An oil-cooled electric machine

Abstract

The application relates to an oil-cooled motor. An oil-cooled circulation system is integrated with an oil storage cavity, an oil pump, a third oil channel, a cooling device, an end cover oil channel and an oil injection part. The oil storage cavity is formed at the bottom of a shell, the third oil channel is integrated in the oil storage cavity, the oil pump is installed in the oil storage cavity and is communicated with the cooling device through the third oil channel; the end cover oil channel is integrated in a rear end cover, the oil injection part is installed on the inner side of the rear end cover, the cooling device is installed on the outer side of the rear end cover and is communicated with the oil injection part through the end cover oil channel; an oil channel is arranged in a rotating shaft, a flow guide oil channel is arranged in the oil injection part, the rotating shaft oil channel is communicated with the flow guide oil channel, and an oil injection hole is formed in the rotating shaft oil channel and communicated with the inner cavity of the shell; the front end cover and the rear end cover are provided with an oil return hole which is communicated with the oil storage cavity. The motor system has high integration degree and compact structure, so that the motor can be reduced in size and designed in light weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy automobile drive motor, in particular to an oil-cooled motor. BACKGROUND

[0002] The new energy drive motor currently tends to high torque density and high power density. Due to the limitation of vehicle space and operating environment, under certain power conditions, reducing the size of the motor can increase its power density, but its loss density also increases, which inevitably leads to difficulty in heat dissipation inside the motor, especially when the vehicle is running in harsh environments and harsh conditions (such as climbing and accelerating), the motor consumes more heat and the temperature rises more seriously, which has an adverse effect on the safety performance and service life of the motor. Therefore, reasonable design of the internal heat dissipation mode of the motor is the premise to ensure the safe and stable operation of the motor.

[0003] The common motor cooling forms on the market at present are air cooling, water cooling and oil cooling, among which water cooling and oil cooling are mostly used for high-power motors. Since the high-temperature part of the motor is mainly concentrated in the stator winding end, the fluid medium cannot directly contact the high-temperature point, so it cannot be directly cooled, and the heat dissipation effect is poor. In order to further improve the heat dissipation capacity of the motor, oil injection cooling method is developed, which sprays oil to the stator winding end, and the oil directly contacts the end to take away heat, which has the characteristics of direct contact and high heat dissipation efficiency.

[0004] The existing oil injection cooling method is mostly used in the integration of motor and transmission, and the lubricating oil of the transmission is used for cooling. In the new energy direct drive motor, since there is no integration of the transmission, the motor itself realizes oil cooling circulation, which is difficult to arrange. In the related technology, the devices of the cooling liquid circulation system need to be connected by oil pipes, which is not compact in space arrangement, has the risk of oil leakage, and the relatively dispersed devices limit the further reduction of the size of the motor, which has an adverse effect on the performance of the motor and its operating environment. SUMMARY

[0005] In order to solve the above problems, the purpose of the present application is to provide an oil-cooled motor with integrated oil cooling circulation system, which has the characteristics of high integration degree, compact structure, good heat dissipation effect and long service life.

[0006] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0007] An oil-cooled motor, comprising a shell, a stator assembly and a rotor assembly both arranged in the shell, a rotating shaft connected to the rotor assembly, a front end cover and a rear end cover supporting the rotating shaft at both ends of the shell, and an oil cooling circulation system, the oil cooling circulation system is integrated with: an oil storage cavity, an oil pump, a third oil channel, a cooling device, an end cover oil channel and an oil injection part;

[0008] The oil storage cavity is formed in the bottom of the shell, the third oil channel is integrated in the oil storage cavity, the oil pump is installed in the oil storage cavity, and the oil pump is communicated with the cooling device through the third oil channel;

[0009] The end cover oil channel is integrated in the rear end cover, the oil injection member is installed on the inner side of the rear end cover, the cooling device is installed on the outer side of the rear end cover, and the cooling device is communicated with the oil injection member through the end cover oil channel;

[0010] The rotating shaft is provided with a rotating shaft oil channel, the oil injection member is provided with a flow guide oil channel, the rotating shaft oil channel is communicated with the flow guide oil channel, and the rotating shaft oil channel is provided with an oil injection hole communicated with the inner cavity of the shell;

[0011] The front end cover and the rear end cover are provided with a return oil hole communicated with the oil storage cavity.

[0012] Further, the rotating shaft is connected to the front and rear end covers through bearings, and the front and rear end covers are provided with a guide flow channel for the flow of oil to the bearings.

[0013] Further, the shell is provided with a cooling water channel, and the outer surface of the shell is provided with a water inlet and a water outlet communicated with both ends of the cooling water channel.

[0014] Further, the cooling water channel is configured as an axial rotary structure and surrounds the shell.

[0015] Further, the water outlet is communicated to the water inlet of the cooling device through an external water pipe and flows out through the water outlet of the cooling device.

[0016] Further, the flow guide oil channel is enclosed by an oil guide groove and an oil groove cover plate.

[0017] Further, annular ribs are arranged on the mounting surface of the oil injection member and the end cover oil channel; a stepped surface is arranged in the circumferential direction in the oil guide groove, and the oil groove cover plate is embedded on the stepped surface and is tightly welded.

[0018] Further, a first annular reinforcing rib is arranged on the outer edge of the oil injection member, a second annular reinforcing rib is arranged on the back of the oil injection member, and the first annular reinforcing rib and the second annular reinforcing rib are coaxially arranged.

[0019] Further, a second oil channel is formed between the oil pump shell and the shell, the second oil channel communicates the first oil outlet and the second oil outlet of the oil pump, and the second oil channel surrounds the oil pump shell.

[0020] Further, the oil cooling circulation system further integrates a suction filter, the suction filter is fixedly arranged in the oil storage cavity, a sealing ring is arranged on the mounting surface of the shell, and the suction filter is communicated with the oil pump.

[0021] The one or more technical solutions provided by the present application have at least the following technical effects or advantages:

[0022] Firstly, the oil cooling circulation system is integrated in the motor itself, which makes up for the difficulty in arranging the oil cooling circulation system in the new energy direct drive motor, and realizes a wider application range of the motor.

[0023] Secondly, the oil cooling circulation system is integrated in the motor itself, which makes up for the difficulty in arranging the oil cooling circulation system in the new energy direct drive motor, and realizes a wider application range of the motor. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of the present application;

[0025] Figure 2 is a structural schematic diagram of the present application;

[0026] Figure 3 is a structural schematic diagram of the present application;

[0027] Figure 4 is a sectional view of the present application;

[0028] Figure 5 is a structural schematic diagram of the present application;

[0029] Figure 6 is a structural schematic diagram of the present application;

[0030] Figure 7 is a structural schematic diagram of the present application;

[0031] Figure 8 is a sectional view of the present application;

[0032] Figure 9 is a structural schematic diagram of the present application;

[0033] Figure 10 is a structural schematic diagram of the present application;

[0034] Figure 11 is a structural schematic diagram of the present application. DETAILED DESCRIPTION

[0035] In order to have a clearer understanding of the technical features, objects and effects of the present application, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0036] It should be noted that the terms "first", "second" in the specification are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0037] When an element is referred to as being "fixed to", "attached to" another element, it can be directly on the other element or there can be an intervening element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or there can be an intervening element.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] The oil-cooled motor of the embodiment of the present application is preferably a new energy direct drive motor, and therefore, the necessary integrated oil cooling circulation system of the motor is integrated in the transmission system of the new energy vehicle. The motor comprises a shell, the shell comprises a shell body 10; a stator assembly fixed in the shell body 10, the stator assembly comprising a stator winding; a rotor assembly rotatably arranged in the stator assembly; a rotating shaft 90 connected to the rotor assembly; a front end cover and a rear end cover 30 connected to both ends of the shell body 10, and the front and rear end covers support the rotating shaft 90 through bearings.

[0040] Please refer to Figures 1 to 4 , the oil cooling circulation system is integrated with an oil storage cavity 20, an oil pump 60, a cooling device 70, an oil injection member, and a shell oil channel formed in the shell and an end cover oil channel 31 formed in the end cover. Those skilled in the art should know that the oil cooling circulation system preferably selects lubricating oil, which can cool and lubricate the components of the motor.

[0041] Specifically, please refer to Figure 5 , the oil storage cavity 20 is formed in the bottom of the shell and located on one side of the shell body 10, and is configured as a cavity defined between the shell and the oil pan 40 installed at the bottom of the shell. The oil pan 40 is provided with a drain plug 41 at the bottom and is configured with a magnet, including but not limited to a magnet and other magnetic materials, for adsorbing iron impurities in the lubricating oil, effectively improving the recycling rate of the lubricating oil. In order to enhance the strength of the shell and reduce the deformation of the shell, a plurality of reinforcing ribs 25 are arranged in the oil storage cavity 20.

[0042] The oil pump 60 is arranged in the oil pump cavity 24 formed in the oil storage cavity 20, the oil inlet of the oil pump 60 is communicated with the suction filter 50 through the first oil channel 21, the suction filter 50 is fixedly arranged in the oil storage cavity 20, one side of the suction filter 50 is an oil suction port 26, and a filter screen is arranged for filtering the lubricating oil entering the oil pump 60, so as to provide protection for safe and effective operation of the motor; the other side is a mounting surface fixed to the shell, and a sealing ring is used for sealing to reduce the risk of oil leakage. In another embodiment, the oil inlet of the oil pump 60 directly extends into the oil or is directly communicated to the oil through the first oil channel 21.

[0043] Preferably, a first oil outlet is arranged on the outer peripheral wall of the oil pump 60 close to the oil inlet end, the oil outlet of the oil pump is a second oil outlet, the second oil channel is formed between the oil pump shell and the oil pump cavity 24, and the first oil inlet and the second oil inlet are communicated, the second oil channel is arranged around the oil pump shell, so that the lubricating oil flowing during the operation of the motor can continuously cool the oil pump, reduce the temperature rise, and effectively improve the working efficiency of the oil pump 60. The oil pump 60 is communicated to the oil inlet of the cooling device 70 through the third oil channel, and the third oil channel includes the oil channel A 22 and the oil channel B 23 which are perpendicular to each other and connected at the head and tail.

[0044] The shell oil channel includes the first oil channel 21, the second oil channel and the third oil channel, and it should be noted that the shell oil channel can be a pipeline channel, and preferably can also be a channel reserved on the shell. By integrating the oil channel in the shell, the layout of the connected devices is compact, and the risk of oil leakage is reduced, which better adapts to the placement needs of the internal and external space of the motor.

[0045] The cooling device 70 is installed on the outside of the rear end cover 30, the oil injection member is installed on the inside of the rear end cover 30, and the oil outlet of the cooling device is communicated to the oil inlet of the oil injection member through the end cover oil channel 31. The end cover oil channel 31 can be a pipeline channel, or a channel reserved on the shell, and also has the beneficial effects of simple structure, convenient installation, not easy to leak oil, and compact layout of the oil injection member and the cooling device.

[0046] Specifically, please refer to Figures 6 to 8The oil injection part is configured in a disc shape and comprises an oil injection disc body 80 and an oil groove cover plate 84, the oil injection disc body 80 has an oil injection disc oil inlet 82 communicated with the oil channel of the end cover, an oil injection disc oil outlet 81 communicated with the oil channel of the rotating shaft, and a guide oil groove 83 communicated with the oil injection disc oil inlet and outlet, and the guide oil groove 83 is tightly combined with the oil groove cover plate 84 to form a guide oil channel. Preferably, a stepped surface is arranged in the guide oil groove 83 in the circumferential direction, the oil groove cover plate 84 is embedded on the stepped surface, and the oil groove cover plate 84 is fixed and sealed by ultrasonic welding, so that the guide oil channel structure is stable, can withstand a large oil pressure, and can continuously and stably deliver oil to the oil outlet of the oil injection disc body. In order to improve the sealing performance of the oil injection disc and the oil channel 31 of the end cover, a plurality of annular convex edges are arranged on the outer circumferential wall of the oil injection disc oil inlet 82, and the oil channel 31 of the end cover is in interference fit, which greatly improves the sealing performance. In addition, a first annular reinforcing rib 85 is arranged on the outer edge of the oil injection disc body 80, and a second annular reinforcing rib 86 is coaxially arranged on the back, thereby enhancing the overall rigidity of the oil injection disc. When the oil injection disc is installed, the oil injection disc is axially pressed into the oil injection disc seat of the rear end cover 30, and the oil outlet 81 of the oil injection disc extends into the oil channel of the rotating shaft and is in interference fit with the end portion of the rotating shaft. At the same time, the first annular reinforcing rib 85 as the installation and fixing stopper is radially limited, and the second annular reinforcing rib 86 is axially limited, so that the device is stable and convenient to operate.

[0047] The oil injection part provided by the embodiment of the present application is used for delivering the lubricating oil in the oil channel 31 of the end cover to the oil channel of the rotating shaft. According to the size of the shaft hole, a suitable oil injection disc is selected to form a certain pressure for oil injection, so that the lubricating oil can be uniformly and stably output. The oil injection part has at least the following advantages: 1) all made of plastic (PA66+30%PF), low part manufacturing cost, light weight, and excellent reliability; 2) the axial space occupied by the disc-shaped structure is small, meeting the needs of the internal installation space of the motor; 3) all in interference fit form during assembly and positioning, axially pressed, without screws and bolts, simple assembly, and compact structure.

[0048] The rotating shaft is internally configured as a rotating shaft oil channel for lubricating oil to flow, the rotating shaft oil channel is arranged in the axial direction, and one end is communicated with the oil outlet of the oil injection disc. A plurality of oil injection holes 91 are arranged at both ends of the rotating shaft oil channel corresponding to the end portions of the stator winding. Preferably, the oil injection holes 91 are uniformly dispersed in the circumferential direction of the rotating shaft 90, so that the lubricating oil sprayed from the oil injection holes 91 by the centrifugal force of the rotating shaft 90 falls uniformly to the end portions of the stator winding in the shape of an umbrella. Under the dual action of gravity and pressure, the lubricating oil flows through all or most of the end portions of the stator winding and carries away heat.

[0049] Please refer to Figure 9Preferably, the front and rear end covers have a guide flow channel 33 that guides the dripping oil to the bearing, and in the present embodiment, the oil-cooled motor uses an open oil lubrication bearing, and the flowing lubricating oil can effectively reduce the temperature of the bearing during operation, and continuously lubricate the bearing, effectively improve the operation condition of the bearing, and improve the service life of the bearing.

[0050] The bottom of the front and rear end covers is provided with an oil return hole 32 that is in communication with the oil storage cavity 20.

[0051] Referring to Figure 10 The oil-cooled motor of the present embodiment further comprises a water cooling circulation system, specifically comprising a water inlet 15 and a water outlet 12 provided on the peripheral wall of the motor housing body, and a cooling water channel 11 formed in the interior of the housing and in communication with the water inlet and the water outlet. The cooling water channel 11 is an internal cavity formed by sand casting, and after casting is completed, sand cleaning is performed to form a complete closed water channel. The cooling water channel 11 is configured in an axial rotation structure and is arranged to surround the motor housing body for one turn, and has a better heat exchange efficiency. Of course, in other embodiments, a circumferential type, a spiral type and a semi-spiral type water channel structure can also be used. The water inlet 15 is in communication with the external vehicle water circuit, and the water outlet 12 is connected to a cooling device 70 through an external water pipe and flows out from the water outlet 12 after passing through multiple layers of labyrinths in the interior of the cooling device 70. The cooling device 70 is provided with inlet and outlet portions corresponding to the oil cooling and water cooling circulation systems, respectively, thereby improving the utilization rate of the cooling water.

[0052] Referring to Figure 11 Preferably, the water outlet 12, the oil outlet 13 and the oil return port 14 are provided with sealing grooves on the surface of the motor housing body 10, and are sealed by cooperating sealing rings and end covers.

[0053] The housing of the present embodiment has at least the following benefits: 1) formed by low-pressure casting of aluminum alloy to enhance the strength of the housing, reduce the deformation of the housing, and the manufacturing process is difficult, and the process forming is convenient; 2) providing water cooling and oil cooling for the motor, effectively improving the heat dissipation efficiency of the motor; 3) greatly improving the integration of the oil-cooled motor, facilitating the lightweight design of the whole machine, and the structure is compact.

[0054] The cooling process of the motor is described in detail as follows: the embodiment of the application adopts a composite cooling mode of water cooling plus oil cooling, and the cooling water channel is integrated in the motor shell body to achieve overall heat dissipation of the stator assembly; in order to improve the heat dissipation effect of the motor, the oil injection cooling mode is implemented for the stator winding end part where the temperature rises are concentrated; specifically, the oil pump pressurizes the oil liquid into the oil channel, the cooled oil liquid is sprayed into the rotating shaft oil channel through the oil injection part, when the motor operates, the centrifugal force generated by the rotation of the rotating shaft causes the oil liquid to be sprayed in an umbrella shape to the stator winding end part through the oil injection hole, under the double action of pressure and gravity, the oil liquid flows through all or most of the windings and then slides down along the end cover, and carries away heat, at the same time, a part of the oil liquid is guided to the inside of the bearing along the guide flow channel formed on the end cover, which can effectively reduce the bearing temperature and continuously lubricate the bearing. The oil liquid that slides down through the end cover flows back to the oil storage cavity through the oil return hole formed through the end cover and the shell, and forms a complete oil cooling circulation system.

[0055] The oil-cooled motor of the embodiment of the application retains the original cooling water channel, and itself integrates the oil sump, the filter, the oil pump, the cooling device, the oil injection disc, and the oil channel in the shell and the end cover, forms an oil cooling circulation system, and can effectively reduce the operating temperature of the motor at high speed and high power, and prolong the service life of the motor; at the same time, the system has high integration degree and compact structure, so that the motor can be reduced in size to a certain extent and designed to be lightweight.

[0056] The above-described embodiments only express several embodiments of the application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent of the application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are all within the protection scope of the application. Therefore, the protection scope of the application should be subject to the appended claims.

Claims

1. An oil-cooled electric machine comprising a housing, a stator assembly and a rotor assembly both disposed within the housing, a rotating shaft (90) connected to the rotor assembly, a front end cover and a rear end cover (30) supporting the rotating shaft (90) at both ends of the housing, characterized in that, Also include oil cooling circulation system, the oil cooling circulation system is integrated with: oil storage cavity (20), oil pump (60), third oil channel, cooling device (70), end cover oil channel (31) and oil injection part; The oil storage cavity (20) is formed on the bottom of the shell, the third oil channel is integrated in the oil storage cavity (20), the oil pump (60) is installed in the oil storage cavity (20), and the third oil channel is communicated with the cooling device (70); The end cover oil channel (31) is integrated in the rear end cover (30), the oil injection part is installed on the inner side of the rear end cover (30), the cooling device (70) is installed on the outer side of the rear end cover (30), and the end cover oil channel (31) is communicated with the oil injection part; The shaft (90) is provided with a shaft oil channel, the oil injection part is provided with a flow guide oil channel, the shaft oil channel is communicated with the flow guide oil channel, and the shaft oil channel is provided with an oil injection hole (91) communicated with the inner cavity of the shell; The front end cover and the rear end cover (30) are provided with a return oil hole (32), and the return oil hole (32) is communicated with the oil storage cavity (20); The flow guide oil channel is surrounded by an oil guide groove (83) and an oil groove cover plate (84); The installation surface of the oil injection part and the end cover oil channel (31) is provided with an annular convex rib, the oil guide groove (83) is provided with a stepped surface in the circumferential direction, and the oil groove cover plate (84) is embedded on the stepped surface and is tightly welded; The outer edge of the oil injection part is provided with a first annular reinforcing rib (85), the back of the oil injection part is provided with a second annular reinforcing rib (86), and the first annular reinforcing rib (85) and the second annular reinforcing rib (86) are coaxially arranged; The shaft (90) is connected to the front and rear end covers through bearings, and the front and rear end covers are provided with a guide flow channel (33) for the flow of oil to the bearings; The second oil channel is formed between the oil pump (60) shell and the shell, the second oil channel is communicated with the first oil outlet and the second oil outlet of the oil pump (60), and surrounds the oil pump (60) shell.

2. An oil-cooled electric machine as set forth in claim 1, characterized in that The shell is provided with a cooling water channel (11), and the outer surface of the shell is provided with a water inlet (15) and a water outlet (12) communicated with both ends of the cooling water channel (11).

3. An oil-cooled electric machine as set forth in claim 2 wherein, The cooling water channel (11) is constructed as an axial rotary structure and surrounds the shell.

4. An oil-cooled electric machine according to claim 2 or 3, characterised in that, The water outlet (12) is communicated to the cooling device water inlet through an external water pipe and flows out through the cooling device water outlet.

5. An oil-cooled electric machine as set forth in claim 1, characterized in that, The oil cooling circulation system is also integrated with a suction filter (50), the suction filter (50) is fixedly arranged in the oil storage cavity (20), a sealing ring is arranged on the mounting surface of the shell, the suction filter (50) is communicated with the oil pump (60).

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