sensor is used to detect the rotor magnetic field when the motor is running, and then detect the angle of the rotor.

[0022] The present invention further provides an AC motor, comprising a front end ring, a rear end ring, a rotor, a housing, a bearing, and any stator structure as described above.

[0023] The stator structure proposed in the present invention includes a stator yoke and a stator winding. A cylindrical cavity is formed inside the stator yoke. The stator winding includes a flexible circuit board containing at least two conductive layers. The flexible circuit board is wound to form a cylindrical stator winding and is attached to the inner wall of the stator yoke. Multiple groups of coils are arranged on the flexible circuit board, and a terminal is provided at one end of the flexible circuit board. The coil is electrically connected to an external AC power supply through the terminal. The multiple groups of coils on the wound flexible circuit board are arranged at intervals along the circumference of the stator yoke. Since the changing circuit generates a magnetic field, the multiple groups of coils generate a magnetic field in the radial direction in the air gap of the motor under the action of the current, so as to drive the rotor to rotate.

[0024] The present application adopts a solution of setting a coil on a flexible circuit board and fitting it to the inner wall of the stator yoke. Compared with the solution of setting the coil in the stator slot of the stator core, the present application can reduce the structural volume occupied by the stator winding. At the same time, there is no need to set the stator slot on the stator yoke. The installation of the stator winding can be achieved only by fitting, which improves the convenience of processing and assembly of the stator structure of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0026] Figure 1 A schematic structural diagram of an AC motor according to an embodiment of the present invention;

[0027] Figure 2 for Figure 1 Section view along AA;

[0028] Figure 3 A schematic structural diagram of a stator yoke in a stator structure provided by the present invention;

[0029] Figure 4 A schematic structural diagram of an unfolded flexible circuit board in an embodiment of a stator structure provided by the present invention;

[0030] Figure 5 for Figure 4 Schematic diagram of the structure of the flexible circuit board stacking;

[0031] Figure 6 for Figure 4 A schematic diagram of the structure of a stator winding formed by winding a flexible circuit board;

[0032] Figure 7 A schematic structural diagram of an unfolded flexible circuit board in another embodiment of a stator structure provided by the present invention;

[0033] Figure 8 for Figure 7 Schematic diagram of the structure of the flexible circuit board stacking;

[0034] Fig. 9 for Figure 8 A schematic diagram of the structure of a stator winding formed by winding a flexible circuit board;

[0035] Fig.10 A schematic structural diagram of an unfolded flexible circuit board in another embodiment of a stator structure provided by the present invention;

[0036] Fig.11 for Fig.10 Schematic diagram of the structure of the flexible circuit board stacking;

[0037] Fig.12 for Fig.11 A schematic diagram of the structure of a stator winding formed by winding a flexible circuit board;

[0038] Fig.13 This is a schematic structural diagram of an unfolded flexible circuit board in another embodiment of the stator structure provided by the present invention.

[0039] Description of Figure Numbers:

[0040] 10. Stator yoke; 11. Annular silicon steel sheet; 12. Cavity; 20. Stator winding; 21. Flexible circuit board; 211. First section; 212. Second section; 213. Third section; 214. Coil; 215. Perforation; 22. Terminal; 23. Conductive layer; 24. Positioning tooth; 30. Magnetic field detection component; 31. Circuit control board; 32. Hall sensor; 33. Positioning groove; 40. Rotor; 50. Front ring; 60. Rear ring; 70. Bearing.

[0041] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0045] exist Figures 1 to 13 middle, Figure 1A schematic structural diagram of an AC motor according to an embodiment of the present invention; Figure 2 for Figure 1 A local enlarged view along AA; Figure 3 A schematic structural diagram of a stator yoke in a stator structure provided by the present invention; Figure 4 A schematic diagram of the structure of the flexible circuit board in an embodiment of the stator structure provided by the present invention when it is unfolded (where a is a schematic diagram of the first conductive layer in the flexible circuit board; b is a schematic diagram of the second conductive layer in the flexible circuit board); Figure 5 for Figure 4 Schematic diagram of the structure of the flexible circuit board stacking; Figure 6 for Figure 4 A schematic diagram of the structure of a stator winding formed by winding a flexible circuit board; Figure 7 A schematic diagram of the structure of an unfolded flexible circuit board in another embodiment of the stator structure provided by the present invention (where a is a schematic diagram of the first conductive layer in the flexible circuit board; b is a schematic diagram of the second conductive layer in the flexible circuit board); Figure 8 for Figure 7 Schematic diagram of the structure of the flexible circuit board stacking; Fig. 9 for Figure 8 A schematic diagram of the structure of a stator winding formed by winding a flexible circuit board; Fig.10 A schematic diagram of a structure in which a flexible circuit board is unfolded in another embodiment of a stator structure provided by the present invention (where a is a schematic diagram of a first conductive layer in the flexible circuit board; b is a schematic diagram of a second conductive layer in the flexible circuit board); Fig.11 for Fig.10 Schematic diagram of the structure of the flexible circuit board stacking; Fig.12 for Fig.11 A schematic diagram of the structure of a stator winding formed by winding a flexible circuit board; Fig.13 This is a schematic structural diagram of an unfolded flexible circuit board in another embodiment of the stator structure provided by the present invention.

[0046] The present invention provides a stator structure.

[0047] Combination Figures 1 to 3 As shown, in one embodiment of the present invention, the stator structure includes a stator yoke 10 and a stator winding 20; a cavity 12 with two ends passing through is formed inside the stator yoke 10; the stator winding 20 includes a flexible circuit board 21 formed by winding and having the same shape as the cavity 12, one end of the flexible circuit board 21 is provided with a terminal 22, the terminal 22 is used to connect an external AC power supply, the flexible circuit board 21 includes at least two conductive layers 23, a plurality of coils 214 are arranged in the conductive layer 23, the plurality of coils 214 are arranged at intervals along the circumference of the stator yoke 10, and are all electrically connected to the terminal 22; the flexible circuit board 21 is attached to the inner wall of the stator yoke 10, the current passes through the coil 214, and a radial magnetic field perpendicular to the stator yoke 10 is generated in the air gap of the motor, and the magnetic field forms a magnetic field loop using the stator yoke 10.

[0048] In this embodiment, the stator yoke 10 is stacked by annular silicon steel sheets 11, or other soft magnetic materials with high magnetic conductivity. By using materials with high magnetic permeability, the magnetic field strength and efficiency of the motor can be improved. When formed using materials such as annular silicon steel sheets 11, the annular silicon steel sheets 11 can be fixed together by bonding, or by external welding, or by bonding and welding to form a hollow cylindrical stator yoke 10. Of course, it can also be a hollow polygonal column or other geometric shapes suitable for motor design.

[0049] At the same time, the stator yoke 10 formed by the above-mentioned fixing method of the annular silicon steel sheet 11 can meet the application occasions of most small motors. Of course, the stator yoke 10 can also be fixed in a metal shell to enhance the mechanical strength of the stator yoke 10.

[0050] An insulating layer made of polyimide or other high temperature resistant and insulating material is provided between the two conductive layers 23 of the flexible circuit board 21 to prevent the two conductive layers 23 from short-circuiting. The coil 214 can be made of copper wire or other materials with good conductivity to reduce resistance loss and improve the efficiency of the motor. The coil 214 is arranged in the conductive layer 23, and the conductive layer 23 protects the coil 214. The insulating layer between the two conductive layers 23 electrically isolates the multiple groups of coils 214 and the coils 214 from the stator yoke 10. The manufacturing process of the flexible circuit board 21 can adopt the existing FPCB (Flexible Printed Circuit Board) production process, and the high-precision manufacturing of the coil 214 can be achieved through precise photolithography, etching and deposition technology.

[0051] A terminal 22 is provided at one end of the flexible circuit board 21, and the terminal 22 is used to connect an external AC power source. The multiple sets of coils 214 arranged in the conductive layer 23 are arranged at intervals along the circumference of the stator yoke 10, and are all electrically connected to the terminal 22. The multiple sets of coils 214 can be clockwise or counterclockwise, and form a stator winding 20. When the AC current passes through the coil 214, a radial magnetic field perpendicular to the stator yoke 10 is generated in the air gap of the motor. When the motor is working, the external AC power supply inputs current into the stator winding 20 through the terminal 22 of the flexible circuit board 21. Since the multiple sets of coils 214 are symmetrically distributed in space, the three-phase time-domain symmetrical current will form a rotating magnetic field in the air gap of the motor, interact with the magnetic field of the rotor 40, and then drive the motor to rotate.

[0052] The flexible circuit board 21 is rectangular in shape before winding, and one end is wound around the other end to form a cylindrical shape, and the wound flexible circuit board 21 is adhered to the inner wall of the stator yoke 10 by gluing to form the stator winding 20. Compared with the existing solution of setting the coil 214 in the stator slot of the stator core, the present application can greatly reduce the structural volume occupied by the stator winding 20, and at the same time, there is no need to set the stator slot on the stator yoke 10, and the stator winding 20 can be installed only by bonding, which improves the convenience of processing and assembly of the stator structure of the motor. At the same time, this design can make the motor structure more compact and reduce the difficulty of processing and assembly.

[0053] Combination Figure 4 , Figure 7 and Fig.10 As shown, in one embodiment of the present invention, the flexible circuit board 21 includes two conductive layers 23 arranged in sequence along the radial direction of the stator yoke 10, and multiple groups of coils 214 are arranged in each conductive layer 23. The number of coils 214 in the two conductive layers 23 is the same, and they are overlapped in pairs along the radial direction of the stator yoke 10, and the magnetic field directions of the two coils 214 overlapped with each other in the two conductive layers 23 are the same.

[0054] In this embodiment, the flexible circuit board 21 is designed to have two layers of conductive layers 23, and the two layers of conductive layers 23 are overlapped. The two layers of conductive layers 23 have the same shape and size, and the number and position of the coils 214 in each conductive layer 23 are the same. When the flexible circuit board 21 is in an extended state, the two layers of conductive layers 23 are overlapped up and down, and the coils 214 in the two layers of conductive layers 23 are also overlapped up and down. The rotation directions of the two coils 214 overlapped with each other in the two layers of conductive layers 23 can be the same or different, but the magnetic field directions of the two coils 214 are the same, so that the magnetic field strength can be improved relative to the scheme of a single layer of coils 214. Therefore, according to the rotation direction setting of the coils 214 of the two layers of conductive layers 23 and the design of the electrical connection line between the coils 214 and the terminal 22, the present application provides the following two implementation methods:

[0055] First embodiment:

[0056] like Figure 4 , Figure 7 and Fig.10 As shown, the conductive layer 23 is provided with a conductive through hole 215 in the middle of each coil 214, and the inner wall of the conductive through hole 215 is plated with a conductive material. The conductive through holes 215 of the two conductive layers 23 overlap, and one end of the coil 214 in one conductive layer 23 is electrically connected to the coil 214 in the other conductive layer 23 through the inner wall of the conductive through hole 215; the two overlapping coils 214 have opposite rotation directions, and the current passes through the coil 214 of one conductive layer 23 and flows to the overlapping coil 214 of the other conductive layer 23 through the inner wall of the conductive through hole 215.

[0057] A conductive through hole 215 is provided in the middle of each coil 214 in the conductive layer 23, and the inner wall of the conductive through hole 215 is plated with a conductive material, such as copper or silver, to improve the conductivity of the electrical connection. One end of the coil 214 is electrically connected to the inner wall of the conductive through hole 215, and the other end is rotated clockwise or counterclockwise to form a coil 214 and connected to another coil 214 or the terminal 22. The design of the conductive through hole 215 not only realizes the electrical connection of the coils 214 in the two conductive layers 23, but also can be used to position the coils 214 according to the position of the conductive through hole 215 when processing the flexible circuit board 21, so as to ensure that the coils 214 overlapped with each other in the two conductive layers 23 are aligned, thereby ensuring the strengthening and uniform distribution of the motor magnetic field.

[0058] Here, for the convenience of explaining the flow path of the current, we define the two conductive layers 23 as the first conductive layer and the second conductive layer, wherein the coil 214 of the first conductive layer is directly connected to the terminal 22 through a wire. When the terminal 22 is connected to an AC power source, the current flows from the terminal 22 to one of the coils 214 of the first conductive layer; then it enters the overlapping coils 214 of the second conductive layer through the inner wall of the conductive through hole 215, and the coil 214 is connected to another coil 214 relative to one end of the conductive through hole 215, so the current enters another coil 214 of the same conductive layer 23 from the coil 214 of the second conductive layer, and the current is conducted between the two coils 214 of the second conductive layer; then the current enters the overlapping coils 214 of the first conductive layer through the conductive through hole 215 of the other coil 214 of the second conductive layer. By analogy, the current flows between the multiple groups of coils 214 in the two conductive layers 23. In this embodiment, the two coils 214 stacked on the two conductive layers 23 have different rotation directions. Therefore, when the current flows between the two stacked coils 214 through the conductive through-holes 215, the current flow direction can be guaranteed to be the same, so that the two coils 214 generate mutually reinforcing magnetic fields.

[0059] Second implementation method:

[0060] The coils 214 of the two conductive layers 23 are directly electrically connected to the terminal 22 through the wire. When the terminal 22 is connected to an AC power source, current flows from the terminal 22 to the multiple groups of coils 214 of the two conductive layers 23, and the two overlapping coils 214 in the two conductive layers 23 are electrically isolated. At the same time, the two overlapping coils 214 have the same rotation direction, so when the current passes through the two overlapping coils 214, a mutually reinforcing magnetic field can be generated.

[0061] It is understandable that the present application is not limited to the technical solution of only setting two layers of conductive layers 23. In another embodiment, the flexible circuit board 21 may also include four, six or more even-numbered conductive layers 23, each conductive layer 23 is provided with the same or similar number of coils 214 that overlap each other, and the magnetic fields of the overlapping multiple coils 214 have a mutually reinforcing effect. Therefore, the technical solutions of double-layer conductive layers 23, multiple conductive layers 23 and multiple coils 214 all fall within the protection scope of the present application.

[0062] Combination Figures 4 to 6 As shown, in one embodiment of the present invention, three coils 214 are provided in the conductive layer 23 , and the flexible circuit board 21 is wound along the circumference of the stator yoke 10 to form a three-phase stator winding 20 with an electrical angle width of 120 degrees.

[0063] In this embodiment, a basic structure of a "non-folding" Y-connected stator winding 20 formed by two layers of flexible circuit boards 21 is shown. The stator winding 20 adopts an asymmetric concentrated winding with an electrical angle width of 120°. The winding of each phase is input with current from the winding terminal 22 in the first layer. After the first conductive layer 23 of the flexible circuit board 21 forms a winding with a width of 120° wound from the outside to the inside, it is electrically connected to the coil 214 winding of the second conductive layer 23 through the conductive through hole 215. The second conductive layer 23 is wound from the inside to the outside to form a winding with a width of 120°.

[0064] When current is connected to the terminal 22, the magnetic field generated by the coil 214 on the first conductive layer 23 of each phase winding and the magnetic field generated by the coil 214 on the second conductive layer 23 are mutually enhanced. The end points of the three-phase windings finally converge to form a Y-type connected three-phase winding.

[0065] The above-mentioned flexible circuit board 21 is Figure 5 and Figure 6 After being rolled in the manner shown, a cylindrical structure is formed, the outer diameter of which is the same as the inner diameter of the stator yoke 10 (see Figure 3 ). The cylindrical stator winding 20 is then fixed to the inner side of the stator yoke 10 by gluing. The terminal 22 of the flexible circuit board 21 extends to the outer side of the stator yoke 10 to facilitate connection to an AC power source. In other embodiments, we can also set two, four, or other numbers of coils 214 in the conductive layer 23 according to needs.

[0066] Combination Figures 7 to 9As shown, in one embodiment of the present invention, the flexible circuit board 21 has a first section 211 and a second section 212, and the first section 211 and the second section 212 are both provided with the same number of coils 214; the second section 212 is connected to one side of the first section 211 and is folded toward the first section 211 so that the second section 212 is located above the first section 211 and partially overlaps with the first section 211; the first section 211 and the second section 212 are wound to form two layers of stator windings 20 arranged in sequence along the radial direction of the stator yoke 10.

[0067] In one embodiment, three coils 214 are provided in the conductive layer 23 of the first section 211 and the second section 212, and the electrical angle width of the three coils 214 in each conductive layer 23 is 120 degrees. The electrical angle of the two layers of stator windings 20 differs by 120 degrees or 240 degrees.

[0068] Figure 7 The figure shows a basic structure of a stator winding 20 in an unfolded state formed by two layers of FPCB in a "single folding" manner. The winding is three-phase and adopts a symmetrical concentrated winding with an electrical angle width of 120°. The flexible circuit board 21 is composed of a first section 211 and a second section 212. The electrical angle distance between the first section 211 and the second section 212 differs by 120° or 240° in the tangential direction, and the coils 214 of the first section 211 and the second section 212 of the flexible circuit board 21 are electrically connected.

[0069] The coil 214 in the first conductive layer 23 of the first section 211 of each phase is input with current through the terminal 22. After the flexible circuit board 21 forms a winding with a width of 120° wound from the outside to the inside, it is electrically connected to the coil 214 in the second conductive layer 23 of the first section 211 through the conductive through hole 215. The second conductive layer 23 located in the first section 211 is wound from the inside to the outside to form a winding with a width of 120°, and then connected to the coil 214 located in the second section 212 on the second conductive layer 23 through the lead wire. After the second conductive layer 23 of the second section 212 forms a winding with a width of 120° wound from the outside to the inside, the coil 214 is electrically connected to the coil 214 in the first conductive layer 23 of the second section 212 through the conductive through hole 215. Then the coil 214 located in the first section 211 on the first layer is transferred through the lead wire.

[0070] The above-mentioned flexible circuit board 21 is Figure 8 and Fig. 9 After being rolled in the manner shown, a cylindrical stator winding 20 structure is formed, and its outer diameter is the same as the inner diameter of the stator yoke 10. In this way, the cylindrical stator winding 20 can be fixed to the inner side of the stator yoke 10 by gluing. The terminal 22 of the flexible circuit board 21 extends to the outside of the stator yoke 10 to facilitate connection to an external AC circuit.

[0071] The flexible circuit board 21 is designed to be two-section, and the first section 211 and the second section 212 are folded and wound to form two cylindrical stator windings 20. The electrical angles of the two layers of stator windings 20 differ by 120 degrees or 240 degrees. This allows the stator windings 20 to generate a more uniform rotating magnetic field, so that the rotor 40 of the motor rotates more stably and reduces the vibration and noise of the motor.

[0072] It can be understood that the present application provides a method of changing the coil 214 and the structural design of the flexible circuit board 21 to achieve windings of different phase numbers and different forms. Therefore, the protection scope of the present application is not limited to the above-mentioned two-segment technical solution with three coils 214 in each segment. In another embodiment, two or more coils 214 can be set in the first segment 211 and the second segment 212, and the electrical angle difference between the two stator windings 20 formed after the first segment 211 and the second segment 212 are folded can also be other angles.

[0073] Combination Figures 10 to 12 As shown, in one embodiment of the present invention, the flexible circuit board 21 has a first section 211, a second section 212 and a third section 213, and the first section 211 and the third section 213 are respectively connected to the same side or two opposite sides of the second section 212; the first section 211, the second section 212 and the third section 213 are all provided with the same number of coils 214, the second section 212 is folded toward the first section 211 to partially overlap above the first section 211, and the third section 213 is folded toward the second section 212 to partially overlap above the second section 212; the first section 211, the second section 212 and the third section 213 are wound to form a three-layer stator winding 20 arranged in sequence along the radial direction of the stator yoke 10.

[0074] In one embodiment, two coils 214 are provided in the conductive layer 23 of the first section 211, the second section 212 and the third section 213, and the electrical angle width of the two coils 214 in each conductive layer 23 is 180 degrees, and the electrical angle of the three-layer stator winding 20 differs by 120 degrees or 240 degrees.

[0075] Fig.10The basic structure of a "double-folded" stator winding 20 formed by two layers of FPCB in an unfolded state is shown. The winding is three-phase and adopts a symmetrical concentrated winding with an electrical angle width of 180°. The flexible circuit board 21 is composed of a first section 211, a second section 212 and a third section 213. The three sections of the flexible circuit board 21 differ in electrical angle distance of 120° or 240° in the tangential direction, and the coils 214 between the first section 211, the second section 212 and the third section 213 are electrically connected. The winding of the A phase is a coil 214 arranged on the first section 211. The flexible circuit board 21 of the first section 211 forms a winding with a width of 180° wound from the outside to the inside. After the coil 214 in the first conductive layer 23 of the A phase winding inputs current through the terminal 22, it is electrically connected to the coil 214 in the second conductive layer 23 of the first section 211 through the through hole 215.

[0076] The second conductive layer 23 located in the first section 211 is wound from the inside to the outside with a width of 180°, and then transferred to the coil 214 of the second section 212 of the flexible circuit board 21 on the same conductive layer 23 through the lead wire. After the second section 212 of the flexible circuit board 21 forms a winding with a width of 180° wound from the outside to the inside, it is electrically connected to the coil 214 of the first conductive layer 23 of the second section 212 of the flexible circuit board 21 through the through hole 215.

[0077] The B-phase winding and the C-phase winding are respectively located on the second section 212 and the third section 213 of the flexible circuit board 21 , and the winding method is the same as that of the A-phase winding.

[0078] The above-mentioned flexible circuit board 21 is Fig.11 and Fig.12 After being rolled in the manner shown, a cylindrical stator winding 20 is formed, whose outer diameter is the same as the inner diameter of the stator yoke 10. The cylindrical stator winding 20 is fixed to the inner side of the stator yoke 10 by gluing. The terminal 22 of the flexible circuit board 21 extends to the outer side of the stator yoke 10 to facilitate connection to an external AC circuit.

[0079] In this embodiment, the flexible circuit board 21 is designed to have a first section 211, a second section 212 and a third section 213. The second section 212 is folded toward the first section 211 to partially overlap the first section 211, and the third section 213 is folded toward the second section 212 to partially overlap the second section 212. The first section 211, the second section 212 and the third section 213 are respectively wound to form a three-layer stator winding 20 structure, and the electrical angle between each layer is 120° or 240°. This structure can make the rotating magnetic field generated by the stator winding 20 more stable and more uniform, so as to improve the stability of the rotation of the rotor 40 and the working efficiency of the motor, and reduce the vibration of the motor when it is running.

[0080] Of course, the present application is not limited to the structural design, winding method and wiring design of the flexible circuit board 21 in the stator structure proposed in the above embodiments. In other embodiments, the flexible circuit board 21 may also include a fourth section, and the number of coils 214 in each section is not limited to the above two or three. The stator winding 20 on the flexible circuit board 21 can be in the form of distributed, centralized or wave winding, and the three-phase system can be realized in a Y-type connection or a triangle connection. In addition, the winding can also be a single-phase, two-phase, or other multi-phase stator winding 20. All of the above belong to the protection scope of the present application.

[0081] Combination Figure 1 and Fig.13 As shown, in one embodiment of the present invention, the stator structure further includes a magnetic field detection component 30, and the magnetic field detection component 30 includes a circuit control board 31 and a Hall sensor 32;

[0082] The Hall sensor 32 is arranged on the circuit control board 31, and the circuit control board 31 is connected to the side of the flexible circuit board 21 where the terminal 22 is provided. The flexible circuit board 21 is wound to form a cylindrical stator winding 20. The shape of the circuit control board 31 is annular. After the flexible circuit board 21 is wound to form a cylindrical stator winding 20, the circuit control board 31 is arranged in a cover shape at the opening of the stator winding 20. A positioning groove is provided on the outer periphery of the circuit control board 31, and a positioning tooth is provided at the opening of the stator winding, and the positioning tooth is limited in the positioning groove 33; the Hall sensor 32 is used to detect the magnetic field of the rotor 40 when the motor is running, and then detect the angle of the rotor 40.

[0083] In this embodiment, the circuit control board 31 is also flexible, so that the circuit control board 31 can be folded and covered at the opening of the stator winding 20. The circuit control board 31 is set on the side of the flexible circuit board 21 close to the terminal 22, so that the circuit control board 31 is electrically connected to the external power supply through the terminal 22. In addition to the positive pole of the power supply, the ground and the signal output pins, the Hall sensor 32 is also provided with pins for control signals and speed signals. Therefore, the Hall sensor 32 needs to be connected to multiple external connection lines. By designing the circuit control board 31 to be flexible, the circuit control board 31 and the flexible circuit board 21 can be integrated together during processing, so that the Hall sensor 32 can be electrically connected to the external circuit through the terminal 22, which greatly improves the space utilization of the motor, reduces the structural volume, and improves the convenience of wiring.

[0084] There are multiple Hall sensors 32, which are arranged at intervals along the circumference of the circuit control board 31 to improve the detection accuracy of the magnetic field of different positions of the rotor 40 by the magnetic field detection component 30. A plurality of positioning grooves 33 are provided on the outer circumference of the annular circuit control board 31, and a plurality of positioning teeth 24 are convexly provided on one side of the flexible circuit board 21. The plurality of positioning teeth 24 and the circuit control board 31 are located on the same side of the flexible circuit board 21. When the circuit control board 31 is covered at the opening of the stator winding 20, each positioning tooth 24 fits with the positioning groove 33 of the circuit control board 31, so that the circuit control board 31 is accurately installed on the stator winding 20, thereby improving the accuracy and stability of the Hall sensor 32 in detecting the magnetic field of the rotor 40 when the motor is running.

[0085] The present invention further proposes an AC motor, which includes a front ring 50, a rear ring 60, a rotor 40, a bearing 70 and a stator structure. The specific structure of the stator structure refers to the above embodiment. Since the AC motor adopts all the technical solutions of all the above embodiments of the stator structure, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0086] Among them, the two ends of the stator structure are respectively provided with a front ring 50 and a rear ring 60, which are respectively arranged at the two ends of the stator yoke 10 and fixedly connected to the stator yoke 10 by bonding. The stator yoke 10 can be formed by splicing a plurality of annular silicon steel sheets 11. In order to strengthen the strength of the stator yoke 10, the bonded stator yoke 10 can also be welded together by welding a plurality of annular silicon steel sheets 11. The front ring 50 and the rear ring 60 are made of metal material or other hard material to improve the structural strength of the stator. When the front ring 50 and the rear ring 60 are made of metal material, they can also be fixedly connected to the stator yoke 10 by welding.

[0087] The two bearings 70 of the motor are respectively mounted on the front ring 50 and the rear ring 60 of the motor. The magnetic steel of the motor is mounted on the rotating shaft of the rotor 40, and the two ends of the rotor 40 are rotatably connected with the front ring 50 and the rear ring 60 of the motor through the two bearings 70. When the motor is working, the external controller inputs the current into the three-phase winding of the motor through the terminal 22 of the flexible circuit board 21. Since the winding formed by the stator structure introduced in the implementation is symmetrically distributed in space, the three-phase time-domain symmetrical current will form a rotating magnetic field in the air gap of the motor, and interact with the magnetic field of the rotor 40 to drive the rotor 40 to rotate.

[0088] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A stator structure, characterized in that: The stator structure comprises: A stator yoke, wherein a cavity with two ends passing through is formed inside the stator yoke; and a stator winding, wherein the stator winding comprises a flexible circuit board formed by winding to have the same shape as the cavity, wherein one end of the flexible circuit board is provided with a terminal, wherein the terminal is used to connect to an external AC power source, wherein the flexible circuit board comprises at least two conductive layers, wherein a plurality of groups of coils are arranged in the conductive layers, wherein the plurality of groups of coils are arranged at intervals along the circumferential direction of the stator yoke and are all electrically connected to the terminal, wherein at least two conductive layers are arranged in an upper and lower overlapped manner, and the plurality of groups of coils in the mutually overlapping conductive layers are arranged in pairs in a radial direction of the stator yoke, and the magnetic field directions of the two mutually overlapping coils in the two conductive layers are the same; The flexible circuit board is attached to the inner wall of the stator yoke, and the current passes through the coil, and generates a radial magnetic field perpendicular to the stator yoke in the air gap of the motor, and the magnetic field forms a magnetic field loop using the stator yoke; The conductive layer is provided with a conductive through hole in the middle of each coil, the conductive through holes of the two conductive layers overlap, and one end of the coil in one conductive layer is electrically connected to the coil in the other conductive layer through the conductive through hole; The two coils overlapped with each other allow current to pass through the coil of one conductive layer and flow through the conductive through-holes to the coil overlapped with the other conductive layer. The rotation direction of the two coils enables the magnetic fields generated by the two conductive layers after current flows through them to be superimposed in the same direction.

2. The stator structure according to claim 1, characterized in that: The flexible circuit board includes two conductive layers sequentially arranged along the radial direction of the stator yoke, a plurality of groups of coils are arranged in each conductive layer, and the number of coils in the two conductive layers is the same.

3. The stator structure according to claim 2, characterized in that: Three coils are arranged in the conductive layer, and the flexible circuit board is wound along the circumferential direction of the stator yoke to form a three-phase stator winding with an electrical angle width of 120 degrees.

4. The stator structure according to any one of claims 1 to 3, characterized in that: The flexible circuit board has a first section and a second section, and the first section and the second section are both provided with the same number of coils; The second section is connected to one side of the first section and folded toward the first section so that the second section is located above the first section and partially overlaps with the first section; The first section and the second section are wound to form two layers of the stator winding which are sequentially arranged along the radial direction of the stator yoke.

5. The stator structure according to claim 4, characterized in that: Three coils are arranged in the conductive layers of the first section and the second section, the electrical angle width of the three coils in each conductive layer is 120 degrees, and the electrical angles of the two layers of stator windings differ by 120 degrees or 240 degrees.

6. The stator structure according to any one of claims 1 to 3, characterized in that: The flexible circuit board has a first section, a second section and a third section, wherein the first section and the third section are respectively connected to the same side or two opposite sides of the second section; The first section, the second section and the third section are all provided with the same number of coils, the second section is folded toward the first section to partially overlap the first section, and the third section is folded toward the second section to partially overlap the second section; The first section, the second section and the third section are wound to form three layers of the stator winding which are sequentially arranged along the radial direction of the stator yoke.

7. The stator structure according to claim 6, characterized in that: Two coils are provided in the conductive layers of the first section, the second section and the third section, the electrical angle width of the two coils in each section of the conductive layer is 180 degrees, and the electrical angles of the three sections of the stator winding differ by 120 degrees or 240 degrees.

8. The stator structure according to any one of claims 1 to 3, characterized in that: The stator structure also includes a magnetic field detection component, which includes a circuit control board and a Hall sensor; The Hall sensor is arranged on the circuit control board, and the circuit control board is connected to a side of the flexible circuit board where the terminal is arranged. The flexible circuit board is wound to form the cylindrical stator winding, and the circuit control board is in the shape of a circular ring. After the flexible circuit board is wound to form the cylindrical stator winding, the circuit control board is arranged at the opening of the stator winding in a cover shape. A positioning groove is provided on the outer periphery of the circuit control board, and a positioning tooth is provided at the opening of the stator winding, and the positioning tooth is limited to the positioning groove; the Hall sensor is used to detect the rotor magnetic field when the motor is running, and then detect the angle of the rotor.

9. An AC motor, characterized in that: The AC motor comprises a front end ring, a rear end ring, a rotor, a bearing and a stator structure according to any one of claims 1 to 8.

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