Stator structure and AC motor

Abstract

To simplify the processing and assembly of the motor stator structure. [Solution] The motor includes a stator yoke with a cavity formed through both ends, and a stator winding 20 including a flexible circuit board 21 that is wound around the stator yoke and has the same shape as the cavity. One end of the flexible circuit board is provided with a connection terminal 22 for connecting to an external AC power supply. The flexible circuit board includes at least two conductive layers, and within the conductive layers are multiple sets of coils arranged at intervals along the circumferential direction of the stator yoke, all of which are electrically connected to the connection terminal. The flexible circuit board is attached to the inner wall of the stator yoke. Current flows through the coils and generates a radial magnetic field perpendicular to the stator yoke in the air gap of the motor, and this magnetic field forms a magnetic field circuit using the yoke.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and particularly to a stator structure and an alternating current motor.

Background Art

[0002] With the progress of science and technology, high-performance motors are playing an increasingly important role in many fields such as robots and medical devices. Among them, three-phase alternating current motors, especially three-phase permanent magnet alternating current motors, are widely applied in fields such as robots and medical devices due to their high torque density and good reliability. Such a 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 in the rotor.

[0003] However, the stator structure of such a 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. Such a structure can be easily realized in large motors, but in small motors, due to the presence of stator slots and armature windings, the processing and assembly of the stator structure of the motor become difficult.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The main object of the present invention is to propose a stator structure and an alternating current motor aimed at solving the problem that the conventional stator structure is difficult to process and assemble in small motors.

Means for Solving the Problems

[0005] To achieve the above object, the stator structure according to the present invention includes a stator yoke having a cavity formed therein with both ends penetrating therethrough, and A stator winding comprising a flexible circuit board formed by winding, having the same shape as the cavity, wherein one end of the flexible circuit board is provided with a connection terminal for connection to an external AC power supply, the flexible circuit board includes at least two conductive layers, a plurality of sets of coils are provided within the conductive layers, the plurality of sets of coils are arranged at intervals along the circumferential direction of the stator yoke, and each set is electrically connected to the connection terminal, The flexible circuit board is attached to the inner wall of the stator yoke, and current flows through the coil, generating a radial magnetic field perpendicular to the stator yoke in the motor's air gap. This magnetic field forms a magnetic field circuit using the stator yoke.

[0006] In one embodiment of the present invention, the flexible circuit board includes two conductive layers arranged sequentially along the radial direction of the stator yoke, each of which contains multiple sets of coils, the number of coils in the two conductive layers is the same, and they are stacked in pairs along the radial direction of the stator yoke, and the direction of the magnetic field due to the current of the two coils stacked on top of each other in these two conductive layers is the same.

[0007] In one embodiment of the present invention, the conductive layer has conductive through-holes in the middle of each coil, the conductive through-holes of the two conductive layers overlap, one end of the coil in one conductive layer is electrically connected to the coil in the other conductive layer via the conductive through-hole, and the two coils stacked on top of each other cause current to flow through the coil in one conductive layer and through the conductive through-hole to the coil in the other conductive layer, and the magnetic fields generated after current flows through the two conductive layers can be superimposed in the same direction depending on the rotation direction of the two coils.

[0008] In one embodiment of the present invention, three coils are provided within 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.

[0009] In one embodiment of the present invention, the flexible circuit board has a first segment and a second segment, and the same number of coils are provided in both the first segment and the second segment. The second segment is connected to one side of the first segment and folded toward the first segment such that the second segment is located above the first segment and partially overlaps the first segment. The first and second segments form two layers of stator windings that are wound around the stator yoke and arranged sequentially along its radial direction.

[0010] In one embodiment of the present invention, three coils are provided within the conductive layers of both the first and second segments, the width of the electrical angles of the three coils within the conductive layer of each segment is 120 degrees, and the difference in the electrical angles of the two stator windings is 120 degrees or 240 degrees.

[0011] In one embodiment of the present invention, the flexible circuit board has a first segment, a second segment, and a third segment, and the first segment and the third segment are connected to the same side or opposite sides of the second segment, The first segment, the second segment, and the third segment are each provided with the same number of coils, the second segment is folded toward the first segment so as to partially overlap the top of the first segment, and the third segment is folded toward the second segment so as to partially overlap the top of the second segment. The first segment, the second segment, and the third segment form three layers of stator windings that are wound around the stator yoke and arranged sequentially along the radial direction.

[0012] In one embodiment of the present invention, two coils are provided within the conductive layers of the first segment, the second segment, and the third segment, the width of the electrical angle between the two coils in the conductive layer of each segment is 180 degrees, and the difference in the electrical angles of the three stator windings is 120 degrees or 240 degrees.

[0013] In one embodiment of the present invention, the stator structure further includes a circuit control board and a magnetic field detection assembly including a Hall sensor, The Hall sensor is provided on the circuit control board, the circuit control board is connected to the side of the flexible circuit board where the connection terminals are provided, the flexible circuit board is wound to form the cylindrical stator winding, the shape of the circuit control board is ring-shaped, after the flexible circuit board is wound to form the cylindrical stator winding, the circuit control board is provided in a cover-like manner over the opening of the stator winding, a positioning groove is made on the outer circumference of the circuit control board, positioning teeth are provided in the opening of the stator winding, the positioning teeth are restricted to the position within the positioning groove, and the Hall sensor is used to detect the rotor magnetic field during motor operation and, consequently, to detect the rotor angle.

[0014] The present invention further provides an AC motor comprising a front end ring, a rear end ring, a rotor, a case, bearings, and a stator structure as described above. [Effects of the Invention]

[0015] The stator structure according to the present invention includes a stator yoke in which a cylindrical cavity is formed internally, and a stator winding including a flexible circuit board containing at least two conductive layers. The flexible circuit board is wound to form a cylindrical stator winding and bonded to the inner wall of the stator yoke. Multiple sets of coils are provided on the flexible circuit board, and a connection terminal is provided at one end of the flexible circuit board, and the coils are electrically connected to an external AC power supply via the connection terminal. The multiple sets of coils on the wound flexible circuit board are arranged at intervals along the circumferential direction of the stator yoke, and since the changing circuit generates a magnetic field, the multiple sets of coils are used to generate a magnetic field along the radial direction in the air gap of the motor under the action of an electric current, thereby driving the rotor to rotate.

[0016] In this invention, a coil is provided on a flexible circuit board and attached to the inner wall of the stator yoke. Compared to the method in which the coil is provided on the stator rod of the stator core, this invention can reduce the volume of the structure occupied by the stator winding, and it does not require a stator rod to be provided on the stator yoke. The stator winding can be attached simply by attaching it, improving the convenience of processing and assembling the motor stator structure.

[0017] To more clearly illustrate embodiments of the present invention or technical concepts in the prior art, the following is a brief introduction to the drawings that may be used in the description of embodiments or the prior art. Clearly, the drawings in the following description represent only a few embodiments of the present invention, and those skilled in the art can obtain other drawings based on the structures shown in these drawings without expending any creative effort. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram of the structure of one embodiment of an AC motor according to the present invention. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3]It is a schematic diagram of the structure of the stator yoke in the stator structure according to the present invention. [Figure 4] It is a schematic diagram of the structure in which the flexible circuit board is unfolded in one embodiment of the stator structure according to the present invention. [Figure 5] It is a schematic diagram of the structure in which the flexible circuit board of FIG. 4 is laminated. [Figure 6] It is a schematic diagram of the structure of the stator winding formed by winding the flexible circuit board of FIG. 4. [Figure 7] It is a schematic diagram of the structure in which the flexible circuit board is unfolded in another embodiment of the stator structure according to the present invention. [Figure 8] It is a schematic diagram of the structure in which the flexible circuit board of FIG. 7 is laminated. [Figure 9] It is a schematic diagram of the structure of the stator winding formed by winding the flexible circuit board of FIG. 8. [Figure 10] It is a schematic diagram of the structure in which the flexible circuit board is unfolded in still another embodiment of the stator structure according to the present invention. [Figure 11] It is a schematic diagram of the structure in which the flexible circuit board of FIG. 10 is laminated. [Figure 12] It is a schematic diagram of the structure of the stator winding formed by winding the flexible circuit board of FIG. 11. [Figure 13] It is a schematic diagram of the structure in which the flexible circuit board is unfolded in yet another embodiment of the stator structure according to the present invention.

Embodiments for Carrying Out the Invention

[0019] The realization of the object, functions, features, and advantages of the present invention will be further described in conjunction with the embodiments while referring to the drawings. The following is a description of the technical solutions in the embodiments of the present invention in combination with the drawings in the embodiments of the present invention, clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present invention.

[0020] It should be explained that in embodiments of the present invention, if there are directional indicators (e.g., up, down, left, right, front, back, etc.), these directional indicators are used solely to interpret the relative positional relationships and motion conditions between each component in a specific posture, and when this specific posture changes, the directional indicators also change accordingly.

[0021] Furthermore, in the embodiments of the present invention, if there are descriptions such as "first," "second," etc., these descriptions are merely for descriptive purposes and should not be understood as indicating or implying their relative importance or implicitly indicating the number of specified technical features. Thus, features limited by "first" and "second" may explicitly or implicitly include at least one such feature. Also, the meaning of "and / or" or "and / or" appearing throughout the text includes three parallel embodiments, and taking "A and / or B" as an example, it includes embodiment A, or embodiment B, or an embodiment in which both A and B are satisfied simultaneously. In addition, technical ideas between each embodiment may be combined with each other, but this must be based on the fact that they can be realized by a person skilled in the art, and if a combination of technical ideas contradicts or cannot be realized with respect to each other, then such a combination of technical ideas should be considered not to exist and should be considered outside the scope of protection required by the present invention.

[0022] Figures 1 to 13 show the following: Figure 1 is a schematic diagram of the structure of one embodiment of the AC motor according to the present invention; Figure 2 is a partially enlarged view along AA in Figure 1; Figure 3 is a schematic diagram of the structure of the stator yoke in the stator structure according to the present invention; Figure 4 is a schematic diagram of the unfolded flexible circuit board in one embodiment of the stator structure according to the present invention (of which a is a schematic diagram of the first conductive layer in the flexible circuit board, and b is a schematic diagram of the second conductive layer in the flexible circuit board); Figure 5 is a schematic diagram of the stacked flexible circuit boards of Figure 4; Figure 6 is a schematic diagram of the structure of the stator winding formed by winding the flexible circuit boards of Figure 4; and Figure 7 is a schematic diagram of the unfolded flexible circuit board in another embodiment of the stator structure according to the present invention (of which a is the first conductive layer in the flexible circuit board). Figure 11 is a schematic diagram of the structure in which the flexible circuit boards of Figure 7 are stacked (where a is a schematic diagram of the second conductive layer in the flexible circuit board), Figure 8 is a schematic diagram of the structure in which the flexible circuit boards of Figure 7 are stacked, Figure 9 is a schematic diagram of the structure of the stator winding formed by winding the flexible circuit boards of Figure 8, Figure 10 is a schematic diagram of the structure in which the flexible circuit board is unfolded in yet another embodiment of the stator structure according to the present invention (where a is a schematic diagram of the first conductive layer in the flexible circuit board, and b is a schematic diagram of the second conductive layer in the flexible circuit board), Figure 11 is a schematic diagram of the structure in which the flexible circuit boards of Figure 10 are stacked, Figure 12 is a schematic diagram of the structure of the stator winding formed by winding the flexible circuit boards of Figure 11, and Figure 13 is a schematic diagram of the structure in which the flexible circuit board is unfolded in yet another embodiment of the stator structure according to the present invention.

[0023] This invention proposes a stator structure.

[0024] As shown in Figures 1 to 3, in one embodiment of the present invention, the stator structure includes a stator yoke 10 and stator windings 20, a cavity 12 formed inside the stator yoke 10 with both ends penetrating, the stator windings 20 include a flexible circuit board 21 formed by winding and having the same shape as the cavity 12, a connection terminal 22 for connection to an external AC power supply provided at one end of the flexible circuit board 21, the flexible circuit board 21 includes at least two conductive layers 23, a plurality of sets of coils 214 provided within the conductive layers 23, the plurality of sets of coils 214 are arranged at intervals along the circumferential direction of the stator yoke 10 and are all electrically connected to the connection terminal 22, the flexible circuit board 21 is attached to the inner wall of the stator yoke 10, current flows through the coils 214 and generates a magnetic field perpendicular to the radial direction of the stator yoke 10 in the air gap of the motor, and this magnetic field forms a magnetic field circuit using the stator yoke 10.

[0025] In this embodiment, the stator yoke 10 is stacked from an annular silicon steel sheet 11 or another soft magnetic material with high magnetic permeability. By using a material with high magnetic permeability, the magnetic field strength and efficiency of the motor can be improved. When formed from a material such as an annular silicon steel sheet 11, the annular silicon steel sheet 11 may be bonded, welded on the outside, or fixed by bonding and welding to form a hollow cylindrical stator yoke 10, or of course it may be a hollow polygonal prism shape or other geometric shapes suitable for the motor design.

[0026] Furthermore, the stator yoke 10 formed using the above-described fixing method for the annular silicon steel plate 11 has sufficient strength to meet the application requirements of most small motors. Of course, to enhance the mechanical strength of the stator yoke 10, it may be fixed within a single metal housing.

[0027] To prevent short circuits between the two conductive layers 23, an insulating layer made of polyimide or another high-temperature resistant, highly insulating material is provided between the two conductive layers 23 of the flexible circuit board 21. The coil 214 may be made of copper wire or another highly conductive material to reduce resistance loss and improve motor efficiency. The coil 214 is provided within the conductive layer 23, which protects the coil 214, and the insulating layer between the two conductive layers 23 electrically isolates multiple sets of coils 214 and between the coil 214 and the stator yoke 10. The manufacturing process of the flexible circuit board 21 can achieve high-precision manufacturing of the coil 214 through precise photoetching, etching, and deposition techniques using a conventional FPCB (Flexible Printed Circuit Board) production process.

[0028] A connection terminal 22 for connecting to an external AC power supply is provided at one end of the flexible circuit board 21. Multiple sets of coils 214 provided within the conductive layer 23 are arranged at intervals along the circumferential direction of the stator yoke 10 and are all electrically connected to the connection terminal 22. The multiple sets of coils 214 may rotate clockwise or counterclockwise and form the stator winding 20. When an AC current flows through the coils 214, they generate a magnetic field perpendicular to the radial direction of the stator yoke 10 in the air gap of the motor. When the motor is operating, the external AC power supply inputs current to the stator winding 20 via the connection terminal 22 of the flexible circuit board 21. Because the multiple sets of coils 214 are spatially symmetrically distributed, the current, which is symmetrical in the three-phase time domain, forms a rotating magnetic field in the air gap of the motor, interacts with the magnetic field of the rotor 40, and thereby drives the motor to rotate.

[0029] The flexible circuit board 21 has a rectangular shape before winding, and one end is wound around the other end to form a cylindrical shape. The wound flexible circuit board 21 is then adhesively attached to the inner wall of the stator yoke 10 to form the stator winding 20. Compared to the conventional configuration in which the coil 214 is provided on the stator rod of the stator core, this invention significantly reduces the structural volume occupied by the stator winding 20. Furthermore, there is no need to provide a stator rod on the stator yoke 10, and the stator winding 20 can be attached simply by adhesive bonding, improving the convenience of processing and assembling the motor stator structure. In addition, this design makes the motor structure more compact and reduces the difficulty of processing and assembly.

[0030] As shown in Figures 4, 7, and 10, in one embodiment of the present invention, the flexible circuit board 21 includes two conductive layers 23 arranged sequentially along the radial direction of the stator yoke 10, each conductive layer 23 containing multiple sets of coils 214, the number of coils 214 in the two conductive layers 23 being the same and arranged in pairs along the radial direction of the stator yoke 10, and the magnetic field direction of the two coils 214 stacked on top of each other within the two conductive layers 23 being the same.

[0031] In this embodiment, the flexible circuit board 21 is designed with two conductive layers 23, and the two conductive layers 23 are stacked together. The shape and size of the two conductive layers 23 are all the same, and the number and position of the coils 214 in each conductive layer 23 are all the same. When the flexible circuit board 21 is unfolded, the two conductive layers 23 are stacked vertically, and at this time, the coils 214 within the two conductive layers 23 are stacked relative to each other vertically. The rotation directions of the two coils 214 stacked relative to each other within the two conductive layers 23 may be the same or different, but the magnetic field direction of the two coils 214 is the same, and the magnetic field strength can be improved compared to the configuration of a single-layer coil 214. Therefore, based on the placement of the rotation direction of the coils 214 in the two conductive layers 23 and the circuit design in which the coils 214 and connection terminals 22 are electrically connected, this application provides the following two embodiments.

[0032] First embodiment: As shown in Figures 4, 7, and 10, the conductive layer 23 has conductive through-holes 215 in the middle of each coil 214, and the inner walls of the conductive through-holes 215 are 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 via the inner wall of the conductive through-hole 215. The rotation directions of the two coils 214 stacked on top of each other are opposite, and current flows through the coil 214 of one conductive layer 23 and through the inner wall of the conductive through-hole 215 to the coil 214 of the other conductive layer 23.

[0033] A conductive through-hole 215 is drilled in the middle of each coil 214 within the conductive layer 23. 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 rotates clockwise or counterclockwise to form another coil 214 and is connected to another coil 214 or a connection terminal 22. The design of the conductive through-hole 215 not only enables the electrical connection of the coils 214 within the two conductive layers 23, but also allows the coils 214 to be positioned at the location of the conductive through-hole 215 during the processing of the flexible circuit board 21, ensuring the alignment of the coils 214 stacked on top of each other in the two conductive layers 23, thereby ensuring the strengthening and uniform distribution of the motor's magnetic field.

[0034] Here, in order to interpret the current flow path, the two conductive layers 23 are defined as the first conductive layer and the second conductive layer, of which the coil 214 of the first conductive layer is directly connected to the connection terminal 22 via a conductor. When an AC power supply is applied to the connection terminal 22, the current flows from the connection terminal 22 to one of the coils 214 in the first conductive layer, then flows through the inner wall of the conductive through-hole 215 and enters the coils 214 stacked on top of each other in the second conductive layer. Since this coil 214 is connected to the other coil 214 at one end of the conductive through-hole 215, the current enters the other coil 214 of the same conductive layer 23, and the current is conducted between the two coils 214 of the second conductive layer. Subsequently, the current flows through the conductive through-hole 215 of the other coil 214 of the second conductive layer and enters the coils 214 stacked on top of each other in the first conductive layer. In this way, the current flows between multiple sets of coils 214 within the two conductive layers 23. In this embodiment, since the rotational directions of the two coils 214 stacked on top of each other in the two conductive layers 23 are different, the direction of current flow is ensured to be the same as the direction of current flow as it flows through the conductive through-holes 215 and between the two stacked coils 214, thereby generating a mutually reinforcing magnetic field in the two coils 214.

[0035] Second embodiment: Each of the coils 214 in the two conductive layers 23 is electrically connected directly to the connection terminals 22 via conductors. When an AC power supply is applied to the connection terminals 22, current flows from the connection terminals 22 into each of the multiple sets of coils 214 in the two conductive layers 23, and the two coils 214 stacked on top of each other within the two conductive layers 23 are electrically isolated. Furthermore, since the rotation direction of the two stacked coils 214 is the same, when current flows through the two stacked coils 214, a mutually reinforced magnetic field can be generated.

[0036] To ensure understanding, this application is not limited to a technical proposal in which only two conductive layers 23 are provided. In other embodiments, the flexible circuit board 21 may include four, six, or more even-numbered conductive layers 23, and each conductive layer 23 is provided with the same or nearly the same number of coils 214 stacked relative to each other, and the magnetic fields of the stacked coils 214 exhibit a mutually reinforcing effect. Therefore, the technical proposals of two conductive layers 23, multilayer conductive layers 23, and multiple coils 214 all fall within the scope of protection of this application.

[0037] As shown in Figures 4 to 6, in one embodiment of the present invention, three coils 214 are provided within the conductive layer 23, and the flexible circuit board 21 is wound along the circumferential direction of the stator yoke 10 to form a three-phase stator winding 20 with an electrical angle width of 120 degrees.

[0038] This embodiment clearly shows the basic structure of a Y-connected, "non-folding" stator winding 20 formed by a two-layer flexible circuit board 21. The stator winding 20 uses an asymmetrical concentrated winding with an electrical angle width of 120°. Current is input to each phase winding from the winding connection terminals 22 in the first layer. The conductive layer 23 of the first layer of the flexible circuit board 21 forms a winding with a width of 120°, wound from the outside to the inside, and is then electrically connected to the winding of the coil 214 of the conductive layer 23 of the second layer via conductive through-holes 215. The conductive layer 23 of the second layer is wound from the inside to the outside, forming a winding with a width of 120°.

[0039] When current is applied to the connection terminal 22, the magnetic fields generated by the coils 214 in the first conductive layer 23 and the magnetic fields generated by the coils 214 in the second conductive layer 23 are mutually reinforced. The ends of the three-phase windings finally converge to form a Y-connected three-phase winding.

[0040] After the flexible circuit board 21 is manufactured by winding it in the manner shown in Figures 5 and 6, a cylindrical structure is formed whose outer diameter is the same as the inner diameter of the stator yoke 10 (see Figure 3). This cylindrical stator winding 20 is then fixed to the inside of the stator yoke 10 by adhesive. The connection terminals 22 of the flexible circuit board 21 extend to the outside of the stator yoke 10 for easy connection to an AC power supply. In other embodiments, two, four, or other numbers of coils 214 may be provided within the conductive layer 23 as needed.

[0041] As shown in Figures 7 to 9, in one embodiment of the present invention, the flexible circuit board 21 has a first segment 211 and a second segment 212, each of which is provided with the same number of coils 214. The second segment 212 is connected to one side of the first segment 211 and folded toward the first segment 211, such that the second segment 212 is located above the first segment 211 and partially overlaps it. The first segment 211 and the second segment 212 are wound together to form two layers of stator windings 20 that are sequentially provided along the radial direction of the stator yoke 10.

[0042] In one embodiment, three coils 214 are provided within the conductive layer 23 of both the first segment 211 and the second segment 212, and the width of the electrical angle of the three coils 214 within the conductive layer 23 of each segment is 120 degrees, and the difference in the electrical angles of the two layers of stator windings 20 is 120 degrees or 240 degrees.

[0043] Figure 7 shows the basic structure of the unfolded "single-fold type" stator winding 20 formed by two layers of FPCB. The winding is three-phase and uses symmetrical concentrated winding with an electrical angle width of 120°, and the flexible circuit board 21 is composed of a first segment 211 and a second segment 212. The electrical angle distance between the first segment 211 and the second segment 212 differs by 120° or 240° in the tangential direction, and the coil 214 of the first segment 211 of the flexible circuit board 21 is electrically connected to the coil 214 of the second segment 212.

[0044] Current is input from the connection terminals 22 to the coil 214 in the first conductive layer 23 of the first segment 211 for each phase winding. The flexible circuit board 21 forms a winding with a width of 120° wound from the outside in, and is then electrically connected to the coil 214 in the second conductive layer 23 of the first segment 211 via conductive through-holes 215. The second conductive layer 23 located in the first segment 211 forms a winding with a width of 120° wound from the inside out, and is then connected via leads to the coil 214 in the second conductive layer 23 located in the second segment 212. After the second conductive layer 23 in the second segment 212 forms a winding with a width of 120° wound from the outside in, the coil 214 is electrically connected via conductive through-holes 215 to the coil 214 in the first conductive layer 23 of the second segment 212, and is then connected via leads to the coil 214 located in the first segment 211 in the first layer.

[0045] After the flexible circuit board 21 is manufactured by winding it in the manner shown in Figures 8 and 9, a cylindrical stator winding 20 structure is formed, whose 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 inside of the stator yoke 10 by adhesive. The connection terminals 22 of the flexible circuit board 21 extend to the outside of the stator yoke 10 for easy connection to an external AC circuit.

[0046] The flexible circuit board 21 is designed in a two-segment configuration, and the first segment 211 and the second segment 212 are folded and wound to form two cylindrical stator windings 20. The difference in electrical angles between the two layers of stator windings 20 is 120 degrees or 240 degrees. In this way, a more uniform rotating magnetic field can be generated in the stator windings 20, which makes the motor rotor 40 more stable during rotation and reduces motor vibration and noise.

[0047] To ensure understanding, the present invention provides a method for modifying the coils 214 and structural design of the flexible circuit board 21 to realize different numbers of phases and different types of windings. Therefore, the scope of protection of the present invention is not limited to the above two-segment technical proposal in which three coils 214 are provided in each segment. In another embodiment, two or more coils 214 may be provided in the first segment 211 and the second segment 212, and the electrical angles of the two stator windings 20 formed after the first segment 211 and the second segment 212 are folded may differ only by other angles.

[0048] As shown in Figures 10 to 12, in one embodiment of the present invention, the flexible circuit board 21 has a first segment 211, a second segment 212, and a third segment 213, the first segment 211 and the third segment 213 are connected to the same side or opposite sides of the second segment 212, the same number of coils 214 are provided in the first segment 211, the second segment 212, and the third segment 213, the second segment 212 is folded toward the first segment 211 so as to partially overlap the top of the first segment 211, the third segment 213 is folded toward the second segment 212 so as to partially overlap the top of the second segment 212, and the first segment 211, the second segment 212, and the third segment 213 are wound together to form three layers of stator windings 20 which are sequentially provided along the radial direction of the stator yoke 10.

[0049] In one embodiment, two coils 214 are provided within the conductive layer 23 of the first segment 211, the second segment 212, and the third segment 213. The width of the electrical angle between the two coils 214 in the conductive layer 23 of each segment is 180 degrees, and the difference in the electrical angles of the three layers of stator windings 20 is 120 degrees or 240 degrees.

[0050] Figure 10 shows the basic structure of the "double-folded" stator winding 20, formed by two layers of FPCB, in its unfolded state. The winding is three-phase and uses symmetrical concentrated winding with an electrical angle width of 180°. The flexible circuit board 21 consists of a first segment 211, a second segment 212, and a third segment 213. These three segments of the flexible circuit board 21 differ by an electrical angle distance of 120° or 240° in the tangential direction, and the coils 214 between the first segment 211, the second segment 212, and the third segment 213 are electrically connected. The A-phase winding is a coil 214 provided in the first segment 211. The flexible circuit board 21 of the first segment 211 forms a winding with a width of 180° wound from the outside to the inside. The coil 214 in the first conductive layer 23 of the A-phase winding is electrically connected to the coil 214 in the second conductive layer 23 of the first segment 211 via through-holes 215 after current is input via connection terminals 22.

[0051] The second conductive layer 23 located in the first segment 211 forms a winding with a width of 180° wound from the inside out and is connected via leads to the coil 214 of the flexible circuit board 21 of the second segment 212 in the same conductive layer 23. The flexible circuit board 21 of the second segment 212 forms a winding with a width of 180° wound from the outside in and is electrically connected via through-holes 215 to the coil 214 of the first conductive layer 23 of the flexible circuit board 21 of the second segment 212.

[0052] The windings for phase B and phase C are located on the flexible circuit boards 21 of the second segment 212 and third segment 213, respectively, and the winding and manufacturing method is the same as that for the phase A winding.

[0053] After the flexible circuit board 21 is manufactured by winding it in the manner shown in Figures 11 and 12, a cylindrical stator winding 20 is formed, whose outer diameter is the same as the inner diameter of the stator yoke 10. This cylindrical stator winding 20 is fixed to the inside of the stator yoke 10 by adhesive. The connection terminals 22 of the flexible circuit board 21 extend to the outside of the stator yoke 10 to facilitate connection to an external AC circuit.

[0054] In this embodiment, the flexible circuit board 21 is designed to have a first segment 211, a second segment 212, and a third segment 213, with the second segment 212 folded toward the first segment 211 so as to partially overlap it above, and the third segment 213 folded toward the second segment 212 so as to partially overlap it above. The first segment 211, the second segment 212, and the third segment 213 are each wound to form a three-layer stator winding 20 structure, and the electrical angles between each layer differ by only 120° or 240°. This structure makes the rotating magnetic field generated by the stator winding 20 more stable and uniform, improving the rotational stability of the rotor 40 and the operating efficiency of the motor, as well as reducing vibrations during motor operation.

[0055] Of course, this application is not limited to the structural design, winding and manufacturing method, and wiring design of the coil 214 of the flexible circuit board 21 in the stator structure according to the above embodiment. In other embodiments, the flexible circuit board 21 may further include a fourth segment, and the number of coils 214 in each segment is not limited to the two or three described above. The stator windings 20 in the flexible circuit board 21 may be of the distributed winding type, concentrated winding type, or wave winding type, and the three-phase system may be implemented using a Y connection method or a triangular connection method. Furthermore, the windings may be single-phase, two-phase, or other multi-phase stator windings 20. All of the above fall within the scope of protection of this application.

[0056] As shown in Figures 1 and 13, in one embodiment of the present invention, the stator structure further includes a magnetic field detection assembly 30 which includes a circuit control board 31 and a Hall sensor 32. The Hall sensor 32 is provided on the circuit control board 31, which is connected to the side of the flexible circuit board 21 where the connection terminals 22 are provided. The flexible circuit board 21 is wound to form a cylindrical stator winding 20. The shape of the circuit control board 31 is ring-shaped. After winding the flexible circuit board 21 to form the cylindrical stator winding 20, the circuit control board 31 is provided as a cover over the opening of the stator winding 20. Positioning grooves are made on the outer circumference of the circuit control board 31, and positioning teeth are provided in the opening of the stator winding. The positioning teeth are restricted to the position within the positioning grooves 33. The Hall sensor 32 is used to detect the magnetic field of the rotor 40 during motor operation, and thereby to detect the angle of the rotor 40.

[0057] In this embodiment, the circuit control board 31 is flexible to facilitate folding and covering the opening of the stator winding 20. To facilitate electrical connection of the circuit control board 31 to an external power supply via the connection terminals 22, the circuit control board 31 is located on the side of the flexible circuit board 21 closest to the connection terminals 22. The Hall sensor 32 includes pins for the positive terminal of the power supply, ground, and signal output, as well as additional pins for control signals and rotational speed signals. Therefore, multiple connection lines need to be connected to the Hall sensor 32 externally. By designing the circuit control board 31 flexibly, the circuit control board 31 and the flexible circuit board 21 can be integrated during processing, and the Hall sensor 32 can be electrically connected to an external circuit via the connection terminals 22. This greatly improves the space utilization rate of the motor, reduces the volume of the structure, and improves the convenience of wiring.

[0058] Multiple Hall sensors 32 are provided and spaced apart along the circumferential direction of the circuit control board 31 in order to improve the detection accuracy of the magnetic field at different positions on the rotor 40 by the magnetic field detection assembly 30. Multiple positioning grooves 33 are made on the outer circumference of the ring-shaped circuit control board 31, and multiple positioning teeth 24 are provided on one side of the flexible circuit board 21, with the multiple positioning teeth 24 and the circuit control board 31 all located on the same side of the flexible circuit board 21. When the circuit control board 31 is placed over the opening of the stator winding 20, each positioning tooth 24 engages with the positioning groove 3 of the circuit control board 31, thereby accurately attaching the circuit control board 31 to the stator winding 20, and consequently improving the detection accuracy and stability of the magnetic field of the rotor 40 by the Hall sensors 32 during motor operation.

[0059] The present invention further proposes an AC motor including a front end ring 50, a rear end ring 60, a rotor 40, a bearing 70, and a stator structure. The specific structure of this stator structure is described in the above embodiments, and since the AC motor utilizes all the technical proposals of all embodiments of the above stator structure, it has at least all the beneficial effects of the technical proposals of the above embodiments, which will not be described in general terms here.

[0060] The stator structure is provided with a front end ring 50 and a rear end ring 60 at both ends, respectively. The front end ring 50 and the rear end ring 60 are provided at both ends of the stator yoke 10 and are fixed and connected to the stator yoke 10 by adhesive. The stator yoke 10 may be formed by joining multiple annular silicon steel plates 11, and to strengthen the stator yoke 10, the multiple annular silicon steel plates 11 may be welded to the bonded stator yoke 10 by welding. The front end ring 50 and the rear end ring 60 are made of metal or other hard material to improve the structural strength of the stator. If the front end ring 50 and the rear end ring 60 are made of metal, they may be fixed and connected to the stator yoke 10 by welding.

[0061] The motor's two bearings 70 are attached to the motor's front ring 50 and rear ring 60, respectively. The motor's magnetic steel is attached to the rotor 40's rotating shaft, and both ends of the rotor 40 are rotatably connected to the motor's front ring 50 and rear ring 60 via the two bearings 70. When the motor is operating, an external controller inputs current to the motor's three-phase windings via the connection terminals 22 of the flexible circuit board 21. Because the windings formed using the stator structure described in this embodiment are spatially symmetrically distributed, the current, which is symmetrical in the three-phase time domain, forms a rotating magnetic field in the motor's air gap and interacts with the magnetic field of the rotor 40 to drive the rotor 40 and cause it to rotate.

[0062] The above describes only exemplary embodiments of the present invention and does not limit the scope of the patent. All transformations of equivalent structures created using the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, under the technical concept of the present invention, are all included within the scope of patent protection of the present invention. [Explanation of symbols]

[0063] 10: State York, 11: Annular silicon steel sheet, 12: Cavity, 20: Stator winding, 21: Flexible circuit board, 211: First segment, 212: Second segment, 213: Third segment, 214: Coil, 215: Through hole, 22: Wiring terminals, 23: Conductive layer, 24: Positioning teeth, 30: Magnetic field detection assembly, 31: Circuit control board, 32: Hall sensor, 33: Positioning groove, 40: Rotor, 50: Front end ring, 60: Rear end ring, 70: Bearing.

Claims

1. It has a stator structure, Inside is a stator yoke with a cavity formed through both ends, A stator winding comprising a flexible circuit board formed by winding, having the same shape as the cavity, wherein a connection terminal for connection to an external AC power supply is provided at one end of the flexible circuit board, the flexible circuit board comprises at least two conductive layers, a plurality of sets of coils are provided within the conductive layers, the plurality of sets of coils are arranged at intervals along the circumferential direction of the stator yoke and are all electrically connected to the connection terminal, the stator winding comprising at least two of the conductive layers stacked vertically, and the plurality of sets of coils within the guide layers, which are stacked on top of each other, are stacked in pairs along the radial direction of the stator yoke, and the magnetic field directions of two of the coils stacked on top of each other within the two conductive layers are the same, The stator structure is characterized in that the flexible circuit board is attached to the inner wall of the stator yoke, current flows through the coil, and generates a radial magnetic field perpendicular to the stator yoke in the air gap of the motor, and this magnetic field forms a magnetic field circuit using the stator yoke.

2. The stator structure according to claim 1, characterized in that the flexible circuit board includes two conductive layers arranged sequentially along the radial direction of the stator yoke, each of the conductive layers contains multiple sets of the coils, and the number of coils in the two conductive layers is the same.

3. Each of the conductive layers has a conductive through-hole in the middle of each coil, and 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 via the conductive through-hole. The stator structure according to claim 2, characterized in that, by the two coils stacked on top of each other, current flows through the coil of one of the conductive layers and through the conductive through-holes to the coil of the other conductive layer, and the magnetic fields generated after current flows through the two conductive layers can be superimposed in the same direction depending on the rotation direction of the two coils.

4. The stator structure according to claim 3, characterized in that three coils are provided within 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.

5. The flexible circuit board has a first segment and a second segment, and both the first segment and the second segment are provided with the same number of coils. The second segment is located above the first segment and is connected to one side of the first segment so as to partially overlap it, and is folded toward the first segment. The stator structure according to any one of claims 1 to 4, characterized in that the first segment and the second segment form two layers of stator windings that are wound and sequentially provided along the radial direction of the stator yoke.

6. The stator structure according to claim 5, characterized in that three coils are provided within the conductive layers of the first segment and the second segment, the width of the electrical angle of the three coils within the conductive layer of each segment is 120 degrees, and the difference in the electrical angles of the two layers of stator windings is 120 degrees or 240 degrees.

7. The flexible circuit board has a first segment, a second segment, and a third segment, and the first segment and the third segment are connected to the second segment on the same side or on opposite sides, The first segment, the second segment, and the third segment are each provided with the same number of coils, the second segment is folded toward the first segment until it partially overlaps the top of the first segment, and the third segment is folded toward the second segment until it partially overlaps the top of the second segment. The stator structure according to any one of claims 1 to 4, characterized in that the first segment, the second segment, and the third segment form three layers of stator windings that are wound and sequentially provided along the radial direction of the stator yoke.

8. The stator structure according to claim 7, characterized in that two coils are provided in the conductive layers of the first segment, the second segment, and the third segment, the width of the electrical angle between the two coils in the conductive layer of each segment is 180 degrees, and the difference in the electrical angles of the stator windings of the three segments is 120 degrees or 240 degrees.

9. The stator structure further includes a circuit control board and a magnetic field detection assembly including a Hall sensor. The stator structure according to any one of claims 1 to 4, characterized in that the Hall sensor is provided on the circuit control board, the circuit control board is connected to the side of the flexible circuit board where the connection terminals are provided, the flexible circuit board is wound to form the cylindrical stator winding, the shape of the circuit control board is ring-shaped, after the flexible circuit board is wound to form the cylindrical stator winding, the circuit control board is provided in a lid-like manner over the opening of the stator winding, a positioning groove is made on the outer circumference of the circuit control board, positioning teeth are provided in the opening of the stator winding, the positioning teeth are restricted to the position within the positioning groove, and the Hall sensor is used to detect the rotor magnetic field during motor operation and thereby to detect the rotor angle.

10. An AC motor characterized by comprising a front end ring, a rear end ring, a rotor, a bearing, and a stator structure according to any one of claims 1 to 4.

Images