Oil-cooled asynchronous motor

Abstract

A closed cavity is jointly defined by a machine shell and end covers, a stator assembly is arranged in the closed cavity, a rotor assembly is arranged on the inner side of the stator assembly in a penetrating mode, a closed conductor is arranged on the inner side of the rotor assembly, and the two ends of the rotor assembly are rotationally connected with the end covers correspondingly; the rotor assembly and the closed conductor are internally provided with cooling flow channels, and the cooling flow channels of the closed conductor are communicated with the closed cavity. When the motor runs, cooling oil firstly enters the rotor assembly for cooling, then flows through the closed conductor for cooling, is sprayed into the closed cavity from the end part of the closed conductor, cools the end part of the stator assembly, and finally flows out from the oil outlet in the side part of the closed cavity. The asynchronous motor has the advantages of being compact in structure and high in heat dissipation efficiency, the temperature of the rotor assembly and the temperature of the stator assembly are reduced, the problem that due to electromagnetic induction current, temperature rise of key parts such as a motor rotor and a bearing is too high is solved, and meanwhile the continuous performance of the asynchronous motor is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of enclosed passenger car motor, and particularly relates to an oil-cooled asynchronous motor. BACKGROUND

[0002] The motor is one of important components of the three-electricity system of a passenger car, and its safe and reliable operation will be related to the running condition of the vehicle. The asynchronous motor has the advantages of low cost, simple structure and easy control at high speed, and gradually attracts people's attention. With the development of electric vehicles towards high power density and miniaturization, the demand for good heat dissipation of auxiliary drive asynchronous motors is increasing. Since the rotor of the asynchronous motor has induced current, the rotor is seriously heated, which becomes a key factor restricting the development of the asynchronous motor. At present, the oil cooling method of the asynchronous rotor of the new energy vehicle driving motor mainly is: the hollow shaft is filled with oil for cooling, and the cooling oil is then thrown out through the oil hole of the shaft to cool the stator winding end part. The cooling of the rotor of the asynchronous motor needs to be carried out through the convection heat exchange between the cooling oil and the rotor shaft, and then the rotor core conducts heat, and the rotor core exchanges heat with the rotor bar. The heat exchange path is long, the thermal resistance is large, and the cooling effect of the asynchronous motor is limited. SUMMARY

[0003] The present application aims at solving the problems of the prior art, and provides an oil-cooled asynchronous motor which has compact structure, remarkable heat dissipation effect and is beneficial to reducing manufacturing cost.

[0004] In order to solve the above technical problems, the technical scheme adopted by the present application is as follows: An oil-cooled asynchronous motor comprises an end cover, a casing, a stator assembly and a rotor assembly. The casing and the end cover jointly enclose a closed cavity, the stator assembly is arranged in the closed cavity, the rotor assembly is arranged on the inner side of the stator assembly, and a closed conductor is arranged on the inner side of the rotor assembly. The two ends of the rotor assembly are rotatably connected with the end cover. Cooling flow channels are arranged in the rotor assembly and the closed conductor, and the cooling flow channel of the closed conductor is communicated with the closed cavity. When the motor is running, the cooling oil first enters the rotor assembly to cool the rotor assembly, then flows through the closed conductor to cool the closed conductor, and finally is sprayed from the end of the closed conductor into the closed cavity to cool the end of the stator assembly, and finally flows out of the motor from the oil outlet on the side of the closed cavity.

[0005] As a further improvement of the present application, the rotor assembly comprises a hollow shaft and a rotor core, the hollow shaft is nested on the inner side of the rotor core, and the closed conductor is nested on the inner side of the rotor core. The two ends of the hollow shaft are rotatably connected with the end cover. The inside of the hollow shaft is a shaft oil channel, and the side of the hollow shaft is provided with a first oil throwing hole which is communicated with the shaft oil channel. The cooling oil in the shaft oil channel flows to the end face of the rotor core through the first oil throwing hole, and then flows into the closed conductor.

[0006] As a further improvement of the present application, the closed conductor comprises a rotor end ring and a rotor bar, the rotor bar is nested inside the rotor core, and a plurality of cooling oil channels are arranged inside the rotor bar, the left and right ends of the rotor bar are both provided with a rotor end ring, the rotor end ring is provided with an oil inlet and a second oil throwing hole, the oil inlet is used to realize that the cooling oil thrown out of the first oil throwing hole enters the cooling oil channel, and the second oil throwing hole is used to realize that the cooling oil in the cooling oil channel sprays into the sealed cavity and cools the end part of the stator assembly.

[0007] As a further improvement of the present application, the plurality of oil inlets and the plurality of second oil throwing holes are arranged alternately on the rotor end ring, and the flow directions of the cooling oils in the adjacent two cooling oil channels are opposite in the axial direction.

[0008] As a further improvement of the present application, the hollow shaft is provided with a bearing at the connection between the two ends of the hollow shaft and the end cover.

[0009] As a further improvement of the present application, the side part of the shell is provided with an oil return flow channel communicated with the oil outlet, and the side part of the end cover is provided with an oil return port communicated with the oil return flow channel and the sealed cavity, so as to realize that the cooling oil is discharged from the motor.

[0010] As a further improvement of the present application, the stator assembly comprises a stator winding and a stator core, the stator core is fixed in the shell, the stator winding is nested in the stator core, and the end part of the stator winding extends out of the stator core; the rotor assembly is arranged to penetrate the inside of the stator core.

[0011] Compared with the prior art, the oil-cooled asynchronous motor has the following advantages: The oil-cooled asynchronous motor of the present application cools the rotor bar by arranging a bidirectional cooling structure in the rotor bar, thereby inhibiting the temperature rise of the rotor assembly, achieving the cooling effect, and having the following beneficial effects: (1) The flow directions of the cooling oils in the adjacent rotor bar cooling oil channels are opposite, which can be beneficial to improve the thermal uniformity of the rotor bar and the rotor assembly in the axial direction and reduce the thermal stress of the rotor assembly.

[0012] (2) The temperature rise of the rotor assembly is inhibited, the continuous performance of the asynchronous motor is greatly improved, the stack length of the motor is reduced under the condition that other performance requirements remain unchanged, and the cost of the asynchronous motor is reduced.

[0013] (3) The heat transferred from the rotor assembly to the bearing through heat conduction is reduced, the heat resistance requirement of the bearing is reduced under the condition of ensuring safety, and the cost is further reduced. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The structure principle schematic diagram of the oil-cooled asynchronous motor in the embodiment of the present application is shown in the figure. Figure 2Fig. 3 is a schematic view of a three-dimensional structure of a rotor assembly in an embodiment of the present application; Figure 3 Fig. 4 is a schematic view of a three-dimensional structure of a closed conductor in an embodiment of the present application; Figure 4 Fig. 5 is a schematic view of an oil passage in an embodiment of the present application; Figure 5 Fig. 6 is a schematic view of a structure of a semicircular cooling oil passage in an embodiment of the present application.

[0015] Fig. 7 is a schematic view of an embodiment of the present application. DETAILED DESCRIPTION

[0016] The present application will be further described by the following description of the drawings and preferred embodiments, but the scope of the present application is not limited by the following description.

[0017] In the description of the present application, it should be understood that the terms "side", "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0018] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to, and therefore the features with "first", "second" can explicitly or implicitly include one or more of the features, and in the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0019] EMBODIMENT As Figure 1As shown, the oil-cooled asynchronous motor of the present application comprises an end cover 5, a casing 17, a stator assembly and a rotor assembly. The casing 17 and the end cover 5 jointly enclose a closed cavity 15, the stator assembly is arranged in the closed cavity 15, the rotor assembly is arranged inside the stator assembly, the inside of the rotor assembly is provided with a closed conductor, and the two ends of the rotor assembly are rotatably connected with the end cover 5. The rotor assembly and the closed conductor are both provided with cooling flow channels, and the cooling flow channel of the closed conductor is communicated to the closed cavity 15. When the motor is running, the cooling oil first enters the rotor assembly to cool the rotor assembly, then flows through the closed conductor to cool the closed conductor, and then is sprayed from the end of the closed conductor into the closed cavity 15 to cool the end of the stator assembly, and finally flows out of the motor from the oil outlet 18 on the side of the closed cavity 15.

[0020] In this embodiment, the side of the casing 17 is provided with an oil return flow channel 14 communicated with the oil outlet 18, and the side of the end cover 5 is provided with an oil return port 16 communicated with the oil return flow channel 14 and the closed cavity 15, so as to realize the discharge of the cooling oil from the motor.

[0021] In this embodiment, the stator assembly comprises a stator winding 6 and a stator core 8, the stator core 8 is fixed in the casing 17, the stator winding 6 is nested in the stator core 8, and the end of the stator winding 6 extends out of the stator core 8. Figure 2 As shown, the rotor assembly comprises a hollow shaft 2 and a rotor core 13, the hollow shaft 2 is nested in the inside of the rotor core 13, the inside of the rotor core 13 is provided with a closed conductor, and the closed conductor is close to the stator core 8. The two ends of the hollow shaft 2 are rotatably connected with the end cover 5 through bearings 12, the inside of the hollow shaft 2 is a shaft oil channel 1, the side of the hollow shaft 2 is provided with a first oil throwing hole 3 communicated with the shaft oil channel 1, and the cooling oil in the shaft oil channel 1 flows to the end face of the rotor core 13 through the first oil throwing hole 3, and then flows into the closed conductor.

[0022] As shown in Figure 1 , Figure 3 and Figure 5 , the closed conductor comprises a rotor end ring 7 and a rotor bar 9. The rotor bar 9 is nested in the inside of the rotor core 13. The closed conductor generates an induced electromotive force in the varying magnetic field generated by the stator assembly, which generates a large current on the rotor bar 9, resulting in a large amount of Joule heat generated by the rotor bar 9. Therefore, a plurality of cooling oil channels 10 are arranged in the inside of the rotor bar 9, the left and right ends of the rotor bar 9 are both provided with a rotor end ring 7, the rotor end ring 7 is provided with an oil inlet 4 and a second oil throwing hole 11, the oil inlet 4 is used to realize that the cooling oil thrown out of the first oil throwing hole 3 enters the cooling oil channel 10, and the second oil throwing hole 11 is used to realize that the cooling oil in the cooling oil channel 10 is sprayed into the closed cavity 15 to cool the end of the stator assembly. It can be understood that the shape of the cooling oil channel 10 can be rectangular, circular or square, or can be fan-shaped or similar shapes, and the semicircular cooling oil channel is as shown in Figure 5The cooling oil channel 10 can also be arranged outside the rotor bar 9 or between the rotor bar 9 and the rotor core 13.

[0023] As shown in Figure 1 , the cooling oil enters the shaft oil channel 1 of the hollow rotor shaft 2, and part of the cooling oil flows to the oil inlet channel of the rotor end ring 7 on the left side of the hollow rotor shaft 2 through the first oil throwing hole 3 under the action of centrifugal force, and then enters the cooling oil channel 10 inside the rotor bar 9 to directly cool the rotor bar 9, and then enters the second oil throwing hole 11 of the rotor end ring 7 at the right end of the hollow rotor shaft 2, and then directly cools the end ring 7, and then under the action of centrifugal force, it is thrown to the inner circle of the stator winding 6 to directly cool the winding.

[0024] As shown in Figure 3 and Figure 4 , a plurality of oil inlets 4 and a plurality of second oil throwing holes 11 are alternately arranged on the rotor end ring 7, and the flow directions of the cooling oils in the adjacent two cooling oil channels 10 are opposite in the axial direction, which is beneficial to improve the thermal uniformity of the rotor bar 9 and the rotor assembly in the axial direction and reduce the thermal stress of the rotor assembly.

[0025] When the motor is running, the cooling oil is input into the motor through the oil inlet, and then flows into the hollow rotor shaft 2 to cool the rotor shaft. The cooling oil in the hollow rotor shaft 2 is thrown to the oil inlet 4 of the rotor end ring 7 through the first oil throwing hole 3 under the action of centrifugal force, flows to the cooling oil channel 10 inside the rotor bar 9, and directly cools the rotor bar 9. The cooling oil from the cooling oil channel 10 enters the second oil throwing hole 11 of the rotor end ring 7 to cool the rotor end ring 7, and the cooling oil in the second oil throwing hole 11 is thrown to the inner surface of the stator winding 6 through the oil channel outlet under the action of centrifugal force to cool the winding end, and then collects in the oil return flow channel 14 at the bottom of the casing 17, and flows out of the motor through the oil outlet 18. The cooling oil path of the stator assembly and the rotor assembly is shown by the arrow path in Figure 1 .

[0026] The above is only the preferred embodiment of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the present application shall also be considered as the protection scope of the present application.

Claims

1. An oil-cooled asynchronous motor, characterized in that, include: End cap (5), housing (17), stator assembly and rotor assembly; the housing (17) and end cap (5) together form a sealed cavity (15), the stator assembly is set in the sealed cavity (15), the rotor assembly is set through the inside of the stator assembly, and a closed conductor is provided inside the rotor assembly. The two ends of the rotor assembly are rotatably connected to the end cap (5). Cooling channels are provided in both the rotor assembly and the closed conductor, and the cooling channels of the closed conductor are connected to the sealed cavity (15); when the motor is running, the cooling oil first enters the rotor assembly to cool the rotor assembly, then flows through the closed conductor to cool the closed conductor, and then sprays from the end of the closed conductor into the sealed cavity (15) to cool the end of the stator assembly, and finally flows out of the motor from the oil outlet (18) on the side of the sealed cavity (15).

2. The oil-cooled asynchronous motor according to claim 1, characterized in that, The rotor assembly includes a hollow shaft (2) and a rotor core (13). The hollow shaft (2) is nested inside the rotor core (13). A closed conductor is nested inside the rotor core (13). The two ends of the hollow shaft (2) are rotatably connected to the end cover (5). The interior of the hollow shaft (2) is a shaft oil passage (1). The side of the hollow shaft (2) is provided with a first oil-throwing hole (3) that communicates with the shaft oil passage (1). The cooling oil in the shaft oil passage (1) flows through the first oil-throwing hole (3) to the end face of the rotor core (13) and then flows into the closed conductor.

3. The oil-cooled asynchronous motor according to claim 2, characterized in that, The closed conductor includes a rotor end ring (7) and a rotor guide bar (9). The rotor guide bar (9) is nested inside the rotor core (13) and has multiple cooling oil channels (10) inside. Both ends of the rotor guide bar (9) are provided with rotor end rings (7). The rotor end ring (7) is provided with an oil inlet (4) and a second oil-throwing hole (11). The oil inlet (4) is used to allow the cooling oil thrown out by the first oil-throwing hole (3) to enter the cooling oil channel (10). The second oil-throwing hole (11) is used to allow the cooling oil in the cooling oil channel (10) to be sprayed into the sealed cavity (15) and to cool the end of the stator assembly.

4. The oil-cooled asynchronous motor according to claim 3, characterized in that, Multiple oil inlets (4) and multiple second oil slingers (11) are alternately arranged on the rotor end ring (7), and the flow direction of cooling oil in two adjacent cooling oil passages (10) is opposite in the axial direction.

5. The oil-cooled asynchronous motor according to any one of claims 2 to 4, characterized in that, The hollow shaft (2) is provided with bearings (12) at both ends of the connection with the end cover (5).

6. The oil-cooled asynchronous motor according to any one of claims 1 to 4, characterized in that, The housing (17) has an oil return channel (14) connected to the oil outlet (18) on its side, and the end cap (5) has an oil return port (16) connected to the oil return channel (14) and the sealed cavity (15) on its side, so as to realize the discharge of cooling oil from the motor.

7. The oil-cooled asynchronous motor according to any one of claims 1 to 4, characterized in that, The stator assembly includes a stator winding (6) and a stator core (8). The stator core (8) is fixed inside the housing (17). The stator winding (6) is nested inside the stator core (8), and the end of the stator winding (6) extends to the outside of the stator core (8). The rotor assembly is disposed through the inside of the stator core (8).

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