An electric drive system and an electric drive vehicle

Abstract

The application provides an electric drive system, which comprises a motor, a gearbox and a bottom oil circuit. The motor comprises a motor shell, which has a motor cavity and an oil inlet; the gearbox is connected with the motor in power, and the gearbox comprises a gearbox shell, which has a gearbox cavity and an oil outlet; the bottom oil circuit is connected with the motor cavity and the gearbox cavity. When the electric drive system is in a horizontal state, the height of all the oil inlets is not lower than the height of any oil outlet, and the oil inlets connected with the bottom oil circuit are arranged circumferentially at the bottom of the motor shell, so that when the electric drive system is in a first preset slope state, the oil in the motor cavity can flow back to the gearbox cavity, and the electric drive system has a suitable oil level. The application also provides an electric drive vehicle, which is provided with the electric drive system and can adapt to roads with different slopes.

Description

Technical Field

[0001] This application relates to the field of electric vehicles, and more particularly to an electric drive system and an electric drive vehicle. Background Technology

[0002] With the increasing integration of pure electric drives, oil cooling of drive motors has become a trend. Both the motor rotor and stator are cooled directly by transmission oil spray. After cooling the windings, the transmission oil flows into the lower part of the motor housing due to its own weight. This portion of transmission oil flows back to the gear chamber and continues to participate in the cooling and lubrication cycle of the electric drive.

[0003] Some vehicles, such as off-road vehicles, often tilt when driving in harsh conditions such as longitudinal slopes and transverse slopes. This can cause abnormal oil levels in the electric drive system installed on the vehicle, which may lead to air intake in the oil pump, resulting in insufficient cooling, noise and vibration problems, increased oil stirring losses in the motor, and reduced mechanical efficiency. Summary of the Invention

[0004] In view of this, embodiments of this application provide an electric drive system and an electric drive vehicle to solve the problem of abnormal oil level affecting the operation of the electric drive system under harsh working conditions.

[0005] This application provides an electric drive system, including: a motor, comprising a motor housing having a motor cavity and an oil inlet communicating with the motor cavity; a gearbox, poweredly connected to the motor, the gearbox including a gearbox housing having a gearbox cavity and an oil outlet communicating with the gearbox cavity; and a bottom oil passage connecting the motor cavity and the gearbox cavity, one end of the bottom oil passage being connected to the corresponding oil inlet and the other end being connected to the corresponding oil outlet;

[0006] When the electric drive system is in a horizontal state, the height of all the oil inlets is not lower than the height of any of the oil outlets. The oil inlets connected to the bottom oil circuit are arranged circumferentially at the bottom of the motor housing so that when the electric drive system is in a first preset slope state, the oil in the motor cavity can flow back to the gearbox cavity.

[0007] In some embodiments, the motor housing and the gearbox housing are integrally formed housings.

[0008] In some embodiments, the bottom oil passage is provided on the motor housing to form a bottom oil channel.

[0009] In some embodiments, the motor housing has a partition wall separating the motor cavity and the gearbox cavity, and the bottom oil passage is provided on the partition wall to form an oil return port, which is circumferentially arranged on the partition wall.

[0010] In some embodiments, the electric drive system includes a first control valve fixed to the partition wall for controlling the opening and closing of the bottom oil passage; when the electric drive system is in a horizontal state, the first control valve is in an open state; when the electric drive system is in a first preset slope state, the first control valve is in a closed state.

[0011] In some embodiments, the first control valve is a movable baffle, the orthographic projection of which covers the oil outlet connected to the bottom oil passage.

[0012] In some embodiments, the gearbox housing includes a stepped wall located below the bottom oil passage. The stepped wall includes an inclined wall located in the oil outlet direction connected to the bottom oil passage. When the electric drive system is in a second preset slope state, the movable baffle can fit against the inclined wall.

[0013] In some embodiments, the cross-sectional shape of the bottom oil passage or the return oil port is fan-shaped.

[0014] In some embodiments, the electric drive system further includes a bypass oil passage disposed outside the motor housing, the bypass oil passage connecting the motor cavity and the gearbox cavity, with one end of each bypass oil passage connected to the corresponding oil inlet and the other end connected to the corresponding oil outlet.

[0015] In some embodiments, the gearbox includes an input shaft and an output shaft with a height difference between them. When the electric drive system is in a horizontal state, the line connecting the oil inlet and the oil outlet of the bypass oil circuit is set at an angle to the horizontal plane.

[0016] In some embodiments, the motor includes a reinforcing plate, one side of which is connected to the outside of the gearbox housing and the other side is connected to the outside of the motor housing, and the bypass oil passage is disposed within the reinforcing plate to form a bypass oil passage.

[0017] In some embodiments, the motor includes a second control valve disposed within the reinforcing plate and connected to the bypass oil passage. When the bypass oil passage is tilted and the connected oil outlet is higher than the connected oil inlet, the second control valve disconnects the bypass oil passage.

[0018] In some embodiments, the gearbox housing includes an oil baffle, the gearbox cavity includes a gear cavity and an oil suction cavity, the gear cavity and the oil suction cavity are separated by the oil baffle, the bypass oil passage connects to the oil outlet in the gear cavity, and the bottom oil passage connects to the oil outlet in the oil suction cavity.

[0019] This application also provides an electric drive vehicle equipped with the electric drive system described in any of the above embodiments.

[0020] The electric drive system provided in this application includes a gearbox, a motor, and a bottom oil circuit. The motor includes a motor housing with a motor cavity and an oil inlet communicating with the motor cavity. The gearbox is powered by the motor and includes a gearbox housing with a gearbox cavity and an oil outlet communicating with the gearbox cavity. The bottom oil circuit connects the motor cavity and the gearbox cavity, with one end connected to the corresponding oil inlet and the other end connected to the corresponding oil outlet. When the electric drive system is in a horizontal state, the height of all the oil inlets is not lower than the height of any oil outlet, allowing oil in the motor cavity to flow back into the gearbox cavity, maintaining a suitable oil level in the gearbox cavity. When the electric drive system is in a first preset slope state, because the oil inlets connected to the bottom oil circuit are circumferentially arranged at the bottom of the motor housing, the bottom oil circuit allows oil in the motor cavity to still flow back into the gearbox cavity. Under different operating conditions, the gearbox cavity maintains a suitable oil level as much as possible. This application also provides an electric drive vehicle equipped with the above-mentioned electric drive system, which can adapt to driving conditions on different inclined road surfaces and improve the stability of the electric drive system. Attached Figure Description

[0021] Figure 1 A schematic diagram of an electric drive system structure is provided in this application;

[0022] Figure 2 The diagram provided in this application shows a partial structural view of an electric drive system from the right perspective, omitting the gearbox gears;

[0023] Figure 3 This application provides a partial structural schematic diagram of an electric drive system from a rear-view cross-section, wherein the electric drive system is in a horizontal position;

[0024] Figure 4 This is a partial structural schematic diagram of an electric drive system from a rear-view cross-section, provided in this application, wherein the electric drive system is in a first preset slope state;

[0025] Figure 5 This is a partial structural diagram of an electric drive system from the left perspective, provided in this application.

[0026] Figure 6 A schematic diagram of the oil level in an electric drive system under a preset cross slope state is provided in this application;

[0027] Explanation of reference numerals in the attached figures

[0028] 1-Electric drive system

[0029] 10-Motor; 11-Motor housing; 11A-Motor cavity; 12-Partition wall; 13-Reinforcing plate;

[0030] 20 - Gearbox; 21 - Gearbox housing; 21A - Gear chamber; 21B - Oil suction chamber; 21C - Gearbox cavity;

[0031] 211-Step wall, 2111-Sloping wall; 212-Oil baffle;

[0032] 30 - First control valve;

[0033] 40 - Bottom oil passage; 41 - Bottom oil channel; 42 - Oil return port

[0034] 50 - Bypass oil passage; 51 - Bypass oil channel. Detailed Implementation

[0035] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0036] In the description of the embodiments of this application, it should be noted that the terms "front," "rear," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0038] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature and the second feature are in direct contact, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0039] This application provides an electric drive system 1, with reference to... Figures 1 to 5 The system includes a motor 10, a gearbox 20, and a bottom oil passage 40. The motor 10 includes a motor housing 11, which has a motor cavity 11A and an oil inlet communicating with the motor cavity 11A. The gearbox 20 is powered by the motor 10 and includes a gearbox housing 21, which has a gearbox cavity 21C and an oil outlet communicating with the gearbox cavity 21C. The bottom oil passage 40 connects the motor cavity 11A and the gearbox cavity 21C, with one end of the bottom oil passage 40 connected to the corresponding oil inlet and the other end connected to the corresponding oil outlet.

[0040] When the electric drive system 1 is in a horizontal state, the height of all the oil inlets is not lower than the height of any of the oil outlets. The oil inlets connected to the bottom oil passage 40 are arranged circumferentially at the bottom of the motor housing 11 so that when the electric drive system 1 is in a first preset slope state, the oil in the motor cavity 11A can flow back to the gearbox cavity 21C.

[0041] It should be noted that, as Figure 1 As shown, the above "horizontal state" refers to the electric drive system maintaining a horizontal state in both the front-to-back and left-to-right directions.

[0042] It should be noted that the aforementioned "first preset slope state" refers to the electric drive system tilting forward or backward in certain operating conditions. For example, if the electric drive system 1 is fixedly mounted on the vehicle, the first preset slope state could be when the vehicle is climbing a 100% slope, and the electric drive system 1 tilts backward by 45°. Depending on the installation method of the drive components of the electric drive vehicle, the first preset slope state can be a preset longitudinal slope state or a preset transverse slope state.

[0043] It should be noted that "circumferential arrangement at the bottom of the motor housing" refers to the bottom position of the circumferential area centered on the motor shaft. For example, it could be the circumferential area of ​​the lower half of the motor housing 11, or the circumferential area with a central angle of 60 to 120° directly below the motor housing 11.

[0044] When the electric drive system 1 tilts in the forward / backward direction, the oil in the motor housing 11A will also change adaptively. Because the corresponding oil inlet connected to the bottom oil circuit is circumferentially arranged on the motor housing 11, and the angle of arrangement can be adjusted according to the required operating conditions, the oil will always enter the corresponding oil inlet connected to the bottom oil circuit 40, thus returning to the gearbox housing 21C, improving the internal oil level when the electric drive system 1 tilts forward / backward. For example, see... Figure 2 If the electric drive system 1 has a higher front and lower rear, then the oil will flow along... Figure 2 The oil inlet located towards the middle and rear (e.g., for) Figure 2 The oil enters the bottom oil passage 40 from the rear portion of the annular region 41 and 42 indicated in the diagram. If the electric drive system 1 is lower at the front and higher at the rear, the oil flows along... Figure 2 The oil inlet located at the front of the middle (e.g., the one at the front of the middle) Figure 2 The front portion of the annular region 41, 42 (as indicated in the diagram) enters the bottom oil passage 40. In some embodiments, the motor housing 11 and the gearbox housing 21 are integrally formed housings, for example, the housings are manufactured using a casting process, which improves the overall sealing and integration of the electric drive system 1.

[0045] In some embodiments, reference is made to Figures 2 to 4 A bottom oil passage 40 is provided on the motor housing 11 to form a bottom oil channel 41. The bottom oil channel 41 extends along the main shaft direction of the motor 10 on the motor housing 11, guiding the oil absorbed by the oil inlet to the corresponding connected oil outlet. It can be understood that, see [reference needed] Figure 3 The oil inlet is located at the left end of the bottom oil passage 41, and the oil outlet is located at the right end of the bottom oil passage 41.

[0046] In some embodiments, reference is made to Figures 2 to 4 The motor housing 11 has a partition wall 12 that separates the motor cavity 11A and the gearbox cavity 21C. The bottom oil passage 40 is provided on the partition wall 12 to form an oil return port 42. One end of the oil return port 42 is an oil inlet and the other end is an oil outlet. It is arranged circumferentially on the partition wall 12. It can be seen that the oil return port 42 directly connects the motor cavity 11A and the gearbox cavity 21C, and quickly guides the oil absorbed by the oil inlet to the corresponding oil outlet. The oil return port 42 arranged circumferentially on the partition wall 12 can play a similar role to the bottom oil passage 41. When the electric drive system 1 is tilted in the front and rear directions, it still guides the oil to the gearbox cavity 21C.

[0047] In some embodiments, the electric drive system 1 includes a first control valve 30, which is fixed on the partition wall 12 and is used to control the opening and closing of the bottom oil passage 40. When the electric drive system 1 is in a horizontal state, the first control valve 30 is in an open state, and at this time, the oil flows from the oil inlet to the oil outlet of the bottom oil passage. When the electric drive system 1 is in a second preset slope state, the first control valve 30 is in a closed state.

[0048] It should be noted that the aforementioned "second preset slope state" refers to the electric drive system tilting left or right under certain operating conditions. For example, if the electric drive system 1 is fixedly mounted on the vehicle, the second preset slope state is when driving on a transverse slope with a transverse slope of 60%, the electric drive system 1 will tilt left or right by approximately 31°, with the tilt direction influenced by the vehicle's driving direction. Depending on the installation method of the drive components in the electric drive vehicle, the second preset slope state can be either a preset longitudinal slope state or a preset transverse slope state.

[0049] For example, such as Figure 4 As shown, when the electric drive system 1 tilts to the left, there is a risk that the oil in the gearbox cavity 21C on the right side may flow back into the motor cavity 11A through the bottom oil passage 40. At this time, the first control valve 30 is closed, the connection between the bottom oil passage 40 and the gearbox cavity 21C is cut off, the backflow of oil is prevented, and the oil level inside the electric drive system 1 is improved when it tilts in the left and right directions.

[0050] In some embodiments, such as Figure 4 As shown, the first control valve 30 is a movable baffle, the orthographic projection of which covers the oil outlet connected to the bottom oil passage 40. Thus, the movable baffle can control the opening and closing of the bottom oil passage 40 by covering the oil outlet connected to it through gravity. It is understood that the first control valve can also be a one-way valve, arranged in each bottom oil passage 41 and return port 42, which can also control the opening and closing of the bottom oil passage 40.

[0051] In some embodiments, such as Figure 3 or Figure 4 As shown, the gearbox housing 21 includes a stepped wall 211, a stepped wall 22 located below the bottom oil passage 41, and a stepped wall 211 including an inclined wall 2111. The inclined wall 2111 is located in the oil outlet direction connected to the bottom oil passage 41. When the electric drive system 1 is in the second preset slope state, the movable baffle tilts in the direction of the electric drive system 1 due to its own weight or oil pressure, and fits against the inclined wall 2111, thereby forming a partition on the side of the inclined wall 2111 facing the bottom oil passage 41, preventing the oil in the gearbox cavity from entering the bottom oil passage 40 and causing backflow.

[0052] In some embodiments, see Figure 2 The bottom oil passage 41 or return port 42 has a fan-shaped cross-section. It should be noted that the term "fan-shaped" refers to the shape formed by a segment of a circular ring in its arc direction. A circumferentially arranged fan-shaped bottom oil passage or return port can cover a wider circumferential range, accommodating more severe forward and backward tilting conditions of the electric drive system 1. The cross-section of the bottom oil passage 41 or return port 42 can also be circular, square, or irregular.

[0053] In some embodiments, the electric drive system 1 further includes a bypass oil passage 50, which is disposed outside the motor housing 11. The bypass oil passage 50 connects the motor cavity 11A and the gearbox cavity 21C. One end of each bypass oil passage 50 is connected to the corresponding oil inlet, and the other end is connected to the corresponding oil outlet. The bypass oil passage 50 can guide the oil in the motor cavity 11A to the gearbox cavity 21C.

[0054] In some embodiments, such as Figure 6 As shown, the gearbox 20 includes an input shaft 22 and an output shaft 23. When the electric drive system 1 is in a horizontal state, there is a vertical height difference (diff drop) between the input shaft 22 and the output shaft 23. The line connecting the oil inlet and the oil outlet of the bypass oil circuit 50 is set at an angle φ with the horizontal plane.

[0055] It is understandable that output shaft 22 is along the power shaft direction of motor 10, and output shaft 23 is along the last gear shaft direction of gearbox 20. Therefore, the height difference between the bottom of motor housing 11 and the bottom of gearbox housing 21 is positively correlated with the magnitude of the aforementioned vertical height difference diffdrop. The larger the diffdrop, the more difficult it is for the oil in gearbox cavity 21C to flow back into motor cavity 11A. In this embodiment, the bypass oil passage 50 serves the following function: when the electric drive system is in a second preset slope state and oil backflow occurs in gearbox cavity 21C, the bypass oil passage 50, due to the included angle φ, has an inlet height that is still higher than the outlet height, allowing the oil accumulated in motor cavity 11A to flow back into gearbox cavity 21C through the bypass oil passage 50. To adapt to different inclination conditions, the included angle φ should be adjusted according to the magnitude of diffdrop; the larger the diffdrop, the larger the included angle φ.

[0056] In some embodiments, such as Figure 5 As shown, the motor 10 includes a reinforcing plate 13. One side of the reinforcing plate 13 is connected to the outside of the gearbox housing 21, and the other side is connected to the outside of the motor housing 11. A bypass oil passage 50 is provided in the reinforcing plate to form a bypass oil passage 51.

[0057] It should be noted that in some embodiments, the motor 10 does not include a reinforcing plate and does not form a bypass oil passage 51, but instead uses an external oil pipe as a bypass oil passage 50.

[0058] In some embodiments, the motor 10 includes a second control valve disposed within the reinforcing plate 13 and connected to a bypass oil passage 51. When the bypass oil passage 51 is tilted and the connected oil outlet is higher than the connected oil inlet, the second control valve disconnects the bypass oil passage, thereby preventing the oil from flowing back through the bypass oil passage 51.

[0059] In some embodiments, reference is made to Figures 1 to 2 The gearbox housing 21 includes an oil baffle 212, and the gearbox cavity 21C includes a gear cavity 21A and an oil suction cavity 21B, which are separated by the oil baffle 212. The oil outlet of the bypass oil passage 50 is connected to the gear cavity 21A, and the oil outlet of the bottom oil passage 40 is connected to the oil suction cavity 21B. The bypass oil passage 50 and the bottom oil passage 40 have different oil outlet directions, which can prevent oil leakage and also prevent backflow in the bypass oil passage 50 and the bottom oil passage 40 from occurring simultaneously due to the tilt of the electric drive system 1 caused by changes in the oil level caused by the operation of other components in the gearbox 20, such as the oil suction pump.

[0060] This application also provides an electric drive vehicle equipped with the electric drive system 1 described in any of the above embodiments. The electric vehicle can adapt to longitudinal or transverse slopes with different gradients, and its electric drive system operates stably.

[0061] The various embodiments / implementations provided in this application can be combined with each other without creating contradictions.

[0062] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An electric drive system, characterized in that, include: An electric motor includes a motor housing, the motor housing having a motor cavity and an oil inlet communicating with the motor cavity; A gearbox, which is powered by the electric motor, includes a gearbox housing, which has a gearbox cavity and an oil outlet communicating with the gearbox cavity; The bottom oil passage connects the motor cavity and the gearbox cavity, with one end connected to the corresponding oil inlet and the other end connected to the corresponding oil outlet. When the electric drive system is in a horizontal state, the height of all the oil inlets is not lower than the height of any of the oil outlets. The oil inlets connected to the bottom oil circuit are arranged circumferentially at the bottom of the motor housing so that when the electric drive system is in a first preset slope state, the oil in the motor cavity can flow back to the gearbox cavity. The bottom oil passage is provided on the motor housing to form a bottom oil channel; the motor housing has a partition wall that separates the motor cavity and the gearbox cavity, and the bottom oil passage is provided on the partition wall to form an oil return port, which is arranged circumferentially on the partition wall; The electric drive system includes a first control valve, which is fixed on the partition wall and used to control the opening and closing of the bottom oil circuit. When the electric drive system is in a horizontal state, the first control valve is in an open state, and when the electric drive system is in a second preset slope state, the first control valve is in a closed state. The first control valve is a movable baffle. The orthographic projection of the movable baffle covers the oil outlet connected to the bottom oil passage. The gearbox housing includes a stepped wall. The stepped wall is located below the bottom oil passage. The stepped wall includes an inclined wall. The inclined wall is located in the oil outlet direction connected to the bottom oil passage. When the electric drive system is in the second preset slope state, the movable baffle can fit against the inclined wall.

2. The electric drive system according to claim 1, characterized in that, The motor housing and the gearbox housing are integrally formed housings.

3. The electric drive system according to claim 1, characterized in that, The cross-sectional shape of the bottom oil passage or the return oil port is fan-shaped.

4. The electric drive system according to claim 1, characterized in that, The electric drive system also includes a bypass oil circuit, which is disposed outside the motor housing and connects the motor cavity and the gearbox cavity. One end of each bypass oil circuit is connected to the corresponding oil inlet, and the other end is connected to the corresponding oil outlet.

5. The electric drive system according to claim 4, characterized in that, The gearbox includes an input shaft and an output shaft, which have a height difference. When the electric drive system is in a horizontal state, the line connecting the oil inlet and the oil outlet of the bypass oil circuit is set at an angle to the horizontal plane; and / or, The motor includes a reinforcing plate, one side of which is connected to the outside of the gearbox housing, and the other side is connected to the outside of the motor housing. The bypass oil passage is arranged inside the reinforcing plate to form a bypass oil channel.

6. The electric drive system according to claim 5, characterized in that, The motor includes a second control valve, which is disposed inside the reinforcing plate and connected to the bypass oil passage. When the bypass oil passage is tilted and the connected oil outlet is higher than the connected oil inlet, the second control valve disconnects the bypass oil passage.

7. The electric drive system according to claim 4, characterized in that, The gearbox housing includes an oil baffle rib, the gearbox cavity includes a gear cavity and an oil suction cavity, the gear cavity and the oil suction cavity are separated by the oil baffle rib, the bypass oil passage connects to the oil outlet in the gear cavity, and the bottom oil passage connects to the oil outlet in the oil suction cavity.

8. An electric-driven vehicle, characterized in that, Includes the electric drive system according to any one of claims 1-7.

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