Noise reduction motor shell and motor
By using a double-layer structure of inner and outer shells and a constraint damping layer design, the problem of motor vibration and noise is solved, effectively attenuating motor vibration energy and reducing noise, thus improving the NVH performance of the motor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHONGQING SOKON POWER CO LTD
- Filing Date
- 2025-05-28
- Publication Date
- 2026-05-26
AI Technical Summary
In the existing technology, the damping material coated on the outside of the motor lacks constraint and cannot fully exert its vibration reduction effect, resulting in the motor vibration and noise problem not being effectively solved.
The design employs a double-layer structure with an inner shell and an outer shell. The inner and outer shells are separated by an annular gap filled with damping material to form a constrained damping layer. The rigid connection point between the inner and outer shells is only at the end caps, while the middle section is connected by a flexible connection. The high internal loss characteristics of the damping material are used to convert vibration energy into heat energy, thereby blocking the transmission path of vibration waves.
It effectively reduces motor structural vibration, improves the contact stiffness between the damping layer and the housing, avoids secondary noise radiation caused by interface slippage, and improves the NVH performance of the motor.
Smart Images
Figure CN224289488U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of motor technology, and in particular to a noise-reducing motor housing and motor. Background Technology
[0002] With the rapid development of new energy vehicles, the noise of electric drive systems has become the main source of vehicle noise. Unlike traditional fuel vehicles, electric vehicles eliminate engine noise, making the noise problem of high-frequency electromagnetic vibration and mechanical vibration radiated outward through the casing of the electric motor increasingly prominent.
[0003] To solve the above problems, the current common practice is to coat the outside of the motor with damping material. This solution is a free damping layer structure. Since the damping layer outside the motor housing is not constrained, the damping effect cannot be fully utilized, resulting in poor vibration reduction. Utility Model Content
[0004] Based on this, the present invention provides a noise-reducing motor housing and a motor to solve the problem of motor vibration being directly transmitted to the outside through the housing.
[0005] On one hand, the present invention provides a noise-reducing motor housing, comprising an end cap and an inner housing and an outer housing fixedly connected to the end cap; wherein,
[0006] The inner shell has an internal cavity for mounting the motor stator and motor rotor.
[0007] The outer shell is fitted over the outer side of the inner shell;
[0008] An annular gap is formed between the outer shell and the inner shell, and the annular gap is filled with damping material. The damping material forms a prestressed constrained damping layer between the inner shell and the outer shell.
[0009] In one embodiment, the first ends of the inner shell and the outer shell are integrally formed with the end cap;
[0010] The second ends of the inner shell and the outer shell are detachably connected to a closed structure.
[0011] In one embodiment, the first end of the annular gap is closed by the end cap;
[0012] The second end of the annular gap is closed by the sealing structure, and when the sealing structure is removed, the second end of the annular gap is opened, and the second end of the inner shell is in a free state.
[0013] In one embodiment, the closed structure is provided with a stop groove opposite to the inner shell, and the second end of the inner shell is embedded in the stop groove and is interference-fitted with the stop groove.
[0014] In one embodiment, the outer periphery of the stop groove is an annular protrusion, which is embedded in the annular gap and is interference-fitted with the annular gap.
[0015] In one embodiment, a sealing ring is provided between the bottom of the stop groove and the second end of the inner shell.
[0016] In one embodiment, a sealing groove is formed on the end face of the second end of the inner shell, the sealing ring is embedded in the sealing groove, and the sealing ring at least partially protrudes from the sealing groove.
[0017] In one embodiment, the damping material is a liquid damping adhesive, which forms the constrained damping layer after curing and expanding.
[0018] In one embodiment, the outer shell or the end cap is provided with an injection channel communicating with the annular gap;
[0019] The injection channel is used to inject liquid damping adhesive into the gap, and the injection channel is sealed by a detachable seal.
[0020] On the other hand, the present invention also provides a motor, which includes the noise-reducing motor housing of any of the above embodiments.
[0021] Compared with the prior art, this utility model has at least the following beneficial effects:
[0022] This invention relates to a noise-reducing motor housing. It employs a double-layer structure consisting of an inner and outer shell, with the rigid connection point between the inner and outer shells located only at the end caps. The middle section is flexibly connected by a constraint damping layer. This design disrupts the continuity of the overall vibration modes of the housing, blocking the transmission path of vibration waves. When the motor stator vibration is transmitted to the inner shell, the vibration wave propagates through the interface between the inner shell and the constraint damping layer. Due to the high internal friction characteristics of the damping material, the vibration energy is converted into heat energy within the material, achieving energy attenuation and effectively reducing structural vibration. Furthermore, the prestress generated by the curing and expansion of the damping material creates a tight seal between the inner and outer shells, increasing the contact stiffness between the constraint damping layer and the shell, and preventing secondary noise radiation caused by interface slippage. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the structure of the noise-reducing motor housing in one embodiment;
[0024] Figure 2 This is a schematic diagram of the noise-reducing motor housing after the enclosure structure has been removed in one embodiment.
[0025] Figure 3 for Figure 1 A magnified view of a portion of point A in the middle.
[0026] The reference numerals in the accompanying drawings include: end cap 100, inner shell 200, sealing groove 210, inner cavity 220, outer shell 300, annular gap 400, constraint damping layer 500, closed structure 600, stop groove 610, annular protrusion 620, glue injection channel 700, removable seal 800, and sealing ring 900. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0028] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model.
[0029] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this utility model can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.
[0030] The orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "middle," "longitudinal," "transverse," "horizontal," "inner," "outer," "radial," and "circumferential" used in this specification are based on the orientations or positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0031] As described in the background section, in order to reduce motor noise, the common practice is to coat the outside of the motor with damping material. This solution is a free damping layer structure. Since the damping layer outside the motor housing is not constrained, the damping effect cannot be fully utilized, resulting in poor vibration reduction.
[0032] To address this, this utility model provides a noise-reducing motor housing, characterized in that it includes an end cover 100 and an inner housing 200 and an outer housing 300 fixedly connected to the end cover 100; wherein,
[0033] The inner housing 200 has an inner cavity 220 inside, which is used to install the motor stator and motor rotor;
[0034] The outer shell 300 is fitted onto the outside of the inner shell 200;
[0035] An annular gap 400 is formed between the outer shell 300 and the inner shell 200. The annular gap 400 is filled with damping material, and the damping material forms a prestressed constrained damping layer 500 between the inner shell 200 and the outer shell 300.
[0036] According to an embodiment of the present invention, the noise-reducing motor housing is constructed with an inner housing 200 and an outer housing 300 forming a double-layer structure. The rigid connection point between the inner and outer housings 300 is located only at the end cap 100, while the middle section is flexibly connected by a constraint damping layer 500. This disrupts the continuity of the overall vibration modes of the housing, blocking the transmission path of vibration waves. When the motor stator vibration is transmitted to the inner housing 200, the vibration wave propagates through the interface between the inner housing 200 and the constraint damping layer 500. Due to the high internal friction characteristics of the damping material, the vibration energy is converted into heat energy within the material, achieving energy attenuation and effectively reducing structural vibration. Furthermore, the prestress generated by the curing and expansion of the damping material creates a tight seal between the inner and outer housings, increasing the contact stiffness between the constraint damping layer 500 and the housing, and preventing secondary noise radiation caused by interface slippage.
[0037] The noise-reducing motor housing provided in the embodiments of this utility model will be described in detail below with reference to the accompanying drawings.
[0038] according to Figure 1 An exemplary embodiment of at least one embodiment of the present invention is shown, the noise-reducing motor housing comprising: an end cap 100, an inner housing 200, and an outer housing 300.
[0039] See Figure 2 The first ends of the inner shell 200 and the outer shell 300 ( Figure 2 The lower end shown is fixedly connected to the end cap 100, forming an outer shell structure with an internal cavity, an open upper end, and a closed lower end.
[0040] The fixed connection between the inner shell 200 and the outer shell 300 and the end cap 100 can be bolted, welded, integrally formed, etc., and this embodiment does not limit it.
[0041] As a preferred option, see Figure 2 In this embodiment, the inner shell 200 and the outer shell 300 can be integrally cast with the end cap 100. The materials can be aluminum alloy, magnesium alloy, cast iron, etc., so that the inner shell 200 and the outer shell 300 and the end cap 100 form an integrated structure. In this way, the one-time molding by die casting results in low cost, eliminates the need for additional bolts or other connection processes, has a simple structure, and has good feasibility for mass production.
[0042] In this embodiment, the outer housing 300 mainly serves as external support and equipment assembly, so its external structure can be designed to be the same as that of existing conventional motor housings, and its structure will not be described in detail here. For example, conventional structures such as support feet and heat dissipation fins can be provided on the outer housing 300.
[0043] Furthermore, it is understood that since the motor housing in this embodiment consists of inner and outer shells, directly using an existing motor housing as the outer shell 300 would result in an excessively thick overall thickness. Therefore, this embodiment can design the external structure of the outer shell 300 to be identical to that of an existing motor housing, while designing its thickness to be slightly smaller than that of an existing motor housing. This allows the outer shell 300 to accommodate the thickness of the inner shell 200, preventing an excessively thick overall shell.
[0044] See Figure 1 and Figure 2 In this embodiment, the inner housing 200 is located inside the outer housing 300 and serves to install internal components such as the motor stator and motor rotor. For example, the inner housing 200 can be a cylindrical structure with an internal cavity 220, open at the upper end and closed at the lower end by an end cap 100. The internal cavity 220 of the inner housing 200 is the mounting cavity of the noise-reducing motor housing, which can be used to install components such as the motor stator and motor rotor.
[0045] Further, see Figure 2 The inner shell 200 is a cylindrical structure with uniform wall thickness.
[0046] To prevent vibrations of the motor rotor and stator from being transmitted through the inner housing 200 to the outer housing 300, and then further to the outside world through the outer housing 300, in this embodiment, see... Figure 2 An annular gap 400 is provided between the inner shell 200 and the outer shell 300. The annular gap 400 breaks the inner shell 200 and the outer shell 300 in the thickness direction, which can disrupt the continuity of the overall vibration mode of the shell and block the transmission path of vibration waves, thereby achieving the effect of vibration reduction.
[0047] Specifically, in this embodiment, the annular gap 400 between the inner shell 200 and the outer shell 300 can be formed in the following way: the inner wall surface of the outer shell 300 is designed as a cylindrical surface, and the outer wall surface of the inner shell 200 is also designed as a cylindrical surface, and the diameter of the outer wall surface of the inner shell 200 is smaller than the diameter of the inner wall surface of the outer shell 300. In this way, when the inner shell 200 and the outer shell 300 are coaxially fixed on the end cap 100, an annular gap 400 with uniform thickness can be formed between the inner shell 200 and the outer shell 300.
[0048] Further, see Figure 1 In this embodiment, the first end of the annular gap 400 ( Figure 1 The lower end of the indicated orientation is closed by the end cap 100, and the second end of the annular gap 400 ( Figure 1 The upper part (as shown) can be sealed during assembly using a detachable sealing structure 600. This ensures the annular gap 400 is sealed, preventing noise from being transmitted outward through the annular gap 400.
[0049] In different application scenarios, the enclosed structure 600 can have different structures. For example, for a single motor, see [reference needed]. Figure 1 The enclosed structure 600 can be a detachable movable end cover, while the corresponding end cover 100 at the lower end of the housing is a fixed end cover. The movable end cover is mainly used to cover the upper end of the housing after the internal parts such as the motor rotor and motor stator are assembled, forming an end support structure. For example, for a geared motor, the enclosed structure 600 can be a gearbox housing that is detachably connected to the motor housing, and it is also covered on the upper end of the housing after the internal parts are assembled.
[0050] See Figure 2 When the closed structure 600 is disassembled, the second end of the annular gap 400 is open, and the upper end of the inner shell 200 is also in an unconstrained free state. The motor shell in this structural state can be used for the assembly of the motor stator.
[0051] In the existing technology, when the motor stator is hot-assembled, the motor housing is prone to deformation. However, due to the uneven structural rigidity of the existing motor housing, uneven deformation of the motor housing is likely to occur, which in turn leads to uneven deformation of the stator, such as stator elliptical deformation, which affects the motor performance.
[0052] In this embodiment, since the upper end of the inner shell 200 is in a free state, and the inner shell 200 and the outer shell 300 are separated by an annular gap 400, the inner shell 200 can deform independently during the stator assembly process. The deformation is absorbed by the annular gap 400, ensuring that its deformation is not affected by the uneven structural stiffness of the outer shell 300. Furthermore, since the inner shell 200 has a thinner wall thickness and more uniform structural stiffness compared to conventional motor shells, the inner shell 200 can produce uniform circular deformation during stator hot assembly. This eliminates the uneven deformation of the stator, ensures the assembly effect, reduces low-order vibration, and improves the NVH performance of the motor.
[0053] In this embodiment, when the closed structure 600 is fixedly installed at the second end of the outer shell, the upper end of the inner shell 200 can be fixedly assembled with the closed structure 600. The closed structure 600 can support and limit the upper end of the inner shell 200. Thus, the two ends of the inner shell 200 are supported by the end cap 100 and the closed structure 600 respectively, which can ensure the structural strength and rigidity.
[0054] For example, see Figure 1 and Figure 3 Taking the movable end cap as an example of the closed structure 600, a stop groove 610 is provided on the side of the movable end cap facing the inner shell 200, which is opposite to the upper end of the inner shell 200. The stop groove 610 is an annular groove that matches the annular contour of the inner shell 200. The upper end of the inner shell 200 is embedded in the stop groove 610, and the inner shell 200 and the stop groove 610 are interference fit. In this way, the upper end of the inner shell 200 can be supported and limited by the stop groove 610.
[0055] Further, see Figure 3 The outer periphery of the stop groove 610 is an annular protrusion 620, which is embedded in the annular gap 400. The annular protrusion 620 and the annular gap 400 can also be an interference fit. In this way, the upper end of the annular gap 400 can be closed by the annular protrusion 620.
[0056] See Figure 1 In this embodiment, the annular gap 400 between the inner shell 200 and the outer shell 300 is further filled with damping material, forming a prestressed constrained damping layer 500 between the inner shell 200 and the outer shell 300. Thus, by placing the constrained damping layer 500 between the inner shell 200 and the outer shell 300, the high internal friction characteristics of the damping material can convert the vibrational energy of the inner shell 200 into heat energy within the material, achieving energy attenuation and further reducing the structural vibration transmitted to the outer shell 300.
[0057] Specifically, the damping material can be liquid damping adhesive. After filling the annular gap 400, the liquid damping adhesive is moderately heated and cured to expand, forming a pre-stressed constrained damping layer 500 inside the housing. This constrained damping layer 500 not only significantly improves the structural damping inside the motor, attenuating the motor's vibration and noise transmission, but also, due to the pre-stress, ensures a tight seal between the inner and outer shells, increasing the contact stiffness between the constrained damping layer and the inner shell 200, thus guaranteeing the overall structural strength and stiffness of the motor housing.
[0058] Furthermore, in this embodiment, the outer shell 300 or the end cap 100 is provided with an injection channel 700 communicating with the annular gap 400 for injecting liquid damping adhesive into the gap. The injection channel 700 is sealed by a removable seal 800. By providing the injection channel 700, adhesive can be injected into the annular gap 400 after the upper end of the closed structure 600 is sealed. Compared with directly injecting adhesive from the upper end of the annular gap 400 before assembly, this method allows the injection action to be performed in a closed state, which can improve the convenience of the injection operation and ensure that the damping adhesive completely fills the annular gap 400, thereby improving the noise reduction and vibration damping effect.
[0059] For example, participate Figure 2 In one example, the glue injection channel 700 is provided on the end cap 100, and the glue injection channel 700 is connected to the bottom of the annular gap 400. In this way, the damping glue can be filled into the entire internal cavity by high pressure injection or other methods, avoiding the generation of air bubbles and improving the damping effect.
[0060] Among them, see Figure 1 The removable seal 800 can be a threaded plug that forms a seal against the glue injection channel 700 from the outside.
[0061] Furthermore, in this embodiment, a sealing structure is provided between the inner shell 200 and the closed structure 600 to achieve a seal between the two. This sealing structure prevents the damping adhesive inside the annular gap 400 from flowing into the inner cavity 220 and compromising the cleanliness of the stator and rotor oil.
[0062] For example, see Figure 3 In this embodiment, the sealing structure may be a sealing ring 900 provided between the bottom of the stop groove 610 and the second end of the inner shell 200.
[0063] Further, see Figure 3A sealing groove 210 is formed on the end face of the second end of the inner shell 200. The sealing ring 900 is embedded in the sealing groove 210, and the sealing ring 900 at least partially protrudes from the sealing groove 210. In this way, the sealing ring 900 is limited by the sealing groove 210, which can prevent the sealing ring 900 from shifting and ensure effective contact between the sealing ring 900 and the bottom of the stop groove 610, thus ensuring the sealing effect.
[0064] On the other hand, the present invention also provides a motor, which includes the noise-reducing motor housing of any of the above embodiments.
[0065] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0066] The above embodiments merely illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A noise-reducing motor housing, characterized in that, It includes an end cap (100) and an inner shell (200) and an outer shell (300) fixedly connected to the end cap (100); wherein, The inner shell (200) has an inner cavity (220) inside, which is used to install the motor stator and the motor rotor; The outer shell (300) is sleeved on the outside of the inner shell (200); There is an annular gap (400) between the outer shell (300) and the inner shell (200), and the annular gap (400) is filled with damping material. The damping material forms a prestressed constrained damping layer (500) between the inner shell (200) and the outer shell (300).
2. The noise-reducing motor housing according to claim 1, characterized in that: The first ends of the inner shell (200) and the outer shell (300) are integrally formed with the end cap (100); The second ends of the inner shell (200) and the outer shell (300) are detachably connected to a closed structure (600).
3. The noise-reducing motor housing according to claim 2, characterized in that: The first end of the annular gap (400) is closed by the end cap (100); The second end of the annular gap (400) is closed by the closed structure (600), and when the closed structure (600) is removed, the second end of the annular gap (400) is opened, and the second end of the inner shell (200) is in a free state.
4. The noise-reducing motor housing according to claim 3, characterized in that: The closed structure (600) is provided with a stop groove (610) opposite to the inner shell (200), and the second end of the inner shell (200) is embedded in the stop groove (610) and is press-fitted with the stop groove (610).
5. The noise-reducing motor housing according to claim 4, characterized in that: The outer periphery of the stop groove (610) is an annular protrusion (620), which is embedded in the annular gap (400) and is in an interference fit with the annular gap (400).
6. The noise-reducing motor housing according to claim 4, characterized in that: A sealing ring (900) is provided between the bottom of the stop groove (610) and the second end of the inner shell (200).
7. The noise-reducing motor housing according to claim 6, characterized in that: A sealing groove (210) is provided on the end face of the second end of the inner shell (200), and the sealing ring (900) is embedded in the sealing groove (210), and the sealing ring (900) at least partially protrudes from the sealing groove (210).
8. The noise-reducing motor housing according to claim 1, characterized in that: The damping material is a liquid damping adhesive, which forms the constrained damping layer (500) after curing and expanding.
9. The noise-reducing motor housing according to claim 1, characterized in that: The outer shell (300) or the end cap (100) is provided with a glue injection channel (700) communicating with the annular gap (400); The injection channel (700) is used to inject liquid damping adhesive into the gap, and the injection channel (700) is closed by a removable seal (800).
10. An electric motor, characterized in that: Includes the noise-reducing motor housing as described in any one of claims 1-9.