Vehicle stator assembly rigidity and damping evaluation method

Abstract

The invention discloses a method for evaluating rigidity and damping of a vehicle stator assembly. The method comprises the following steps: 1) identifying an axial in-phase mode of the stator assembly; 2) calculating a radial stiffness coefficient of the stator assembly; 3) identifying the axial out-phase mode of the stator assembly; 4) calculating a torsional rigidity coefficient of the stator assembly; 5) calculating the equivalent damping coefficient of the outer edge of the stator assembly; 6) calculating a tooth crest-outer edge transfer equivalent damping coefficient of the stator assembly; and 7) evaluating the rigidity and damping performance of the stator assembly. According to the method, the rigidity-damping comprehensive coefficient of the stator assembly can be simply and quickly obtained, an analysis and evaluation conclusion is given, the development period can be effectively shortened, effective targets and bases are provided for adjustment of technological parameters, structural parameters and insulation parameters of the stator assembly, the production qualification rate of products can be effectively increased, and the production cost is reduced. And the influence of the stator assembly on the vibration and noise performance of the electric drive assembly is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of motors, and in particular to a method for evaluating the stiffness and damping of a vehicle stator assembly. Background Art

[0002] As new energy vehicles gain more and more market share, the automotive electric drive market is gradually expanding. As one of the core components of the electric drive assembly, the stator assembly has derived a lot of structural design types, winding shape types, insulating paint coating types and welding process types under the requirements of high efficiency, high power density and high torque output. The combination of so many variables makes the analysis of the stiffness and damping characteristics of the stator assembly very complicated. For product developers, the stiffness and damping characteristics of the stator assembly are very important. The stiffness and damping characteristics of the stator assembly have a decisive influence on the vibration and noise performance of the electric drive assembly. Therefore, it is necessary to propose a method for evaluating the stiffness and damping characteristics of the stator assembly. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a method for evaluating the stiffness and damping of a vehicle stator assembly so as to reduce the influence of the stator assembly on the vibration and noise performance of the electric drive assembly.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A method for evaluating the stiffness and damping of a vehicle stator assembly comprises the following steps:

[0006] Step 1) Identification of axial in-phase modes of the stator assembly;

[0007] Step 2) Calculate the radial stiffness coefficient of the stator assembly;

[0008] Step 3) Identification of axial out-of-phase modes of the stator assembly;

[0009] Step 4) Calculate the torsional stiffness coefficient of the stator assembly;

[0010] Step 5) Calculate the equivalent damping coefficient of the outer edge of the stator assembly;

[0011] Step 6) Calculate the equivalent damping coefficient of the stator assembly tooth top-outer edge transmission;

[0012] Step 7) Evaluation of stator assembly stiffness and damping performance.

[0013] Preferably, the method for identifying the axial in-phase mode of the stator assembly in step 1) is:

[0014] Step 1.1) n / 2 modal points are respectively set on the first axial end face and the second axial end face of the stator assembly at intervals of a first set angle, and there are n modal points in total on the first end face and the second end face;

[0015] Step 1.2) Record the spatial cylindrical coordinates of each modal point in step 1.1) and number them in sequence;

[0016] Step 1.3) The displacement changes of each modal point of the modal results obtained by simulation calculation are recorded and sorted, and based on the number of maximum values ​​and the principle of consistent displacement of the same axial point of the maximum value, the (0, 2) mode, (0, 3) mode, (0, 4) mode, (0, 5) mode and (0, 0) mode of the stator assembly are identified.

[0017] Preferably, the calculation formula of the radial stiffness coefficient of the stator assembly is:

[0018]

[0019] Where: K r is the radial stiffness coefficient of the stator assembly, Feq 0,2 is the (0, 2) modal frequency of the stator assembly, Feq 0,3 is the (0, 3) modal frequency of the stator assembly, Feq 0,4 is the (0, 4) modal frequency of the stator assembly, Feq 0,5 is the (0, 5) modal frequency of the stator assembly, Feq 0,0 is the (0, 0) modal frequency of the stator assembly.

[0020] Preferably, the method for identifying the axial out-of-phase modes of the stator assembly in step 3) is: according to the modal points selected in step 1), the displacement changes of each modal point of the modal results obtained by simulation calculation are recorded and sorted, and based on the principle of consistent maximum value number and maximum / minimum axial displacement of the same point, the (1, 2) mode, (1, 3) mode, (1, 4) mode, (1, 5) mode and (1, 0) mode of the stator assembly are identified.

[0021] Preferably, in step 4), the formula for calculating the torsional stiffness coefficient of the stator assembly is:

[0022]

[0023] Where: Kt is the torsional stiffness coefficient of the stator assembly, Feq 1,2 is the modal frequency of the stator assembly (1, 2), Feq 1,3 is the (1, 3) modal frequency of the stator assembly, Feq 1,4 is the (1, 4) modal frequency of the stator assembly, Feq 1,5 is the (1, 5) modal frequency of the stator assembly, Feq1,0 is the (1, 0) modal frequency of the stator assembly.

[0024] Preferably, in step 5), the calculation method of the equivalent damping coefficient of the outer edge of the stator assembly is:

[0025] Step 5.1) m excitation points are arranged at intervals of a second set angle on the circumference of the stator outer edge of the stator assembly, and a frequency sweep excitation with an amplitude of 1N is performed at intervals of 1 Hz, the frequency change rate is 3s / 1 Hz, and the frequency range is 100 Hz to 10000 Hz;

[0026] Step 5.2) Obtain the vibration acceleration frequency response of each modal point in step 1) under all frequency excitations, and calculate the total frequency response based on the following formula;

[0027]

[0028] Where: f is the excitation frequency, G f (Sum) is the total frequency response, G f (i) is the vibration acceleration frequency response of the i-th mode point;

[0029] Step 5.3) Calculate the equivalent damping coefficient of the outer edge of the stator assembly according to the following formula:

[0030]

[0031] In the formula, C r is the equivalent damping coefficient of the outer edge of the stator assembly, G 0,2 (Sum) is the sum frequency response of the stator assembly (0, 2) mode corresponding to the frequency position, G 0,3 (Sum) is the sum frequency response of the stator assembly (0, 3) mode corresponding to the frequency position, G 0,4 (Sum) is the sum frequency response of the stator assembly (0, 4) mode corresponding to the frequency position, G 0,5 (Sum) is the sum frequency response of the stator assembly (0, 5) mode corresponding to the frequency position, G 0,0 (Sum) is the sum frequency response of the stator assembly (0, 0) mode corresponding to the frequency position.

[0032] Preferably, in step 6), the calculation method of the stator assembly tooth tip-outer edge transfer equivalent damping coefficient is:

[0033] Step 6.1) m response points are arranged at intervals of a second set angle on the inner circumferential stator tooth top of the stator assembly, the angle and axial dimension coordinates of each response point are consistent with the angle and axial dimension coordinates of each excitation point in step 5), and a frequency sweep excitation with an amplitude of 1N is performed at intervals of 1 Hz, the frequency change rate is 3s / 1 Hz, and the frequency range is 100 Hz to 10000 Hz;

[0034] Step 6.2) Obtain the vibration acceleration frequency response of the four response points under all frequency excitations, and calculate the total frequency response of the tooth top based on the following formula;

[0035]

[0036] Where: B f (Sum) is the sum frequency response of the tooth top, B f (i) is the vibration acceleration frequency response of the i-th response point;

[0037] Step 6.3) Calculate the stator assembly tooth tip-outer edge transfer equivalent damping coefficient according to the following formula:

[0038]

[0039] Where: C t B is the equivalent damping coefficient of the stator assembly tooth tip-outer edge transmission, 0,2 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 2) mode, B 0,3 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 3) mode, B 0,4 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 4) mode, B 0,5 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 5) mode, B 0,0 (Sum) is the sum frequency response of the tooth top at the frequency position corresponding to the (0, 0) mode of the stator assembly.

[0040] Preferably, in step 7), the formula for evaluating the stiffness and damping performance of the stator assembly is:

[0041] D kc =K r +K t +1 / C r +1 / C t

[0042] Where D kc is the comprehensive stiffness-damping coefficient of the stator assembly.

[0043] Preferably, two maximum displacement points are identified in the modal points of the first end face of the stator assembly, and two maximum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement points of the first end face and the second end face are the same, then the mode is the (0, 2) mode of the stator assembly, and the frequency of the mode is the (0, 2) modal frequency of the stator assembly;

[0044] Three maximum displacement points are identified in the modal points of the first end face of the stator assembly, and three maximum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement points of the first end face and the second end face are the same, then the mode is the (0, 3) mode of the stator assembly, and the frequency of the mode is the (0, 3) modal frequency of the stator assembly;

[0045] Four maximum displacement points are identified in the modal points of the first end face of the stator assembly, and four maximum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement points of the first end face and the second end face are the same, then the mode is the (0, 4) mode of the stator assembly, and the frequency of the mode is the (0, 4) modal frequency of the stator assembly;

[0046] Five maximum displacement points are identified in the modal points of the first end face of the stator assembly, and five maximum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement points of the first end face and the second end face are the same, then the mode is the (0, 5) mode of the stator assembly, and the frequency of the mode is the (0, 5) modal frequency of the stator assembly;

[0047] If the displacements of the n modal points on the first end face and the second end face of the stator assembly are the same, the mode is the (0, 0) mode of the stator assembly, and the frequency of the mode is the (0, 0) modal frequency of the stator assembly.

[0048] Preferably, two maximum displacement points are identified in the modal points of the first end face of the stator assembly, and two minimum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement point of the first end face and the minimum displacement point of the second end face are the same, then the mode is the (1, 2) mode of the stator assembly, and the frequency of the mode is the (1, 2) modal frequency of the stator assembly;

[0049] Three maximum displacement points are identified among the modal points of the first end face of the stator assembly, and three minimum displacement points are identified among the modal points of the second end face, and the angular coordinates of the maximum displacement point of the first end face and the minimum displacement point of the second end face are the same, then the mode is the (1, 3) mode of the stator assembly, and the frequency of the mode is the (1, 3) modal frequency of the stator assembly;

[0050] Four maximum displacement points are identified among the modal points of the first end face of the stator assembly, and four minimum displacement points are identified among the modal points of the second end face, and the angular coordinates of the maximum displacement point of the first end face and the minimum displacement point of the second end face are the same, then the mode is the (1, 4) mode of the stator assembly, and the frequency of the mode is the (1, 4) modal frequency of the stator assembly;

[0051] Five maximum displacement points are identified among the modal points of the first end face of the stator assembly, and five minimum displacement points are identified among the modal points of the second end face, and the angular coordinates of the maximum displacement point of the first end face and the minimum displacement point of the second end face are the same, then the mode is the (1, 5) mode of the stator assembly, and the frequency of the mode is the (1, 5) modal frequency of the stator assembly;

[0052] If the displacements of the modal points on the first end face of the stator assembly are the same, the displacements of the modal points on the second end face are the same, and the displacements of the modal points on the first end face and the second end face are opposite to each other, then the mode is the (1, 0) mode of the stator assembly, and the frequency of the mode is the (1, 0) modal frequency of the stator assembly.

[0053] Compared with the prior art, the present invention has the following advantages:

[0054] 1. The present invention obtains the comprehensive stiffness-damping coefficient of the stator assembly simply and quickly through the axial in-phase modal identification of the stator assembly, the calculation of the radial stiffness coefficient of the stator assembly, the axial out-of-phase modal identification of the stator assembly, the calculation of the torsional stiffness coefficient of the stator assembly, the calculation of the equivalent damping coefficient of the outer edge of the stator assembly, and the calculation of the equivalent damping coefficient of the tooth top-outer edge transfer of the stator assembly, and gives an analysis and evaluation conclusion, which can effectively shorten the development cycle, provide an effective goal and basis for the adjustment of the process parameters, structural parameters, and insulation parameters of the stator assembly, and can effectively improve the production qualification rate of the product and reduce the influence of the stator assembly on the vibration and noise performance of the electric drive assembly.

[0055] 2. The method of the present invention is based on the modal analysis results and can quickly identify the modal frequencies of key vibration modes of the stator assembly.

[0056] 3. The present invention provides a universal method for evaluating the stiffness and damping performance of the stator assembly, which can achieve rapid and effective evaluation regardless of the process, material, structure, insulation design, and winding type adopted by the stator assembly.

[0057] 4. The present invention provides an effective evaluation basis for the process, material, structure, insulation design, and winding type design of the stator assembly, accelerates the development cycle, reduces development costs, and effectively improves the production qualification rate of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a structural schematic diagram of the stator assembly in the method for evaluating the stiffness and damping of the stator assembly for a vehicle of the present invention;

[0059] Figure 2 It is a schematic diagram of the outer edge distribution points of the stator assembly in the method for evaluating the stiffness and damping of the vehicle stator assembly of the present invention;

[0060] Figure 3is the (0, 2) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0061] Figure 4 is the (0, 3) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0062] Figure 5 is the (0, 4) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0063] Figure 6 is the (0, 5) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0064] Figure 7 is the (0, 0) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0065] Figure 8 is the (1, 2) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0066] Fig. 9 is the (1, 3) modal vibration diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0067] Fig.10 is the (1, 4) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0068] Fig.11 is the (1, 5) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0069] Fig.12 is the (1, 0) modal vibration shape diagram of the stator assembly in the vehicle stator assembly stiffness and damping evaluation method of the present invention;

[0070] Fig.13 is a graph of the total frequency response calculated in the method for evaluating the stiffness and damping of a vehicle stator assembly of the present invention;

[0071] Fig.14 It is a graph of the total frequency response of the tooth tops calculated in the stiffness and damping evaluation method of the vehicle stator assembly of the present invention.

[0072] Description of the reference numerals: first end face 1 , second end face 2 , stator outer edge 3 , stator tooth top 4 . DETAILED DESCRIPTION

[0073] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0074] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] As attached Figure 1 As shown, a method for evaluating the stiffness and damping of a vehicle stator assembly comprises the following steps:

[0076] Step 1) Identification of axial in-phase modes of the stator assembly.

[0077] The method for identifying the axial in-phase mode of the stator assembly in step 1) is:

[0078] Step 1.1) As attached Figure 2 As shown, n / 2 modal points are respectively set at intervals of a first set angle on the stator outer edge 3 of the first end face 1 and the second end face 2 of the stator assembly in the axial direction, and there are n modal points on the first end face 1 and the second end face 2 in total; in this specific embodiment, the modal points are set at intervals of 15° on each end face as an example for explanation, 24 points are evenly selected on each end face as modal points, and there are 48 modal points on the two end faces in total; as shown in the accompanying drawings.

[0079] Step 1.2) Record the spatial cylindrical coordinates of each modal point in step 1.1) and number them in sequence; as shown in Table 1, record the spatial cylindrical coordinates of 48 modal points and number them as 1, 2, ..., 48.

[0080] Table 1: Stator outer edge modal point numbers and specific coordinates

[0081]

[0082]

[0083] Step 1.3) The displacement changes of each modal point of the modal results obtained by simulation calculation are recorded and sorted, and based on the number of maximum values ​​and the principle of consistent displacement of the same axial point of the maximum value, the (0, 2) mode, (0, 3) mode, (0, 4) mode, (0, 5) mode and (0, 0) mode of the stator assembly are identified.

[0084] Specifically, two maximum displacement points are identified among the 24 modal points of the first end face 1 of the stator assembly, and two maximum displacement points are identified among the 24 modal points of the second end face 2, and the angular coordinates of the maximum displacement points of the first end face 1 and the second end face 2 are the same, as shown in Table 2. The 1 and 13 outer edge points of the first end face 1 and the 25 and 37 outer edge points of the second end face 2 are the two maximum displacement points, and the mode is the (0, 2) mode of the stator assembly. Figure 3 As shown, the frequency of this mode is the (0, 2) mode frequency of the stator assembly.

[0085] Table 2: 48-point axial displacement coordinates corresponding to the stator assembly (0, 2) mode

[0086]

[0087]

[0088] Three maximum displacement points are identified in the modal points of the first end face 1 of the stator assembly, and three maximum displacement points are identified in the modal points of the second end face 2. If the angular coordinates of the maximum displacement points of the first end face 1 and the second end face 2 are the same, then the mode is the (0, 3) mode of the stator assembly. Figure 4 As shown, the frequency of this mode is the (0, 3) mode frequency of the stator assembly;

[0089] Four maximum displacement points are identified in the modal points of the first end face 1 of the stator assembly, and four maximum displacement points are identified in the modal points of the second end face 2. If the angular coordinates of the maximum displacement points of the first end face 1 and the second end face 2 are the same, then the mode is the (0, 4) mode of the stator assembly. Figure 5 As shown, the frequency of this mode is the (0, 4) mode frequency of the stator assembly;

[0090] Five maximum displacement points are identified in the modal points of the first end face 1 of the stator assembly, and five maximum displacement points are identified in the modal points of the second end face 2. If the angular coordinates of the maximum displacement points of the first end face 1 and the second end face 2 are the same, then the mode is the (0, 5) mode of the stator assembly. Figure 6 As shown, the frequency of this mode is the (0, 5) mode frequency of the stator assembly;

[0091] If the n modal point displacements of the first end face 1 and the second end face 2 of the stator assembly are the same, then the mode is the (0, 0) mode of the stator assembly. Figure 7 As shown, the frequency of this mode is the (0, 0) mode frequency of the stator assembly.

[0092] The frequencies corresponding to the above-mentioned stator assembly modes are shown in Table 3:

[0093] Table 3: Summary results of modal frequencies of stator assembly (0, 2) mode (0, 3) mode (0, 4) mode (0, 5) mode (0, 0)

[0094] Stator assembly mode (0，2) (0，3) (0，4) (0，5) (0，0) Frequency (Hz) 225 628 1149 2368 3572

[0095] Step 2) Calculate the radial stiffness coefficient of the stator assembly;

[0096] The calculation formula of the radial stiffness coefficient of the stator assembly is:

[0097]

[0098] Where: K r is the radial stiffness coefficient of the stator assembly, Feq 0,2 is the (0, 2) modal frequency of the stator assembly, Feq 0,3 is the (0, 3) modal frequency of the stator assembly, Feq 0,4 is the (0, 4) modal frequency of the stator assembly, Feq 0,5 is the (0, 5) modal frequency of the stator assembly, Feq 0,0 is the (0,0) modal frequency of the stator assembly. Substituting the frequency results corresponding to each mode in Table 3 into the formula, we get:

[0099] K r =225 / 1000+628 / 2000+1149 / 4000+2368 / 7000+3572 / 6000=1.76, the radial stiffness coefficient of the stator assembly is 1.76.

[0100] Step 3) Identification of axial out-of-phase modes of the stator assembly; based on the modal points selected in step 1), the displacement changes of 48 modal points obtained by simulation calculation are recorded and sorted, and based on the number of maximum values ​​and the principle of consistent displacement of the same axial points of maximum / minimum values, the (1, 2) mode, (1, 3) mode, (1, 4) mode, (1, 5) mode and (1, 0) mode of the stator assembly are identified.

[0101] Specifically, two maximum displacement points are identified among the 24 modal points of the first end face 1 of the stator assembly, and two minimum displacement points are identified among the 24 modal points of the second end face 2. The angular coordinates of the maximum displacement point of the first end face 1 and the minimum displacement point of the second end face 2 are the same. Specifically, as shown in Table 4, the two maximum displacement points of the first end face 1 are the 1st and 13th outer edge points, and the two minimum displacement points of the second end face 2 are the 25th and 37th displacement points. Then, the mode is the (1, 2) mode of the stator assembly. Figure 8 As shown, the frequency of this mode is the (1, 2) mode frequency of the stator assembly;

[0102] Table 4: 48-point axial displacement coordinates corresponding to the stator assembly (1, 2) mode

[0103]

[0104]

[0105] Among the 24 modal points of the first end face 1 of the stator assembly, 3 maximum displacement points are identified, and among the 24 modal points of the second end face 2, 3 minimum displacement points are identified, and the angular coordinates of the maximum displacement point of the first end face 1 and the minimum displacement point of the second end face 2 are the same, then the mode is the (1, 3) mode of the stator assembly, as shown in the attached figure. Fig. 9 As shown, the frequency of this mode is the (1, 3) mode frequency of the stator assembly;

[0106] Among the 24 modal points of the first end face 1 of the stator assembly, 4 maximum displacement points are identified, and among the 24 modal points of the second end face 2, 4 minimum displacement points are identified. If the angular coordinates of the maximum displacement point of the first end face 1 and the minimum displacement point of the second end face 2 are the same, then the mode is the (1, 4) mode of the stator assembly. Fig.10 As shown, the frequency of this mode is the (1, 4) mode frequency of the stator assembly;

[0107] Among the 24 modal points of the first end face 1 of the stator assembly, 5 maximum displacement points are identified, and among the 24 modal points of the second end face 2, 5 minimum displacement points are identified. If the angular coordinates of the maximum displacement point of the first end face 1 and the minimum displacement point of the second end face 2 are the same, then the mode is the (1, 5) mode of the stator assembly. Fig.11 As shown, the frequency of this mode is the (1, 5) mode frequency of the stator assembly;

[0108] The displacements of the 24 modal points of the first end face 1 of the stator assembly are the same, the displacements of the 24 modal points of the second end face 2 are the same, and the displacements of the 24 modal points of the first end face 1 and the second end face 2 are opposite numbers to each other, then the mode is the (1, 0) mode of the stator assembly, as shown in the attached figure. Fig.12 As shown, the frequency of this mode is the (1, 0) mode frequency of the stator assembly.

[0109] The frequencies of each stator assembly mode are shown in Table 5;

[0110] Table 5: Summary results of modal frequencies of stator assembly (1, 2) mode (1, 3) mode (1, 4) mode (1, 5) mode (1, 0)

[0111] Stator assembly mode (1，2) (1，3) (1，4) (1，5) (1，0) Frequency (Hz) 275 669 1678 2750 2833

[0112] Step 4) Calculate the torsional stiffness coefficient of the stator assembly;

[0113] The formula for calculating the torsional stiffness coefficient of the stator assembly in step 4) is:

[0114]

[0115] Where: Kt is the torsional stiffness coefficient of the stator assembly, Feq 1,2 is the modal frequency of the stator assembly (1, 2), Feq 1,3 is the (1, 3) modal frequency of the stator assembly, Feq 1,4 is the (1, 4) modal frequency of the stator assembly, Feq 1,5 is the (1, 5) modal frequency of the stator assembly, Feq 1,0 is the (1,0) modal frequency of the stator assembly. Substituting the results in Table 5 into the formula yields:

[0116] K t =0.33*(275 / 225+669 / 628+1678 / 1149+2750 / 2368+2833 / 3572)=1.88, the torsional stiffness coefficient of the stator assembly is 1.88.

[0117] Step 5) Calculate the equivalent damping coefficient of the outer edge of the stator assembly;

[0118] In step 5), the calculation method of the equivalent damping coefficient of the outer edge of the stator assembly is:

[0119] Step 5.1) m excitation points are arranged at intervals of a second set angle in the circumferential direction of the stator outer edge 3 of the stator assembly. In this specific embodiment, the second set angle is 90°, and there are 4 excitation points. The coordinates of each excitation point are shown in Table 6. A frequency sweep excitation with an amplitude of 1N is performed at intervals of 1 Hz, the frequency change rate is 3s / 1 Hz, and the frequency range is 100 Hz to 10000 Hz;

[0120] Table 6: Coordinates of the locations of the excitation points

[0121]

[0122] Step 5.2) Obtain the vibration acceleration frequency response of the 48 modal points in step 1) under all frequency excitations, and calculate the total frequency response based on the following formula;

[0123]

[0124] Where: f is the excitation frequency, G f (Sum) is the total frequency response, G f (i) is the vibration acceleration frequency response of the ith mode point; the calculated total frequency response is shown in the attached figure. Fig.13 shown.

[0125] Step 5.3) Calculate the equivalent damping coefficient of the outer edge of the stator assembly according to the following formula:

[0126]

[0127] In the formula, C r is the equivalent damping coefficient of the outer edge of the stator assembly, G 0,2 (Sum) is the sum frequency response of the stator assembly (0, 2) mode corresponding to the frequency position, G 0,3 (Sum) is the sum frequency response of the stator assembly (0, 3) mode corresponding to the frequency position, G 0,4 (Sum) is the sum frequency response of the stator assembly (0, 4) mode corresponding to the frequency position, G 0,5 (Sum) is the sum frequency response of the stator assembly (0, 5) mode corresponding to the frequency position, G 0,0 (Sum) is the sum frequency response of the stator assembly (0, 0) mode corresponding to the frequency position.

[0128] The sum of the frequency responses corresponding to each frequency is shown in Table 7;

[0129] Table 7: Total frequency response values ​​corresponding to each modal frequency

[0130] Stator assembly mode (0，2) (0，3) (0，4) (0，5) (0，0) Total frequency response 0.41 0.83 0.80 0.31 0.15

[0131] Substituting the results in Table 7 into the formula yields:

[0132] C r =0.41 / 1.5+0.83 / 2.5+0.80 / 2.0+0.31 / 1.0+0.15 / 1.0=1.29, the equivalent damping coefficient of the outer edge of the stator assembly is 1.29.

[0133] Step 6) Calculate the equivalent damping coefficient of the stator assembly tooth top-outer edge transmission;

[0134] In step 6), the calculation method of the stator assembly tooth top-outer edge transfer equivalent damping coefficient is:

[0135] Step 6.1) m response points are arranged upward from the inner circumference of the stator tooth top 4 of the stator assembly at intervals of a second set angle. In this specific embodiment, the second set angle is 90°, and there are 4 response points. The angle and axial dimension coordinates of each response point are consistent with the angle and axial dimension coordinates of each excitation point in step 5), numbered 1 to 4, and the specific coordinates are shown in Table 8. A frequency sweep excitation with an amplitude of 1N is performed at intervals of 1 Hz, the frequency change rate is 3s / 1 Hz, and the frequency range is 100 Hz to 10000 Hz;

[0136] Table 8: Response point layout coordinates

[0137]

[0138] Step 6.2) Obtain the vibration acceleration frequency response of the four response points under all frequency excitations, and calculate the total frequency response of the tooth top based on the following formula;

[0139]

[0140] Where: B f (Sum) is the sum frequency response of the tooth top, B f (i) is the vibration acceleration frequency response of the i-th response point;

[0141] The calculated sum frequency response of the tooth top is shown in Fig.14 .

[0142] Step 6.3) Calculate the stator assembly tooth tip-outer edge transfer equivalent damping coefficient according to the following formula:

[0143]

[0144] Where: C t B is the equivalent damping coefficient of the stator assembly tooth tip-outer edge transmission, 0,2 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 2) mode, B 0,3(Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 3) mode, B 0,4 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 4) mode, B 0,5 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 5) mode, B 0,0 (Sum) is the sum frequency response of the tooth top at the frequency position corresponding to the (0, 0) mode of the stator assembly.

[0145] The sum of the frequency responses corresponding to each frequency is shown in Table 9;

[0146] Table 9: Total frequency response values ​​of tooth top corresponding to each modal frequency

[0147] Stator assembly mode (0，2) (0，3) (0，4) (0，5) (0，0) Addendum sum frequency response 6.10 3.45 2.10 0.95 0.23

[0148] Substituting the results in Table 9 into the formula yields:

[0149] C t =6.10 / 2.5+3.45 / 2.0+2.10 / 2.0+0.95 / 1.0+0.23 / 1.0=6.40, the equivalent damping coefficient of the stator assembly tooth top-outer edge transfer is 6.40.

[0150] Step 7) Evaluation of stator assembly stiffness and damping performance.

[0151] The formula for evaluating the stator assembly stiffness and damping performance is:

[0152] D kc =K r +K t +1 / C r +1 / C t

[0153] Where D kc is the comprehensive stiffness-damping coefficient of the stator assembly.

[0154] D kc =1.76+1.88+1 / 1.29+1 / 6.40=4.24, the stator assembly stiffness-damping comprehensive coefficient is 4.24;

[0155] Substituting the calculated coefficient into Table 10, we can obtain: The comprehensive score of the stator assembly stiffness-damping is: 30

[0156] Table 10: Stator assembly stiffness-damping comprehensive coefficient classification

[0157]

[0158]

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A method for evaluating the stiffness and damping of a vehicle stator assembly, characterized in that: The following steps are involved: Step 1) Identification of axial in-phase modes of the stator assembly; Step 2) Calculate the radial stiffness coefficient of the stator assembly; Step 3) Identification of axial out-of-phase modes of the stator assembly; Step 4) Calculate the torsional stiffness coefficient of the stator assembly; Step 5) Calculate the equivalent damping coefficient of the outer edge of the stator assembly; Step 6) Calculate the equivalent damping coefficient of the stator assembly tooth top-outer edge transmission; Step 7) Evaluation of stator assembly stiffness and damping performance.

2. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 1, characterized in that: The method for identifying the axial in-phase mode of the stator assembly in step 1) is: Step 1.1) n / 2 modal points are respectively set on the first axial end face and the second axial end face of the stator assembly at intervals of a first set angle, and there are n modal points in total on the first end face and the second end face; Step 1.2) Record the spatial cylindrical coordinates of each modal point in step 1.1) and number them in sequence; Step 1.3) The displacement changes of each modal point of the modal results obtained by simulation calculation are recorded and sorted, and based on the number of maximum values ​​and the principle of consistent displacement of the same axial point of the maximum value, the (0, 2) mode, (0, 3) mode, (0, 4) mode, (0, 5) mode and (0, 0) mode of the stator assembly are identified.

3. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 2, characterized in that: In step 2), the formula for calculating the radial stiffness coefficient of the stator assembly is: Where: K r is the radial stiffness coefficient of the stator assembly, Feq 0,2 is the (0, 2) modal frequency of the stator assembly, Feq 0,3 is the (0, 3) modal frequency of the stator assembly, Feq 0,4 is the (0, 4) modal frequency of the stator assembly, Feq 0,5 is the (0, 5) modal frequency of the stator assembly, Feq 0,0 is the (0, 0) modal frequency of the stator assembly.

4. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 2, characterized in that: The method for identifying the axial out-of-phase modes of the stator assembly in step 3) is as follows: according to the modal points selected in step 1), the displacement changes of each modal point of the modal results obtained by simulation calculation are recorded and sorted, and based on the principle of the number of maximum values ​​and the consistency of the maximum / minimum axial displacements of the same points, the (1, 2) mode, (1, 3) mode, (1, 4) mode, (1, 5) mode and (1, 0) mode of the stator assembly are identified.

5. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 4, characterized in that: The formula for calculating the torsional stiffness coefficient of the stator assembly in step 4) is: Where: Kt is the torsional stiffness coefficient of the stator assembly, Feq 1,2 is the modal frequency of the stator assembly (1, 2), Feq 1,3 is the (1, 3) modal frequency of the stator assembly, Feq 1,4 is the (1, 4) modal frequency of the stator assembly, Feq 1,5 is the (1, 5) modal frequency of the stator assembly, Feq 1,0 is the (1, 0) modal frequency of the stator assembly.

6. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 2, characterized in that: In step 5), the calculation method of the equivalent damping coefficient of the outer edge of the stator assembly is: Step 5.1) m excitation points are arranged at intervals of a second set angle on the circumference of the stator outer edge of the stator assembly, and a frequency sweep excitation with an amplitude of 1N is performed at intervals of 1 Hz, the frequency change rate is 3s / 1 Hz, and the frequency range is 100 Hz to 10000 Hz; Step 5.2) Obtain the vibration acceleration frequency response of each modal point in step 1) under all frequency excitations, and calculate the total frequency response based on the following formula; Where: f is the excitation frequency, G f (Sum) is the total frequency response, G f (i) is the vibration acceleration frequency response of the i-th mode point; Step 5.3) Calculate the equivalent damping coefficient of the outer edge of the stator assembly according to the following formula: In the formula, C r is the equivalent damping coefficient of the outer edge of the stator assembly, G 0,2 (Sum) is the sum frequency response of the stator assembly (0, 2) mode corresponding to the frequency position, G 0,3 (Sum) is the sum frequency response of the stator assembly (0, 3) mode corresponding to the frequency position, G 0,4 (Sum) is the sum frequency response of the stator assembly (0, 4) mode corresponding to the frequency position, G 0,5 (Sum) is the sum frequency response of the stator assembly (0, 5) mode corresponding to the frequency position, G 0,0 (Sum) is the sum frequency response of the stator assembly (0, 0) mode corresponding to the frequency position.

7. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 6, characterized in that: In step 6), the calculation method of the stator assembly tooth top-outer edge transfer equivalent damping coefficient is: Step 6.1) m response points are arranged at intervals of a second set angle on the inner circumferential stator tooth top of the stator assembly, the angle and axial dimension coordinates of each response point are consistent with the angle and axial dimension coordinates of each excitation point in step 5), and a frequency sweep excitation with an amplitude of 1N is performed at intervals of 1 Hz, the frequency change rate is 3s / 1 Hz, and the frequency range is 100 Hz to 10000 Hz; Step 6.2) Obtain the vibration acceleration frequency response of the four response points under all frequency excitations, and calculate the total frequency response of the tooth top based on the following formula; Where: B f (Sum) is the sum frequency response of the tooth top, B f (i) is the vibration acceleration frequency response of the i-th response point; Step 6.3) Calculate the stator assembly tooth tip-outer edge transfer equivalent damping coefficient according to the following formula: Where: C t B is the equivalent damping coefficient of the stator assembly tooth tip-outer edge transmission, 0,2 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 2) mode, B 0,3 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 3) mode, B 0,4 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 4) mode, B 0,5 (Sum) is the sum frequency response of the tooth top at the corresponding frequency position of the stator assembly (0, 5) mode, B 0,0 (Sum) is the sum frequency response of the tooth top at the frequency position corresponding to the (0, 0) mode of the stator assembly.

8. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 7, characterized in that: In step 7), the formula for evaluating the stator assembly stiffness and damping performance is: D kc =K r +K t +1 / C r +1 / C t Where D kc is the comprehensive stiffness-damping coefficient of the stator assembly.

9. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 2, characterized in that: Two maximum displacement points are identified in the modal points of the first end face of the stator assembly, and two maximum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement points of the first end face and the second end face are the same, then the mode is the (0, 2) mode of the stator assembly, and the frequency of the mode is the (0, 2) modal frequency of the stator assembly; Three maximum displacement points are identified in the modal points of the first end face of the stator assembly, and three maximum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement points of the first end face and the second end face are the same, then the mode is the (0, 3) mode of the stator assembly, and the frequency of the mode is the (0, 3) modal frequency of the stator assembly; Four maximum displacement points are identified in the modal points of the first end face of the stator assembly, and four maximum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement points of the first end face and the second end face are the same, then the mode is the (0, 4) mode of the stator assembly, and the frequency of the mode is the (0, 4) modal frequency of the stator assembly; Five maximum displacement points are identified in the modal points of the first end face of the stator assembly, and five maximum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement points of the first end face and the second end face are the same, then the mode is the (0, 5) mode of the stator assembly, and the frequency of the mode is the (0, 5) modal frequency of the stator assembly; If the displacements of the n modal points on the first end face and the second end face of the stator assembly are the same, the mode is the (0, 0) mode of the stator assembly, and the frequency of the mode is the (0, 0) modal frequency of the stator assembly.

10. The method for evaluating the stiffness and damping of a vehicle stator assembly according to claim 5, characterized in that: Two maximum displacement points are identified in the modal points of the first end face of the stator assembly, and two minimum displacement points are identified in the modal points of the second end face, and the angular coordinates of the maximum displacement point of the first end face and the minimum displacement point of the second end face are the same, then the mode is the (1, 2) mode of the stator assembly, and the frequency of the mode is the (1, 2) modal frequency of the stator assembly; Three maximum displacement points are identified among the modal points of the first end face of the stator assembly, and three minimum displacement points are identified among the modal points of the second end face, and the angular coordinates of the maximum displacement point of the first end face and the minimum displacement point of the second end face are the same, then the mode is the (1, 3) mode of the stator assembly, and the frequency of the mode is the (1, 3) modal frequency of the stator assembly; Four maximum displacement points are identified among the modal points of the first end face of the stator assembly, and four minimum displacement points are identified among the modal points of the second end face, and the angular coordinates of the maximum displacement point of the first end face and the minimum displacement point of the second end face are the same, then the mode is the (1, 4) mode of the stator assembly, and the frequency of the mode is the (1, 4) modal frequency of the stator assembly; Five maximum displacement points are identified among the modal points of the first end face of the stator assembly, and five minimum displacement points are identified among the modal points of the second end face, and the angular coordinates of the maximum displacement point of the first end face and the minimum displacement point of the second end face are the same, then the mode is the (1, 5) mode of the stator assembly, and the frequency of the mode is the (1, 5) modal frequency of the stator assembly; If the displacements of the modal points on the first end face of the stator assembly are the same, the displacements of the modal points on the second end face are the same, and the displacements of the modal points on the first end face and the second end face are opposite to each other, then the mode is the (1, 0) mode of the stator assembly, and the frequency of the mode is the (1, 0) modal frequency of the stator assembly.

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