A skew-pole permanent magnet rotor and a design method thereof

Abstract

The application discloses a skew pole permanent magnet rotor and a design method thereof, and belongs to the technical field of motor design. In order to solve the problem that a single point positioning of a skew pole segmented rotor of a permanent magnet motor is difficult to bear a large torque, leading to local stress concentration of a rotating shaft, the application comprises a rotating shaft and Ns segmented iron core modules which are sequentially stacked on the rotating shaft in an axial direction; the Ns segmented iron core modules are all made of iron core stampings which are stacked in a same structure; Npro positioning protrusions are arranged on an inner circumference of the segmented iron core modules, and a magnetic steel groove for mounting a permanent magnet is arranged on an upper surface of the segmented iron core modules; a plurality of positioning grooves extending in the axial direction are arranged on an outer cylindrical surface of the rotating shaft; a geometric center line of the magnetic steel groove is set as a magnetic pole center line for representing an electromagnetic phase of the segmented iron core modules; and adjacent segmented iron core modules are assembled in a staggered and shared groove mode to realize skew pole of the rotor. The application effectively improves the operation reliability of a rotor system.

Description

Technical Field

[0001] This invention belongs to the field of motor design technology, specifically relating to a slanted-pole permanent magnet rotor and its design method that balances reliability and ease of manufacturing. Background Technology

[0002] In the design of permanent magnet synchronous motors, a segmented staggered pole technique is often used to reduce cogging torque and electromagnetic torque pulsation. This technique requires that each segment of the rotor core be staggered by a small mechanical angle along the circumferential direction on the shaft.

[0003] Currently, there are two main schemes for achieving segmented misalignment positioning, but both have significant engineering limitations:

[0004] Multiple stamping die scheme: Using stampings with different positioning points to achieve skewed poles. This scheme results in the number of stamping dies increasing exponentially with the number of core segments, leading to high manufacturing costs.

[0005] A single mold combined with a multi-groove shaft design: all segments use identical core laminations, while multiple sets of locating grooves corresponding to the number of segments are independently machined on the shaft. Because the angles of inclination between adjacent core segments are extremely small, the locating grooves are densely distributed in the shaft space, easily causing interference with machining tools. Simultaneously, the dense slotting severely reduces the effective cross-sectional area of ​​the shaft, leading to a significant decrease in fatigue life.

[0006] Furthermore, to simplify the structure, segmented rotors typically have only one positioning protrusion on a single lamination. In applications requiring high dynamics, high-frequency abrupt changes, or extremely high power density, the massive electromagnetic torque between the rotor and the shaft is borne entirely by a single node. This can easily cause the shear stress at that point to exceed the material's yield limit, leading to shear failure of the positioning structure or localized plastic deformation of the core, thus jeopardizing the reliability of the rotor system.

[0007] In summary, the existing segmented rotor positioning structure for permanent magnet motors is difficult to balance between controlling the cost of lamination dies and ensuring the processing quality and reliability of the rotor shaft. There is an urgent need for a segmented rotor design scheme for permanent magnet motors that takes into account both reliability and ease of processing in order to overcome the above-mentioned engineering bottlenecks. Summary of the Invention

[0008] This invention addresses the engineering problems of existing segmented rotor positioning schemes for permanent magnet motors, such as high cost of lamination molds, extremely dense slotting of the shaft leading to machining interference, and difficulty in withstanding large torques at single-point positioning, resulting in local stress concentration on the shaft. It proposes a slanted-pole permanent magnet rotor and its design method that balances reliability and ease of processing.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A slanted-pole permanent magnet rotor that balances reliability and ease of manufacturing includes a rotating shaft and Ns-segment iron core segment modules stacked sequentially on the rotating shaft along the axial direction.

[0011] The Ns segment core modules are all made by stacking core laminations with identical structures.

[0012] The core segmentation module has N protrusions on its inner circumference, and the upper surface of the core segmentation module has a magnetic groove for installing permanent magnets.

[0013] The outer cylindrical surface of the rotating shaft is provided with a number of positioning grooves extending along the axial direction, and the total number of positioning grooves Nslots is Nslots=Ns+Npro-1.

[0014] The geometric symmetry centerline of the magnetic steel groove is set as the magnetic pole centerline characterizing the electromagnetic phase of the iron core segment module;

[0015] A preset circumferential deflection direction is set as the unified angular reference direction for the rotor circumferential distribution; when the Ns segment iron core modules are stacked sequentially along the axial direction, the adjacent two segments of iron core modules are deflected sequentially along the preset circumferential deflection direction by an assembly deflection angle Δθ, so that the magnetic pole center lines of the adjacent two segments of iron core modules are staggered by a slant pole step angle α along the preset circumferential deflection direction.

[0016] Furthermore, the positioning protrusions of the core segmentation module are asymmetrically distributed, and the included angle Δβ between any two adjacent positioning protrusions is:

[0017] Δβ=α+k·θ p

[0018] Where, θ p For the symmetrical period of the rotor structure, and θ p =360° / 2p, where p is the number of rotor pole pairs; k is the space scattering multiplier, and the value of k is a positive integer ranging from 1 to k to 2p-1;

[0019] Set the starting reference coordinate of the first positioning protrusion to P. A Then, the set of angular coordinates of the Npro positioning protrusions on the inner circle of the iron core is Ψ = {ψ1, ψ2, ..., ψ...} Npro}, the position angle coordinate ψ of the i-th positioning protrusion i The calculation formula is:

[0020] ψ i =mod(P A +(i-1)·Δβ,360°)

[0021] Where i is a positive integer from 1 to Npro, and mod is the modulo operation, representing the calculation of (P AThe remainder after dividing (i-1) by 360° is used to ensure that the calculated angular coordinates are always within the circumference range of 0° to 360°.

[0022] Furthermore, if the starting coordinates of the positioning slots on the rotating shaft are set to coincide with the starting reference coordinates of the first positioning protrusion, then the set of position angular coordinates of the N slots positioning slots on the rotating shaft is... The position angle coordinates of the j-th positioning slot The calculation formula is:

[0023]

[0024] Where j is a positive integer from 1 to Npro.

[0025] A design method for a skew-pole permanent magnet rotor that balances reliability and ease of manufacturing includes the following steps:

[0026] S1. Parameter initialization: Determine the number of rotor pole pairs p, the number of core segments Ns, the skew pole step angle α, and the number of positioning protrusions Npro based on the motor design parameters, and set the preset circumferential deflection direction as the unified angular reference direction for the rotor circumferential distribution.

[0027] S2. Determine the total number of positioning slots Nslots as Nslots = Ns + Npro-1;

[0028] S3. Determine the structural parameters of the core segment module and the rotating shaft. Select the optimal k value according to the global anti-interference and force equalization optimization rules. Calculate the mechanical angle Δβ between adjacent positioning protrusions on the inner circle of the core segment module. Then calculate the set of position angle coordinates Ψ of Npro positioning protrusions on the inner circle of the core segment module and the set of position angle coordinates of Nslots positioning slots on the rotating shaft. ;

[0029] S4. Determine the assembly method, complete the common slot assembly of the multi-protrusion structure, and realize the segmented skewed poles of the rotor.

[0030] Furthermore, the specific implementation method of the global anti-interference and force equalization optimization rule in step S3 includes the following steps:

[0031] S3.1. Traverse the spatial scattering multiplier k within the range 1≤k≤2p-1, and calculate the corresponding coordinate set Ψ and Φ for each k value; arrange the coordinate values ​​in Ψ in ascending order to obtain the ordered set Ψ'={ψ1', ψ2',…, ψ...} of the position and angle coordinates of Npro positioning protrusions on the inner circle of the iron core. Npro '}, calculate the physical angle between adjacent positioning protrusions on the circumference to form the set of positioning protrusion spacing {g p,1 ,g p,2 ,…,gp,Npro The calculation formula is:

[0032] g p,i =ψ i+1 '-ψ i '

[0033] g p,Npro =ψ1'+360°-ψ Npro

[0034] Where i is a positive integer from 1 to Npro-1, g p,i ψ is the circumferential angle between the i-th and (i+1)-th positioning protrusions. i 'is the i-th coordinate value in the ordered set Ψ of the position and angle coordinates, g p,Npro The circumferential span between the Npro-th positioning protrusion and the 1st positioning protrusion;

[0035] S3.2. Sort the coordinate values ​​in Φ in ascending order to obtain an ordered set of position and angle coordinates of N slots on the rotating shaft. Calculate the physical angle between adjacent positioning grooves on the circumference to form the set of shaft groove spacing {g s,1 ,g s,2 ,…,g s,Nslots The calculation formula is:

[0036]

[0037]

[0038] Where j is a positive integer from 1 to Nslots-1, g s,j The circumferential angle between the j-th and (j+1)-th positioning slots. The ordered set of position and angle coordinates The j-th coordinate value in g s,Nslots The circumferential span between the Nth positioning protrusion and the first positioning groove;

[0039] S3.3. Calculate the minimum safe clearance G for the slotted shaft. min Standard deviation of the spacing between the core positioning protrusions σ pro and the standard deviation σ of the shaft slot spacing shaft The calculation formula is as follows:

[0040] G min =min{g s,1 ,g s,2 ,…,g s,Nslots}

[0041]

[0042] ;

[0043] S3.4. Set the safe avoidance threshold for machining tools to G. th In satisfying G min ≥G th Under the constraints, construct the evaluation function. The optimal solution is selected by choosing the k value that minimizes the evaluation function F. By finding the minimum value through the spatial distance vector, the surge of any single standard deviation is limited, ensuring that the standard deviation of the core positioning protrusion spacing and the standard deviation of the shaft slot spacing approach the minimum value at the same time. This maximizes the uniformity of torque transmission force while ensuring processing safety.

[0044] Furthermore, the method for determining the assembly method in step S4 is to set the assembly deflection angle Δθ between adjacent core segment modules to be equal to the positioning protrusion spacing Δβ; assemble the Ns segment core segment modules one by one in axial order, taking the starting slot of the rotating shaft as the reference, first align the positioning protrusion of the first segment core segment module with the slot and install it; when assembling the next segment module, rotate the corresponding core segment module along the preset circumferential deflection direction by the assembly deflection angle Δθ and push it into the rotating shaft to complete the common slot assembly of the multi-protrusion structure and realize the rotor segmented skew pole.

[0045] The beneficial effects of this invention are:

[0046] The slanted-pole permanent magnet rotor described in this invention balances reliability and ease of manufacturing. By utilizing the structural periodic symmetry of the segmented iron core modules, the total number of slots on the shaft is reduced while using only a single set of iron core lamination dies, thus improving manufacturing convenience. At the same time, by combining global anti-interference and stress homogenization optimization rules, the global discrete design of the characteristic positioning points of the iron core laminations and shaft is realized, solving the machining interference problem and homogenizing the torque transmission path, thereby significantly improving the overall operational reliability and fatigue life of the rotor system under high torque and high transient load conditions.

[0047] The present invention discloses a skewed permanent magnet rotor that balances reliability and ease of manufacturing. The ease of manufacturing is achieved by using a unified rotor core lamination, allowing for arbitrary skewness with a single set of molds. By reusing shaft slots, the number of shaft slots is reduced from the traditional Ns×Npro to Ns+Npro-1, maximizing manufacturing convenience.

[0048] The present invention provides a slanted-pole permanent magnet rotor that balances reliability and ease of processing, and solves the problem of processing interference: by introducing global anti-interference and force equalization optimization rules, the positioning slots of the shaft are distributed on the circumference to ensure that the distance between adjacent slots is greater than the safe avoidance threshold of the machining tool, effectively eliminating the risk of processing interference and multiple slots being connected and scrapped.

[0049] The present invention provides a slanted-pole permanent magnet rotor that balances reliability and ease of manufacturing, thereby improving operational reliability by homogenizing the load: the rotor core adopts a multi-positioning protrusion structure and is distributed in a dispersed manner, with multiple meshing points simultaneously transmitting torque, effectively distributing the pressure, significantly reducing the shear stress at each meshing point, and effectively improving the operational reliability of the rotor system. Attached Figure Description

[0050] Figure 1 This is an isometric schematic diagram of the overall assembly structure of the slanted pole permanent magnet rotor according to the present invention, which takes into account both reliability and ease of processing. In the diagram, 1 is the rotating shaft, 11 is the rotating shaft positioning groove, 2 is the iron core segment module, 21 is the positioning protrusion, 22 is the magnet groove, and 3 is the permanent magnet.

[0051] Figure 2 This is a schematic diagram of the main structure of the core segment module of a slanted permanent magnet rotor that combines reliability and ease of processing, as described in this invention.

[0052] Figure 3 This is a schematic cross-sectional view of the positioning groove structure of a slanted pole permanent magnet rotor that combines reliability and ease of processing, as described in this invention.

[0053] Figure 4 This is a flowchart illustrating the design method of a slanted-pole permanent magnet rotor that balances reliability and ease of manufacturing, as described in this invention. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described specific embodiments are merely a part of the embodiments of the invention, and not all of them. The components of the specific embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations, and the invention may also have other embodiments.

[0055] Therefore, the following detailed description of specific embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected specific embodiments of the invention. All other specific embodiments obtained by those skilled in the art based on these specific embodiments without inventive effort are within the scope of protection of this invention.

[0056] To further understand the invention's content, features, and effects, the following specific embodiments are provided, along with accompanying drawings. Figure 1 - Appendix Figure 4 Detailed explanation is as follows:

[0057] Example 1:

[0058] A slanted-pole permanent magnet rotor that balances reliability and ease of manufacturing includes a rotating shaft and Ns-segment iron core segment modules stacked sequentially on the rotating shaft along the axial direction;

[0059] The Ns segment core modules are all made by stacking core laminations with identical structures.

[0060] The core segmentation module has N protrusions on its inner circumference, and the upper surface of the core segmentation module has a magnetic groove for installing permanent magnets.

[0061] The outer cylindrical surface of the rotating shaft is provided with a number of positioning grooves extending along the axial direction, and the total number of positioning grooves Nslots is Nslots=Ns+Npro-1.

[0062] The geometric symmetry centerline of the magnetic steel groove is set as the magnetic pole centerline characterizing the electromagnetic phase of the iron core segment module;

[0063] A preset circumferential deflection direction is set as the unified angular reference direction for the rotor circumferential distribution; when the Ns segment iron core modules are stacked sequentially along the axial direction, the adjacent two segments of iron core modules are deflected sequentially along the preset circumferential deflection direction by an assembly deflection angle Δθ, so that the magnetic pole center lines of the adjacent two segments of iron core modules are staggered by a slant pole step angle α along the preset circumferential deflection direction.

[0064] Furthermore, the positioning protrusions of the core segmentation module are asymmetrically distributed, and the included angle Δβ between any two adjacent positioning protrusions is:

[0065] Δβ=α+k·θ p

[0066] Where, θ p For the symmetrical period of the rotor structure, and θ p =360° / 2p, where p is the number of rotor pole pairs; k is the space scattering multiplier, and the value of k is a positive integer ranging from 1 to k to 2p-1;

[0067] Set the starting reference coordinate of the first positioning protrusion to P. A Then, the set of positional angular coordinates of the Npro positioning protrusions on the inner circle of the iron core is Ψ={ψ1, ψ2,…, ψ Npro}, the position angle coordinate ψ of the i-th positioning protrusion i The calculation formula is:

[0068] ψ i =mod(P A +(i-1)·Δβ,360°)

[0069] Where i is a positive integer from 1 to Npro, and mod is the modulo operation, representing the calculation of (P A The remainder after dividing (i-1) by 360° is used to ensure that the calculated angular coordinates are always within the circumference range of 0° to 360°.

[0070] Furthermore, if the starting coordinates of the positioning slots on the rotating shaft are set to coincide with the starting reference coordinates of the first positioning protrusion, then the set of position angular coordinates of the N slots positioning slots on the rotating shaft is... The position angle coordinate ϕ of the j-th positioning slot j The calculation formula is:

[0071]

[0072] Where j is a positive integer from 1 to Npro.

[0073] Furthermore, in this embodiment, the rotor core segment module's inner circle abandons the traditional single keyway positioning, instead featuring multiple positioning protrusions asymmetrically distributed. This multi-protrusion structure, during rotor operation, can evenly distribute the electromagnetic torque across multiple nodes of the shaft, significantly reducing local shear stress and effectively improving the operational reliability of the rotor system under high torque and high-frequency sudden load conditions. Simultaneously, the geometric symmetry center line of the magnet slot is set as the magnetic pole center line characterizing the module's electromagnetic phase. By creating a specific mechanical angle Δβ between adjacent positioning protrusions on the inner circle of the rotor core segment module, the magnetic pole center lines of adjacent core segment modules are sequentially offset by a preset oblique pole step angle α along the preset circumferential deflection direction.

[0074] Furthermore, the locating grooves on the outer cylindrical surface of the shaft are discretely and non-uniformly distributed along the circumference. This specific discrete arrangement ensures a ample safety distance between any adjacent locating grooves, effectively avoiding the machining tool interference and groove failure risks that easily occur in traditional multi-groove schemes, significantly improving the machining convenience and yield of the shaft. Simultaneously, combined with... Figure 1 As can be seen from the three-dimensional assembly relationship, by utilizing the structural periodic symmetry of the core segment modules, each module adopts a common slot assembly, which effectively reduces the total number of shaft positioning slots. This not only reduces the processing difficulty but also preserves the effective solid cross-sectional area of ​​the shaft, thereby enhancing the overall torsional stiffness and fatigue life of the shaft.

[0075] Example 2:

[0076] A design method for a skewed-pole permanent magnet rotor that balances reliability and ease of manufacturing, based on the skewed-pole permanent magnet rotor described in Example 1, includes the following steps:

[0077] S1. Parameter initialization: Determine the number of rotor pole pairs p, the number of core segments Ns, the skew pole step angle α, and the number of positioning protrusions Npro based on the motor design parameters, and set the preset circumferential deflection direction as the unified angular reference direction for the rotor circumferential distribution.

[0078] S2. Determine the total number of positioning slots Nslots as Nslots = Ns + Npro-1;

[0079] S3. Determine the structural parameters of the core segment module and the rotating shaft. Select the optimal k value according to the global anti-interference and force equalization optimization rules. Calculate the mechanical angle Δβ between adjacent positioning protrusions on the inner circle of the core segment module. Then calculate the set of position angle coordinates Ψ of Npro positioning protrusions on the inner circle of the core segment module and the set of position angle coordinates Φ of Nslots positioning slots on the rotating shaft.

[0080] Furthermore, the specific implementation method of the global anti-interference and force equalization optimization rule in step S3 includes the following steps:

[0081] S3.1. Traverse the spatial scattering multiplier k within the range 1≤k≤2p-1, and calculate the corresponding coordinate set Ψ and Φ for each k value; arrange the coordinate values ​​in Ψ in ascending order to obtain the ordered set Ψ'={ψ1', ψ2',…, ψ...} of the position and angle coordinates of Npro positioning protrusions on the inner circle of the iron core. Npro '}, calculate the physical angle between adjacent positioning protrusions on the circumference to form the set of positioning protrusion spacing {g p,1 ,g p,2 ,…,g p,Npro The calculation formula is:

[0082] g p,i =ψ i+1 '-ψ i '

[0083] g p,Npro =ψ1'+360°-ψ Npro

[0084] Where i is a positive integer from 1 to Npro-1, g p,i Let ψ be the circumferential angle between the i-th and (i+1)-th positioning protrusions. i ' represents the i-th coordinate value in the ordered set Ψ of the position and angle coordinates, g p,Npro The circumferential span between the Nproth positioning protrusion and the 1st positioning protrusion;

[0085] S3.2. [The following appears to be a separate, unrelated sentence:] Will The coordinate values ​​are sorted in ascending order to obtain an ordered set of position and angle coordinates of N slots on the rotating shaft. Calculate the physical angle between adjacent positioning grooves on the circumference to form the set of shaft groove spacing {g s,1 ,g s,2 ,…,g s,Nslots The calculation formula is:

[0086]

[0087]

[0088] Where j is a positive integer from 1 to Nslots-1, g s,j The circumferential angle between the j-th and (j+1)-th positioning slots. The ordered set of position and angle coordinates The j-th coordinate value in g s,Nslots The circumferential span between the Nth positioning protrusion and the first positioning groove;

[0089] S3.3. Calculate the minimum safe clearance G for the slotted shaft. min Standard deviation of the spacing between the core positioning protrusions σ pro and the standard deviation σ of the shaft slot spacing shaft The calculation formula is as follows:

[0090] G min =min{g s,1 ,g s,2 ,…,g s,Nslots}

[0091]

[0092] ;

[0093] S3.4. Set the safe avoidance threshold for machining tools to G. th In satisfying G min ≥G th Under the constraints, construct the evaluation function. The optimal solution is selected by choosing the k value that minimizes the evaluation function F. By finding the minimum value through the spatial distance vector, the surge of any single standard deviation is limited, ensuring that the standard deviation of the core positioning protrusion spacing and the standard deviation of the shaft slot spacing approach the minimum value at the same time. This maximizes the uniformity of torque transmission force while ensuring processing safety.

[0094] S4. Determine the assembly method, complete the common slot assembly of the multi-protrusion structure, and realize the segmented skewed poles of the rotor.

[0095] Furthermore, the method for determining the assembly method in step S4 is to set the assembly deflection angle Δθ between adjacent core segment modules to be equal to the positioning protrusion spacing Δβ; assemble the Ns segment core segment modules one by one in axial order, taking the starting slot of the rotating shaft as the reference, first align the positioning protrusion of the first segment core segment module with the slot and install it; when assembling the next segment module, rotate the corresponding core segment module along the preset circumferential deflection direction by the assembly deflection angle Δθ and push it into the rotating shaft to complete the common slot assembly of the multi-protrusion structure and realize the rotor segmented skew pole.

[0096] Example 3:

[0097] To fully illustrate the technical advantages of this invention, a common 8-pole permanent magnet synchronous motor rotor (pole pairs p=4) is used as an example to describe in detail the design and assembly process of a skew-pole permanent magnet rotor that balances reliability and ease of manufacturing:

[0098] S1. Parameter initialization:

[0099] Based on the target motor design requirements, the rotor pole pairs are set to p=4, the core segments to Ns=6, and the target mechanical skew pole step angle to α=2°. To meet the shear strength requirements under high torque conditions, the number of positioning protrusions on the inner circle of the rotor core is set to Npro=3. Simultaneously, a "counterclockwise direction" is defined in physical space as the unified preset angular reference direction for the rotor's circumferential distribution.

[0100] S2 determines the number of slots:

[0101] A multi-protrusion reuse structure is adopted, and the total number of positioning slots that need to be machined on the rotating shaft is calculated using the formula Nslots=Ns+Npro-1. That is, Nslots=6+3-1=8 slots.

[0102] S3 determines the structural parameters of the rotor core and shaft:

[0103] The symmetric period θ of the rotor structure p =360° / 2p=360° / 8=45°. Set the starting reference coordinate P for the first positioning protrusion. A =0°, set the safe avoidance threshold G for machining tools. th =10°, the mechanical included angle Δβ=α+k·θ on the inner circle of the rotor core is 10°. p , where k is the space scattering multiplier.

[0104] Based on the global anti-interference and force equalization optimization rules, the space is traversed and the multiplier k is distributed within the range of 1≤k≤7 (i.e., 2p-1). The computer program then uses the formula ψ... i =mod(P A +(i-1)·Δβ,360°) (i=1,2,…, Npro), ϕ j=mod(P A +(j-1)·Δβ, 360°) (j=1,2,…, Npro), and in the background, for each k value, calculate the position coordinate set Ψ={ψ1, ψ2,…, ψ Npro} of the positioning protrusions on the inner circle of the iron core and the position coordinate set of the positioning slots on the rotating shaft . Sort the coordinate values in the set Ψ in ascending order to obtain an ordered set Ψ'={ψ1', ψ2',…, ψ Npro '}, calculate the physical included angle between adjacent protrusions on the circumference to form a protrusion spacing set {g p,1 ,g p,2 ,…,g p,Npro}; where, g p,i =ψ i+1 '-ψ i}' (for 1≤i<Npro), and the head-to-tail span g p,Npro =ψ1'+360°-ψ Npro}'; similarly, sort the coordinate values in the set in ascending order to obtain an ordered set , calculate the physical included angle between adjacent positioning slots on the circumference to form a rotating shaft slot spacing set {g s,1 ,g s,2 ,…,g s,Nslots}; where, (for 1≤j<Nslots), and the head-to-tail span .

[0105] Based on the above spacing sets, calculate the index minimum safety spacing G for rotating shaft slotting min :

[0106] G min =min{g s,1 ,g s,2 ,…,g s,Nslots}

[0107] Based on the above spacing sets, calculate the index standard deviation σ of the iron core positioning protrusion spacing pro :

[0108]

[0109] Based on the above spacing sets, calculate the index standard deviation σ of the rotating shaft slotting spacing shaft :

[0110]

[0111] The corresponding indexes of all schemes with the spatial dispersion multiplier k are as follows:

[0112] Scheme k=1: Positioning protrusion included angle Δβ=47.00°; Minimum safety clearance G for shaft slotting min =31.00°; Standard deviation of the spacing between core positioning protrusions σ pro =103.24; Standard deviation of shaft slot spacing σ shaft =5.29;

[0113] Scheme k=2: Positioning protrusion included angle Δβ=92.00°; Minimum safety clearance G for shaft slotting min =8.00°; Standard deviation of the spacing between core positioning protrusions σ pro =39.6; Standard deviation of shaft slot spacing σ shaft =37.08;

[0114] Scheme k=3: Positioning protrusion included angle Δβ=137.00°; Minimum safety clearance G for shaft slotting min =35.00°; Standard deviation of the spacing between core positioning protrusions σ pro =24.04; Standard deviation of shaft slot spacing σ shaft =7.75;

[0115] Scheme k=4: Positioning protrusion included angle Δβ=182.00°; Minimum safety clearance G for shaft slotting min =4.00°; Standard deviation of the spacing between core positioning protrusions σ pro =82.02; Standard deviation of shaft slot spacing σ shaft =71.02;

[0116] Scheme k=5: Positioning protrusion included angle Δβ=227.00°; Minimum safety clearance G for shaft slotting min =39.00°; Standard deviation of the spacing between core positioning protrusions σ pro =18.38; Standard deviation of shaft slot spacing σ shaft =7.75;

[0117] Scheme k=6: Positioning protrusion included angle Δβ=272.00°; Minimum safety clearance G for shaft slotting min =8.00°; Standard deviation of the spacing between core positioning protrusions σ pro =45.25; Standard deviation of shaft slot spacing σ shaft =37.08;

[0118] Scheme k=7: Positioning protrusion included angle Δβ=317.00°; Minimum safety clearance G for shaft slotting min =43.00°; Standard deviation of the spacing between the core positioning protrusions σ pro =108.89; Standard deviation of shaft slot spacing σ shaft =5.29;

[0119] Based on the global anti-interference and force homogenization optimization rules, G is first eliminated. min <G th Interference failure solutions (scheme k=2; scheme k=4; scheme k=6), select the ones that satisfy the evaluation function The minimum target value k is used to determine that scheme k=5 is the optimal scheme. This scheme has the best spatial dispersion, with the positioning grooves being highly uniformly distributed on the circumference of the shaft, thus achieving the homogenization of extreme force values; at the same time, the minimum safe distance for the shaft slots is 39.00°, which is much greater than the machining safety avoidance threshold of conventional milling cutters and gear hobbing machines, effectively avoiding the risk of machining interference.

[0120] Based on this optimal solution k=5, the mechanical angle between adjacent positioning protrusions on the inner circle of the rotor core is Δβ=α+k·θ p =2° + 5 × 45° = 227.00°;

[0121] In the counterclockwise direction, according to ψ i =mod(P A The formula +(i-1)·Δβ,360°)=mod(0°+(i-1)·227.00°,360°) calculates the set of position coordinates of the positioning protrusions on the inner circle of the iron core. After sorting them in ascending order, the set of position coordinates of the three positioning protrusions on the inner circle of the iron core is obtained as Ψ'=[0.00°, 94.00°, 227.00°].

[0122] Similarly, in the counterclockwise direction, according to ϕ j =mod(P A The formula is: +(j-1)·Δβ,360°)=mod(0°+(j-1)·227.00°,360°). Calculate the position coordinates of the positioning slots on the rotating shaft. After arranging them in ascending order, we get the set of position coordinates of the 8 positioning slots on the rotating shaft: Φ'=[0.00°, 55.00°, 94.00°, 133.00°, 188.00°, 227.00°, 282.00°,321.00°].

[0123] S4 determines the assembly method:

[0124] Set the assembly deflection angle between adjacent core segment modules to Δθ=Δβ=227.00°; assemble the 8 core segment modules one by one in axial order, using the starting slot of the rotating shaft as a reference, first align the positioning protrusion of the first core module with the slot and insert it; when assembling the next module, rotate the module along the preset circumferential deflection direction by the assembly deflection angle of 227.00° and push it into the rotating shaft, thereby automatically completing the common slot assembly of the multi-protrusion structure and accurately realizing the rotor segmented skew pole.

[0125] The advantage of this invention lies in its comprehensive consideration of the spatial interference problem during the machining process of segmented skewed-pole rotors and the mechanical stress characteristics under high torque conditions. By utilizing the structural periodic symmetry of the rotor's segmented core modules, it achieves a targeted optimization that effectively reduces the number of shaft slots and highly homogenizes the transmission load, all while using only a single set of core lamination dies. This segmented skewed-pole rotor structure is extremely beneficial in improving the reliability of rotor systems, reducing processing costs, and increasing the yield rate, and has significant value for engineering application.

[0126] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0127] Although this application has been described above with reference to specific embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of this application. In particular, as long as there is no structural conflict, the features in the specific embodiments disclosed in this application can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A slanted-pole permanent magnet rotor that balances reliability and ease of manufacturing, characterized in that, It includes a rotating shaft and Ns-segment core segment modules stacked sequentially on the rotating shaft along the axial direction; The Ns segment core modules are all made by stacking core laminations with identical structures. The core segmentation module has N protrusions on its inner circumference, and the upper surface of the core segmentation module has a magnetic groove for installing permanent magnets. The outer cylindrical surface of the rotating shaft is provided with a number of positioning grooves extending along the axial direction, and the total number of positioning grooves Nslots is Nslots=Ns+Npro-1. The geometric symmetry centerline of the magnetic steel groove is set as the magnetic pole centerline characterizing the electromagnetic phase of the iron core segment module; A preset circumferential deflection direction is set as the unified angular reference direction for the rotor circumferential distribution; when the Ns segment iron core modules are stacked sequentially along the axial direction, the adjacent two segments of iron core modules are deflected sequentially along the preset circumferential deflection direction by an assembly deflection angle Δθ, so that the magnetic pole center lines of the adjacent two segments of iron core modules are staggered by a slant pole step angle α along the preset circumferential deflection direction.

2. The skew-pole permanent magnet rotor according to claim 1, which balances reliability and ease of manufacturing, is characterized in that... The positioning protrusions of the core segmentation module are asymmetrically distributed, and the included angle Δβ between any two adjacent positioning protrusions is: Δβ=α+k·θ p Where, θ p For the symmetrical period of the rotor structure, and θ p =360° / 2p, where p is the number of rotor pole pairs; k is the space scattering multiplier, and the value of k is a positive integer ranging from 1 to k to 2p-1; Set the starting reference coordinate of the first positioning protrusion to P. A Then, the set of angular coordinates of the Npro positioning protrusions on the inner circle of the iron core is Ψ = {ψ1, ψ2, ..., ψ...} Npro }, the position angle coordinate ψ of the i-th positioning protrusion i The calculation formula is: ψ i =mod(P A +(i-1)·Δβ,360°) Where i is a positive integer from 1 to Npro, and mod is the modulo operation.

3. The skew-pole permanent magnet rotor according to claim 1, which balances reliability and ease of manufacturing, is characterized in that... If the starting coordinates of the positioning slots on the rotating shaft coincide with the starting reference coordinates of the first positioning protrusion, then the set of position angular coordinates of the N slots positioning slots on the rotating shaft is Φ={ϕ1,ϕ2,…,ϕ…} Nslots }, the position angle coordinates ϕ of the j-th positioning slot j The calculation formula is: ϕ j =mod(P A +(j-1)·Δβ,360°) Where j is a positive integer from 1 to N slots.

4. A design method for a skew-pole permanent magnet rotor that balances reliability and ease of manufacturing, as described in any one of claims 1-3, characterized in that... Includes the following steps: S1. Parameter initialization: Determine the number of rotor pole pairs p, the number of core segments Ns, the skew pole step angle α, and the number of positioning protrusions Npro based on the motor design parameters, and set the preset circumferential deflection direction as the unified angular reference direction for the rotor circumferential distribution. S2. Determine the total number of positioning slots Nslots as Nslots = Ns + Npro-1; S3. Determine the structural parameters of the core segment module and the rotating shaft. Select the optimal k value according to the global anti-interference and force equalization optimization rules. Calculate the mechanical angle Δβ between adjacent positioning protrusions on the inner circle of the core segment module. Then calculate the set of position angle coordinates Ψ of Npro positioning protrusions on the inner circle of the core segment module and the set of position angle coordinates Φ of Nslots positioning slots on the rotating shaft. S4. Determine the assembly method, complete the common slot assembly of the multi-protrusion structure, and realize the segmented skewed poles of the rotor.

5. The design method for a skew-pole permanent magnet rotor that balances reliability and ease of manufacturing, as described in claim 4, is characterized in that... The specific implementation method of the global anti-interference and force homogenization optimization rule in step S3 includes the following steps: S3.

1. Traverse the spatial scattering multiplier k within the range 1≤k≤2p-1, and calculate the corresponding coordinate set Ψ and Φ for each k value; arrange the coordinate values ​​in Ψ in ascending order to obtain the ordered set Ψ'={ψ1', ψ2',…, ψ...} of the position and angle coordinates of Npro positioning protrusions on the inner circle of the iron core. Npro '}, calculate the physical angle between adjacent positioning protrusions on the circumference to form the set of positioning protrusion spacing {g p,1 ,g p,2 ,…,g p,Npro The calculation formula is: g p,i =ψ i+1 '-ψ i ' g p,Npro =ψ1'+360°-ψ Npro Where i is a positive integer from 1 to Npro-1, g p,i Let ψ be the circumferential angle between the i-th and (i+1)-th positioning protrusions. i ' represents the i-th coordinate value in the ordered set Ψ of the position and angle coordinates, g p,Npro The circumferential span between the Nproth positioning protrusion and the 1st positioning protrusion; S3.

2. Arrange the coordinate values ​​in Φ in ascending order to obtain an ordered set of position and angle coordinates of N slots on the rotating shaft: Φ'={ϕ1',ϕ2',…,ϕ Nslots '}, calculate the physical angle between adjacent positioning grooves on the circumference to form the set of shaft groove spacing {g s,1 ,g s,2 ,…,g s,Nslots The calculation formula is: g s,j =ϕ i+1 '-ϕ i ' g s,Nslots =ϕ1'+360°-ϕ Nslots ' Where j is a positive integer from 1 to Nslots-1, g s,j ϕ is the circumferential angle between the j-th and (j+1)-th positioning slots. i ' is the j-th coordinate value in the ordered set Φ of the position angle coordinates, g s,Nslots The circumferential span between the Nth positioning protrusion and the first positioning groove; S3.

3. Calculate the minimum safe clearance G for the slotted shaft. min Standard deviation of the spacing between the core positioning protrusions σ pro and the standard deviation σ of the shaft slot spacing shaft The calculation formula is as follows: G min =min{g s,1 ,g s,2 ,…,g s,Nslots } ； S3.

4. Set the safe avoidance threshold for machining tools to G. th In satisfying G min ≥G th Under the constraints, construct the evaluation function. The optimal solution is selected by choosing the k value that minimizes the evaluation function F. By finding the minimum value through the spatial distance vector, the surge of any single standard deviation is limited, ensuring that the standard deviation of the core positioning protrusion spacing and the standard deviation of the shaft slot spacing approach the minimum value at the same time. This maximizes the uniformity of torque transmission force while ensuring processing safety.

6. The design method for a skew-pole permanent magnet rotor that balances reliability and ease of manufacturing, as described in claim 5, is characterized in that... In step S4, the method for determining the assembly method is to set the assembly deflection angle Δθ between adjacent core segment modules to be equal to the positioning protrusion spacing Δβ; assemble the Ns segment core segment modules one by one in axial order, taking the starting slot of the rotating shaft as the reference, first align the positioning protrusion of the first segment core segment module with the slot and install it; when assembling the next segment module, rotate the corresponding core segment module along the preset circumferential deflection direction by the assembly deflection angle Δθ and push it into the rotating shaft to complete the common slot assembly of the multi-protrusion structure and realize the rotor segmented skew pole.

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