Light motor flange end cover based on acoustic black hole principle

Abstract

The invention discloses a light motor flange end cover based on an acoustic black hole principle, and belongs to the technical field of motor vibration noise control. Comprising a motor flange end cover body, and the motor flange end cover body comprises a flange end cover inner ring, a flange end cover outer ring and circumferential array skeleton ribs for coaxially connecting the flange end cover inner ring and the flange end cover outer ring into a whole; array acoustic black hole assemblies are symmetrically arranged on the end faces of the two sides of the circumferential array skeleton ribs, the array acoustic black hole assembly located on one side comprises a plurality of acoustic black hole assemblies arrayed in the circumferential direction and the radial direction, and the circumferential array period is consistent with the array period of the skeleton ribs. According to the invention, bending wave vibration energy dissipation can be realized in a full frequency band, and the lightweight motor flange end cover based on the acoustic black hole principle has efficient vibration and noise reduction performance.

Description

Technical Field

[0001] The invention belongs to the technical field of motor vibration noise control, and in particular relates to a lightweight motor flange end cover based on the acoustic black hole principle. Background Art

[0002] With the emergence of environmental pollution and scarcity of natural resources, all walks of life are more inclined to use electric motors as industrial power sources. For example, traditional fuel engine cars tend to be gradually replaced by new energy vehicles. Electric motors have significant advantages such as simple structure, reliable operation, small size, light weight, low loss, high efficiency and flexible shape and size. They are widely used in almost all fields of aerospace, national defense, industrial and agricultural production and daily life. With the advancement of science and technology and the improvement of people's living standards, the requirements for all aspects of motors are getting higher and higher, especially in the control of motor vibration and noise. As the power source in the electromechanical system, the size of the vibration and noise of the motor will directly affect the overall performance of the electromechanical system.

[0003] At present, the technologies for reducing vibration and noise for motor end covers include adding vibration-damping pads and buffer blocks inside the cover to properly buffer the vibration of the motor housing, and then using sound-absorbing cotton and noise-reducing materials on the end cover to consume and absorb the noise generated during operation. This structure can play a certain role in buffering, reducing vibration and noise reduction, but it does not fundamentally eliminate vibration and noise. Therefore, there is still reflection of vibration waves during the vibration reduction process, which has an adverse effect on the performance of the motor. In motor vibration reduction, vibration-damping springs are also used for vibration isolation. The use of elastic materials or elastic components can reduce the excitation transmitted to the vibration-damped components, but complex installation structures need to be considered. For example, inappropriate installation positions and structures may lead to poor vibration isolation effects. In high-frequency vibration environments, springs gradually become rigid, elastic, and vibration isolation and damping effects deteriorate, which is called "high-frequency failure."

[0004] In summary, the disclosed motor end cover vibration and noise reduction technologies are difficult to reduce vibration waves to zero reflection, especially in fields such as aerospace that have high demands for vibration and noise reduction, and still cannot meet the requirements. Summary of the invention

[0005] Technical issues to be solved:

[0006] In order to avoid the shortcomings of the prior art, the present invention provides a lightweight motor flange end cover based on the acoustic black hole principle. Based on the principle that the acoustic black hole structure can achieve zero reflection of wave transmission under ideal conditions, the acoustic black hole component is coupled to the motor flange end cover. By designing the layout, structure and other features of the acoustic black hole component, the dissipation of the bending wave vibration energy is achieved, and the motor flange end cover has high-efficiency vibration and noise reduction performance in the full frequency band.

[0007] The technical solution of the present invention is: a lightweight motor flange end cover based on the principle of acoustic black hole, including a motor flange end cover body, wherein the motor flange end cover body includes a flange end cover inner ring, an outer ring and a circumferential array skeleton rib that coaxially connects the two into one; array acoustic black hole components are symmetrically arranged on the end surfaces of both sides of the circumferential array skeleton rib, wherein the array acoustic black hole component located on one side includes a plurality of acoustic black hole components along the circumferential and radial arrays, and the circumferential array period is consistent with the array period of the skeleton ribs.

[0008] A further technical solution of the present invention is that the number of radial arrays of the acoustic black hole components is designed according to the radial length of the skeleton ribs.

[0009] A further technical solution of the present invention is: the length direction of the acoustic black hole component is the tangent direction of the intersection of the skeleton rib and the inner ring of the flange end cover.

[0010] A further technical solution of the present invention is: the acoustic black hole assembly includes an acoustic black hole component and a damping layer applied on the end surface thereof; the acoustic black hole component is a wedge-shaped structure formed by stretching the cross section along the length direction, and the change in the cross-sectional height satisfies the following formula:

[0011] h(x)=kx 2 +j 0≤x≤i

[0012] Among them, k is the coefficient of the acoustic black hole power exponential function, j is the minimum thickness of the acoustic black hole region, and i is the maximum value of the acoustic black hole power exponential function.

[0013] A further technical solution of the present invention is: the end with a larger cross-section of the acoustic black hole component is the starting point and is installed on the end face of the skeleton rib through fasteners; the side with a gradually decreasing cross-section faces the cavity between adjacent skeleton ribs; the end with a smaller cross-section is the end, and a damping layer is laid on its flat side.

[0014] A further technical solution of the present invention is that the material of the damping layer is nitrile rubber.

[0015] A further technical solution of the present invention is that the acoustic black hole component and the motor flange end cover body are made of the same material, both of which are 7055 aluminum alloy.

[0016] A design method for a lightweight motor flange end cover based on the acoustic black hole principle, the specific steps are as follows:

[0017] Construct a finite element simulation model of the motor flange cover body;

[0018] Load radial and axial excitations on the motor flange end cover body model to obtain the displacement modal cloud diagram of the motor flange end cover body model;

[0019] Based on the displacement mode cloud map, the installation position of the acoustic black hole component is determined on the skeleton ribs of the motor flange end cover body;

[0020] The power exponent of the height variation function of the acoustic black hole component section is set to 2, and the external structure of the acoustic black hole component is calculated;

[0021] Determine the number of arrays of the acoustic black hole components according to the number of skeleton rib arrays and the radial length of the motor flange end cover body;

[0022] Fix the starting ends of all acoustic black hole components to the corresponding positions at both ends of the ribs of the circumferential array skeleton through fasteners;

[0023] The mean square vibration velocity level was used to evaluate the vibration reduction performance of the lightweight motor flange end cover based on the acoustic black hole principle.

[0024] A further technical solution of the present invention is: the method of using the mean square vibration velocity level to evaluate the vibration reduction performance is: applying radial excitation and axial excitation to the lightweight motor flange end cover based on the acoustic black hole principle respectively, determining the outer ring end face of the flange end cover as the vibration picking surface, and calculating the mean square vibration velocity level. If the mean square vibration velocity level meets the design requirements, the design is completed; if not, the design variable cross-sectional height of the acoustic black hole component is optimized until the design is met.

[0025] A motor comprises the lightweight motor flange end cover based on the acoustic black hole principle.

[0026] Beneficial Effects

[0027] The beneficial effects of the present invention are as follows: the present invention arrays a plurality of acoustic black hole components on the end faces on both sides of the skeleton ribs of the lightweight motor flange end cover, and when the bending wave energy generated by the vibration is transmitted to the flange end cover, the bending wave can be concentrated on the acoustic black hole component; and then the damping layer laid at the end of the acoustic black hole structure is used to dissipate the bending wave vibration energy, thereby achieving efficient vibration reduction and noise reduction performance, especially the vibration reduction and noise reduction effect on medium and low frequencies is more prominent.

[0028] The present invention introduces an acoustic black hole structure, which is designed as a wedge-shaped cantilever beam connected to the skeleton ribs, so that the wave velocity of the bending wave gradually decreases as the thickness of the beam decreases. In an ideal case, the wave velocity can be reduced to zero to achieve zero reflection of the wave. The end cover can achieve efficient vibration reduction, noise reduction and energy recovery through circumferential and radial array settings. The acoustic black hole component has the advantages of simple structure, light weight, low-frequency high-efficiency vibration reduction and easy processing.

[0029] It has been verified that within the range of 1 to 10,000 Hz, the mean square vibration velocity level of the lightweight motor flange end cover is reduced by an average of 5.82 dB, which has the advantages of efficient vibration reduction and noise reduction performance, and has broad application prospects in the efficient control of motor vibration noise in the fields of aerospace, automobile manufacturing and shipbuilding. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a structural diagram of a lightweight motor flange end cover without an acoustic black hole principle in an embodiment of the present invention;

[0031] Figure 2 This is a structural diagram of a lightweight motor flange end cover based on the acoustic black hole principle in an embodiment of the present invention;

[0032] Figure 3 It is a front view of a lightweight motor flange end cover based on the acoustic black hole principle in an embodiment of the present invention;

[0033] Figure 4 It is a top view of a lightweight motor flange end cover based on the acoustic black hole principle in an embodiment of the present invention;

[0034] Figure 5 A bottom view of a lightweight motor flange end cover based on the acoustic black hole principle in an embodiment of the present invention;

[0035] Figure 6 This is a structural diagram of a single-leaf acoustic black hole component connected to the inner frame of a flange end cover of a lightweight motor based on the acoustic black hole principle in an embodiment of the present invention;

[0036] Figure 7 It is a schematic diagram of a radial excitation measurement point A of a lightweight motor flange end cover based on the acoustic black hole principle in an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of an axial excitation measurement point B of a lightweight motor flange end cover based on the acoustic black hole principle in an embodiment of the present invention;

[0038] Fig. 9 This is a comparison diagram of the mean square vibration velocity levels of the lightweight motor flange end cover with and without the acoustic black hole principle under radial excitation in the embodiment of the present invention, and the frequency range is 1 to 10000 Hz;

[0039] Fig.10 This is a comparison diagram of the mean square vibration velocity levels of the lightweight motor flange end cover with and without the acoustic black hole principle under axial excitation in the embodiment of the present invention, and the frequency range is 1 to 10000 Hz;

[0040] Fig.11The displacement modal cloud diagrams of the lightweight motor flange end cover with / without the acoustic black hole principle in the embodiment of the present invention at the radial excitation measuring point A at a frequency of 3100 Hz in the XYZ coordinate system, the XY coordinate system, the YZ coordinate system and the XZ coordinate system;

[0041] Fig.12 The displacement modal cloud diagrams are of the lightweight motor flange end cover with / without the acoustic black hole principle in the embodiments of the present invention at a frequency of 3100 Hz under the axial excitation measuring point B in the XYZ coordinate system, the XY coordinate system, the YZ coordinate system and the XZ coordinate system.

[0042] Explanation of the accompanying drawings: 1. Motor flange end cover body; 11. Flange end cover outer ring; 12. Flange end cover inner ring; 13. Skeleton ribs; 2. Acoustic black hole assembly; 21. Acoustic black hole component, 22. Damping layer; 3. Connecting bolts. DETAILED DESCRIPTION

[0043] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0044] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0045] Based on the fact that the disclosed motor end cover vibration reduction and noise reduction technology is difficult to reduce the vibration waves to zero reflection, and it still cannot meet the problems in fields such as aerospace that have high demands for vibration reduction and noise reduction. The present invention provides a lightweight motor flange end cover based on the acoustic black hole principle. The acoustic black hole effect is used to concentrate the axial and radial bending waves received by the inner ring of the motor flange end cover on the acoustic black hole component, so that the vibration energy is dissipated.

[0046] Acoustic black hole effect: Similar to the concept of black holes in astrophysics, the gradient change of the geometric parameters or material property parameters of thin-walled structures is used to gradually reduce the propagation speed of waves in the structure. Ideally, the wave speed is reduced to zero so that no reflection occurs. The main method to achieve the acoustic black hole effect is to cut the thickness of the thin plate structure according to a certain rule. The acoustic black hole can be used to gather the wave energy propagating in the structure at a specific position; the acoustic black hole has the characteristics of broadband and high efficiency, simple and flexible implementation methods, etc. Taking the beam structure as an example, when the thickness of the beam structure decreases with a certain power exponential function, the wave speed of the bending wave will gradually decrease as the thickness of the beam decreases. In an ideal situation, the wave speed can be reduced to zero to achieve zero reflection of the wave. This structure is called an acoustic black hole structure. Based on the characteristics of the acoustic black hole, the acoustic black hole structure has the advantages of simple structure, lightweight, low-frequency and high-efficiency vibration reduction, and easy processing.

[0047] The above technical solution is further described below in conjunction with the accompanying drawings:

[0048] In one embodiment, referring to Figure 1-5 As shown, a lightweight motor flange end cover based on the acoustic black hole principle of the present invention includes: a motor flange end cover body 1, wherein the motor flange end cover body 1 includes a flange end cover inner ring 12, an outer ring 11 and a circumferential array skeleton rib 13 that coaxially connects the two into one; array acoustic black hole components are symmetrically arranged on the end surfaces of both sides of the circumferential array skeleton rib 13, wherein the array acoustic black hole component located on one side includes a plurality of acoustic black hole components 2 along the circumferential and radial arrays, and the circumferential array period is consistent with the array period of the skeleton rib 13.

[0049] In one embodiment, the length direction of the acoustic black hole assembly is the tangent direction of the intersection of the skeleton rib and the inner ring of the flange end cover.

[0050] In one embodiment, referring to Figure 6 As shown, the acoustic black hole assembly includes an acoustic black hole component 21 and a damping layer 22 applied on the end surface thereof; the acoustic black hole component is a wedge-shaped structure formed by stretching the cross section along the length direction, and the change in the cross-sectional height satisfies the following formula:

[0051] h(x)=kx 2 +j 0≤x≤i

[0052] Among them, k is the coefficient of the acoustic black hole power exponential function, j is the minimum thickness of the acoustic black hole region, and i is the maximum value of the acoustic black hole power exponential function.

[0053] Preferably, the acoustic black hole component 2 includes a tapered surface on one side that changes along a power exponential function and a platform with bolt holes on the other side. The acoustic black hole component 21 is connected to the end surfaces on both sides of the skeleton rib 13 by connecting bolts 3.

[0054] In one embodiment, the end with a larger cross-section of the acoustic black hole component is the starting point and is installed on the end face of the skeleton rib through fasteners; the side with a gradually decreasing cross-section faces the cavity between adjacent skeleton ribs; the end with a smaller cross-section is the end, and a damping layer is laid on its flat side.

[0055] Preferably, the material of the damping layer is nitrile rubber.

[0056] Preferably, the acoustic black hole component and the motor flange end cover body are made of the same material, both of which are 7055 aluminum alloy.

[0057] In one embodiment, a design method for a lightweight motor flange end cover based on the acoustic black hole principle comprises the following specific steps:

[0058] Step 1: Construct a finite element simulation model of the motor flange cover body;

[0059] Step 2: Load radial and axial excitations on the motor flange end cover body model to obtain the displacement modal cloud diagram of the motor flange end cover body model;

[0060] Step 3: Based on the displacement mode cloud map, the installation position of the acoustic black hole component is determined on the skeleton rib of the motor flange end cover body;

[0061] Step 4: Set the power exponent of the acoustic black hole component cross-sectional height variation function to 2, and calculate the external structure of the acoustic black hole component;

[0062] Step 5: Determine the number of arrays of the acoustic black hole components according to the number of skeleton rib arrays and the radial length of the motor flange end cover body;

[0063] Step 6: Fix the starting ends of all acoustic black hole components to the corresponding positions at both ends of the circumferential array skeleton ribs through fasteners;

[0064] Step 7: Use the mean square vibration velocity level to evaluate the vibration reduction performance of the lightweight motor flange end cover based on the acoustic black hole principle. The method of using the mean square vibration velocity level to evaluate the vibration reduction performance is: apply radial excitation and axial excitation to the lightweight motor flange end cover based on the acoustic black hole principle respectively, determine the outer ring end face of the flange end cover as the vibration pickup surface, calculate the mean square vibration velocity level, and if the mean square vibration velocity level meets the design requirements, the design is completed; if not, the design variable cross-sectional height of the acoustic black hole component is optimized until the design is met.

[0065] In one embodiment, referring to Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, the outer diameter of the flange end cover outer ring 11 is 120mm, the inner diameter is 104mm, and the wall thickness is 18mm; the outer diameter of the flange end cover inner ring 12 is 60mm, the inner diameter is 51mm, and the axial thickness is 33mm; the skeleton rib 13 has a rib length of 28mm, a width of 10mm, and a thickness of 18mm, and there are 6 ribs in total, which are equidistantly distributed around the circumference between the skeleton rib flange end cover outer ring 11 and the flange end cover inner ring 12.

[0066] The acoustic black hole component 21 has an overall side length of 81 mm, a width of 4 mm, and a thickness of 6 mm, wherein the side length of the platform is 15 mm. The change h(x) of the acoustic black hole region in the x direction can be calculated by the following formula:

[0067] h(x)=kx 2 +j 0≤x≤i

[0068] Among them, k is the coefficient of the acoustic black hole power exponential function, which is 6 / 6561, j is the minimum thickness of the acoustic black hole region, which is 0.8 mm, and i is the maximum value of the acoustic black hole power exponential function, which is 81 mm.

[0069] Then there is,

[0070]

[0071] The damping layer 22 has a side length of 15 mm, a width of 4 mm, and a thickness of 1 mm.

[0072] In this embodiment, the acoustic black hole components 21 are connected and distributed on the end surfaces of both sides of the skeleton ribs 13, and three acoustic black hole components 21 are evenly distributed on one side of each skeleton rib, with a total of 36 acoustic black hole components 21 on the inner skeleton of the lightweight motor flange end cover.

[0073] In this embodiment, the motor flange cover body 1, the flange cover outer ring 11, the flange cover inner ring 12, the skeleton ribs 13, the acoustic black hole component 21 and the connecting bolts 3 are made of 7055 aluminum alloy, and the density of 7055 aluminum alloy is 2830 kg / m 3 , Young's modulus is 2.1×10 10 Pa, Poisson's ratio is 0.30.

[0074] The material of the damping layer 22 in this embodiment is nitrile rubber, and the density of nitrile rubber is 1100 kg / m 3 , Young's modulus is 5×10 7 Pa, Poisson's ratio is 0.49, and loss factor is 1.0.

[0075] The motor flange cover body 1, the flange cover outer ring 11, the flange cover inner ring 12, the skeleton ribs 13, the acoustic black hole component 21 and the connecting bolts 3 in this embodiment are prepared by cutting or wire cutting.

[0076] The acoustic black hole component 21 in this embodiment is connected to both sides of the end surface of the inner frame rib by connecting bolts 3 respectively.

[0077] The damping layer nitrile rubber of the damping layer 22 in this embodiment is connected by gluing.

[0078] The working principle of this embodiment is as follows: when the motor vibrates and generates bending waves, the bending waves are transmitted to the acoustic black hole component 21 of the motor flange end cover body 1. As the thickness of the structure gradually decreases, the accumulated phase of the elastic wave gradually increases and the wave speed gradually decreases. When the elastic wave is transmitted to the thinnest part of the edge of the acoustic black hole component, the accumulated phase of the bending wave reaches the maximum and the equivalent wave speed is reduced to the minimum. The damping layer 22 applied to the acoustic black hole component can achieve efficient control of motor vibration reduction and noise reduction.

[0079] Next, a simulation model is established through the solid mechanics module in Comsol Mutiphysics 6.3 finite element simulation software to calculate the mean square vibration velocity level and displacement modal cloud diagram of a lightweight motor flange end cover based on the acoustic black hole principle.

[0080] Reference Figure 7 and Figure 8 As shown in the figure, in a lightweight motor flange end cover based on the acoustic black hole principle, the radial and axial excitation sources are both 1N, the radial excitation direction is radially outward, and the axial excitation direction is axially downward. The radial excitation point A and the axial excitation point B are set as the excitation points, and the lower surface of the outer ring 1 of the flange end cover is picked up as the vibration picking surface. The mean square vibration velocity level of the lightweight motor flange end cover with an acoustic black hole and the lightweight motor flange end cover without an acoustic black hole under the radial and axial excitation measuring points is calculated to evaluate the vibration reduction performance. The mean square vibration velocity level is defined as:

[0081]

[0082] Where: S represents the area of ​​the vibration surface; V is the normal velocity distribution function of the vibration surface.

[0083] The mean square vibration velocity level is expressed as:

[0084] L v =10log( <v 2 > / v0 2 )

[0085] Where v0 = 1 × 10 -5 m / s is the reference speed.

[0086] Reference Fig. 9 and Fig.10As shown, the solid line represents the mean square vibration velocity level of the lightweight motor flange end cover based on the acoustic black hole principle in the frequency range of 1 to 10000 Hz at radial excitation point A and axial excitation point B in this embodiment, and the dotted line represents the mean square vibration velocity level of the lightweight motor flange end cover without acoustic black holes in the frequency range of 1 to 10000 Hz at radial excitation point A and axial excitation point B in this embodiment. It can be clearly seen in this embodiment that compared with the condition where the acoustic black hole component is not connected, when the acoustic black hole component is connected to the inner skeleton ribs of the flange end cover, the mean square vibration velocity level of the excitation points A and B within the calculated frequency range is reduced by an average of 5.82dB, and in the frequency band of 1 to 10000Hz, the mean square vibration velocity level under radial excitation is reduced by an average of 6.39dB, and the maximum peak value at 3100Hz is reduced from 47.07dB to 24.80dB, a decrease of 52.69%, and the mean square vibration velocity level under axial excitation is reduced by an average of 5.25dB, especially the maximum peak value at 3100Hz is reduced from 22.18dB to 1.69dB, a significant decrease of 92.38%. The lightweight motor flange end cover based on the acoustic black hole principle has high-efficiency vibration and noise reduction performance in the entire frequency band.

[0087] Reference Fig.11 and 12 As shown in the figure, the post-processing function of Comsol Mutiphysics 6.3 finite element simulation software gives the displacement modal cloud diagram of the flange end cover of the lightweight motor with or without acoustic black hole at a frequency of 3150Hz under radial excitation point A and axial excitation point B. It can be seen from the XYZ view, XY view, YZ view and XZ view that the vibration displacement of the flange end cover of the lightweight motor without acoustic black hole is mainly concentrated on the inner frame of the flange end cover, and the vibration displacement of the flange end cover of the lightweight motor with acoustic black hole is mainly concentrated on the acoustic black hole structure. Multiple circularly distributed acoustic black hole structures are connected to the inner frame of the flange end cover. When the motor is working, the bending vibration generated can be well transmitted to the acoustic black hole structure. Under the combined action of the acoustic black hole effect of the acoustic black hole structure and the energy dissipation of the damping layer, the vibration velocity is forced to realize energy convergence at the end position of the structure, and the damping layer at the end can efficiently dissipate the energy at the end. This process reflects the physical nature of the flange end cover structure based on the acoustic black hole principle to weaken and dissipate the harmful vibration energy of the motor.

[0088] The present invention provides a lightweight motor flange end cover based on the acoustic black hole principle. By connecting a plurality of acoustic black hole components distributed in a circumference on both sides of the end surface of the skeleton ribs in the lightweight motor flange end cover, the vibration bending wave energy can be concentrated in the acoustic black hole area to achieve energy absorption and dissipation. In the range of 1 to 10,000 Hz, the mean square vibration velocity level of the lightweight motor flange end cover is reduced by an average of 5.82 dB, which has the advantages of efficient vibration reduction and noise reduction performance, and has broad application prospects in the fields of aerospace, automobile manufacturing and shipbuilding in the efficient control of motor vibration noise.

[0089] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A lightweight motor flange end cover based on the acoustic black hole principle, comprising a motor flange end cover body, wherein the motor flange end cover body comprises a flange end cover inner ring, an outer ring and a circumferential array skeleton ribs that coaxially connect the two into one; characterized in that: Array acoustic black hole components are symmetrically arranged on the end faces of both sides of the circumferential array skeleton ribs, wherein the array acoustic black hole component located on one side includes a plurality of acoustic black hole components along the circumferential and radial arrays, and the circumferential array period is consistent with the array period of the skeleton ribs.

2. According to claim 1, a lightweight motor flange end cover based on the acoustic black hole principle is characterized in that: The number of radial arrays of the acoustic black hole components is designed according to the radial length of the skeleton ribs.

3. According to the lightweight motor flange end cover based on the acoustic black hole principle of claim 1, it is characterized by: The length direction of the acoustic black hole assembly is the tangent direction of the intersection of the skeleton ribs and the inner ring of the flange end cover.

4. According to claim 1, a lightweight motor flange end cover based on the acoustic black hole principle is characterized in that: The acoustic black hole assembly includes an acoustic black hole component and a damping layer applied on the end surface thereof; the acoustic black hole component is a wedge-shaped structure formed by stretching the cross section along the length direction, and the change in the cross-sectional height satisfies the following formula: h(x)=kx 2 +j 0≤x≤i Among them, k is the coefficient of the acoustic black hole power exponential function, j is the minimum thickness of the acoustic black hole region, and i is the maximum value of the acoustic black hole power exponential function.

5. The lightweight motor flange end cover based on the acoustic black hole principle according to claim 1 is characterized in that: The acoustic black hole component has a larger cross-section end as a starting point and is installed on the end surface of the skeleton rib through a fastener; the side with a gradually reduced cross-section faces the cavity between adjacent skeleton ribs; The end with the smaller cross section is the terminal end, and the damping layer is laid on the flat side thereof.

6. A lightweight motor flange end cover based on the acoustic black hole principle according to claim 5, characterized in that: The material of the damping layer is nitrile rubber.

7. The lightweight motor flange end cover based on the acoustic black hole principle according to claim 5 is characterized by: The acoustic black hole component and the motor flange end cover body are made of the same material, both of which are 7055 aluminum alloy.

8. A design method for a lightweight motor flange end cover based on the acoustic black hole principle, characterized in that The specific steps are as follows: Construct a finite element simulation model of the motor flange cover body; Load radial and axial excitations on the motor flange end cover body model to obtain the displacement modal cloud diagram of the motor flange end cover body model; Based on the displacement mode cloud map, the installation position of the acoustic black hole component is determined on the skeleton ribs of the motor flange end cover body; The power exponent of the height variation function of the acoustic black hole component section is set to 2, and the external structure of the acoustic black hole component is calculated; Determine the number of arrays of the acoustic black hole components according to the number of skeleton rib arrays and the radial length of the motor flange end cover body; Fix the starting ends of all acoustic black hole components to the corresponding positions at both ends of the ribs of the circumferential array skeleton through fasteners; The mean square vibration velocity level was used to evaluate the vibration reduction performance of the lightweight motor flange end cover based on the acoustic black hole principle.

9. The design method of a lightweight motor flange end cover based on the acoustic black hole principle according to claim 8 is characterized in that: The method for evaluating vibration reduction performance using mean square vibration velocity level is as follows: radial excitation and axial excitation are applied to the lightweight motor flange end cover based on the acoustic black hole principle respectively, the outer ring end face of the flange end cover is used as the vibration pickup surface, and the mean square vibration velocity level is calculated. If the mean square vibration velocity level meets the design requirements, the design is completed; if not, the design variable cross-sectional height of the acoustic black hole component is optimized until the design is met.

10. A motor, characterized in that: Including the lightweight motor flange end cover based on the acoustic black hole principle as described in any one of claims 1-8.

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