Flat wire winding motor stator oil duct structure, motor stator and motor

Abstract

The invention belongs to the technical field of electrical and mechanical transmission, and discloses a flat wire winding motor stator oil duct structure, a motor stator and a motor, the flat wire winding motor stator oil duct structure comprises a stator iron core, a plurality of uniformly distributed stator grooves are formed in the stator iron core along the circumferential direction of the stator iron core, each stator groove is arranged along the axial direction of the stator iron core; two ends of each stator slot are open, and the stator slots are close to the inner ring of the stator core; cooling oil inlets which are the same as the stator grooves in number and are evenly distributed are formed in the middle section of the stator iron core in the circumferential direction of the stator iron core, and each cooling oil inlet is formed in the radial direction of the stator iron core and communicated with one stator groove. The heat resistance between the middle part of the winding and the iron core lamination is effectively reduced, a cooling medium flows through a cooling flow channel provided by the oil channel, heat caused by motor winding copper loss and stator iron loss can be rapidly taken away, the heat dissipation capability of the flat wire winding motor stator is effectively improved, and the temperature rise of the motor stator is obviously reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrical and mechanical transmission, and particularly relates to a stator oil duct structure of a flat wire winding motor, a motor stator and a motor. Background Art

[0002] With the rapid development of modern technology and the increasingly severe energy problem, the research and development of electric vehicles with high performance, low emissions and multi-energy utilization has important strategic significance and has received great attention from countries around the world. As one of the core components of current electric vehicles, the performance of the permanent magnet synchronous motor directly affects the reliability and economy of electric vehicles. In pursuit of the economy of the motor, that is, achieving higher output capacity at a lower unit cost, in recent years, domestic and foreign scholars have shifted their attention to flat wire winding motors supported by flat wire winding technology. Compared with traditional round wire winding motors, the flat wire winding technology uses thicker rectangular wires to directly insert into the stator slots from the stator end face, which is not affected by the stator slot opening size, improving the slot fill factor of the stator winding. At the same time, the end size of the flat wire winding is shorter, which can reduce the volume of the motor, and thus the motor has a higher power density, thereby achieving the purpose of improving the motor efficiency. However, due to the skin effect, as the frequency increases, the AC loss in the copper loss of the flat wire winding motor increases too fast, which will accelerate the aging of the insulating material and shorten the life; it will even reduce the performance of magnetic materials such as the stator core and permanent magnet, which limits the development of flat wire winding motors towards high-speed motors. Therefore, in order to ensure the service life of flat wire motors, it is urgent to solve the technical difficulties of motor heat dissipation.

[0003] Currently, the main motor cooling methods include forced air cooling, spray cooling, oil immersion cooling, etc., with the main optimization goals of increasing the heat dissipation area, expanding the heat dissipation path, improving the heat dissipation structure and enhancing the heat dissipation efficiency. Forced air cooling is a simple motor cooling method, in which the air duct takes away heat from the component surface through convective heat transfer, and is suitable for the heat dissipation requirements of low heat density motors. For flat wire winding motors, the motor has a large power and a high power density, and dust in the air is extremely easy to enter the motor during operation, affecting the cooling effect. Therefore, it is not suitable for the forced air cooling method. Spray cooling is a cooling method that uses a nozzle to form a spray of a cooling medium and attach it to the surface of the motor component. However, spray cooling requires additional equipment to assist in forming the spray, and is not suitable for flat wire winding motors with limited space. Oil immersion cooling uses the insulating property of oil and directly immerses the motor stator and rotor with cooling oil. This immersion method can effectively improve the cooling efficiency inside the motor and is widely used in the heat dissipation design of high power density motors. However, due to the viscosity of the oil, the rotor will generate certain frictional losses during operation, thereby reducing the efficiency of the motor. General oil immersion cooling still cannot meet the cooling requirements of flat wire winding motors under the conditions of compactness and high heat density. Therefore, it is necessary to further improve the existing cooling solutions.

[0004] The main heat source of the motor is the winding coil. Therefore, the winding is often the component with the most concentrated heat in the motor and also the area with the highest temperature in the motor temperature field. This is not only related to the high copper loss of the winding coil, but also to the poor heat dissipation conditions of the winding caused by the outer insulation material of the winding, the gaps between wires, and the exposure of the winding ends to the air.

[0005] In the common oil duct structure, the oil flows through the oil duct in the stator yoke and flows out at the end, resulting in that most of the cooling oil can only flow through the end of the stator winding. For the middle part of the stator winding, almost no cooling oil flows through. Therefore, the temperature rise of the middle part of the winding does not decrease significantly, resulting in an insignificant overall cooling effect.

[0006] In view of this, the present invention provides an oil duct structure for a flat wire winding motor to improve and solve the above problems. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a stator oil duct structure for a flat wire winding motor, a motor stator and a motor, which solves the heat dissipation problem of the flat wire winding motor under the conditions of compactness and high heat density in the prior art.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A stator oil duct structure for a flat wire winding motor, comprising:

[0010] A stator core, on which a plurality of uniformly distributed stator slots are axially arranged along the circumferential direction of the stator core. Each stator slot is axially arranged along the stator core, and both ends of the stator slot are open, and the stator slot is close to the inner circle of the stator core;

[0011] In the middle section of the stator core, cooling oil inlets with the same number as the stator slots and uniformly distributed are axially arranged along the circumferential direction of the stator core. Each cooling oil inlet is radially arranged along the stator core, and each cooling oil inlet communicates with one of the stator slots.

[0012] In a preferred example of the present invention, it can be further configured that the cross-sectional shape of the cooling oil inlet is rectangular.

[0013] In a preferred example of the present invention, it can be further configured that an annular groove is formed in the middle section of the stator core, the groove communicates with the outside of the stator core, and the cooling oil inlet is located in the groove.

[0014] In a preferred example of the present invention, it can be further configured that the distances between the groove and the ends of both ends of the stator core are the same.

[0015] In a preferred embodiment, the present invention can be further configured as follows: a plurality of uniformly distributed slender oil grooves are formed in the stator core along the circumferential direction of the stator core, each of the slender oil grooves is arranged along the axial direction of the stator core, the slender oil grooves communicate with the grooves, and both ends of the slender oil grooves are open.

[0016] In a preferred embodiment, the present invention can be further configured as follows: the cross-sectional area of the cooling oil inlet is smaller than the cross-sectional area of the slender oil groove.

[0017] In a preferred embodiment, the present invention can be further configured as follows: the cross-sectional shape of the slender oil groove is trapezoidal, the lower base of the trapezoid is close to the stator slot, and the upper base of the trapezoid is far from the stator slot.

[0018] A stator of a flat wire winding motor includes an oil duct structure of a stator of a flat wire winding motor.

[0019] A flat wire winding motor includes a stator of a flat wire winding motor.

[0020] The explanations of the nouns, conjunctions or adjectives involved in the above technical solutions are as follows:

[0021] Fixed connection means that after the parts or components are fixed, there is no relative movement between them. It is divided into two types: detachable connection and non-detachable connection.

[0022] (1) Detachable connection uses screws, splines, wedge pins, etc. to fix the components together. This connection method can be disassembled during maintenance and will not damage the parts. However, the specifications of the connecting parts used must be correct (such as the length of bolts, keys, wedge pins), and they must be fastened properly.

[0023] (2) Non-detachable connection mainly refers to welding, riveting and mortise fitting, etc. Since it needs to be forged, sawed or oxy-cut to be disassembled during maintenance or replacement, the spare parts generally cannot be used twice. At the same time, during connection, attention should be paid to process quality, technical inspection and remedial measures (such as correction, polishing, etc.).

[0024] Threaded connection refers to a detachable connection that connects the connected parts together with threaded parts (or the threaded parts of the connected parts).

[0025] Sliding connection means that two objects are in contact but not fixed, and they can slide relative to each other.

[0026] Rotational connection means that the connection between parts allows the parts to rotate relative to each other.

[0027] The beneficial effects of the present invention:

[0028] 1. The present invention proposes a stator oil duct structure for a flat wire winding motor, which effectively reduces the thermal resistance between the middle of the winding and the iron core laminations. The cooling flow path provided by the oil duct can quickly remove the heat generated by the copper loss of the motor winding and the iron loss of the stator through the flowing cooling medium, effectively improving the heat dissipation capacity of the stator of the flat wire winding motor and significantly reducing the temperature rise of the stator of the motor.

[0029] 2. The oil duct structure proposed by the present invention enhances the heat dissipation capacity in the middle of the winding on the premise of ensuring the high mechanical strength of the motor and still having a relatively strong heat dissipation capacity at the end of the stator winding.

[0030] 3. The oil duct structure proposed by the present invention can increase the effective heat dissipation area and optimize the cooling effect by adopting a trapezoidal oil duct structure on the premise of ensuring that the cross-sectional area of the oil duct remains unchanged.

[0031] 4. The oil duct structure proposed by the present invention can also be implemented in other high-power density motors with strict heat dissipation requirements that adopt non-flat wire winding technology. It has the advantages of simple structure, easy implementation, and high cooling efficiency, improving the heat dissipation capacity of the stator of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 Isometric view of the stator core oil duct structure of the embodiment of the present invention;

[0034] Figure 2 Front view of the stator core oil duct structure of the embodiment of the present invention;

[0035] Figure 3 Cross-sectional view of the stator core oil duct structure of the embodiment of the present invention;

[0036] Figure 4 Simulation assembly drawing of the embodiment of the present invention;

[0037] Figure 5 Fluid domain extraction distribution diagram of the embodiment of the present invention;

[0038] Figure 6 Three-dimensional diagram of the oil phase distribution of the embodiment of the present invention;

[0039] Figure 7 Cross-sectional view of the oil phase distribution of the embodiment of the present invention.

[0040] Reference numerals:

[0041] 1. Stator core; 2. Groove; 3. Cooling oil inlet; 4. Stator slot; 5. Elongated oil groove. Detailed implementation manner

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] In the description of the present invention, it should be understood that the terms "open hole", "upper", "lower", "thickness", "top", "middle", "length", "inner", "periphery", etc. indicating the orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention.

[0044] As Figures 1 to 3 shown, a stator oil duct structure of a flat wire winding motor includes:

[0045] A stator core 1, on which a plurality of uniformly distributed stator slots 4 are axially provided along the circumferential direction of the stator core 1. Each stator slot 4 is axially arranged along the stator core 1, and both ends of the stator slot 4 are open, and the stator slot 4 is close to the inner circle of the stator core 1;

[0046] In the middle section of the stator core 1, cooling oil inlets 3 having the same number and uniformly distributed as the stator slots 4 are axially provided along the circumferential direction of the stator core 1. Each cooling oil inlet 3 is radially arranged along the stator core 1, and each cooling oil inlet 3 communicates with one of the stator slots 4.

[0047] The oil duct structure of the present application is designed and improved on the premise of ensuring the mechanical strength of the motor. Cooling oil flows into each stator slot 4 from the cooling oil inlet 3 on the stator core 1, flows through the middle part of the stator winding, and then is discharged from the end part of the stator winding. This structure enables the cooling oil to directly communicate with the middle part of the stator winding, forming a new oil duct system, thereby enhancing the thermal contact area between the cooling oil and the winding.

[0048] In one embodiment of the present invention, the cross-sectional shape of the cooling oil inlet 3 is rectangular. Under the same opening area, due to the asymmetry of the rectangular hole and the flow separation at the corner, the eddy current increases, the pressure distribution is uneven, and the resistance of the fluid passing through the orifice is increased, so that the flow rate of the cooling oil in the middle of the winding can be controlled, and the problem of eddy current or excessive local flow of the cooling oil when flowing through the middle of the winding is avoided, so as to ensure that the cooling oil can maintain a stable flow rate and achieve sufficient heat exchange with the stator winding when flowing through the middle of the winding.

[0049] In one embodiment of the present invention, an annular groove 2 is provided in the middle section of the stator core 1, the groove 2 communicates with the outside of the stator core 1, and a cooling oil inlet 3 is located in the groove 2. The cooling oil is collected in the groove 2 in advance, and then enters the stator slot 4 from the groove 2 through the cooling oil inlet 3, ensuring that the flow rate of the cooling oil entering the stator slot 4 is as uniform as possible.

[0050] In one embodiment of the present invention, the distances between the groove 2 and the ends of the stator core 1 are the same. The purpose is to allow the cooling oil to enter the middle of the winding from the cooling oil inlet 3, so that the cooling oil flows along the stator slot 4 to the two ends of the stator slot 4 in the same path, so as to ensure that the cooling oil can maintain a stable flow rate when flowing through the middle of the winding and achieve sufficient heat exchange with the stator winding.

[0051] In one embodiment of the present invention, a stator core 1 is provided with a plurality of evenly distributed elongated oil grooves 5 along the circumference of the stator core 1, each of the elongated oil grooves 5 is arranged along the axial direction of the stator core 1, the elongated oil grooves 5 are communicated with the grooves 2, and both ends of the elongated oil grooves 5 are open. A portion of the cooling oil flows in from the cooling oil inlet 3 of the stator core 1, and gradually flows through the middle of the stator winding, and then is discharged through the end of the stator winding. Another portion flows into the elongated oil grooves 5 provided in the grooves 2 of the stator core 1, and is discharged along the oil passages of the elongated oil grooves of the stator yoke at the ends of the stator. Through this cooling path design, the cooling oil can effectively take away the heat generated in the middle of the winding and the stator iron loss area. Especially for motors with concentrated winding structures, this improved oil passage can significantly reduce the temperature gradient inside the winding, optimize the heat dissipation effect, and help extend the service life of the motor.

[0052] In one embodiment of the present invention, the cross-sectional area of ​​the cooling oil inlet 3 is smaller than the cross-sectional area of ​​the elongated oil groove 5. The flow resistance is increased, so that the flow rate of the cooling oil in the middle of the winding can be controlled, and the problem of eddy current or excessive local flow of the cooling oil when flowing through the middle of the winding is avoided, so that the cooling oil can cover the middle area of ​​the winding more evenly, thereby ensuring that the temperature of the middle and end of the winding is more balanced, so as to ensure that the middle of the winding and the cooling oil achieve a better thermal contact effect.

[0053] In one embodiment of the present invention, the cross-sectional shape of the slender oil groove 5 is trapezoidal, with the lower base of the trapezoid close to the stator slot 4 and the upper base of the trapezoid away from the stator slot 4. Compared with a rectangular cross-section of equal cross-sectional area, the trapezoidal cross-section can make the side length closer to the stator winding side longer, thereby increasing the effective heat dissipation area and optimizing the cooling effect of the cooling oil on the stator winding when flowing through the oil passage.

[0054] A stator of a flat wire winding motor includes an oil passage structure of a stator of a flat wire winding motor.

[0055] A flat wire winding motor includes a stator of a flat wire winding motor.

[0056] The oil passage structure of the stator of the flat wire winding motor of the present invention is particularly suitable for high-heat-density flat wire winding motors, can maintain the temperature stability of the stator under extreme working conditions, and has high application value. Compared with the traditional cooling method, the structure of the present invention does not require additional cooling equipment, avoids complex structural design, and reduces production costs. Therefore, this technical solution is not only applicable to the flat wire winding motors of electric vehicles, but also can be popularized and applied to other motor fields with high power density and strict heat dissipation requirements.

[0057] To briefly illustrate the oil passage structure, a scenario is simulated as follows: Figure 4 As shown, the stator core and the stator winding are placed in a cylindrical shell 6 with a certain thickness. The cooling oil flows in from the inlet 61 and flows out from the outlet 62 and the outlet 63. The fluid domain extraction is as shown in Figure 5 As shown. The oil phase flow is simulated using Ansys Fluent software, and the obtained oil phase distribution diagrams are as shown in Figure 6 、 Figure 7 As shown. The color from red to blue represents that the ratio of the volume occupied by the cooling oil to the air decreases from large to small. It can be seen from Figure 6 that the cooling oil flows from the cooling oil inlet 3 of the stator core into the stator slot 4 and is in full contact with the stator winding, especially in the middle of the stator winding. Figure 7 This is a cross-sectional view of the oil phase distribution, which is used to assist in understanding the flow characteristics of the cooling oil in this oil passage structure.

[0058] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0059] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. A flat wire winding motor stator oil channel structure, characterized in that: include: A stator core (1), wherein the stator core (1) is provided with a plurality of evenly distributed stator slots (4) along the circumference of the stator core (1), each of the stator slots (4) is arranged along the axial direction of the stator core (1), both ends of the stator slots (4) are open, and the stator slots (4) are close to the inner ring of the stator core (1); The middle section of the stator core (1) is provided with cooling oil inlets (3) along the circumference of the stator core (1), the number of which is the same as the number of the stator slots (4) and which are evenly distributed, each of the cooling oil inlets (3) is arranged along the radial direction of the stator core (1), and each of the cooling oil inlets (3) is communicated with one of the stator slots (4).

2. The stator oil channel structure of a flat wire winding motor according to claim 1, characterized in that: The cross-sectional shape of the cooling oil inlet (3) is rectangular.

3. The stator oil channel structure of a flat wire winding motor according to claim 1, characterized in that: An annular groove (2) is provided in the middle section of the stator core (1), the groove (2) is communicated with the outside of the stator core (1), and the cooling oil inlet (3) is located in the groove (2).

4. The stator oil channel structure of a flat wire winding motor according to claim 3, characterized in that: The groove (2) is at the same distance from the ends of both ends of the stator core (1).

5. The stator oil channel structure of a flat wire winding motor according to claim 3, characterized in that: The stator core (1) is provided with a plurality of evenly distributed elongated oil grooves (5) along the circumference of the stator core (1), each of the elongated oil grooves (5) is arranged along the axial direction of the stator core (1), the elongated oil grooves (5) are communicated with the grooves (2), and both ends of the elongated oil grooves (5) are open.

6. The stator oil channel structure of a flat wire winding motor according to claim 5, characterized in that: The cross-sectional area of ​​the cooling oil inlet (3) is smaller than the cross-sectional area of ​​the elongated oil groove (5).

7. The stator oil channel structure of a flat wire winding motor according to claim 5, characterized in that: The cross-sectional shape of the elongated oil groove (5) is a trapezoid, the lower base of the trapezoid is close to the stator slot (4), and the upper base of the trapezoid is far away from the stator slot (4).

8. A flat wire winding motor stator, characterized in that: It comprises a stator oil channel structure of a flat wire winding motor as described in any one of claims 1 to 7.

9. A flat wire winding motor, characterized in that: The utility model comprises a flat wire winding motor stator.

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