Electric bridge drive system and vehicle

Abstract

An electric bridge drive system and a vehicle comprising the electric bridge drive system. The electric bridge drive system comprises a housing (1), a motor (2), a transmission (3), a transmission shaft (4), and a valve assembly (5). The housing (1) comprises a first space (S1) and a second space (S2), the motor (2) is accommodated in the first space (S1), the transmission (3) is accommodated in the second space (S2), and the transmission shaft (4) enables the motor (2) to be in transmitting connection with the transmission (3). The housing (1) is provided with at least one communicating path (11h), the first space (S1) and the second space (S2) can be communicated in a controlled manner by means of the at least one communicating path (11h), and the valve assembly (5) is provided in the corresponding communicating path (11h), so that the communicating path (11h) is closed by the valve assembly (5) only when the angle of inclination of the electric bridge drive system toward the side of the motor (2) relative to a horizontal direction is greater than or equal to a predetermined angle.

Description

Electric bridge drive system and vehicle Technical Field

[0001] The present application relates to the field of vehicle power systems, and in particular to an electric axle drive system for a vehicle and a vehicle comprising the electric axle drive system. Background Art

[0002] In pure electric vehicles, an electric motor is used as the power source. The motor and transmission form what's known as an e-bridge drive system. To achieve superior performance, the motor in an e-bridge drive system is typically oil-cooled. This pumps oil stored in the transmission housing into the motor housing, effectively cooling the motor. After cooling the motor, the oil is returned to the transmission housing via a communication path within the housing, ensuring a high oil level within the transmission housing.

[0003] However, when the vehicle travels over uneven or inclined roads, the e-axle drive system may tilt relative to the horizontal, toward the motor. A significant tilt can cause oil to flow from the transmission housing into the motor housing through the aforementioned communication path, resulting in insufficient oil and a low oil level in the transmission housing. This not only negatively impacts lubrication of the transmission mechanism, but also may prevent the cooling system of the oil-cooled motor from extracting sufficient oil from the transmission housing for cooling. Furthermore, excessive oil in the motor housing can create bubbles, negatively impacting motor performance.

[0004] Summary of the Invention

[0005] This application is based on the above-mentioned shortcomings of the prior art. One purpose of this application is to provide a novel electric bridge drive system that can alleviate or avoid the adverse effects on the lubrication effect of the transmission mechanism, the cooling effect of the cooling system, and the performance of the motor caused by excessive oil in the transmission housing entering the motor housing through the connecting passage when the electric bridge drive system is tilted significantly toward the motor side.

[0006] In order to achieve the above application objectives, this application adopts the following technical solutions.

[0007] The present application provides the following electric bridge drive system, including a housing, a motor, a transmission, and a transmission shaft assembled together. The housing includes a first space and a second space arranged side by side in the axial direction of the transmission shaft. The first space is located on one side of the axial direction relative to the second space. The motor is accommodated in the first space, and the transmission is accommodated in the second space. The transmission shaft extends from the first space to the second space, and the transmission shaft connects the motor and the transmission.

[0008] The shell is formed with at least one connecting passage, and the first space and the second space can be controlled to be connected via the at least one connecting passage. The electric bridge drive system also includes a valve assembly, which is arranged in the corresponding connecting passage, so that the connecting passage is closed by the valve assembly only when the angle at which the electric bridge drive system is tilted toward the motor side relative to the horizontal direction is greater than or equal to a predetermined angle.

[0009] In an optional solution, the valve assembly includes a plunger and an elastic member assembled together, the plunger is inserted and installed into the corresponding connecting passage, and the elastic member applies a spring force to the plunger along the axial direction, so that when the angle of inclination of the electric bridge drive system relative to the horizontal direction toward the motor side is greater than or equal to a predetermined angle, the plunger offsets the spring force under the action of gravity and thus closes the connecting passage.

[0010] In another optional scheme, the plunger includes a plug head and a plug rod fixed to each other, the plug head is fixed to the other axial end of the plug rod, the cross-sectional area of ​​the plug head is larger than the cross-sectional area of ​​the plug rod and larger than the cross-sectional area of ​​the opening of the connecting passage, the plug rod is inserted into the connecting passage, and the plug head can abut against the shell to close the opening of the connecting passage.

[0011] In another optional solution, the elastic member is a coil spring, which is sleeved on the plug rod, with one end of the coil spring abutting against the housing and the other end of the coil spring abutting against the plug head.

[0012] In another optional solution, the valve assembly further includes a limit pin, which is inserted through one axial end portion of the plug rod and cooperates with the housing to prevent the plunger from escaping from the communication passage from the other axial side.

[0013] In another optional solution, the shell includes a partition wall, which divides the internal space of the shell into the first space and the second space, and the at least one communication passage is located at the bottom of the partition wall.

[0014] In another optional scheme, the partition wall includes a central cylindrical portion and a support portion located in the connecting passage, the connecting passage is formed as a cylindrical through hole, the central cylindrical portion is arranged coaxially with the connecting passage, the central cylindrical portion is used for the valve assembly to be inserted and installed, and the support portion is arranged at intervals in the circumferential direction of the connecting passage for supporting the central cylindrical portion.

[0015] In another optional solution, a plurality of the communication passages are formed at the bottom of the partition wall, and the plurality of communication passages are spaced apart and evenly distributed within a circumferential range in which the communication passages are provided.

[0016] The present application also provides a vehicle, comprising the electric bridge drive system described in any one of the above technical solutions.

[0017] In an optional solution, the axial direction of the transmission shaft is consistent with the width direction of the vehicle.

[0018] By adopting the above-mentioned technical solution, the present application provides a novel electric bridge drive system. The electric bridge drive system includes a housing, a motor, a transmission, and a transmission shaft assembled together. The housing includes a first space and a second space arranged side by side in the axial direction of the transmission shaft, with the first space located axially to one side of the second space. The motor is housed in the first space, the transmission is housed in the second space, and the transmission shaft extends from the first space to the second space, connecting the motor and the transmission. The housing is formed with a connecting passage, through which the first and second spaces can be controlled to communicate. Furthermore, the electric bridge drive system also includes a valve assembly, which is disposed in the corresponding connecting passage, such that the connecting passage is closed by the valve assembly only when the electric bridge drive system is tilted toward the motor at an angle greater than or equal to a predetermined angle relative to the horizontal direction; in other cases, the connecting passage is not closed by the valve assembly, that is, the first and second spaces are connected via the connecting passage in other cases.

[0019] In this way, when the electric bridge drive system is tilted relative to the horizontal toward the motor side (the side where the motor is located) at an angle greater than or equal to a predetermined angle (the acute angle between the axial direction of the transmission shaft and the horizontal direction), the connecting passage is closed by the valve assembly, thereby preventing the oil in the second space from flowing into the first space via the connecting passage. This can alleviate or prevent the adverse effects on the lubrication of the transmission mechanism, the cooling effect of the cooling system, and the performance of the motor caused by excessive oil in the transmission housing entering the motor housing through the connecting passage when the electric bridge drive system is tilted significantly toward the motor side. Furthermore, since the connecting passage is closed by the valve assembly only in this situation, it does not affect the normal connectivity of the connecting passage in other situations, and thus does not affect the normal flow of oil in other situations. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1A is a schematic cross-sectional view showing an electric bridge drive system according to a first embodiment of the present application, wherein the electric bridge drive system is in a non-tilted state relative to a horizontal direction.

[0021] FIG. 1B is a perspective schematic diagram showing a partial structure of the electric bridge driving system in FIG. 1A .

[0022] FIG1C is a partially enlarged schematic diagram of FIG1A .

[0023] 2A is a schematic cross-sectional view showing the bridge drive system in FIG. 1A , wherein the bridge drive system is in a tilted state relative to the horizontal direction and tilted toward the motor side.

[0024] FIG2B is a partially enlarged schematic diagram of FIG2A .

[0025] FIG. 3 is a schematic diagram showing a partial structure (motor housing) of a housing of the electric bridge drive system in FIG. 1A .

[0026] FIG. 4A is a perspective schematic diagram illustrating a plunger of the bridge drive system in FIG. 1A .

[0027] FIG. 4B is a perspective schematic diagram showing an elastic member of the electric bridge driving system in FIG. 1A .

[0028] FIG. 4C is a perspective schematic diagram showing a limiting pin of the electric bridge driving system in FIG. 1A .

[0029] Explanation of reference numerals 1 housing; 11 motor housing; 11p partition wall; 11h communication passage; 11c central cylinder; 11s support portion; 12 transmission housing; S1 first space; S2 second space; 2 motor; 21 stator; 22 rotor; 3 transmission; 4 drive shaft; 5 valve assembly; 51 plunger; 511 plug head; 512 plug rod; 512h mounting hole; 52 elastic member; 53 limit pin; A axial direction; R radial direction. DETAILED DESCRIPTION

[0030] The following describes exemplary embodiments of the present application with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not intended to exhaust all possible methods of the present application, nor to limit the scope of the present application.

[0031] In this application, unless otherwise specified, "axial", "radial" and "circumferential" refer to the axial, radial and circumferential directions of the electric bridge drive system (drive shaft), respectively; "one axial side" refers to the left side in Figures 1A and 1C, and "the other axial side" refers to the right side in Figures 1A and 1C; "radially outer side" refers to the side radially away from the central axis of the electric bridge drive system (drive shaft), and "radially inner side" refers to the side radially close to the central axis of the electric bridge drive system (drive shaft).

[0032] An electric bridge driving system according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0033] As shown in Figures 1A to 2B, an electric bridge drive system according to an embodiment of the present application includes an assembled housing 1, a motor 2, a transmission 3, a transmission shaft 4, and a valve assembly 5. The housing 1 defines an installation space within which the motor 2, transmission 3, and transmission shaft 4 are located. The valve assembly 5 is installed in a communication passage 11h of the housing 1, enabling controlled communication between a first space S1 and a second space S2 within the housing 1 via the communication passage 11h.

[0034] In this embodiment, as shown in Figures 1A and 2A , the housing 1 includes a motor housing 11 and a transmission housing 12 that are detachably assembled. Together, they define a first space S1 and a second space S2 that are separated from each other. The first space S1 and the second space S2 are arranged side by side in the axial direction A, with the first space S1 located axially to one side of the second space S2. The motor 2 is housed in the first space S1, and the transmission 3 is housed in the second space S2.

[0035] Furthermore, as shown in Figures 1A to 3, the motor housing 11 includes a partition wall 11p located on the other axial side. When the motor housing 11 and the transmission housing 12 are assembled together, the partition wall 11p partitions the housing 1 into a first space S1 and a second space S2. Furthermore, three communication passages 11h are formed at the bottom (vertically lower half) of the partition wall 11p. These communication passages 11h are evenly spaced and spaced apart within the circumferential range in which the communication passages 11h are provided. In each communication passage 11h, the partition wall 11p includes a central cylindrical portion 11c and a support portion 11s located within the communication passage 11h. The communication passage 11h is formed as a cylindrical through-hole and extends linearly along the axial direction A. The cross-sectional shape and cross-sectional area of ​​the communication passage 11h are uniform throughout its entire axial length. As shown in Figure 3, the central cylindrical portion 11c is coaxially arranged with the communication passage 11h and is used to insert and install the plunger 51 of the valve assembly 5. Four support portions 11s are evenly spaced apart in the circumferential direction of the communication passage 11h to support the central cylindrical portion 11c. Different support portions 11s extend linearly along different radial directions of the communication passage. One end of each support portion 11s is connected to the central cylindrical portion 11c, and the other end of each support portion 11s is connected to the wall defining the communication passage 11h. Thus, even when the plug rod 512 of the plunger 51 is inserted and installed within the central cylindrical portion 11c, as long as the plug head 511 does not close the other axial opening of the communication passage 11h, the bottom of the first space S1 and the bottom of the second space S2 can communicate via the portion of the communication passage 11h defined by the outer circumferential surface of the central cylindrical portion 11c and the inner circumferential surface of the communication passage.

[0036] In this embodiment, as shown in Figures 1A and 2A, the motor 2 includes a stator 21 fixed relative to the housing 1 and a rotor 22 rotatable relative to the stator 21. The rotor 22 is located inward of the stator 21 in the radial direction R and is torque-proof connected to the transmission shaft 4, so that the transmission shaft 4 can rotate with the rotor 22 to output torque.

[0037] In this embodiment, as shown in Figures 1A and 2A, the transmission 3 includes a transmission mechanism composed of multiple gears (which can be one or more planetary gears), and the drive shaft 4 also serves as the input shaft of the transmission 3 to transmit the torque from the rotor 22 of the motor 2 to the transmission 3.

[0038] In this embodiment, as shown in Figures 1A and 2A , a transmission shaft 4 extends linearly from a first space S1 to a second space S2 along an axial direction A. The transmission shaft 4 is coaxially arranged with and torque-proof connected to the rotor 22 of the motor 2. The transmission shaft 4 also serves as the input shaft of the transmission 3. Thus, torque from the rotor 22 of the motor 2 can be transmitted to the transmission 3 via the transmission shaft 4.

[0039] In this embodiment, as shown in Figures 1A to 2B , the valve assembly 5 is disposed in a corresponding communication passage 11h, enabling controlled communication between the first space S1 and the second space S2 within the housing 1 via the communication passage 11h. Specifically, the valve assembly 5 comprises a plunger 51, an elastic member 52, and a stop pin 53, all assembled together. As shown in Figures 1B, 1C, and 2B , the plunger 51 is inserted and mounted in the corresponding communication passage 11h, with the elastic member 52 constantly applying a spring force to the plunger 51 toward the other axial direction.

[0040] As shown in FIG4A , the plunger 51 includes a plug head 511 and a plug rod 512 fixed to each other by integral molding, and the plug head 511 is fixed to the other axial end of the plug rod 512. The cross-sectional area of ​​the plug head 511 is larger than the cross-sectional area of ​​the plug rod 512 and larger than the cross-sectional area of ​​the opening on the other axial side of the connecting passage 11h. After being installed in place, the plug rod 512 extends into the connecting passage 11h and is inserted through the central cylindrical portion 11c. The end of one axial side of the plug rod 512 is inserted into the first space S1. Furthermore, a mounting hole 512h is formed at the end of one axial side of the plug rod 512, and the mounting hole 512h extends through the plug rod 512 in a direction perpendicular to the axial direction A of the connecting passage 11h.

[0041] As shown in FIG4B , the elastic member 52 may be a cylindrical coil spring. The cylindrical coil spring is mounted on the plug rod 512. One end of the cylindrical coil spring abuts the central cylindrical portion 11c and the support portion 11s, while the other end abuts the plug head 511. This allows the cylindrical coil spring to exert a constant spring force along the axial direction A on the plug head 511, away from the other axial opening of the communication passage 11h.

[0042] As shown in Figures 1C and 2B, the support portion 11s may be formed only in a portion of the axial region of the communication passage 11h. Thus, when the elastic member 52 in the form of a cylindrical coil spring is uncompressed or slightly compressed (see Figure 1C), the cylindrical coil spring is partially located within the communication passage 11h and partially located outside the communication passage 11h. When the elastic member 52 in the form of a cylindrical coil spring is significantly compressed (see Figure 2B), the cylindrical coil spring can be completely accommodated within the communication passage 11h, thereby facilitating the abutment of the plug 511 against the housing 1 (partition wall 11p), thereby closing the communication passage 11h.

[0043] As shown in FIG4C , the stopper pin 53 is inserted through a mounting hole 512h formed at one axial end of the plunger rod 512. The stopper pin 53 forms an interference fit with the mounting hole 512h, and both ends of the stopper pin 53 extend from the mounting hole 512h. Thus, the stopper pin 53 cooperates with the central cylindrical portion 11c to prevent the plunger 51 from escaping from the communication passage 11h from the other axial end.

[0044] It is understood that the stop pin 53 is not limited to the form shown in the figure. The stop pin can also be an elastic pin, or the stop pin can be appropriately bent or curved. As long as the stop pin can prevent the plunger 51 from axially escaping from the communication passage 11h from the other side.

[0045] The working principle of the valve assembly 5 of the electric bridge drive system will be described below by taking a vehicle using the electric bridge drive system according to an embodiment of the present application as an example.

[0046] When a vehicle using the above-described electric bridge drive system travels on a flat road, as shown in Figures 1A and 1C , the electric bridge drive system is not tilted relative to the horizontal. Due to the elastic force of the elastic member 52, the plug head 511 of the plunger 51 does not abut against the housing 1 and does not close the other axial opening of the communication passage 11h, thereby keeping the communication passage 11h open.

[0047] When a vehicle using the above-described electric bridge drive system travels over uneven or inclined roads, as shown in Figures 2A and 2B , the electric bridge drive system may tilt relative to the horizontal toward the motor side, meaning that the motor side is lower than the transmission side. When the angle of inclination of the electric bridge drive system relative to the horizontal toward the motor side (this angle is the acute angle between the axial direction A and the horizontal) is greater than or equal to a predetermined angle (this predetermined angle can be adjusted based on parameters such as the vehicle's roll angle, and an example of this predetermined angle is 30 degrees), the weight of the plug 511 overcomes the elastic force of the elastic member 52, causing the plug 511 to abut against the housing 1, thereby closing the other axial opening of the communication passage 11h. This prevents oil in the second space S2 from flowing into the first space S1 via the communication passage 11h. This prevents excessive oil in the transmission housing 12 from entering the motor housing 11 through the communication passage 11h when the electric bridge drive system is significantly tilted toward the motor side, adversely affecting the lubrication of the transmission mechanism, the cooling system, and the performance of the motor 2.

[0048] When a vehicle using the above-described electric axle drive system travels over uneven or inclined roads, the electric axle drive system may tilt relative to the horizontal toward the transmission side, meaning that the transmission side is lower than the motor side. Due to the weight of the plug 511 and the elastic force of the elastic member 52, the plug 511 of the plunger 51 does not abut against the housing 1, thereby preventing the other axial opening of the communication passage 11h from being sealed. Consequently, the communication passage 11h remains open.

[0049] By adopting the above solution, the communication passage 11h is closed by the valve assembly 5 only when the electric bridge drive system is tilted toward the motor side relative to the horizontal at an angle greater than or equal to a predetermined angle; in other cases, the communication passage 11h is not closed by the valve assembly 5. Thus, the objectives of the present invention are achieved without affecting the normal operation of the electric bridge drive system.

[0050] The specific technical solutions of the present application are described in detail in the above embodiments. Those skilled in the art can make various modifications to the above embodiments of the present application under the guidance of the present application without departing from the scope of the present application. The following is a supplementary explanation of the technical solutions of the present application.

[0051] i. It can be understood that the number of communication passages 11h is not limited to three as described in the above embodiment. As long as the shell 1 is formed with at least one communication passage 11h, the bottom of the first space S1 and the bottom of the second space S2 can be controlled to communicate via the at least one communication passage 11h.

[0052] ii. In the electric axle drive system according to the present application, the valve assembly 5 has a simple structure and is easy to assemble and disassemble. Regardless of the vehicle's state, the oil level in the transmission housing 12 is maintained, thereby ensuring adequate lubrication of the transmission mechanism. Furthermore, the oil level in the motor housing 11 is ensured to be low enough to affect the performance of the motor 2.

[0053] iii. It can be understood that in the electric axle drive system according to the present application, an oil pump, oil circuit, etc. can be provided to pump the oil stored in the transmission housing to the motor housing.

[0054] iv. The electric bridge drive system of the present application can be used in pure electric vehicles or as part of a hybrid power system for hybrid vehicles. In addition, when the electric bridge drive system is applied to a vehicle, the axial direction A of the transmission shaft 4 is consistent with the width direction of the vehicle.

Claims

1. An electric bridge drive system, comprising a housing (1), a motor (2), a transmission (3) and a transmission shaft (4) assembled together, the housing (1) comprising a first space (S1) and a second space (S2) arranged side by side in an axial direction (A) of the transmission shaft (4), the first space (S1) being located on one side of the axial direction relative to the second space (S2) in the axial direction (A), the motor (2) being received in the first space (S1), the transmission (3) being received in the second space (S2), the transmission shaft (4) extending from the first space (S1) to the second space (S2), the transmission shaft (4) enabling the motor (2) to be transmission-coupled with the transmission (3), The housing (1) is formed with at least one connecting passage (11h), and the first space (S1) and the second space (S2) can be controlled to be connected via the at least one connecting passage (11h). The electric bridge drive system also includes a valve assembly (5), and the valve assembly (5) is arranged in the corresponding connecting passage (11h), so that the connecting passage (11h) is closed by the valve assembly (5) only when the angle of inclination of the electric bridge drive system toward the motor side relative to the horizontal direction is greater than or equal to a predetermined angle.

2. The electric bridge drive system according to claim 1, characterized in that: The valve assembly (5) comprises a plunger (51) and an elastic member (52) assembled together, wherein the plunger (51) is inserted and installed into the corresponding connecting passage (11h), and the elastic member (52) applies a spring force to the plunger (51) along the axial direction (A), so that when the angle of inclination of the electric bridge drive system relative to the horizontal direction toward the motor side is greater than or equal to a predetermined angle, the plunger (51) counteracts the spring force under the action of gravity and thereby closes the connecting passage (11h).

3. The electric bridge drive system according to claim 2, characterized in that: The plunger (51) comprises a plug head (511) and a plug rod (512) fixed to each other, the plug head (511) being fixed to the other axial end of the plug rod (512), the cross-sectional area of ​​the plug head (511) being larger than the cross-sectional area of ​​the plug rod (512) and larger than the cross-sectional area of ​​the opening of the communication passage (11h), the plug rod (512) being inserted into the communication passage (11h), and the plug head (511) being able to abut against the housing (1) to close the opening of the communication passage (11h).

4. The electric bridge drive system according to claim 3, characterized in that: The elastic member (52) is a coil spring, which is sleeved on the plug rod (512), one end of the coil spring abuts against the housing (1), and the other end of the coil spring abuts against the plug head (511).

5. The electric bridge drive system according to claim 3, characterized in that: The valve assembly (5) further comprises a limit pin (53), wherein the limit pin (53) is inserted through one axial end portion of the plug rod (512), and the limit pin (53) cooperates with the housing (1) to prevent the plunger (51) from escaping from the connecting passage (11h) from the other axial side.

6. The electric bridge drive system according to any one of claims 1 to 5, characterized in that: The housing (1) comprises a partition wall (11p) which partitions the internal space of the housing (1) into the first space (S1) and the second space (S2), and the at least one communication passage (11h) is located at the bottom of the partition wall (11p).

7. The electric bridge drive system according to claim 6, characterized in that: The partition wall (11p) includes a central cylindrical portion (11c) and a support portion (11s) located in the connecting passage (11h), wherein the connecting passage (11h) is formed as a cylindrical through hole, the central cylindrical portion (11c) is coaxially arranged with the connecting passage (11h), the central cylindrical portion (11c) is used for the valve assembly (5) to be inserted and installed, and the support portion (11s) is arranged at intervals in the circumferential direction of the connecting passage (11h) for supporting the central cylindrical portion (11c).

8. The electric bridge drive system according to claim 6, characterized in that: A plurality of communication passages (11h) are formed at the bottom of the partition wall (11p), and the plurality of communication passages (11h) are evenly distributed at intervals from each other within a circumferential range in which the communication passages (11h) are provided.

9. A vehicle comprising the electric bridge drive system according to any one of claims 1 to 8.

10. The vehicle according to claim 9, characterized in that The axial direction (A) of the transmission shaft (4) is consistent with the width direction of the vehicle.

Images