An electric machine

Abstract

The present application relates to the technical fields of motor manufacturing and design, and specifically relates to a motor, comprising: a stator, a stator core with parallel tooth structure, the number of stator slots is N; a winding structure, located in the stator slot and comprising two sets of conductor stack columns symmetrical along the center line of the stator slot, each set is formed by N layers of conductors stacked from the bottom of the slot to the slot opening in turn, the thickness of each layer of conductors is selected from a limited set of standard thicknesses, and the widths are not completely equal; the included angle between the width side of the conductor cross section and the center line of the stator slot satisfies: each layer of conductors, the actual assembly gap between the outer edge of each layer of conductors and the slot side wall increases layer by layer along the direction from the slot opening to the slot bottom, and the non-uniform distribution is jointly determined by the thickness tolerance accumulation and the width manufacturing tolerance. The motor absorbs the manufacturing tolerance through the non-uniform gap, ensures a very high assembly yield, and realizes the maximization of slot fill rate.

Description

Technical Field

[0001] This invention relates to the field of motor manufacturing and design technology, and specifically to a motor. Background Technology

[0002] With the increasing demand for high-power-density motors in fields such as new energy vehicles and aerospace, improving stator slot fill factor has become one of the core research directions. While traditional flat wire windings offer the advantage of high slot fill factor, they can only be applied to parallel slot structures, resulting in significant limitations in structural adaptability. To further improve slot fill factor and adapt to complex slot shapes, high-fill-rate variable cross-section heterogeneous winding structures based on multi-specification conductor stacking have been proposed in recent years. This technology adjusts the conductor cross-section layer by layer according to the slot shape, pushing the slot fill factor to its physical limit while effectively reducing winding copper losses.

[0003] However, such high fill rate windings face severe assembly interference and yield bottlenecks in actual manufacturing. Processing tolerances are unavoidable in winding conductors. In existing nominal size designs, designers typically only reserve fixed safety gaps. However, when multiple conductors are stacked sequentially in slots, the minute thickness tolerances of a single conductor layer accumulate in the slot depth direction. Due to the inclined sidewalls of the trapezoidal slots, the positional offset in the thickness direction directly causes a change in the effective physical slot width corresponding to that conductor layer. When the accumulated thickness error is superimposed on the conductor's own width tolerance, it easily exceeds the effective boundary of the stator slot, causing assembly jamming; if forced assembly is attempted, there is a risk of scratching the insulation layer and causing short-circuit faults. Currently, engineering often uses globally enlarged reserved gaps to avoid the above interference problems, but this greatly suppresses the advantage of high slot fill rate in variable cross-section windings; blindly pursuing a high fill rate will lead to a serious decrease in batch manufacturing yield.

[0004] In conclusion, the industry urgently needs a high fill rate motor that can comprehensively consider tolerance accumulation and dimensional optimization while ensuring assembly yield. Summary of the Invention

[0005] This invention aims to provide a motor that addresses the problems of assembly interference and low yield caused by accumulated manufacturing tolerances in existing high-fill-rate variable cross-section windings. Specifically, this invention aims to optimize the thickness, width, and rotation angle of each conductor layer by comprehensively considering the accumulated thickness tolerances, width tolerances, and stator slot geometric constraints, while ensuring assembly yield (i.e., mass production success rate). It also employs non-uniformly distributed assembly gaps to maximize stator slot fill factor, reduce winding copper losses, and improve the motor's power density and manufacturing economy, all while avoiding assembly jamming and insulation damage. The technical solution adopted by this invention is as follows: This invention provides an electric motor, comprising: a stator, wherein the stator has a stator core with a parallel tooth structure, and the stator core has stator slots, the number of which is: The winding structure is installed within the stator slots. The winding structure includes two sets of conductor stacks symmetrically distributed along the centerline of the stator slots. Each set of conductor stacks consists of N layers of conductors stacked sequentially from the bottom of the slot to the opening of the slot along the thickness direction. The thickness of each conductor layer is selected from a finite set of standard thicknesses, and the width dimensions of each conductor layer are not exactly equal; the angle between the cross-sectional width side of each conductor layer and the center line of the stator slot. satisfy: The actual assembly gap between the outer edge of each conductor layer and the side wall of the stator slot increases layer by layer along the direction from the slot opening to the slot bottom. The non-uniform distribution of the actual assembly gap is determined by the cumulative thickness tolerance of each conductor layer and the width manufacturing tolerance, which is used to absorb manufacturing tolerances to prevent assembly interference.

[0006] In a preferred embodiment, each conductor layer is a heterogeneous conductor with a rectangular cross-section, made of copper plates of standard thickness through stamping or laser cutting processes, and the conductor layers are stacked and connected sequentially.

[0007] In a preferred embodiment, in the conductor stack, the shortest distance between two adjacent conductor layers is greater than the interlayer insulation distance threshold. The shortest distance between the inner end of each conductor and the center line of the stator slot is greater than the center line insulation gap threshold. The shortest distance between the outer end of each conductor and the stator slot sidewall is greater than the tooth wall insulation gap threshold. The shortest distance between the conductor at the bottom of the slot and the inner wall of the stator yoke is greater than the yoke insulation gap threshold. .

[0008] In a preferred embodiment, the effective thickness of each conductor layer along the depth direction of the stator slot is... The sum of the values ​​of the two layers and the sum of the nominal interlayer gaps shall not exceed the slot depth of the stator slot, where Let be the thickness of the i-th conductor layer.

[0009] In a preferred embodiment, the stator slot is a trapezoidal slot, with the bottom width being greater than the opening width.

[0010] In a preferred embodiment, the winding conductor layers within the stator slot have an insulating layer, the actual interlayer distance between adjacent conductors is configured to ensure interlayer withstand voltage, and the thickness, width, and included angle of each conductor layer are specified. It is configured to maximize the winding fill rate and make the cross-sectional area of ​​each conductor layer relatively uniform, under the condition that the geometric and spatial constraints are met and the overall assembly success rate of the winding structure is greater than or equal to a preset threshold.

[0011] In a preferred embodiment, the overall assembly success rate Determined by the following model: in , The total horizontal assembly deviation of the i-th conductor layer is... For the nominal assembly allowance of the i-th layer conductor, when E x,i When the probability density function is fi(x), ; The total horizontal assembly deviation is formed by superimposing the horizontal deviation mapped from the thickness tolerance and the width tolerance.

[0012] In a preferred embodiment, the thickness, width, and included angle of each conductor layer are... The parameter combination is obtained by using a mixed integer nonlinear programming solver or a heuristic optimization algorithm to maximize the winding fill rate and make the cross-sectional area of ​​each conductor layer relatively uniform, under the conditions of satisfying geometric and spatial constraints and the overall assembly success rate being greater than or equal to a preset threshold.

[0013] In a preferred embodiment, in the winding structure, the nominal assembly gap of each conductor layer is non-uniformly distributed, and the gradient of the non-uniform distribution satisfies that: from the slot opening to the slot bottom, for each additional conductor layer, the increase in the unilateral gap between that conductor layer and the slot sidewall is determined by the statistical characteristics of the cumulative thickness tolerance.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention is the first to optimize the assembly yield of high-fill-rate variable cross-section windings as a hard constraint. Addressing the assembly interference problem caused by the accumulation of thickness tolerances during multi-layer conductor stacking, this invention establishes a physical mapping model from thickness tolerances to interference deviations in the slot width direction, and quantitatively calculates the overall assembly success rate based on probability density functions and Monte Carlo simulations. Existing technologies (such as the Taguchi method in CN102693344A) mainly focus on the impact of manufacturing tolerances on the electromagnetic performance of motors (efficiency, power factor, etc.), without addressing the impact of tolerance accumulation during multi-layer conductor stacking on assembly feasibility. This invention maximizes slot fill rate while ensuring an assembly yield rate no lower than a preset threshold (e.g., 99.9%), effectively avoiding risks such as slot jamming, insulation scratches, and assembly failures.

[0015] This invention also proposes a non-uniform gap distribution strategy that gradually increases from the slot opening to the slot bottom. Specifically, to match the geometric characteristics of the trapezoidal slot (wider bottom, narrower opening) and the cumulative effect of thickness tolerances, conductors closer to the slot bottom have a larger gap to absorb accumulated dimensional deviations, while conductors closer to the slot opening have a smaller gap to improve slot fill rate. Existing technologies (such as CN101416370A and CN109075624A) all use fixed or uniform gap designs, which cannot simultaneously achieve high fill rate and tolerance compensation. This invention achieves the optimal balance between assembly reliability and space utilization through non-uniform gaps.

[0016] Furthermore, the manufacturability of the electrical engineering of this invention is significantly enhanced. Based on the characteristics of actual processing techniques, this invention constrains the conductor thickness to a discrete variable selectable from a set of standard commercially available copper plate thicknesses, while the conductor width can be arbitrarily adjusted (to adapt to laser cutting processes). While existing technologies (such as CN109075624A) mention common layering compatible with different conductor shapes, they do not consider the discrete constraints of standard thickness specifications. The constraint design of this invention avoids the customization of non-standard materials, reduces manufacturing costs and supply chain complexity, and has excellent adaptability to mass production.

[0017] This invention deeply integrates the product structure features and optimization results of the motor. In the final motor winding structure, the thickness, width, rotation angle, and non-uniform gap distribution of each conductor layer are specific parameter combinations optimized through mixed-integer nonlinear programming or heuristic algorithms, with the goals of maximizing fill factor and uniform cross-sectional area, while satisfying geometric and spatial constraints and assembly success rate thresholds. Existing technologies (such as CN101416370A) only provide empirical geometric ratio ranges and do not provide a design method that leads to the optimal structure; while this invention solidifies the optimization results into the product structure, resulting in a motor with not only a higher slot fill factor but also better manufacturing quality stability.

[0018] This invention solves the dilemma of "high fill rate and high yield": In traditional design, to avoid interference caused by tolerance accumulation, it is often necessary to globally enlarge the safety clearance, thereby sacrificing the slot fill rate; if a high fill rate is pursued, it will lead to a serious decrease in batch yield. This invention achieves both by jointly optimizing tolerance accumulation modeling, non-uniform gap distribution, and discrete thickness constraints, thus breaking through a long-standing technical bottleneck in the field of motor winding design. Attached Figure Description

[0019] Figure 1 This is a schematic cross-sectional view of the variable cross-section conductor stacked winding structure in the stator slot of the motor according to the present invention; Figure 2 This is a partially enlarged schematic diagram showing the definition of the winding conductor space constraint and tilt angle parameters of the motor according to the present invention; Figure 3This is a partially enlarged schematic diagram of the winding structure of the motor according to the present invention.

[0020] Explanation of reference numerals in the attached figures: 1-Stator slot; 2-Winding conductor; 3-Stator core. Detailed Implementation

[0021] To make the objectives, technical solutions, and beneficial effects of this invention clearer, preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described below are only for explaining the invention and are not intended to limit the scope of the claims. Any modifications, equivalent substitutions, or improvements made to parts of the structure within the concept and principles of this invention should be included within the protection scope of this invention.

[0022] like Figure 1 The diagram shows a cross-sectional view of the stator slot winding structure of the motor of the present invention. The motor winding structure of the present invention achieves high assembly success rate and high slot fill factor by optimizing the spatial layout of the windings, taking into account conductor manufacturing tolerances and their cumulative effects. The motor and winding structure will be described in detail below with reference to the accompanying drawings.

[0023] Specifically, Figure 1 The motor includes a stator, which has a stator core 3 with a parallel tooth structure, and stator slots 1 are formed on the stator core 3. In this embodiment, the stator slots have a parallel tooth structure, and the stator slot structure parameters include at least the number of stator slots N. s Stator slot wall profile parameters, such as slot bottom width, slot opening width, slot depth, and slot wall inclination angle, define the boundaries of the conductor's spatial position. Simultaneously, the number of conductor layers on one side of the winding is N (N≥2), i.e., the number of conductor stacked layers on one side of the stator slot centerline (symmetrically arranged on the other side). The winding conductor thickness is selected from a finite set of standard thicknesses Hset={h1, h2,…, hm}, where m is the total number of selectable standard conductor thickness specifications, and m≥1. Thickness specifications are, for example, 1.0 mm, 1.2 mm, 1.5 mm, etc., specifically determined based on commonly used electromagnetic wire specifications. The conductor width manufacturing process has its own tolerance distribution function, and the conductor thickness manufacturing process also has its own tolerance distribution function. These tolerance distribution functions can be determined by statistically analyzing historical production data or the process capability index provided by the supplier, and are typically normally distributed.

[0024] The winding structure of the present invention satisfies the following geometric and insulation safety constraints in its spatial arrangement within the stator slots. The conductor width w of each layer of the single-sided winding is... i Thickness h iThe angle α between the conductor cross-sectional width and the center line of the stator slot is used as a design variable (where the subscript i=1,2,…,N represents the layer number from the bottom of the slot to the opening of the slot), and spatial constraints including conductor spatial position boundaries, insulation safety gaps and stacking direction size constraints are constructed.

[0025] Specifically, the conductor spatial boundary constraints are as follows: the outer contour of the i-th layer conductor must be completely within the available space of the stator slot (the available space refers to the net area after deducting the insulating pad). The insulation safety clearance constraints are as follows: a minimum electrical insulation clearance of not less than a preset threshold must be maintained between adjacent conductors, between conductors and the slot wall, and between conductors and the slot wedge. The stacking direction dimension constraints are as follows: along the slot depth direction, the sum of the effective thicknesses of each conductor layer and the sum of the nominal interlayer clearances must not exceed the slot depth of the stator slot. Furthermore, a reasonable range of values ​​for the included angle α is also included, the specific expression of which will be given below.

[0026] Reference Figure 1 and Figure 2 In the winding structure of this invention, the spatial arrangement of conductors in the stator slots must meet the following geometric and insulation safety constraints: interlayer distance constraint for conductors on the same side, and the shortest distance between two adjacent layers of conductors on the same side is greater than the interlayer insulation distance threshold δ. layer This constraint is used to ensure interlayer insulation strength and provide tolerance space for assembly tolerances; the distance constraint between the conductor and the stator slot centerline requires that, in each winding, the shortest distance between the inner end of the conductor and the stator slot centerline is greater than the centerline insulation gap threshold. δ center This constraint prevents breakdown of the conductors on both sides due to manufacturing or assembly deviations, and also avoids phase-to-phase short circuits caused by the conductor's sharp corners crossing the centerline after rotation. The distance constraint between the conductor and the stator slot sidewall ensures that the shortest distance between the outer end (the side closest to the stator slot sidewall) of each conductor in each winding and the stator slot sidewall is greater than the tooth wall insulation gap threshold. δ teeth This constraint ensures sufficient electrical clearance between the conductor and the core teeth to prevent conductor grounding; the distance constraint between the bottom conductor of the slot and the inner wall of the stator yoke ensures that the shortest distance between the conductor closest to the bottom of the slot (i.e., the first layer of conductor) and the inner wall of the stator yoke is greater than the yoke insulation clearance threshold. δ yoke This constraint ensures the insulation safety between the bottom of the winding and the yoke core; stacking direction dimensional constraint: the effective thickness of each conductor layer ( The sum of the values ​​of the two layers and the sum of the nominal interlayer gaps shall not exceed the depth of the stator slot.

[0027] like Figure 3As shown, the included angle α is defined as the acute angle between the width side of the conductor cross-section and the center line of the stator slot. To prevent the conductor's end from encroaching into the space of adjacent slots after rotation, the range of values ​​for the included angle α is constrained to: ; Within this range, the effective thickness and width of the conductor can be flexibly adjusted to optimize the utilization of space within the slot.

[0028] The winding structure of this invention fully considers manufacturing tolerances and their cumulative effects in its design. Specifically, based on the tolerance distribution function of the thickness manufacturing process, the cumulative tolerance formed by the stacking of multiple conductors in the thickness direction is calculated; based on the stator core parallel tooth structure parameters, the cumulative tolerance in the thickness direction is mapped to the assembly interference deviation in the slot width direction; simultaneously, combined with the tolerance distribution function of the width manufacturing process, the overall assembly success rate P of the multilayer conductors in a single-sided winding is calculated. success Considering the actual width of each conductor layer in the width direction, successful assembly requires that, after considering all tolerances, each conductor still meets the spatial constraints. Assembly success rate P success The tolerance distribution function can be used for calculation through numerical integration or Monte Carlo simulation. For example, the estimated value can be obtained using the first-order second-moment method or the Monte Carlo method.

[0029] More specifically, in this embodiment, the assembly success rate prediction model is constructed as follows: First, let the thickness tolerance of the i-th conductor be T. hi Width tolerance is T wi Where i = 1, 2, ..., N. These tolerances are derived from the conductor thickness manufacturing process tolerance distribution function and the width manufacturing process tolerance distribution function, and in this embodiment, the width tolerance T wi With thickness tolerance T hi They are treated as independent random variables, each following its own probability distribution.

[0030] Secondly, calculate the cumulative tolerance of the i-th conductor in the thickness stacking direction. Since the conductor layers are stacked sequentially along the trench depth, the thickness tolerance of each layer will affect the spatial position of the subsequent layers. Therefore, the cumulative thickness deviation of the i-th layer is the algebraic sum of the thickness tolerances of the previous i layers.

[0031] Then, based on the stator slot tilt angle caused by the parallel tooth structure θ =180° / N s The cumulative tolerance in the thickness direction is mapped to the horizontal deviation in the effective groove width direction. Specifically, when there is an angle between the groove wall and the vertical direction... θ At that time, calculate the horizontal deviation of the effective groove width of the i-th layer caused by the accumulation of thickness tolerance. .

[0032] Furthermore, considering the width tolerance T of the i-th conductor layer... wi Calculate the total horizontal assembly deviation E faced by this conductor layer. x,i The total deviation consists of two parts: one is the horizontal offset caused by the accumulation of thickness tolerances, and the other is the dimensional change caused by the width tolerance itself. Therefore, the total horizontal assembly deviation is calculated as follows: ; The nominal assembly allowance M of the i-th layer conductor i Let M be the minimum horizontal margin between the outer edge of the i-th layer conductor and its corresponding effective slot boundary, under geometric and spatial constraints, with all conductors taking nominal dimensions and manufacturing tolerances ignored. This margin is a safety space reserved during design. Based on the nominal assembly margin M of the i-th layer conductor... i and the total horizontal assembly deviation E x,i Given the probability density distribution, calculate the independent assembly success rate P of the i-th conductor layer. i P i The calculation formula is as follows: P i =P(E x,i ≤M i ) When E x,i When the probability density function is fi(x), ; This is the probability that the total horizontal assembly deviation does not exceed the nominal assembly allowance. This probability value reflects the likelihood that, after considering manufacturing tolerances, the i-th layer conductor can be successfully installed into the slot without interference.

[0033] Finally, the overall assembly success rate P is obtained by multiplying the individual assembly success rates of all layer conductors. success : .

[0034] Furthermore, the tolerance distribution of the conductor width manufacturing process is independent of the tolerance distribution of the thickness manufacturing process, and the width tolerance T wi (i=1,2,…, N) and thickness tolerance T hi (i=1,2,…,N) are independent random variables, each following its own probability distribution function. Width tolerance T wi It follows the width manufacturing process tolerance distribution function, and the thickness tolerance T hi It follows the thickness manufacturing process tolerance distribution function. Since the width and thickness are controlled by different process steps (such as rolling, drawing, or punching), there is no statistical correlation between them, so the assumption that they are independent is reasonable.

[0035] In the winding structure of this invention, the parameter combinations of the thickness, width, and included angle α of each conductor layer are obtained through optimized configuration. Specifically, the parameter configuration aims to maximize the winding fill rate and ensure relatively uniform cross-sectional areas of each conductor layer, while satisfying the aforementioned geometric and spatial constraint model and achieving an overall assembly success rate P. success Under the condition that the thickness is greater than or equal to a preset threshold, the discrete thickness set H is obtained by optimizing the solution algorithm. set The optimal thickness hi is matched for each conductor layer, and the corresponding optimal conductor width wi and optimal included angle are calculated. α The optimization algorithm can employ, for example, a genetic algorithm, a particle swarm optimization algorithm, or a simulated annealing algorithm. Specifically, the optimization objective is: .

[0036] Preferably, since the design variables include continuous variables (the width wi of each conductor layer and the included angle) α Given the discrete variables (the thickness of each conductor layer, *hi*, must be selected from a pre-defined set of standard thicknesses), this optimization problem is essentially a mixed-integer nonlinear programming problem. To solve this problem, a mixed-integer nonlinear programming solver or a heuristic optimization algorithm (such as a genetic algorithm, particle swarm optimization, simulated annealing, etc.) is employed. This embodiment preferably uses a genetic algorithm because it can effectively handle a mixture of discrete and continuous variables and is less prone to getting trapped in local optima.

[0037] Based on the above optimized configuration, the winding structure of this invention features symmetrically arranged conductor stacks on both sides of the stator slot centerline. Within each stack, the nominal assembly gaps between conductors at different layers and the slot sidewalls are non-uniformly distributed. To compensate for the risk of assembly interference caused by accumulated tolerances, the gaps near the slot bottom gradually increase. This non-uniform distribution ensures that even if the actual total thickness increases due to positive tolerances, the gaps near the slot opening are not excessively large due to the narrower slot width, while the larger gaps near the slot bottom effectively absorb accumulated dimensional deviations, preventing interference.

[0038] The final winding structure consists of two rows of conductors symmetrically arranged along the centerline of the stator slots. Each row contains N layers of conductors, and the thickness, width, and rotation angle α of each layer are set according to the optimization results. The interlayer and end gaps are distributed according to the aforementioned non-uniform compensation rules. This structure can significantly improve the assembly success rate while maintaining a high slot fill factor and current density uniformity.

[0039] The present invention also provides a solid winding structure based on the above-described design method. The specific form, physical characteristics, and beneficial effects of this winding structure are described in detail below with reference to the accompanying drawings.

[0040] Reference Figure 1The winding structure is installed within the stator slot 1 of the stator core 3 with a parallel tooth structure. The stator core 3 is, for example, made of laminated silicon steel sheets, and the stator slots 1 are uniformly distributed along the circumferential direction, having a parallel tooth structure. The winding structure includes two sets of variable cross-section conductor stacks symmetrically distributed along the center line of the stator slots. Each stack is formed by stacking multiple layers of conductors sequentially along the radial (depth) direction of the stator slot. The two stacks are separated by the slot center line and are insulated from each other.

[0041] Winding conductor 2 is a heterogeneous conductor with a rectangular cross-section. "Heterogeneous" refers to the fact that conductors in different layers within the same stack are not identical in width and / or thickness, thus forming a variable cross-section structure. These conductors are manufactured from copper plates of standard thicknesses (e.g., 1.0 mm, 1.2 mm, 1.5 mm, etc.) using stamping or laser cutting processes. Unlike traditional round or square electromagnetic wires, this embodiment uses stamping or laser cutting processes to precisely control the conductor's outline dimensions and facilitates consistent tolerances in mass production. After stamping or laser cutting, the conductor edges can be deburred and chamfered to avoid damaging the interlayer insulation. Subsequently, the conductor layers are stacked sequentially and connected using methods such as welding, snap-fitting, or bonding to form continuous winding turns.

[0042] Reference Figure 3 After optimization using the design method of this invention, the winding structure exhibits significant physical characteristics: in the same stacked column, the thickness of each conductor layer is selected from a finite set of standard thicknesses, and the width dimensions of each conductor layer are not completely equal; the most crucial feature is that the gaps between the outer edges of each conductor layer and the sidewalls of stator slot 1 and the centerline of the slot exhibit a non-uniform distribution as the number of stacked layers increases. This non-uniform gap gradient is a result of the combined effect of the accumulated thickness tolerances and width manufacturing tolerances of the multi-layer conductors. The conductors closer to the bottom of the slot tend to have relatively larger reserved assembly gaps to absorb the interference risks caused by the accumulation of tolerances. Thus, the stator slot fill factor is maximized while ensuring the assembly yield meets the standards.

[0043] Specifically, refer to Figure 3The winding structure exhibits the following physical characteristics: (1) Variable cross-sectional characteristics of thickness and width: In the same stack, the thickness of each conductor layer is selected from a finite set of standard thicknesses, and the width of each conductor layer is not completely equal. Specifically, the conductor near the bottom of the slot (layer 1) is usually designed to be wider to withstand higher magnetic flux density; the conductor near the slot opening (layer N) can be appropriately narrowed to reserve more space for assembly adjustment. This variable cross-sectional design allows the winding to make more efficient use of the irregular space of the stator slot. (2) Non-uniformly distributed assembly gap: The most core feature is that the gap between the outer edge of each conductor layer and the side wall of stator slot 1 and the center line of the slot is non-uniformly distributed as the number of stacked layers increases. Specifically, from the slot opening to the slot bottom, the single-sided gap between the outer edge of each conductor layer and the slot wall gradually increases. (3) Formation mechanism of gap gradient: This non-uniformly distributed gap gradient is not arbitrarily set, but is the result of the cumulative thickness tolerance of the multilayer conductors and the width manufacturing tolerance. The cumulative thickness tolerances of multilayer conductors can cause overall offset in the stacked array. However, conductors near the slot opening have smaller widths and are less sensitive to lateral deviations, and the narrowing of the slot width at the opening has a self-guiding effect. Simultaneously, width manufacturing tolerances also contribute to determining the actual gaps required for each layer. Therefore, conductors near the slot bottom have larger assembly gaps to effectively absorb accumulated dimensional deviations; conductors near the slot opening have smaller gaps, but still ensure smooth assembly, thus achieving an optimal balance between assembly yield and slot fill factor overall.

[0044] By employing the aforementioned non-uniform gap distribution (the gap gradually increases from the slot opening to the slot bottom) and combining it with a variable cross-section conductor design, this winding structure can significantly improve the stator slot fill factor while ensuring assembly yield (e.g., greater than 99.9%). Compared to traditional uniform gap designs, this structure avoids wasting valuable space in the narrow slot opening area, while utilizing the ample area at the slot bottom to provide sufficient tolerance compensation, achieving an optimal match between space utilization and manufacturability.

[0045] In summary, compared with the prior art, the present invention has the following beneficial effects: Balancing high slot fill rate and high assembly yield: This invention constructs an assembly success rate prediction model that considers the accumulation of thickness tolerance and width tolerance. It accurately maps the accumulated tolerance in the thickness direction to the assembly interference deviation in the slot width direction, and optimizes the thickness, width, and rotation angle of each conductor layer accordingly. While ensuring the overall assembly success rate is not lower than a preset threshold (e.g., 99.9%), it maximizes the slot fill rate, overcoming the fill rate loss caused by globally enlarging the safety clearance to avoid interference in traditional designs.

[0046] A non-uniform gap distribution strategy is proposed: from the slot opening to the slot bottom, the gap between the conductor and the slot wall gradually increases on one side. This distribution matches the cumulative effect of thickness tolerance and the trapezoidal slot geometry with a wide bottom and narrow opening. A larger gap is reserved near the slot bottom to absorb the cumulative dimensional deviation, while a smaller gap is maintained near the slot opening to improve space utilization.

[0047] High manufacturability: This invention limits the thickness of each conductor layer to a discrete set of standard thicknesses, allowing conductors to be directly manufactured from standard copper plates through stamping or laser cutting processes. This avoids the customization of non-standard materials, significantly reduces manufacturing costs and supply chain complexity, and has good adaptability to mass production.

[0048] Hybrid variable optimization strategy: The design variables include both continuous variables (width and rotation angle of each conductor layer) and discrete variables (thickness of each conductor layer). Hybrid integer nonlinear programming or heuristic algorithms are used to find the optimal configuration of space utilization for variable cross-section windings.

[0049] Establish a tolerance accumulation physical mapping model: based on the slot inclination angle of the parallel tooth structure (θ=180° / N) s This method accurately maps the cumulative amount of thickness tolerance of multilayer conductors in the stacking direction to the horizontal deviation in the slot width direction. Combined with the probability distribution of width tolerance, it enables quantitative prediction of assembly success rate and provides a scientific basis for gap allocation.

[0050] The above describes in detail the specific implementation of the solid winding structure based on the design method of this invention. Those skilled in the art should understand that equivalent changes made to the conductor material, connection method, and specific values ​​of gap allocation, without departing from the principles of this invention, still fall within the protection scope of this invention.

Claims

1. An electric motor, characterized in that, include: The stator has a stator core with a parallel tooth structure, and stator slots are formed on the stator core. The number of stator slots is [number missing]. ; The winding structure is installed within the stator slots. The winding structure includes two sets of conductor stacks symmetrically distributed along the centerline of the stator slots. Each set of conductor stacks consists of N layers of conductors stacked sequentially from the bottom of the slot to the opening of the slot along the thickness direction. ; The thickness of each conductor layer is selected from a finite set of standard thicknesses, and the width dimensions of each conductor layer are not exactly equal. The angle between the cross-sectional width side of each conductor layer and the center line of the stator slot satisfy: ； The actual assembly gap between the outer edge of each conductor layer and the sidewall of the stator slot increases layer by layer along the direction from the slot opening to the slot bottom. The non-uniform distribution of the actual assembly gap is determined by the cumulative thickness tolerance of each conductor layer and the width manufacturing tolerance, which is used to absorb manufacturing tolerances to prevent assembly interference.

2. The motor according to claim 1, characterized in that, Each conductor layer is a heterogeneous conductor with a rectangular cross-section, made from copper plates of standard thickness through stamping or laser cutting processes, and the conductor layers are stacked and connected sequentially.

3. The motor according to claim 1, characterized in that, In the conductor stack, the shortest distance between two adjacent conductor layers is greater than the interlayer insulation distance threshold. The shortest distance between the inner end of each conductor and the center line of the stator slot is greater than the center line insulation gap threshold. The shortest distance between the outer end of each conductor and the stator slot sidewall is greater than the tooth wall insulation gap threshold. The shortest distance between the conductor at the bottom of the slot and the inner wall of the stator yoke is greater than the yoke insulation gap threshold. .

4. The motor according to claim 1, characterized in that, The stator slot is a trapezoidal slot, with the bottom width being greater than the opening width.

5. The motor according to claim 1, characterized in that, The winding conductors within the stator slots have an insulating layer between their layers. The actual interlayer distance between adjacent conductors is configured to ensure interlayer withstand voltage. Furthermore, the thickness, width, and included angle of each conductor layer are also specified. It is configured to maximize the winding fill rate and make the cross-sectional area of ​​each conductor layer relatively uniform, under the condition that the geometric and spatial constraints are met and the overall assembly success rate of the winding structure is greater than or equal to a preset threshold.

6. The motor according to claim 5, characterized in that, The overall assembly success rate Determined by the following model: in , The total horizontal assembly deviation of the i-th conductor layer is... For the nominal assembly allowance of the i-th layer conductor, when E x,i When the probability density function is fi(x), ; The total horizontal assembly deviation is formed by superimposing the horizontal deviation mapped from the thickness tolerance and the width tolerance.

7. The motor according to claim 1, characterized in that, The thickness, width, and included angle of each conductor layer The parameter combination is obtained by using a mixed integer nonlinear programming solver or a heuristic optimization algorithm to maximize the winding fill rate and make the cross-sectional area of ​​each conductor layer relatively uniform, under the conditions of satisfying geometric and spatial constraints and the overall assembly success rate being greater than or equal to a preset threshold.

8. The motor according to claim 1, characterized in that, In the winding structure, the nominal assembly gap of each conductor layer is non-uniformly distributed, and the gradient of the non-uniform distribution satisfies the following: from the slot opening to the slot bottom, for each additional conductor layer, the increase in the unilateral gap between that conductor layer and the slot sidewall is determined by the statistical characteristics of the cumulative thickness tolerance.

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