Motor heat dissipation structure and electric drive system heat dissipation structure

Abstract

This invention provides a heat dissipation structure for an electric motor and an electric drive system, relating to the field of new energy vehicle technology. The motor heat dissipation structure includes a housing, an inner water jacket, and auxiliary heat dissipation components. The housing has an internal space for accommodating components; the inner water jacket is located within this space and forms a cooling channel with the housing; the auxiliary heat dissipation component is located within the cooling channel, with one end connected to the inner water jacket and the other end extending towards the housing. Both the auxiliary heat dissipation component and the cooling channel are arranged in a spiral structure along the circumference of the inner water jacket. This results in a longer flow path and residence time for the coolant within a limited axial length, and the heat dissipation component can disrupt the laminar boundary layer of the coolant, enhancing the turbulence and further improving heat dissipation efficiency. Without increasing the overall system envelope size, this invention optimizes the flow field, increases the effective heat exchange area, and improves the heat dissipation capacity per unit volume.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and more specifically, to a motor heat dissipation structure and an electric drive system heat dissipation structure. Background Technology

[0002] With the rapid development of new energy vehicle technology, electric drive systems are evolving towards higher power and higher integration. Electric drive systems generate a large amount of heat during operation; if this heat cannot be dissipated in a timely and effective manner, it will lead to decreased motor efficiency, performance degradation, and even component damage.

[0003] Currently, most mainstream electric drive systems employ liquid cooling solutions. The coolant first flows through the motor controller to cool the internal power electronic components, and then flows through specially designed water connectors into water channels inside the motor housing. Traditional motor housings are typically assembled from an inner water jacket and an outer shell, forming an annular or axial water channel for coolant flow. The coolant flows within this channel, exchanging heat with the motor's interior through the housing walls, and finally exits from the outlet.

[0004] However, due to limitations in the overall size of the casing and manufacturing process, the geometry of the cooling channels and the heat dissipation area are relatively fixed, resulting in a limited heat dissipation area and low heat exchange efficiency, leading to poor overall heat dissipation performance. Summary of the Invention

[0005] The purpose of this invention is to provide a heat dissipation structure for an electric motor and a heat dissipation structure for an electric drive system, so as to alleviate the technical problems in the prior art where the geometry of the cooling water channel and the heat dissipation area are relatively fixed, the heat dissipation area is limited and the heat exchange efficiency is low, resulting in poor overall heat dissipation effect.

[0006] The present invention provides a motor heat dissipation structure, comprising: a housing, an inner water jacket, and auxiliary heat dissipation components.

[0007] The outer casing has internal spaces for accommodating components; An inner water jacket is installed in the space and forms a cooling water channel between it and the outer shell; The auxiliary heat dissipation component is located inside the cooling water channel, with one end connected to the inner water jacket and the other end extending towards the outer shell; The auxiliary heat dissipation components and the cooling water channels are both arranged in a spiral structure along the circumference of the inner water jacket.

[0008] Furthermore, the auxiliary heat dissipation component includes: heat dissipation fins.

[0009] Heat dissipation fins are disposed within the cooling water channel, and multiple grooves are formed within the heat dissipation fins. The multiple grooves form multiple flow guide channels within the cooling water channel.

[0010] Furthermore, the heat dissipation fins are rectangular fins or corrugated fins.

[0011] Furthermore, the spacing between any two adjacent heat dissipation fins is 2mm to 5mm; The fin height of the heat dissipation fins is 3 mm to 10 mm.

[0012] Furthermore, the heat dissipation fins are welded to the inner water jacket.

[0013] The present invention also aims to provide a heat dissipation structure for an electric drive system, including a motor assembly, a controller assembly, and a transition water connector; The motor assembly includes a provided motor heat dissipation structure; Both the motor assembly and the controller assembly are provided with transition ports in opposite positions; The two ends of the transition water connector are respectively connected to the two transition ports to form a sealed coolant passage.

[0014] Furthermore, the transition water connector includes a connector body and a sealing part; The connector body has a flow hole, and both ends of the connector body are respectively inserted into the two transition sockets; The sealing parts are multiple and spaced apart along the axial direction of the connector body. Each of the sealing parts is interference-fitted with one of the two transition sockets to fill the gap between the connector body and the transition socket.

[0015] Furthermore, the sealing part is made of an elastic material; The sealing part has two parts, each of which is interference-fitted with one of the two transition sockets.

[0016] Furthermore, the end of the sealing part away from the connector body has an outwardly convex arc-shaped structure.

[0017] Furthermore, the transition water connector is an integrated structure.

[0018] Beneficial effects: In the motor heat dissipation structure provided in this application, both the heat sink and the cooling water channel are designed as spiral structures. This results in a longer flow path and residence time for the coolant within a limited axial length. Furthermore, the heat sink can disrupt the laminar boundary layer of the coolant, enhancing the turbulence and further improving heat dissipation efficiency. Thus, without increasing the overall system envelope size, it not only optimizes the flow field but also increases the effective heat exchange area, thereby improving the heat dissipation capacity per unit volume. This makes it more suitable for high-power-density electric drive systems with high space and heat dissipation requirements. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the motor heat dissipation structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the heat dissipation fins in the motor heat dissipation structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the heat dissipation structure of the electric drive system provided in an embodiment of the present invention; Figure 4 This is a schematic diagram showing the installation relationship of the water connector in the heat dissipation structure of the electric drive system provided in an embodiment of the present invention.

[0021] icon: 100 - Outer shell; 200 - Inner water jacket; 210 - Cooling water channel; 300 - Auxiliary heat dissipation component; 310 - Heat dissipation fins; 10 - Motor assembly; 20 - Controller assembly; 30 - Transition water connector; 31 - Sealing part. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and 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 a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply 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.

[0027] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0029] Please see Figure 1 , Figure 2 The motor heat dissipation structure provided in this embodiment includes a housing 100, an inner water jacket 200, and an auxiliary heat dissipation component 300.

[0030] The housing 100 has an internal space for accommodating components. The inner water jacket 200 is located in the space and forms a cooling water channel 210 between it and the housing 100. The auxiliary heat dissipation component 300 is located in the cooling water channel 210, with one end connected to the inner water jacket 200 and the other end extending towards the housing 100.

[0031] Among them, the auxiliary heat dissipation component 300 and the cooling water channel 210 are both arranged in a spiral structure along the circumference of the inner water jacket 200.

[0032] Specifically, in this embodiment, both the heat dissipation component and the cooling water channel 210 are configured as a spiral structure. When the coolant flows through the water channel, it is forced to flow along the spiral path. Compared with the traditional straight or simple annular water channel, the spiral flow channel significantly increases the flow path and residence time of the coolant within a limited axial length.

[0033] Meanwhile, the spiral structure of the heat sink itself constitutes a turbulence element in the flow channel, which can disrupt the laminar boundary layer of the coolant and enhance the turbulence of the coolant. The enhanced turbulence makes the heat exchange between the coolant and the heat sink and the inner water jacket 200 wall more intense, further improving the heat dissipation efficiency.

[0034] Under this structure, the motor heat dissipation structure provided in this embodiment not only optimizes the flow field but also increases the effective heat exchange area without increasing the overall outer envelope size of the system, thereby improving the heat dissipation capacity per unit volume. It is more suitable for high power density electric drive systems with high space and heat dissipation requirements.

[0035] In this embodiment, the auxiliary heat sink 300 includes heat sink fins 310.

[0036] The heat dissipation fins 310 are disposed in the cooling water channel 210, and multiple grooves are formed in the heat dissipation fins 310. The multiple grooves form multiple guide channels in the cooling water channel 210.

[0037] Specifically, in this embodiment, the heat dissipation fins 310 divide the originally single cooling channel 210 into several parallel guide channels. Under this structure, the total flow rate of the coolant is diverted to multiple small channels formed by the multiple guide channels.

[0038] Within a single flow channel, the contact area ratio (i.e., specific surface area) between the coolant and the heat dissipation fins 310 and the channel wall is larger. Furthermore, the spacing of the heat dissipation fins 310 themselves constitutes continuous turbulence points, further promoting coolant mixing and heat exchange. The presence of multiple parallel flow channels also provides flow redundancy, ensuring that even if minor flow unevenness occurs locally due to manufacturing reasons, the overall heat dissipation performance remains stable. Therefore, this multi-fin heat dissipation fin 310 flow channel structure further enhances the heat dissipation effect and system robustness by subdividing the flow channels and increasing the heat exchange interface.

[0039] In this embodiment, the heat dissipation fins 310 are rectangular fins or corrugated fins.

[0040] In this embodiment, the heat dissipation fins 310 are specifically rectangular fins. Rectangular fins have a simple structure and are easy to reliably connect to the inner water jacket 200 by brazing, welding, or other methods. Their regular shape also facilitates precise control of fin spacing and fin height within a limited space, thereby enabling quantitative design of the heat dissipation area.

[0041] As an feasible approach, the heat dissipation fins 310 can also be corrugated fins. The surface of the corrugated fins has curved variations, which can generate more complex secondary flows and eddies when the coolant flows through them, more effectively disrupting the thermal boundary layer and enhancing heat transfer. At the same time, the corrugated structure provides a larger actual surface area for the same projected area.

[0042] In this embodiment, the spacing between any two adjacent heat dissipation fins 310 is 2mm to 5mm. The fin height of the heat dissipation fins 310 is 3mm to 10mm.

[0043] The fin pitch setting in this embodiment is based on a balance between fluid mechanics and heat transfer. Too small a fin pitch leads to a sharp increase in flow resistance, placing excessive demands on the cooling system's pumping power. Too large a fin pitch reduces the number of fins per unit volume, decreasing the heat dissipation area. A fin pitch range of 2mm to 5mm ensures sufficient heat dissipation area while keeping flow resistance within a reasonable range for conventional water pumps. In this embodiment, the fin pitch is specifically 3mm.

[0044] Furthermore, the fin height setting is related to the increase in heat dissipation volume and structural strength. A suitable fin height can significantly increase the volume of the heat sink, thereby accommodating more coolant and increasing the heat exchange area. However, excessively high fins may affect structural stability or occupy too much water channel space. A fin height within the range of 3mm to 10mm allows the heat dissipation fins 310 to achieve a significant increase in heat dissipation area within a compact space, while maintaining good structural reliability and manufacturability. In this embodiment, the fin height is specifically 6mm.

[0045] In this embodiment, the heat dissipation fins 310 are welded to the inner water jacket 200.

[0046] In this embodiment, the heat dissipation fins 310 are specifically fixedly connected to the inner water jacket 200 by brazing. Brazing can form a metallurgical bond between the metal contact surfaces of the heat dissipation fins 310 and the inner water jacket 200, and its thermal resistance is much lower than that of mechanical contact (such as interference fit) or the presence of gaps. Low thermal resistance means that the heat generated by heat sources such as the motor stator core can be transferred more smoothly through the inner water jacket 200 to the heat dissipation fins 310, reducing thermal bottlenecks in the heat transfer path.

[0047] Meanwhile, the brazing connection method has high connection strength and reliability, and can withstand the pulsating pressure caused by long-term coolant flow and vibration during vehicle operation, ensuring the long-term stable operation of the heat dissipation structure, thereby optimizing the heat transfer interface and providing mechanical reliability, and ensuring the longevity and stability of heat dissipation performance.

[0048] Please see Figure 3 , Figure 4The heat dissipation structure of the electric drive system provided in this embodiment includes a motor assembly 10, a controller assembly 20, and a transition water connector 30.

[0049] The motor assembly 10 includes a provided motor cooling structure. Both the motor assembly 10 and the controller assembly 20 are provided with opposing transition ports. The two ends of the transition water connector 30 are respectively connected to the two transition ports to form a sealed coolant passage.

[0050] Specifically, in this embodiment, the motor assembly 10 employs a spiral cooling water channel 210 and heat dissipation fins 310 inside to dissipate heat from the motor. The controller assembly 20 is connected to the cooling water channel 210 via a transition water connector 30 to dissipate heat from the power electronic components in the controller assembly 20.

[0051] The transition water connector 30 connects the coolant circuits of the motor assembly 10 and the controller assembly 20. In this structure, the cooling water channel 210 with heat dissipation fins 310 in the motor assembly 10 and the controller assembly 20 can be independently optimized and manufactured according to their respective heat dissipation requirements, and then integrated through a standardized transition port and transition water connector 30. The integration is high, which helps to improve the flexibility of the heat dissipation design and production efficiency of the entire electric drive system.

[0052] In this embodiment, the transition water connector 30 includes a connector body and a sealing part 31.

[0053] A flow hole is formed inside the connector body, and the two ends of the connector body are respectively inserted into two transition sockets. There are multiple sealing parts 31, which are spaced apart along the axial direction of the connector body. The multiple sealing parts 31 are respectively interference-fitted with the two transition sockets to fill the gap between the connector body and the transition sockets.

[0054] Specifically, in this embodiment, the flow hole within the connector body forms a passage for the coolant. When the transition water connector 30 is inserted into the transition socket, multiple axially spaced sealing parts 31 sequentially contact the inner wall of the socket and undergo compression deformation. Each axially spaced sealing part 31 can independently and completely fill the annular gap at its corresponding axial position. This structure not only compensates for dimensional errors in the inner diameter of the transition socket on a single cross-section but also effectively adapts to comprehensive shape errors such as taper, irregularity, or different axialities that may exist in the socket throughout its entire axial depth.

[0055] Multiple axial seals 31 together form multiple lines of sealing defense. Even if one of these lines of defense experiences instantaneous pressure fluctuations or slight material loosening due to extreme operating conditions, subsequent seals 31 can still ensure the overall sealing integrity, significantly reducing the risk of leakage. Compared to a single sealing point or circumferential partial sealing, axially spaced multi-point sealing, by establishing a deep sealing defense, greatly improves the sealing reliability and fault tolerance of the connection under complex assembly conditions and long-term operating conditions.

[0056] In this embodiment, the sealing part 31 is made of an elastic material. There are two sealing parts 31, each of which is interference-fitted with one of the two transition sockets.

[0057] Specifically, in this embodiment, both the sealing part 31 and the connector body are made of rubber. With this material, the transition connector has good compression and rebound characteristics. During assembly, the sealing part 31 is squeezed and deformed, filling all the microscopic unevenness and gaps between the connector body and the inner wall of the transition socket. The contact pressure is maintained continuously by relying on the elastic recovery force of the material, thereby achieving a static seal.

[0058] Two independent sealing parts 31 respectively seal the interfaces on one side of the motor assembly 10 and the other side of the controller assembly 20, achieving decoupling of the sealing function. Assembly stress or sealing status on one side will not be directly transmitted to and affect the other side, allowing the interfaces on both sides to be assembled and inspected independently, simplifying the assembly process and preventing the risk of leakage at the entire connection due to single-point seal failure.

[0059] It should be noted that in this embodiment, the two sealing parts 31 and the connector body form a spindle-shaped transition water connector.

[0060] The spindle-shaped design provides excellent alignment guidance during assembly. During assembly, the spindle-shaped transition connector 30 is aligned with the corresponding cylindrical transition sockets on the motor assembly 10 and controller assembly 20. An axial force is then applied, pressing the sealing portions 31 at both ends of the connector into their respective transition sockets. Due to the elasticity of the sealing portion 31 material and its dimensional interference fit, it undergoes elastic deformation under radial compression, thus tightly filling the annular gap between the outer wall of the connector and the inner wall of the socket, forming two independent and reliable radial seals.

[0061] In this embodiment, the end of the sealing part 31 away from the connector body has an outwardly convex arc surface structure.

[0062] Specifically, in this embodiment, the end of the sealing part 31 furthest from the connector body is a convex spherical surface. This structure provides good guidance when inserting into the transition socket. The contact between the arc surface and the edge of the socket is a gradual line contact or a small-area contact, resulting in low frictional resistance and facilitating assembly.

[0063] After full insertion, the contact area between the arc surface and the inner wall of the socket can adapt to a certain angle deflection. When there is a slight misalignment of the axes between the motor assembly 10 and the controller assembly 20 due to installation or thermal deformation, the spherical sealing structure allows the joint to self-adjust within a certain angle without causing severe stress concentration or sealing failure at the sealing interface. This improves assembly guidance and allows for angle tolerance, further reducing assembly difficulty, while also enhancing the sealing reliability of the connection structure under complex working conditions.

[0064] In this embodiment, the transition water connector 30 is an integrated structure.

[0065] In this embodiment, the connector body and the sealing part 31 are formed into a transition water connector 30 through a one-time molding process (specifically injection molding in this embodiment). The integrated structure eliminates the step of assembling the sealing ring separately in traditional split connectors, and avoids problems such as sealing ring twisting, cutting or falling off that may occur during the assembly process.

[0066] Furthermore, the integrated transition water connector 30 reduces the number of parts, simplifying material management and the supply chain. Simultaneously, the one-piece molding ensures a seamless connection between the sealing part 31 and the connector body, eliminating microscopic leakage paths and preventing failure due to relative displacement of the sealing ring and groove during long-term use caused by vibration or thermal cycling. This achieves the effects of simplified structure, elimination of secondary assembly steps, and optimized interface integrity, improving sealing reliability while also reducing manufacturing costs and assembly time.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A motor heat dissipation structure, characterized in that, include: The outer casing (100) has an interior space for accommodating components; An inner water jacket (200) is provided in the installation space and forms a cooling water channel (210) between it and the outer shell (100); An auxiliary heat dissipation component (300) is disposed in the cooling water channel (210) and one end is connected to the inner water jacket (200), while the other end extends toward the outer shell (100); The auxiliary heat dissipation component (300) and the cooling water channel (210) are both arranged in a spiral structure along the circumference of the inner water jacket (200).

2. The motor heat dissipation structure according to claim 1, characterized in that, The auxiliary heat sink (300) includes: Heat dissipation fins (310) are disposed in the cooling water channel (210), and multiple grooves are formed in the heat dissipation fins (310), and the multiple grooves form multiple guide channels in the cooling water channel (210).

3. The motor heat dissipation structure according to claim 2, characterized in that, The heat dissipation fins (310) are rectangular fins or corrugated fins.

4. The motor heat dissipation structure according to claim 2, characterized in that, The spacing between any two adjacent heat dissipation fins (310) is 2mm to 5mm; The fin height of the heat dissipation fins (310) is 3 mm to 10 mm.

5. The motor heat dissipation structure according to claim 2, characterized in that, The heat dissipation fins (310) are welded to the inner water jacket (200).

6. A heat dissipation structure for an electric drive system, characterized in that, Includes a motor assembly (10), a controller assembly (20), and a transition water connector (30); The motor assembly (10) includes a motor heat dissipation structure as described in any one of claims 1 to 5; Both the motor assembly (10) and the controller assembly (20) are provided with transition ports in opposite positions; The two ends of the transition water connector (30) are respectively connected to the two transition ports to form a sealed coolant passage.

7. The heat dissipation structure of the electric drive system according to claim 6, characterized in that, The transition water connector (30) includes a connector body and a sealing part (31); The connector body has a flow hole, and both ends of the connector body are respectively inserted into the two transition sockets; The sealing part (31) is multiple and spaced apart along the axial direction of the connector body. The multiple sealing parts (31) are respectively interference-fitted with the two transition sockets to fill the gap between the connector body and the transition socket.

8. The heat dissipation structure of the electric drive system according to claim 7, characterized in that, The sealing part (31) is made of elastic material; The sealing part (31) has two parts and is respectively interference-fitted with the two transition sockets.

9. The heat dissipation structure of the electric drive system according to claim 7, characterized in that, The end of the sealing part (31) away from the connector body has an outwardly convex arc surface structure.

10. The heat dissipation structure of the electric drive system according to claim 6, characterized in that, The transition water connector (30) is an integrated structure.

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