Energy-saving direct-drive motor for new energy automobile

Abstract

The invention discloses an energy-saving direct drive motor for a new energy automobile. The direct drive motor comprises a motor shell, an end cover, a main shaft, a rotor and a stator, the rotor and the stator are coaxially arranged from inside to outside in the radial direction of the main shaft, and the main shaft is installed on the motor shell and the end cover through bearings. The stator comprises a stator body, a graphene oxide layer arranged in the inner surface of the stator body and a heat conduction layer arranged on the outer surface of the stator body, the thickness of the heat conduction layer is larger than that of the graphene oxide layer, the heat conduction layer is tightly attached to the inner surface of the motor shell, a copper-aluminum layer is arranged on the outer surface of the motor shell, and the thickness of the copper-aluminum layer is larger than that of the graphene oxide layer. And radiating ribs are arranged on the copper-aluminum layer. Through the cooperation of the above structures, a heat dissipation gradient which is gradually enhanced from inside to outside is formed, the heat dissipation efficiency of the motor is greatly improved, the energy consumption loss of the motor is reduced, and the energy conservation of the motor is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and in particular relates to an energy-saving direct-drive motor for new energy vehicles. Background Art

[0002] With the development of science and technology, the application of new energy has been greatly improved. New energy vehicles are undoubtedly the most popular products in new energy projects, and the motor is the most important component in the existing new energy vehicle electric drive system.

[0003] Since new energy vehicles need to control the driving speed by adjusting the motor speed during driving, the rotation of the motor rotor will generate a lot of heat during the long-term use of existing traditional motors, and the existing motors often do not have the function of autonomous heat dissipation. The large amount of heat accumulation will have a great impact on the performance of the motor, causing the motor to consume more energy. The motor is prone to failure, which has a great impact on the internal structure and performance of the motor itself as well as the service life of the motor. Summary of the invention

[0004] In view of this, an object of the present invention is to provide an energy-saving direct-drive motor for new energy vehicles, aiming to solve the technical problem that the existing direct-drive motor has poor heat dissipation and causes high motor energy consumption.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An energy-saving direct-drive motor for new energy vehicles comprises a motor housing, an end cover mounted on the motor housing, a main shaft arranged in the motor housing, a rotor coaxially arranged from the inside to the outside along the radial direction of the main shaft, and a stator for driving the rotor to rotate, the main shaft is mounted on the motor housing and the end cover through a bearing, the motor housing and the end cover are combined to form an accommodating space for accommodating the rotor and the stator, the stator comprises a stator body, a graphene oxide layer built into the inner surface of the stator body, and a heat-conducting layer arranged on the outer surface of the stator body, the thickness of the heat-conducting layer is greater than the thickness of the graphene oxide layer, the heat-conducting layer is closely attached to the inner surface of the motor housing, a copper-aluminum layer is provided on the outer surface of the motor housing, and heat-dissipating ribs for guiding heat transfer of the heat-conducting layer are provided on the copper-aluminum layer.

[0007] Furthermore, the heat conductive layer comprises an inner layer, an intermediate layer, and an outer layer, wherein the inner layer is composed of a mixture of a boron nitride heat conductive filler having a smaller particle size and a zinc nitride heat conductive filler, the outer layer is composed of a boron nitride heat conductive filler having a larger particle size, and the intermediate layer is composed of a mixture of polyethylene and a coupling agent material; the filler of the inner layer, the material of the intermediate layer, and the filler of the outer layer are composed of the following mass ratio components:

[0008] Filler of the inner layer: 30-60wt%;

[0009] The material of the intermediate layer: 1-10wt%;

[0010] The filler of the outer layer: 40-70wt%.

[0011] Furthermore, the particle size of the boron nitride filler in the inner layer is 3-10 microns, and the particle size of the zinc nitride filler is 0.1-2 microns.

[0012] Furthermore, the particle size of the boron nitride filler in the outer layer is 150-200 microns.

[0013] Furthermore, the coupling agent is one or more of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltrimethoxyethoxysilane, and γ-methacryloxypropyltrimethoxysilane.

[0014] Furthermore, the liquid viscosity of the polyethylene is 1200-2000cps.

[0015] Furthermore, the copper-aluminum layer has a thickness of 5-8 mm.

[0016] Furthermore, the graphene oxide layer is a polypropylene-modified graphene oxide layer.

[0017] Furthermore, the end cover is provided with a heat dissipation through hole.

[0018] Furthermore, a graphene oxide layer is provided on the inner wall of the bearing.

[0019] The beneficial effects of the present invention are:

[0020] (1) By providing a graphene oxide layer, the high thermal conductivity of graphene oxide is utilized to help improve the conduction of heat toward the stator body, thereby improving the thermal conductivity and heat dissipation performance of the stator, and the heat generated by the rotor can be conducted to the outside through the stator; on the other hand, the lubricity of graphene oxide can be utilized to reduce the friction between the stator and the rotor;

[0021] (2) A heat-conducting layer is provided on the outer layer of the stator body, and the heat-conducting layer is closely attached to the inner wall of the motor housing, so that heat can be directly transferred to the motor housing through the heat-conducting layer, avoiding heat conduction through air and improving heat conduction efficiency;

[0022] (3) The thickness of the heat-conducting layer is greater than that of the graphene oxide layer, thereby facilitating the formation of a gradually increasing heat dissipation gradient from the inside to the outside, facilitating the graphene oxide layer to conduct heat to the outside, thereby improving the guidance coefficient and heat dissipation function of the stator;

[0023] (4) By providing a copper-aluminum layer on the motor housing, compared with the material of the traditional motor housing, the copper-aluminum layer can be easily cut and processed to improve the processing efficiency, and the copper-aluminum layer has a better heat dissipation effect. In addition, by providing heat dissipation ribs on the copper-aluminum layer, the heat dissipation effect of the motor housing is further enhanced;

[0024] In the present application, through the coordinated cooperation of the above-mentioned structures, a heat dissipation gradient that gradually increases from the inside to the outside is formed, that is, the graphene oxide layer acts as the first rapid heat conduction layer to transfer heat to the thermal conductive layer, and the thermal conductive layer acts as the second rapid heat conduction layer to transfer heat to the motor housing due to its close contact with the motor housing. Since the motor housing is provided with a copper-aluminum layer and heat dissipation ribs, the copper-aluminum layer and the heat dissipation ribs act as the third rapid heat conduction layer to quickly conduct heat away, thereby greatly improving the heat dissipation efficiency of the motor, reducing the energy loss of the motor, and achieving motor energy saving.

[0025] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0027] Figure 1 A schematic diagram of the structure of an energy-saving direct-drive motor for a new energy vehicle proposed in one embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the internal structure of a direct drive housing without a motor housing and an end cover according to an embodiment of the present invention;

[0029] Figure 3 This is a schematic structural diagram of a stator according to an embodiment of the present invention.

[0030] Figure Number:

[0031] 1-motor housing; 11-copper-aluminum layer; 12-heat dissipation ribs;

[0032] 2-spindle;

[0033] 3-end cover; 31-heat dissipation hole;

[0034] 4-Rotor;

[0035] 5-stator; 51-stator body; 52-graphene oxide layer; 53-heat conducting layer;

[0036] 6-Bearings. DETAILED DESCRIPTION

[0037] like Figures 1 to 3 As shown, this embodiment proposes an energy-saving direct-drive motor for new energy vehicles, including a motor housing 1 and an end cover 3, the end cover 3 is installed on the motor housing 1, a main shaft 2 is arranged in the motor housing 1, the main shaft 2 can drive external equipment to rotate, the main shaft 2 is coaxially provided with a rotor 4 and a stator 5 from the inside to the outside along its radial direction, the stator 5 can drive the rotor 4 to rotate, the two ends of the main shaft 2 are respectively installed on the motor housing 1 and the end cover 4 through bearings 6, the motor housing 1 and the end cover 3 are combined into a accommodating space, and the accommodating space can be used to accommodate the rotor 4 and the stator 5. Specifically, the stator 5 includes a stator body 51, the inner surface of which is provided with a graphene oxide layer 52, and the outer surface of the stator body 51 is provided with a heat-conducting layer 53, the thickness of the heat-conducting layer 53 is greater than the thickness of the graphene oxide layer 52, and in addition, the heat-conducting layer 53 is tightly attached to the inner surface of the motor housing 1, and the outer surface of the motor housing 1 is provided with a copper-aluminum layer 11, and the copper-aluminum layer 11 is provided with heat dissipation ribs 12, and the heat dissipation ribs 12 can be used to transfer the heat of the heat-conducting layer 53 to the outside.

[0038] In the present application, by setting the graphene oxide layer 52, on the one hand, the high thermal conductivity of graphene oxide is utilized to help improve the conduction of heat toward the stator body 51, thereby improving the thermal conductivity and heat dissipation performance of the stator 5, and the heat generated by the rotor 4 can be conducted to the outside through the stator; on the other hand, the lubricity of graphene oxide can be utilized to reduce the friction between the stator 5 and the rotor 4; the thickness of the heat-conducting layer 53 is greater than the thickness of the graphene oxide layer 52, thereby facilitating the formation of a gradually increasing heat dissipation gradient from the inside to the outside, which is beneficial for the graphene oxide layer 52 to conduct heat to the outside, thereby improving the stator. 5 guide coefficient and heat dissipation function; the outer layer of the stator body 51 is provided with a heat-conducting layer 53, and the heat-conducting layer 53 is closely attached to the inner wall of the motor housing 1, so that the heat can be directly transferred to the motor housing 1 through the heat-conducting layer 53, avoiding air heat conduction and improving the heat conduction efficiency; the copper-aluminum layer 11 is provided on the motor housing 1, and compared with the material of the traditional motor housing, the copper-aluminum layer 11 can be convenient for cutting and processing, improve the processing efficiency, and on the other hand, the copper-aluminum layer 11 has a good heat dissipation effect, and the heat dissipation ribs 12 are provided on the copper-aluminum layer 11, thereby enhancing the heat dissipation effect of the motor housing 1;

[0039] In the present application, through the coordinated cooperation of the above-mentioned structures, a heat dissipation gradient gradually enhanced from the inside to the outside is formed, that is, the graphene oxide layer 52 acts as the first rapid heat conduction layer to transfer heat to the thermal conductive layer 53, and the thermal conductive layer 53, which is tightly attached to the motor housing 1, acts as the second rapid heat conduction layer to transfer heat to the motor housing 1. Since the copper-aluminum layer 11 and the heat dissipation ribs 12 are provided on the motor housing 1, the copper-aluminum layer 11 and the heat dissipation ribs 12 act as the third rapid heat conduction layer to quickly conduct heat away, thereby greatly improving the heat dissipation efficiency of the motor, reducing the energy loss of the motor, and achieving motor energy saving.

[0040] Preferably, the graphene oxide layer 52 can be disposed on the stator body 51 by spraying or pasting. Of course, according to actual conditions and specific requirements, the graphene oxide layer 52 can also be disposed on the stator body 51 by other methods, which are not limited here.

[0041] Further, the heat conductive layer 53 includes an inner layer, an intermediate layer, and an outer layer, wherein the inner layer is composed of a mixture of a boron nitride heat conductive filler with a smaller particle size and a zinc nitride heat conductive filler, the outer layer is composed of a boron nitride heat conductive filler with a larger particle size, and the intermediate layer is composed of a mixture of polyethylene and a coupling agent material; in addition, the filler of the inner layer, the material of the intermediate layer, and the filler of the outer layer are composed of the following mass ratio components:

[0042] Filler of the inner layer: 30-60wt%;

[0043] The material of the intermediate layer: 1-10wt%;

[0044] The filler of the outer layer: 40-70wt%.

[0045] In the present application, the heat-conducting layer 53 is configured with three layers, and the fillers of the inner and outer layers are prepared with materials of different particle sizes and types. A variety of filler powders of different types and particle sizes are combined to produce a synergistic effect between the fillers, forming a rich heat-conducting network in the middle layer, and taking into account the properties of the particles themselves, a suitable amount of coupling agent is calculated to increase the affinity between polyethylene and the filler, promote the dispersion of the filler in the polyethylene, and then the filler is evenly filled in the polyethylene through stirring and grinding. Heat can be conducted in the thermal interface material body layer through multiple paths, thereby improving the heat conduction efficiency; at the same time, a rich heat-conducting grid is formed through the heat-conducting layer, so that the thermal conductivity of the heat-conducting layer is better than that of the graphene oxide layer, forming a heat dissipation gradient that gradually increases from the inside to the outside.

[0046] In the present application, by setting the middle layer as a mixture of polyethylene and coupling agent material, a filler with high viscosity is formed, which effectively ensures that the particles are closely connected and more heat conduction paths can be formed. The prepared composite material has high thermal conductivity and good flexibility and has strong practical value.

[0047] Preferably, the heat-conducting layer 53 is provided on the stator body 51 by pasting. Of course, it can also be provided by spraying, which is not the only limitation here.

[0048] Preferably, the mass ratio of the inner layer filler can be 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%; the mass ratio of the middle layer material can be 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%; the mass ratio of the outer layer filler can be 40wt%, 45wt%, 50wt%, 55wt%, 60wt%, 65wt%, 70wt% and the like.

[0049] Table 1 is a comparison table of thermal conductivity layer performance with different mass ratios

[0050]

[0051] It can be seen from Table 1 that different mass ratios of the inner layer and the outer layer will have different effects on the thermal conductivity. When the proportion of the inner layer filler is high, the thermal conductivity will increase positively; when the mass ratio of the middle layer is high, the thermal conductivity will not change significantly, which indicates that the middle layer mainly plays the role of bonding the inner layer and the outer layer.

[0052] Preferably, the particle size of the boron nitride filler in the inner layer is 3-10 microns, and the particle size of the zinc nitride filler is 0.1-2 microns. Specifically, the particle size of the boron nitride filler can be 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 8 microns, 10 microns, etc.; the particle size of the zinc nitride filler can be 0.1 micron, 0.2 micron, 0.3 micron, 0.5 micron, 1.0 micron, 1.2 micron, 1.4 micron, 1.6 micron, 1.8 micron, 2.0 micron, etc.

[0053] In the present application, by selecting fillers of different particle sizes, small-particle fillers can be filled between large-particle fillers, so that a synergistic effect is generated between the fillers, forming a rich heat-conducting network in the middle layer, and improving the heat-conducting efficiency.

[0054] Preferably, the mass ratio of boron nitride to zinc nitride may be (0.5:1) to (0.1:0.5). Specifically, the mass ratio of boron nitride to zinc nitride may be 0.5:0.5, 0.6:0.4, 0.65:0.35, 0.7:0.3, 0.75:0.25, 0.8:0.2, 0.85:0.15, etc.

[0055] Table 2 is a comparison table of the inner layer performance at different mass ratios

[0056]

[0057] It can be seen from Table 2 that as the proportion of boron nitride increases, the thermal conductivity will increase slightly. When a certain proportion of boron nitride is reached, the thermal conductivity will gradually stabilize.

[0058] Preferably, the particle size of the boron nitride is 150-200 microns. Specifically, the particle size of the boron nitride can be 150 microns, 155 microns, 160 microns, 165 microns, 166 microns, 198 microns, etc.

[0059] Preferably, the liquid viscosity of the polyethylene is 1200-2000cps. The inner and outer layers have lower viscosity and are easier to fit the equipment. The middle layer has a high polyethylene filling amount and a larger viscosity. The particles are tightly connected to form more heat conduction paths. The prepared layered composite material has higher thermal conductivity and good flexibility.

[0060] Further, the thickness of the copper-aluminum layer 11 is 5-8mm. Specifically, the thickness of the copper-aluminum layer 11 is 5mm, 6mm, 7mm, 8mm, etc. In this way, by setting a copper-aluminum layer 11 of a certain thickness on the motor housing 1, it is convenient to process the heat dissipation ribs 12; by selecting the copper-aluminum layer 11, the better heat dissipation performance of copper and aluminum can be utilized, so that the motor housing 1 has better heat dissipation performance, and by setting the motor housing 1 as a copper-aluminum layer, the thickness of the motor housing made of cast iron material can be reduced accordingly, ensuring that the motor housing 1 has better heat dissipation; in addition, by setting the heat dissipation ribs 12 and the copper-aluminum layer 11, the heat dissipation of the motor housing 1 is due to the heat conductive layer 53, so that the motor 1 forms a heat dissipation gradient that gradually increases from the inside to the outside, which is convenient for rapid heat transfer.

[0061] Preferably, the graphene oxide layer 52 is a polypropylene-modified graphene oxide layer. By using the polypropylene-modified graphene oxide layer and grafting polypropylene onto the graphene oxide, the interlayer spacing of the graphene oxide can be extended, which helps to inhibit the aggregation of the graphene oxide and improves the stability of the high heat dissipation performance of the stator.

[0062] Specifically, the method for modifying the graphene oxide layer with polypropylene is as follows:

[0063] According to weight, 4 parts of amino-modified graphene oxide were ultrasonically dispersed in 1 part of xylene, and then 5 parts of maleic anhydride grafted polypropylene (MAPP) were added, and the mixture was heated to 150°C and stirred under nitrogen reflux for 2 hours. After the reaction was terminated, the reaction was also filtered (using a PTFE filter membrane with a pore size of 0.22 μm), and the filter cake was extracted with toluene for 48 hours and then dried in a vacuum oven at 90°C to obtain polypropylene-modified graphene oxide.

[0064] Furthermore, the end cover 3 is provided with a heat dissipation through hole 31. In this way, the heat can also be quickly dissipated through the end cover 3, which is energy-saving and environmentally friendly; by providing the end cover 3, the direct drive motor can be protected from external collisions by the end cover 3, thereby extending the service life of the direct drive motor.

[0065] Preferably, a graphene oxide layer 52 is provided on the inner wall of the bearing 6. By providing the graphene oxide layer 52 on the inner wall of the bearing 6, the lubricity between the bearing 6 and the main shaft 2 can be enhanced, the friction loss between the main shaft 2 can be reduced, and energy saving can be achieved. Specifically, the graphene oxide layer 52 can be sprayed on the inner wall of the bearing 6. In this way, the bonding force between the bearing 6 and the graphene oxide layer 52 can be enhanced. Of course, in this embodiment, the graphene oxide layer 52 can also be provided on the bearing 6 by bonding, which is not limited here.

[0066] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. An energy-saving direct-drive motor for new energy vehicles, characterized in that: The invention comprises a motor housing, an end cover mounted on the motor housing, a main shaft arranged in the motor housing, a rotor coaxially arranged from the inside to the outside along the radial direction of the main shaft, and a stator for driving the rotor to rotate, the main shaft is mounted on the motor housing and the end cover through a bearing, the motor housing and the end cover are combined to form an accommodation space for accommodating the rotor and the stator, the stator comprises a stator body, a graphene oxide layer built into the inner surface of the stator body, and a heat conducting layer arranged on the outer surface of the stator body, the thickness of the heat conducting layer is greater than the thickness of the graphene oxide layer, the heat conducting layer is closely attached to the inner surface of the motor housing, a copper-aluminum layer is arranged on the outer surface of the motor housing, and a heat dissipation rib for guiding the heat transfer of the heat conducting layer is arranged on the copper-aluminum layer.

2. The energy-saving direct-drive motor for new energy vehicles according to claim 1, characterized in that: The heat-conducting layer comprises an inner layer, an intermediate layer, and an outer layer. The inner layer is composed of a mixture of boron nitride heat-conducting filler with a smaller particle size and zinc nitride heat-conducting filler, the outer layer is composed of boron nitride heat-conducting filler with a larger particle size, and the intermediate layer is composed of a mixture of polyethylene and a coupling agent material; the filler of the inner layer, the material of the intermediate layer, and the filler of the outer layer are composed of the following mass ratio components: Filler of the inner layer: 30-60wt%; The material of the intermediate layer: 1-10wt%; The filler of the outer layer: 40-70wt%.

3. The energy-saving direct-drive motor for new energy vehicles according to claim 2, characterized in that: The particle size of the boron nitride filler in the inner layer is 3-10 microns, and the particle size of the zinc nitride filler is 0.1-2 microns.

4. The energy-saving direct-drive motor for new energy vehicles according to claim 2, characterized in that: The particle size of the boron nitride filler in the outer layer is 150-200 microns.

5. The energy-saving direct-drive motor for new energy vehicles according to claim 2, characterized in that: The coupling agent is one or more of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltrimethoxyethoxysilane, and γ-methacryloxypropyltrimethoxysilane.

6. The energy-saving direct-drive motor for new energy vehicles according to claim 2, characterized in that: The liquid viscosity of the polyethylene is 1200-2000 cps.

7. The energy-saving direct-drive motor for new energy vehicles according to claim 1, characterized in that: The thickness of the copper-aluminum layer is 5-8 mm.

8. The energy-saving direct-drive motor for new energy vehicles according to claim 1, characterized in that: The graphene oxide layer is a polypropylene-modified graphene oxide layer.

9. The energy-saving direct-drive motor for new energy vehicles according to claim 1, characterized in that: The end cover is provided with a heat dissipation through hole.

10. The energy-saving direct-drive motor for new energy vehicles according to claim 1, characterized in that: A graphene oxide layer is provided on the inner wall of the bearing.

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