A high power density motor with oil-immersed cooling structure at both ends

Abstract

The utility model provides a kind of high power density motor with two ends oil immersion cooling structure, it is related to motor cooling technical field, including shell, stator, rotor and cooling oil circuit, the cooling oil circuit includes: oil immersion cover assembly, the oil immersion cover assembly with the stator end face, the shell inner surface jointly enclose the closed cavity for accommodating cooling oil;The oil immersion cover assembly is set in the both ends of the stator, to end portion winding is completely wrapped, so that the end portion winding is immersed in the cooling oil;At least one axial oil channel, formed in the stator, to communicate the oil immersion cover assembly located in the both ends of the stator.From fundamentally solved the low cooling efficiency, the problem of big temperature difference of two ends that traditional oil shower or single end oil immersion scheme exists, realizes direct, efficient and uniform heat exchange to end portion winding, and simple structure.

Description

Technical Field

[0001] This utility model relates to the field of motor cooling technology, specifically to a high power density motor with an oil-immersed cooling structure at both ends. Background Technology

[0002] Oil-cooled motors, as a highly efficient cooling method, are widely used in electric vehicles, aerospace and other fields to address the problem of high heat loss caused by high electromagnetic loads.

[0003] Currently, oil-cooled motors typically employ oil spray cooling or partial oil immersion cooling methods, such as installing an oil spray structure at the motor end or using oil immersion at one end and oil spraying at the other end for cooling.

[0004] However, these existing cooling methods have the following drawbacks: First, the cooling scheme of spraying oil at both ends, although simple in structure, has low cooling efficiency. The cooling oil cannot fully cover the winding ends, resulting in high motor temperature rise, which is difficult to meet the heat dissipation requirements of high power density motors, and there is also the problem of uneven cooling.

[0005] Secondly, the method of immersing one end in oil and spraying oil on the other end, although the oil-immersed end has a better cooling effect, the oil-sprayed end is not sufficiently cooled, resulting in a large temperature difference between the two ends of the motor, which affects the stability and efficiency of the motor operation.

[0006] To further improve cooling efficiency, existing technologies have also developed stator oil immersion cooling solutions. For example, Chinese invention patent CN114337015B discloses a high-power-density motor with a stator oil immersion cooling structure. This solution enhances the cooling of the stator core and windings by segmenting the stator core and setting alternating oil channels in the yoke and tooth sections. While this solution improves the cooling uniformity within the stator, it still focuses on the design of the stator axial oil channels and does not address the direct immersion cooling of the windings at both ends of the motor. Therefore, there is still room for improvement in the cooling efficiency of the end windings, and the overall structure is relatively complex.

[0007] It is evident that existing oil-cooled motors still suffer from low efficiency and poor uniformity in end-cooling. Utility Model Content

[0008] The technical problem to be solved by this utility model is how to design a solution that can achieve uniform and efficient oil immersion cooling at both ends of the motor.

[0009] To solve the above-mentioned technical problems, this utility model provides a high power density motor with an oil-immersed cooling structure at both ends, including a housing, a stator, a rotor, and a cooling oil circuit, wherein the cooling oil circuit includes: An oil immersion shroud assembly, together with the stator end face and the inner surface of the housing, forms a sealed cavity for containing cooling oil; the oil immersion shroud assembly is disposed at both ends of the stator to completely enclose the end windings, so that the end windings are immersed in the cooling oil; At least one axial oil passage is formed in the stator to connect the oil sump assembly located at both ends of the stator.

[0010] Furthermore, the oil immersion shroud assembly includes a first oil immersion shroud and a second oil immersion shroud, wherein the cooling oil flows in from the first oil immersion shroud, flows through the axial oil passage to the second oil immersion shroud, and flows out.

[0011] Furthermore, the top of the first oil immersion hood is provided with an oil inlet pipe; the bottom of the second oil immersion hood is provided with an oil return port.

[0012] Furthermore, both the first oil immersion hood and the second oil immersion hood include: The first sealing surface is configured to contact the inner surface of the housing to form a seal; The second sealing surface is configured to contact the stator end face to form a seal.

[0013] Furthermore, the axial oil passage includes an oil passage formed along the stator axial direction on at least one of the stator yoke, tooth, or outer surface.

[0014] Furthermore, the axial oil passage comprises multiple layers of oil passages distributed radially along the stator.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention constructs a cooling structure with oil immersion at both ends by forming a sealed cavity with the housing and stator end face by setting oil immersion covers at the two axial ends of the motor, and combining them with stator axial oil passages connecting the two cavities. This fundamentally solves the problems of low cooling efficiency and large temperature difference at both ends in traditional oil spraying or single-end oil immersion schemes, and realizes direct, efficient and uniform heat exchange for the end windings, and the structure is simple. Attached Figure Description

[0016] Figure 1 This is a partial cross-sectional view of the motor disclosed in this utility model; Figure 2 This is a schematic diagram of the cooling oil flow direction disclosed in this utility model; Figure 3 This is a schematic diagram of the structure of the oil immersion hood assembly disclosed in this utility model; Figure 4 This is a schematic diagram of the structure of the first oil-immersion hood disclosed in this utility model; Figure 5This is a schematic diagram of the structure of the second oil immersion hood disclosed in this utility model.

[0017] In the picture: 10. Housing; 20. Stator; 30. Oil immersion hood assembly; 31. First oil immersion hood; 31a. Oil inlet pipe; 32. Second oil immersion hood; 32a. Oil return port; 31b, 32b, first sealing surface; 31c, 32c, second sealing surface; 40. Axial oil passage. Detailed Implementation

[0018] To make the technical solutions and effects of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0019] The present invention aims to provide a high power density motor with an oil-immersed cooling structure at both ends, in order to solve the technical problems of low end cooling efficiency, poor uniformity and large temperature difference at both ends of existing oil-cooled motors.

[0020] like Figure 1 As shown, the high power density motor mainly includes a housing 10, a stator 20, a rotor, and a cooling oil circuit. The core of this invention lies in the fact that the cooling oil circuit includes an oil immersion shroud assembly and at least one axial oil passage.

[0021] First, the oil immersion hood assembly 30 in this solution will be described in detail.

[0022] In this design, the oil immersion shroud assembly 30, together with the end face of the stator 20 and the inner surface of the housing 10, forms a sealed cavity for containing cooling oil. The oil immersion shroud assembly 30 is located at both ends of the stator 20 to completely enclose the end windings, ensuring that the end windings are completely immersed in the cooling oil. Compared with traditional spray cooling, this immersion cooling achieves direct and continuous contact between the cooling oil and the end windings over the maximum area, greatly improving the heat exchange efficiency and uniformity of the end windings, and fundamentally eliminating the problems of localized hot spots and excessive temperature differences between the two ends caused by uneven cooling.

[0023] Please see Figure 3-5 The oil immersion shroud assembly 30 includes a first oil immersion shroud 31 and a second oil immersion shroud 32. Cooling oil flows into the first oil immersion shroud 31, fills its cavity and immerses the end winding, and then flows to the second oil immersion shroud 32 through the axial oil passage 40 under pressure. After immersing the end winding again, it finally flows out from the second oil immersion shroud 32.

[0024] The first oil immersion hood 31 has an oil inlet pipe 31a at the top for connecting to an external oil pump and introducing cooling oil; the second oil immersion hood 32 has an oil return port 32a at the bottom for connecting to an oil return pipeline.

[0025] To ensure the reliability of the sealed cavity, a further solution is proposed: The first oil-immersed cover 31 is provided with a first sealing surface 31b and a second sealing surface 31c, wherein the first sealing surface 31b is used to contact the inner surface of the housing 10 to form a seal; and the second sealing surface 31c is used to contact the end face of the stator 20 to form a seal.

[0026] The second oil-immersion cover 32 is provided with a first sealing surface 32b and a second sealing surface 32c, wherein the first sealing surface 32b is used to contact the inner surface of the housing 10 to form a seal; and the second sealing surface 32c is used to contact the end face of the stator 20 to form a seal.

[0027] Next, the axial oil passage 40 in this scheme will be described in detail.

[0028] like Figure 1-2 As shown, at least one axial oil passage 40 is provided and formed in the stator 20 to connect the first oil immersion cover 31 and the second oil immersion cover 32 located at both ends of the stator 20. The axial oil passage 40 connects the sealed cavities of the first oil immersion cover 31 and the second oil immersion cover 32 located at both ends of the stator, which not only completes the transportation from one end of the stator to the other end, but also effectively cools the stator yoke, teeth and slot windings during the flow of cooling oil.

[0029] Specifically, the axial oil passage 40 includes oil passages formed along the axial direction of the stator 20 on at least one of the yoke, teeth, or outer surface of the stator 20. Preferably, the axial oil passage 40 includes three layers of oil passages distributed radially along the stator 20. The advantage of this design is that the outer layer of oil passages is more effective at carrying away heat from the housing and the outer edge of the stator; the middle layer of yoke oil passages directly cools the stator core; and the inner layer of tooth oil passages is closest to the slot windings where heat is most concentrated, enabling the most direct cooling of them. This ensures that the temperature of all critical parts inside the motor is effectively controlled. During operation, cooling oil is injected into the first immersion shroud 31 through the oil inlet pipe 31a. The oil level gradually rises until the end winding at that end is completely submerged, undergoing the first efficient heat exchange. Subsequently, under pressure, the cooling oil flows through the axial oil passage 40 to the second immersion shroud 32. During its flow through the axial oil passage 40, the cooling oil provides a second cooling effect on the stator core and the windings in the slots. When the oil enters the second immersion shroud 32, it similarly submerges the end winding at that end, undergoing a third heat exchange. Finally, the cooling oil, having completed heat exchange and reached a higher temperature, flows out from the return port 32a at the bottom of the second immersion shroud 32. After being cooled by an external heat exchanger, it can be recycled for reuse.

[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-power-density motor with an oil-immersed cooling structure at both ends, comprising a housing (10), a stator (20), a rotor, and cooling oil passages, characterized in that, The cooling oil circuit includes: An oil immersion shroud assembly (30) is provided, which together with the end face of the stator (20) and the inner surface of the housing (10) forms a sealed cavity for containing cooling oil; the oil immersion shroud assembly (30) is provided at both ends of the stator (20) to completely wrap the end windings so that the end windings are immersed in the cooling oil; At least one axial oil passage (40) is formed in the stator (20) to connect the oil sump assembly (30) located at both ends of the stator (20).

2. The high power density motor with an oil-immersed cooling structure at both ends according to claim 1, characterized in that, The oil immersion shroud assembly (30) includes a first oil immersion shroud (31) and a second oil immersion shroud (32), wherein the cooling oil flows in from the first oil immersion shroud (31), flows through the axial oil passage (40) to the second oil immersion shroud (32) and flows out.

3. The high power density motor with an oil-immersed cooling structure at both ends according to claim 2, characterized in that, The first oil immersion hood (31) is provided with an oil inlet pipe (31a) at the top; the second oil immersion hood (32) is provided with an oil return port (32a) at the bottom.

4. The high power density motor with an oil-immersed cooling structure at both ends according to claim 2, characterized in that, Both the first oil immersion hood (31) and the second oil immersion hood (32) include: The first sealing surfaces (31b, 32b) are configured to contact the inner surface of the housing (10) to form a seal; The second sealing surfaces (31c, 32c) are configured to contact the end face of the stator (20) to form a seal.

5. The high power density motor with an oil-immersed cooling structure at both ends according to claim 1, characterized in that, The axial oil passage (40) includes an oil passage formed along the axial direction of the stator (20) on at least one of the yoke, tooth, or outer surface of the stator (20).

6. The high power density motor with an oil-immersed cooling structure at both ends according to claim 1, characterized in that, The axial oil passage (40) includes multiple layers of oil passages radially distributed along the stator (20).

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