A motor winding, a motor stator and a motor

Abstract

The utility model provides a kind of motor winding, motor stator and motor, belong to motor technical field, including m phase winding, each phase winding includes multiple parallel branches, each parallel branch is wound in z stator slot, and each parallel branch includes multiple sequentially connected hairpin conductors;Multiple hairpin conductors of each parallel branch are sequentially wound all magnetic pole pairs, and multiple hairpin conductors of each parallel branch are cyclically crossed between outermost layer and innermost layer in z stator slot in sequence.The pitch of hairpin conductor in outermost layer cross line is not equal to pole pitch, the pitch of hairpin conductor in innermost layer cross line is not equal to pole pitch, and the pitch of hairpin conductor in adjacent two layers cross line is less than pole pitch.The utility model can make the end of multiple hairpin conductors staggered distribution in space, compress the end space of stator core, reduce the amount of copper, and can eliminate the circulation between parallel branch, reduce internal loss, improve the efficiency and performance of motor.

Description

Technical Field

[0001] This utility model belongs to the field of motor technology, and more specifically, it relates to a motor winding, a motor stator, and a motor. Background Technology

[0002] A flat-wire motor is a type of motor in which flat copper hairpin wire is used instead of traditional thin round wire in the stator winding of the drive motor. The stator winding of a flat-wire motor is shaped like a hairpin. The stator winding consists of multiple hairpin conductors, which are arranged in a certain way and inserted into the stator slots of the stator core to form the winding of the required single-phase or multi-phase motor.

[0003] In the existing technology, the arrangement of multiple hairpin conductors is complicated, resulting in a high stator end height and a large amount of copper used for welding. This leads to a larger overall size, higher cost, and lower efficiency of the motor. Utility Model Content

[0004] The purpose of this utility model is to provide a motor winding, a motor stator, and a motor, aiming to solve the technical problems in the prior art where the stator end height is too high, resulting in a large overall size, high cost, and low efficiency of the motor.

[0005] To achieve the above objectives, in a first aspect, this utility model provides a motor winding, including an m-phase winding, each phase winding including multiple parallel branches, each parallel branch being wound in z stator slots, each stator slot having N layers of hairpin windings, N≥4, and N being an odd number, the motor winding having p pole pairs, each parallel branch including multiple sequentially connected hairpin conductors; the multiple hairpin conductors of each parallel branch are continuously wound around all pole pairs to form a closed loop, and the multiple hairpin conductors of each parallel branch are sequentially and cyclically interleaved between the outermost and innermost layers in the z stator slots; Among them, the pitch of the hairpin conductor in the outermost layer of the same cross line is not equal to the pole pitch, the pitch of the hairpin conductor in the innermost layer of the same cross line is not equal to the pole pitch, and the pitch of the hairpin conductor in the two adjacent layers of the cross line is less than the pole pitch.

[0006] Compared with the prior art, the solution shown in this application embodiment has multiple hairpin conductors of each parallel branch continuously and sequentially winding around all magnetic pole pairs to form a closed loop. Each parallel branch itself is a series loop, which passes through each pair of magnetic poles of the motor in sequence, ensuring that the electromagnetic environment of each parallel branch in the same phase is completely symmetrical, so that their induced electromotive force is absolutely equal, thereby eliminating the circulating current between parallel branches, reducing internal losses, and improving the efficiency and performance of the motor. The multiple hairpin conductors of each parallel branch are sequentially and cyclically arranged between the outermost and innermost layers of the z stator slots, so that the ends of the hairpin conductors are spatially staggered, compressing the axial space at the stator ends and reducing the amount of copper used; moreover, each parallel branch cyclically passes through the outermost to the innermost layer of the stator slot, and the total length of the hairpin conductors contained in each parallel branch is nearly equal, ensuring that the DC resistance of each parallel branch is highly consistent, and the heat source of the hairpin conductors is more evenly distributed in space, avoiding local hot spots and facilitating heat dissipation; When the pitch of the hairpin conductors in adjacent crossover layers is less than the electrode pitch, this type of hairpin conductor uses a short pitch and a small crossover distance, which can correspondingly reduce the length of the ends, reduce the amount of copper used, and reduce resistance. When the pitch of the hairpin conductors in the same crossover layer is not equal to the electrode pitch, this type of hairpin conductor uses a combination of short pitch and long pitch. The ends of the long pitch hairpin conductors are more arched, while the ends of the short pitch hairpin conductors are less arched. The ends of hairpin conductors with different pitches will naturally be staggered in space, which can accommodate all hairpin conductors in a limited axial space, thereby reducing the height of the stator ends, reducing the amount of copper used, and reducing resistance.

[0007] In conjunction with the first aspect, in one possible implementation, the starting end of each of the parallel branches is located at the outermost layer of the stator slot, and the ending end is located at the adjacent layer of the outermost layer of the stator slot; or The starting end of each of the parallel branches is located in the innermost layer of the stator slot, and the ending end is located in the adjacent layer of the innermost layer of the stator slot.

[0008] By placing the starting end of the parallel branch on the outermost layer and the ending end on the adjacent layer of the outermost layer, all parts that need electrical connection are concentrated on the outermost or second outermost layer, which simplifies the bus structure and optimizes the hairpin conductor arrangement. There is no need to reserve extra messy space for bus and welding operations, making the stator end structure more modular and hierarchical.

[0009] In conjunction with the first aspect, in one possible implementation, the hairpin conductor includes an insertion section that passes through the stator slot, a closed section located outside the stator slot and connected to one end of the insertion section, and a welding section located outside the stator slot and connected to the other end of the insertion section; the welding section is arranged at an angle to the insertion section. In the same parallel branch, the multiple hairpin conductors from the outermost layer to the innermost layer are wound clockwise, and the multiple hairpin conductors from the innermost layer to the outermost layer are wound counterclockwise. The hairpin conductors crossing the same line in the outermost layer change their winding direction through the welding section, and the hairpin conductors crossing the same line in the innermost layer change their winding direction through the closing section.

[0010] Different combinations of hairpin conductors are wound in opposite directions, with their ends interlaced and nested together, rather than all stacked in the same direction. This interlaced and nested structure makes efficient use of space, compressing the overall volume and height of the ends to a theoretically minimum.

[0011] In conjunction with the first aspect, in one possible implementation, the number of slots per pole and per phase of the motor winding is three, each of the parallel branches forms p winding units, and the multiple hairpin conductors of each winding unit are distributed in adjacent layers from the outermost layer to the innermost layer and from the innermost layer to the outermost layer in z stator slots.

[0012] A parallel branch is divided into p winding units (i.e., the number of pole pairs), with each unit corresponding to one pole pair. This means that the winding excitation obtained by each pole pair is completely consistent, thus ensuring the electromagnetic symmetry of the motor throughout the entire circumference.

[0013] In some embodiments, the motor winding has three pole pairs, and each of the parallel branches forms three winding units, namely a first winding unit, a second winding unit, and a third winding unit; The pitch of the hairpin conductor in each of the winding units across two adjacent layers is τ-1; In each winding unit, the pitch of the hairpin conductor in the innermost layer of the same-layer crossover is τ-2 or τ+1, and the pitch of the hairpin conductor in the outermost layer of the same-layer crossover is τ-2 or τ+1. Where τ is the pole pitch of the motor winding, and τ = z / 2p.

[0014] The two winding units are electrically adjacent, but their main co-layer pitches (τ-2 and τ+1) are complementary. A specific order of magnetomotive force harmonics generated by one pitch is effectively canceled out by harmonics of similar amplitude but opposite phase generated by the other pitch.

[0015] In conjunction with the first aspect, in one possible implementation, the hairpin conductor includes an insertion section that passes through the stator slot, a closed section located outside the stator slot and connected to one end of the insertion section, and a welding section located outside the stator slot and connected to the other end of the insertion section; the welding section is arranged at an angle to the insertion section. In each of the parallel branches, the closed segment of one of the hairpin conductors is the starting end of the parallel branch, and the closed segment of the other hairpin conductor is the ending end of the parallel branch.

[0016] The starting and ending points of a parallel branch are critical nodes for connecting to external power sources or adjacent branches. Moving them all to the closed section means that the welding section no longer undertakes any external electrical input / output functions. The welding section only needs to handle the interconnection welding between internal conductors, eliminating the need to reserve extra space for power line introductions and terminal block installations. This allows for more flexible and compact layout of the welding section and solder joints.

[0017] In conjunction with the first aspect, in one possible implementation, the hairpin conductor includes an insertion section that passes through the stator slot, a closed section located outside the stator slot and connected to one end of the insertion section, and a welding section located outside the stator slot and connected to the other end of the insertion section; the welding section is arranged at an angle to the insertion section. In the same parallel branch, the welding segments of two adjacent hairpin conductors adopt one of the following: lap welding, plug welding, or short pin welding, in order to reduce the end height of the motor winding and reduce the amount of copper used.

[0018] In conjunction with the first aspect, in one possible implementation, each phase winding includes three parallel branches; the three parallel branches have the same position relative to the magnet, and each position has the same number of slot layers.

[0019] The fact that the three parallel branches are in the same position relative to the magnet means that their spatial positions on the circumference are exactly the same, ensuring that the magnetic field change pattern of each parallel branch is exactly the same, and the amplitude and phase of the generated back electromotive force are also completely consistent.

[0020] Secondly, this utility model embodiment also provides a motor stator, including a stator core having multiple stator slots and the aforementioned motor windings passing through the multiple stator slots.

[0021] Thirdly, this utility model embodiment also provides an electric motor, including the motor stator described above.

[0022] The motor stator and motor provided by this utility model, by adopting the above-mentioned motor winding, can make the ends of multiple hairpin conductors spatially staggered, compress the end space of the stator core, reduce the amount of copper used, and eliminate the circulating current between parallel branches, reduce internal losses, and improve the efficiency and performance of the motor. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A planar unfolded schematic diagram of the arrangement structure of one of the parallel branches of the motor winding provided in an embodiment of this utility model; Figure 2 for Figure 1 A schematic diagram of the planar arrangement of the first winding unit in the diagram; Figure 3 for Figure 1 A schematic diagram of the layout structure of the second winding unit in the diagram; Figure 4 for Figure 1 A schematic diagram of the layout structure of the third winding unit in the diagram; Figure 5 This is a schematic diagram of the structure of the hairpin conductor provided in an embodiment of the present invention.

[0025] In the picture: 11. First winding unit; 12. Second winding unit; 13. Third winding unit; 2. Hairpin conductor; 21. Insertion section; 22. Closing section; 23. Welding section. Detailed Implementation

[0026] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0027] It should be noted that when an element is referred to as being "set on" another element, it can be directly on or indirectly on that other element. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a number" means two or more, unless otherwise explicitly specified.

[0029] In permanent magnet synchronous motors, the stator can be classified into round wire conductors and flat copper wire conductors according to the cross-sectional shape of the stator windings. Motors using flat copper wire conductors are called flat wire motors. Flat wire motors can effectively improve slot fill factor, power density, and torque density.

[0030] The stator winding of a flat wire motor is shaped like a hairpin. The stator winding consists of multiple hairpin conductors, which are arranged in a certain way and inserted into the stator slots of the stator core to form the winding of the desired single-phase or multi-phase motor.

[0031] Traditional hairpin windings use a multi-layer independent bridging method, where each layer of conductors needs to be bent and stacked at the end, resulting in a significant increase in axial height. This increases the axial length of the motor, which is detrimental to compact designs. Moreover, in traditional layouts, the bridging paths of the hairpin conductors are not optimized, and the end jumpers are too long, leading to wasted copper. Multi-layer independent bridging requires additional conductor connections, further increasing copper consumption.

[0032] To address the aforementioned problems, this utility model provides a motor winding.

[0033] For ease of understanding, the technical terms appearing in the embodiments of this utility model will be explained below.

[0034] Stator: refers to the stationary part of an electric motor, whose function is to generate a rotating magnetic field.

[0035] Rotor: refers to the rotating part in an electric motor, which is used to convert electrical energy into mechanical energy.

[0036] A magnetic pole pair, or simply a pole pair, is the basic unit of magnetic field in an electric motor. A magnetic pole pair always consists of an N (north) pole and a S (south) pole.

[0037] Number of poles: This refers to the number of magnetic poles of the motor. If the number of pole pairs of a motor is 1, 2, 3, or 4, then the number of poles of the motor is 2, 4, 6, or 8.

[0038] Pole pitch: The distance on the circumferential surface occupied by each magnetic pole. For AC motors, it refers to the slot pitch occupied by each magnetic pole along the inner circle of the stator core, expressed in terms of the number of slots. The pole pitch is equal to the ratio of the number of stator slots Z to the number of magnetic poles 2p.

[0039] Pitch: refers to the number of slots occupied by the two effective sides of a single coil. For example, a pitch of 6 means that the two effective sides of the coil are 6 slots apart, that is, the two effective sides are embedded in the 1st and 7th slots respectively.

[0040] Slots per pole per phase: The number of slots occupied by each phase winding under each magnetic pole. It is usually expressed by the formula q=z / 2mp, where z is the number of stator slots, m is the number of phases of the motor, and p is the number of pole pairs.

[0041] Please refer to the following: Figures 1 to 5 The motor winding provided by this utility model will now be described. The motor winding includes an m-phase winding, each phase winding including multiple parallel branches, each parallel branch being wound in z stator slots, each stator slot having N layers of hairpin windings, N≥4, and N being an odd number, the motor winding having p magnetic pole pairs, each parallel branch including multiple sequentially connected hairpin conductors 2; the multiple hairpin conductors 2 of each parallel branch are continuously wound around all magnetic pole pairs to form a closed loop, and the multiple hairpin conductors 2 of each parallel branch are sequentially and cyclically straddled between the outermost and innermost layers in the z stator slots.

[0042] Among them, the pitch of the hairpin conductor 2 in the outermost layer of the same-layer crossover is not equal to the pole pitch, the pitch of the hairpin conductor 2 in the innermost layer of the same-layer crossover is not equal to the pole pitch, and the pitch of the hairpin conductor 2 in the two adjacent layers of crossover is less than the pole pitch.

[0043] The stator slots contain N layers of hairpin windings, which can be understood as each stator slot having N layers, each with a hairpin conductor 2. Among the N layers of the stator slot, the layer closest to the motor rotor is the innermost layer. The innermost layer can be either the first layer or the Nth layer. For ease of description, the following embodiment defines the innermost layer as the Nth layer and the outermost layer as the first layer.

[0044] Each parallel branch is arranged in a superimposed manner, and a complete parallel branch no longer belongs to only one magnetic pole pair. The multiple hairpin conductors 2 of each parallel branch are continuously wound around all magnetic pole pairs in sequence. Its starting hairpin conductor 2 is located in a slot of the first magnetic pole pair. Then, this parallel branch does not immediately return to the bus to connect with other parallel branches of the same phase. Instead, it is wound to the corresponding position of the second magnetic pole pair, and then connected to the third magnetic pole pair, and so on, until it continuously and in series passes through all p magnetic pole pairs.

[0045] Since the magnetic field under each pole pair of the motor is ideally identical, and the parallel branches connect all pole pairs in series, the total electromotive force induced in the parallel branches is Etotal = E1 + E2 + ... + Ep. Because the electromotive force of each pole pair is E1 ≈ E2 ≈ ... ≈ Ep, therefore Etotal = P * E1. For the other parallel branches of this phase, they all connect all pole pairs in series along the exact same path and in the exact same manner. Therefore, the magnitude and phase of the total electromotive force generated by all parallel branches are almost perfectly identical.

[0046] The multiple hairpin conductors 2 of each parallel branch are sequentially and cyclically installed between the outermost and innermost layers in z stator slots. This can be understood as each parallel branch being installed from the first layer to the second layer, then to the third layer, ... to the Nth layer, then to the N-1th layer, ... to the first layer, then to the first layer, and so on, repeating the above installation process.

[0047] In traditional designs, the ends of the hairpin conductors 2 connected in the same layer (especially long-pitch connections) are all stacked at the same height, resulting in tall and thick stator ends. The cyclic span design forces the connection points of the hairpin conductors 2 to spread out circumferentially, preventing them from being concentrated at one or two specific axial heights.

[0048] In the same parallel branch, the pitch of the hairpin conductor 2 in two adjacent layers is less than the pole pitch. "In two adjacent layers" means that the two effective sides of a hairpin conductor 2 are not in the same layer. For example, crossing from layer 1 to layer 2.

[0049] The cross-layer hairpin conductor 2 needs to exit from one depth in one stator slot and then enter another adjacent or nearby stator slot. If a long-pitch hairpin conductor 2 (i.e., pitch greater than pole pitch) is used, it means that the hairpin conductor 2 needs to traverse a long distance, and its end must be very long to achieve the long-distance jump. Conversely, if a short-pitch hairpin conductor 2 (i.e., pitch less than pole pitch) is used, the hairpin conductor 2 only needs to cross between adjacent or very close slots, and the length of its end bend can be shortened. Shortening the end length directly reduces the amount of ineffective copper used, thus reducing costs.

[0050] In the same parallel branch, the pitch of the hairpin conductor 2 in the same layer is not equal to the pole pitch. Here, "same layer" refers to the two effective edges of a hairpin conductor 2 being located in the same layer. For example, both entering and exiting from layer 1.

[0051] In a traditional layout, if all hairpin conductors 2 in the same layer use the same pitch, then the ends of all hairpin conductors 2 in this layer will have the same height and curvature. When a large number of hairpin conductors 2 are densely arranged, their ends will be stacked layer by layer at the same spatial height. In order to leave space for welding and avoid physical interference, the height (axial dimension) of the entire stator end has to be made higher, which leads to an increase in the axial length of the motor.

[0052] In this embodiment, the hairpin conductors 2 spanning the same layer employ a combination of long and short pitches, meaning that within the same layer, some hairpin conductors 2 jump further apart, while others jump closer together. The ends of the long-pitch hairpin conductors 2 are arched higher, while the ends of the short-pitch hairpin conductors 2 are arched lower. In this way, the ends of the hairpin conductors 2 with different pitches will naturally be staggered in space, thereby compressing the overall height of the end bundle.

[0053] Compared with the prior art, the motor winding provided by this utility model has multiple hairpin conductors 2 of each parallel branch continuously and sequentially wound through all magnetic pole pairs to form a closed loop. Each parallel branch itself is a series loop, which passes through each pair of magnetic poles of the motor in sequence, ensuring that the electromagnetic environment of each parallel branch in the same phase is completely symmetrical, so that their induced electromotive force is absolutely equal, thereby eliminating the circulating current between parallel branches, reducing internal losses, and improving the efficiency and performance of the motor. The multiple hairpin conductors 2 of each parallel branch are sequentially arranged between the outermost and innermost layers of the z stator slots, so that the ends of the hairpin conductors 2 are spatially staggered, which compresses the axial space at the stator ends and reduces the amount of copper used. Moreover, each parallel branch circulates through the outermost to the innermost layer of the stator slot, and the total length of the hairpin conductors 2 contained in each parallel branch is almost equal, which ensures that the DC resistance of each parallel branch is highly consistent. The heat source of the hairpin conductors 2 is more evenly distributed in space, avoiding local hot spots and facilitating heat dissipation. In the case of hairpin conductors 2 spanning adjacent layers, the pitch is smaller than the electrode pitch. This type of hairpin conductor 2 uses a short pitch and a small span distance, which can correspondingly reduce the length of the ends, reduce the amount of copper used, and reduce the resistance. In the case of hairpin conductors 2 spanning the same layer, the pitch is not equal to the electrode pitch. This type of hairpin conductor 2 uses a combination of short pitch and long pitch. The ends of the long pitch hairpin conductor 2 are arched higher, and the ends of the short pitch hairpin conductor 2 are arched lower. The ends of hairpin conductors 2 with different pitches will be naturally staggered in space. All hairpin conductors 2 can be accommodated in a limited axial space, thereby reducing the height of the stator ends, reducing the amount of copper used, and reducing the resistance.

[0054] In some embodiments, the above-mentioned parallel branches can be adopted as follows: Figure 1 The structure shown is described in the following document. Figure 1 The starting point of each parallel branch is located on the outermost layer of the stator slot, and the ending point is located on the adjacent layer of the outermost layer of the stator slot. If the first layer is defined as the outermost layer, then the starting point of each parallel branch is located on the first layer of the stator slot, and the ending point is located on the second layer of the stator slot.

[0055] In complex winding arrangements, the starting and ending points of each parallel branch may be distributed at different axial heights (different layers) and different circumferential angles. To connect them, the busbar must be designed as a complex three-dimensional structure with steps and bends of varying heights to accurately contact each dispersed connection point. This complex-shaped busbar is not only difficult to design, but also incurs high mold costs.

[0056] In this embodiment, the starting end of the parallel branch is located on the outermost layer, and the ending end is located on the adjacent layer of the outermost layer. All parts requiring electrical connection are concentrated on the outermost or second-outermost layer. The busbar can be designed as a simple two-dimensional planar ring or strip structure, eliminating the need for complex axial bending and height changes. Simple planar ring or strip busbars are standard parts, easy to design and mass-produce.

[0057] In addition, concentrating all electrical connection points in the outermost and second outermost layers means that the internal space can be used more fully to optimize the arrangement of hairpin conductors 2, without the need to reserve extra messy space for busbars and welding operations, making the stator end structure more modular and hierarchical.

[0058] In another embodiment, the starting end of each parallel branch is located in the innermost layer of the stator slot, and the ending end is located in the adjacent layer of the innermost layer of the stator slot.

[0059] In some embodiments, the hairpin conductor 2 includes an insertion section 21 that passes into the stator slot, a closed section 22 located outside the stator slot and connected to one end of the insertion section 21, and a welding section 23 located outside the stator slot and connected to the other end of the insertion section 21; the welding section 23 is arranged at an angle to the insertion section 21, such as... Figure 5 As shown.

[0060] In the same parallel branch, multiple hairpin conductors 2 from the outermost layer to the innermost layer are wound clockwise, and multiple hairpin conductors 2 from the innermost layer to the outermost layer are wound counterclockwise. The hairpin conductors 2 that cross the same line in the outermost layer change the winding direction through the welding section 23, and the hairpin conductors 2 that cross the same line in the innermost layer change the winding direction through the closing section 22.

[0061] The insertion section 21, closing section 22 and welding section 23 of the hairpin conductor 2 are existing technologies. The insertion section 21 is inserted into the slot of the stator core and carries the motor operating current. It is the main part of the winding conduction. When the current flows through the insertion section 21, a magnetic field is generated in the stator slot, which interacts with the rotor magnetic field to realize the conversion of electrical energy into mechanical energy.

[0062] The closed section 22 is located outside one end slot of the stator core, connecting one end of the two insertion sections 21 of the same hairpin conductor 2, forming the electrical circuit basis of the hairpin conductor 2 itself, and affecting the end space structure. The shape and height of the closed section 22 directly affect the axial dimension of the motor end.

[0063] The welding section 23 is located outside the slot at the other end of the stator core and is connected to the other end of the insertion section 21 to realize the electrical connection between different hairpin conductors 2 and construct a complete winding circuit.

[0064] The welding section 23 and the insertion section 21 are set at an angle, which allows the ends of the insertion sections 21 in adjacent slots (i.e., the starting ends of the welding sections 23) to be spatially offset by a certain angle or distance. By selecting which two conductors to weld the welding sections 23 and adjusting the bending angle of the welding sections 23, the path length of the current flow can be precisely controlled, thereby achieving different winding pitches.

[0065] In the same parallel branch, multiple hairpin conductors 2 are wound clockwise from the outermost to the innermost layer, and counterclockwise from the innermost to the outermost layer. The ends (closed section 22 and soldered section 23) of the clockwise-wound hairpin conductors 2 naturally tilt in one direction. The ends of the counterclockwise-wound hairpin conductors 2 naturally tilt in the opposite direction. When different combinations of hairpin conductors 2 are wound in opposite directions, their ends interlock and nest together, rather than being stacked in the same direction. This interlocking and nesting structure efficiently utilizes space, compressing the overall volume and height of the ends to a theoretically minimum.

[0066] Furthermore, the number of hairpin conductors 2 in a parallel branch is very large, and the ends of the hairpin conductors 2 are very close together. If the bending direction and curvature of all hairpin conductors 2 are consistent, serious physical contact and short circuit risks can easily occur. This embodiment, by specifying the winding direction, is equivalent to controlling the extension trajectory of the end of each hairpin conductor 2 in space. The bending in opposite directions naturally creates a safe electrical clearance in the dense cluster of ends, ensuring that hairpin conductors 2 at different potentials will not touch each other, thus improving the reliability of the motor.

[0067] In some embodiments, the above-mentioned parallel branches can also adopt, for example... Figure 2 , Figure 3 and Figure 4 The structure shown is described in the following document. Figure 2 , Figure 3 and Figure 4 Each pole and each phase of the motor winding has three slots. Each parallel branch forms p winding units. Multiple hairpin conductors 2 of each winding unit are distributed in z stator slots in adjacent layers from the outermost to the innermost layer and from the innermost to the outermost layer.

[0068] A parallel branch is divided into p winding units (i.e., the number of pole pairs), with each unit corresponding to one pole pair. This means that the winding excitation obtained by each pole pair is completely consistent, thus ensuring the electromagnetic symmetry of the motor across the entire circumference. The highly symmetrical magnetic field and extremely low harmonic content reduce the motor's torque ripple and vibration noise.

[0069] The multiple hairpin conductors 2 of each winding unit are distributed in a cross-layout pattern from the outside to the inside and then from the inside to the outside. The spatial paths of all hairpin conductors 2 become highly regular and predictable, eliminating the redundant space caused by randomness and compressing the end volume to the theoretical limit.

[0070] Preferably, based on the above embodiment, the motor winding has three magnetic pole pairs, and each parallel branch forms three winding units, namely the first winding unit 11, the second winding unit 12 and the third winding unit 13.

[0071] The pitch of the hairpin conductor in the adjacent two layers of each winding unit is τ-1; the pitch of the hairpin conductor in the innermost layer of each winding unit is τ-2 or τ+1, and the pitch of the hairpin conductor in the outermost layer of each winding unit is τ-2 or τ+1; where τ is the pole pitch of the motor winding, and τ=z / 2p.

[0072] The two winding units are electrically adjacent, but their main co-layer pitches (τ-2 and τ+1) are complementary. A specific order of magnetomotive force harmonics generated by one pitch is effectively canceled out by harmonics of similar amplitude but opposite phase generated by the other pitch.

[0073] Specifically, for one of the parallel branches, the pitch of the hairpin conductor 2 in the outermost layer of the first winding unit 11 is τ-2, and the pitch of the hairpin conductor 2 in the innermost layer is τ+1; the pitch of the hairpin conductor 2 in the outermost layer of the second winding unit 12 is τ+1, and the pitch of the hairpin conductor 2 in the innermost layer is τ-2; the pitch of the hairpin conductor 2 in the outermost layer of the third winding unit 13 is τ+1, and the pitch of the hairpin conductor 2 in the innermost layer is τ+1.

[0074] For the second parallel branch, the pitch of the hairpin conductor 2 in the outermost layer of the first winding unit 11 is τ+1, and the pitch of the hairpin conductor 2 in the innermost layer is τ-2; the pitch of the hairpin conductor 2 in the outermost layer of the second winding unit 12 is τ+1, and the pitch of the hairpin conductor 2 in the innermost layer is τ+1; the pitch of the hairpin conductor 2 in the outermost layer of the third winding unit 13 is τ-2, and the pitch of the hairpin conductor 2 in the innermost layer is τ+1.

[0075] For the third parallel branch, the pitch of the hairpin conductor 2 in the outermost layer of the first winding unit 11 is τ+1, and the pitch of the hairpin conductor 2 in the innermost layer is τ+1; the pitch of the hairpin conductor 2 in the outermost layer of the second winding unit 12 is τ-2, and the pitch of the hairpin conductor 2 in the innermost layer is τ+1; the pitch of the hairpin conductor 2 in the outermost layer of the third winding unit 13 is τ+1, and the pitch of the hairpin conductor 2 in the innermost layer is τ-2.

[0076] In some embodiments, the above-mentioned parallel branches can also adopt, for example... Figure 1 The structure shown is described in the following document. Figure 1 In each parallel branch, the closed segment 22 of one hairpin conductor 2 is the starting end of the parallel branch, and the closed segment 22 of the other hairpin conductor 2 is the ending end of the parallel branch. That is to say, the starting and ending ends of the parallel branch are far away from the welding segment 23, which saves space in the welding segment 23 and reserves space for welding.

[0077] Due to the limited space at the end of the welding section 23, which needs to accommodate a large number of bending, crossing, and welding operations of the hairpin conductors 2, it is the most complex area in terms of process. The starting and ending points of the parallel branch are key nodes for connecting external power sources or adjacent branches. Moving them all to the closed section 22 means that the welding section 23 no longer undertakes any external electrical input / output functions.

[0078] Welding section 23 only needs to handle the interconnection welding between internal conductors, without requiring additional space for power line introduction or terminal block installation. This allows for more flexible and compact layout of welding section 23 and solder joint arrangement.

[0079] In some embodiments, in the same parallel branch, the welding segments 23 in two adjacent hairpin conductors 2 adopt one of the following: lap welding, plug welding, and short pin welding.

[0080] The welding pins of the traditional welding section 23 are parallel to the insertion section 21. After welding, they will protrude, thereby increasing the end height of the motor winding and requiring a large amount of copper wire.

[0081] In this embodiment, the welding pins in welding segment 23 are constructed using one of the following methods: lap welding, plug welding, or short pin welding. Lap welding and plug welding increase the contact area between adjacent welding segments 23, improving the structural stability after welding. Furthermore, lap welding and plug welding do not require welding pins, thereby reducing the end height of the motor winding and decreasing the amount of copper wire used. For short pin welding, the welding pins in welding segment 23 are short pins. Preferably, the height of the welding pin is less than or equal to 5mm, which reduces the amount of copper wire used and saves space compared to existing pin heights.

[0082] In some embodiments, each phase winding includes three parallel branches; the three parallel branches are at the same position relative to the magnet, and each position has the same number of slot layers.

[0083] The fact that the three parallel branches have the same position relative to the magnet means that their spatial positions on the circumference are exactly the same. This ensures that the magnetic field change pattern of each parallel branch is exactly the same, and therefore the amplitude and phase of the generated back electromotive force are also exactly the same.

[0084] Since the induced electromotive force of each parallel branch is exactly the same, no harmful circulating current will be generated when they are connected in parallel. Furthermore, the total current from the power supply will be automatically and evenly distributed according to the DC resistance of each parallel branch, avoiding local overcurrent and additional losses caused by uneven current distribution.

[0085] Example 1 See Figure 1 The stator shown in the diagram is the stator of a 54-slot, 6-pole motor. That is, the stator core comprises 54 stator slots, all of which are sequentially numbered. The rotor has 6 poles (i.e., 3 pole pairs p) and a pole pitch of 9. Furthermore, the winding includes five layers of hairpin conductors 2, specified as the fifth layer to the first layer radially from the inside out within the same stator slot. Figure 1 In the middle row, the numbers represent the stator slot numbers, and the five lines from left to right in each slot correspond to the first to fifth layers respectively.

[0086] The motor windings consist of three phases: phase A, phase B, and phase C. Each phase winding includes three parallel branches. The three-phase stator windings employ three types of hairpin conductors 2: the first type has a pitch of 7, the second type has a pitch of 10, and the third type has a pitch of 8.

[0087] exist Figure 1 In the diagram, A1 is the input terminal of one of the parallel branches of the A-phase winding, and X1 is the output terminal corresponding to the parallel branch. The arrangement of the windings of each phase of the motor is now explained using the winding method of the A-phase winding.

[0088] Specifically, the A-phase winding includes parallel branches A1, A2, and A3. The positions of the multiple stator slots corresponding to the insertion sections 21 of the multiple hairpin conductors 2 in parallel branch A1 are as follows: 8-slot layer 1, 1-slot layer 1, 9-slot layer 2, 1-slot layer 3, 9-slot layer 4, 1-slot layer 5, 45-slot layer 5, 53-slot layer 4, 45-slot layer 3, 53-slot layer 2 45 slots, 1 layer; 35 slots, 1 layer; 43 slots, 2 layers; 35 slots, 3 layers; 43 slots, 4 layers; 35 slots, 5 layers; 28 slots, 5 layers; 36 slots, 4 layers; 28 slots, 3 layers; 36 slots, 2 layers 28 slots, 1 layer; 18 slots, 1 layer; 26 slots, 2 layers; 18 slots, 3 layers; 26 slots, 4 layers; 18 slots, 5 layers; 8 slots, 5 layers; 16 slots, 4 layers; 8 slots, 3 layers; 16 slots, 2 layers The 8-slot layer 1 represents the position of the stator slot corresponding to the insertion section 21 at the starting end of the parallel branch A1, and the 16-slot layer 2 represents the position of the stator slot corresponding to the insertion section 21 at the ending end of the parallel branch A1. Among them, the first winding unit 11 of A1 is from the 8-slot layer 1 to the 53-slot layer 2, the second winding unit 12 of A1 is from the 45-slot layer 1 to the 36-slot layer 2, and the third winding unit 13 of A1 is from the 28-slot layer 1 to the 16-slot layer 2.

[0089] The positions of the multiple stator slots corresponding to the insertion sections 21 of the multiple hairpin conductors 2 in the parallel branch A2 are as follows: 9 slots, 1 layer; 53 slots, 1 layer; 7 slots, 2 layers; 53 slots, 3 layers; 7 slots, 4 layers; 53 slots, 5 layers; 46 slots, 5 layers; 54 slots, 4 layers; 46 slots, 3 layers; 54 slots, 2 layers 46 slots, 1 layer; 36 slots, 1 layer; 44 slots, 2 layers; 36 slots, 3 layers; 44 slots, 4 layers; 36 slots, 5 layers; 26 slots, 5 layers; 34 slots, 4 layers; 26 slots, 3 layers; 34 slots, 2 layers 26 slots, 1st layer; 19 slots, 1st layer; 27 slots, 2nd layer; 19 slots, 3rd layer; 27 slots, 4th layer; 19 slots, 5th layer; 9 slots, 5th layer; 17 slots, 4th layer; 9 slots, 3rd layer; 17 slots, 2nd layer Slot 9, Layer 1 represents the position of the stator slot corresponding to the insertion section 21 at the starting end of parallel branch A2, and Slot 17, Layer 2 represents the position of the stator slot corresponding to the insertion section 21 at the ending end of parallel branch A2. Specifically, Slot 9, Layer 1 to Slot 54, Layer 2 constitute the first winding unit 11 of A2, Slot 46, Layer 1 to Slot 34, Layer 2 constitute the second winding unit 12 of A2, and Slot 26, Layer 1 to Slot 17, Layer 2 constitute the third winding unit 13 of A2.

[0090] The positions of the multiple stator slots corresponding to the insertion sections 21 of the multiple hairpin conductors 2 in the parallel branch A3 are as follows: 10 slots per layer, 54 slots per layer, 8 slots per layer, 54 slots per layer, 8 slots per layer, 54 slots per layer, 44 slots per layer, 52 slots per layer, 44 slots per layer, 52 slots per layer, 52 slots per layer 44 slots, 1st layer; 37 slots, 1st layer; 45 slots, 2nd layer; 37 slots, 3rd layer; 45 slots, 4th layer; 37 slots, 5th layer; 27 slots, 5th layer; 35 slots, 4th layer; 27 slots, 3rd layer; 35 slots, 2nd layer 27 slots, 1 layer; 17 slots, 1 layer; 25 slots, 2 layers; 17 slots, 3 layers; 25 slots, 4 layers; 17 slots, 5 layers; 10 slots, 5 layers; 18 slots, 4 layers; 10 slots, 3 layers; 18 slots, 2 layers Slot 10, layer 1 represents the position of the stator slot corresponding to the insertion section 21 at the starting end of parallel branch A3, and Slot 18, layer 2 represents the position of the stator slot corresponding to the insertion section 21 at the ending end of parallel branch A3. Specifically, slots 10, layer 1 to 52, layer 2 constitute the first winding unit 11 of A3; slots 44, layer 1 to 35, layer 2 constitute the second winding unit 12 of A3; and slots 27, layer 1 to 18, layer 2 constitute the third winding unit 13 of A3.

[0091] Since the arrangement of the insertion section 21 between parallel branches is the same under every two pairs of rotor poles, this embodiment only analyzes the arrangement of the insertion section 21 between parallel branches of the A-phase winding. For the analysis of parallel branches of the B-phase and C-phase windings, the A-phase winding can be referred to, and for the sake of saving space, it will not be explained in detail here.

[0092] Based on the same inventive concept, this application also provides a motor stator, including a stator core and the aforementioned motor winding. The stator core includes a plurality of stator slots distributed circumferentially. The motor winding is wound around the stator core, and the insertion section 21 is located in the stator slot.

[0093] Based on the same inventive concept, this application also provides an electric motor, including the above-mentioned motor stator.

[0094] The motor stator and motor provided by this utility model, by adopting the above-mentioned motor winding, can make the ends of multiple hairpin conductors 2 spatially staggered, compress the end space of the stator core, reduce the amount of copper used, and eliminate the circulating current between parallel branches, reduce internal losses, and improve the efficiency and performance of the motor.

[0095] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A motor winding, comprising m-phase windings, each phase winding comprising multiple parallel branches, each of the parallel branches being wound in z stator slots, each of the stator slots having N layers of hairpin windings, N≥4, and N being an odd number, the motor winding having p pole pairs, characterized in that, Each of the parallel branches includes multiple hairpin conductors connected in sequence; the multiple hairpin conductors of each of the parallel branches continuously and sequentially wind around all magnetic pole pairs to form a closed loop, and the multiple hairpin conductors of each of the parallel branches are sequentially and cyclically arranged between the outermost and innermost layers in the z stator slots; Among them, the pitch of the hairpin conductor in the outermost layer of the same cross line is not equal to the pole pitch, the pitch of the hairpin conductor in the innermost layer of the same cross line is not equal to the pole pitch, and the pitch of the hairpin conductor in the two adjacent layers of the cross line is less than the pole pitch.

2. The motor winding of claim 1, wherein, The starting end of each of the parallel branches is located at the outermost layer of the stator slot, and the ending end is located at the adjacent layer of the outermost layer of the stator slot; or The starting end of each of the parallel branches is located in the innermost layer of the stator slot, and the ending end is located in the adjacent layer of the innermost layer of the stator slot.

3. The motor winding of claim 1, wherein, The hairpin conductor includes an insertion section that passes through the stator slot, a closed section located outside the stator slot and connected to one end of the insertion section, and a welding section located outside the stator slot and connected to the other end of the insertion section; the welding section is arranged at an angle to the insertion section; In the same parallel branch, the multiple hairpin conductors from the outermost layer to the innermost layer are wound clockwise, and the multiple hairpin conductors from the innermost layer to the outermost layer are wound counterclockwise. The hairpin conductors crossing the same line in the outermost layer change their winding direction through the welding section, and the hairpin conductors crossing the same line in the innermost layer change their winding direction through the closing section.

4. The motor winding of claim 1, wherein, The motor winding has three slots per pole and per phase. Each parallel branch forms p winding units. The multiple hairpin conductors of each winding unit are distributed in adjacent layers from the outermost layer to the innermost layer and from the innermost layer to the outermost layer in z stator slots.

5. The motor winding of claim 4, wherein, The motor winding has three pole pairs, and each of the parallel branches forms three winding units; The pitch of the hairpin conductor in each of the winding units across two adjacent layers is τ-1; In each winding unit, the pitch of the hairpin conductor in the innermost layer of the same-layer crossover is τ-2 or τ+1, and the pitch of the hairpin conductor in the outermost layer of the same-layer crossover is τ-2 or τ+1. Where τ is the pole pitch of the motor winding, and τ = z / 2p.

6. The motor winding of claim 1, wherein, The hairpin conductor includes an insertion section that passes through the stator slot, a closed section located outside the stator slot and connected to one end of the insertion section, and a welding section located outside the stator slot and connected to the other end of the insertion section; the welding section is arranged at an angle to the insertion section. In each of the parallel branches, the closed segment of one of the hairpin conductors is the starting end of the parallel branch, and the closed segment of the other hairpin conductor is the ending end of the parallel branch.

7. The motor winding of claim 1, wherein The hairpin conductor includes an insertion section that passes through the stator slot, a closed section located outside the stator slot and connected to one end of the insertion section, and a welding section located outside the stator slot and connected to the other end of the insertion section; the welding section is arranged at an angle to the insertion section. In the same parallel branch, the welding segments of two adjacent hairpin conductors adopt one of the following: lap welding, plug welding, and short pin welding.

8. The motor winding of claim 1, wherein, Each phase winding includes three parallel branches; the three parallel branches are in the same position relative to the magnet, and each position has the same number of slot layers.

9. An electric machine stator, characterized by It includes a stator core having multiple stator slots and a motor winding as described in any one of claims 1-8, which is connected within the multiple stator slots.

10. An electric machine characterized by Includes the motor stator as described in claim 9.

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