Bridge driving system and vehicle

Abstract

The invention provides a bridge driving system and a vehicle. In the bridge driving system, the double motors are included, the torque from the rotors of the motors can be output to the outside through the output shafts which are off-axis arranged with the rotors, and therefore a framework with the double motors and the off-axis arranged output ends is achieved. In addition, the transmission in each bridge driving unit comprises a planet row, so that a torque transmission path for transmitting torque towards the outside is formed. Therefore, compared with an electric bridge driving system which only forms a transmission through an external meshing gear set, the electric bridge driving system has the advantages that a torque transmission path with a large transmission ratio can be realized in a relatively compact structure under the condition of occupying a small radial space, the torque requirement on the motor is correspondingly reduced, the size of the motor can be correspondingly reduced, and the cost of the motor is saved.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically to an electric bridge drive system for a vehicle and a vehicle including the electric bridge drive system. Background Art

[0002] At present, the electric bridge drive system can be used for pure electric vehicles and hybrid vehicles to drive the vehicle. In a typical electric bridge drive system, two motors arranged coaxially are included as power sources, which can improve the dynamic performance of the vehicle (for example, the acceleration time from starting to 100 km / h). Furthermore, in the above-mentioned electric bridge drive system, transmissions are respectively set for the two motors, so that the motors can drive the wheels of the vehicle via the corresponding transmissions and the electric bridge drive system adopts an architecture in which the input end and the output end are set off-axis.

[0003] However, the above-mentioned transmission usually adopts a gear transmission mechanism composed of a multi-stage external meshing gear set to achieve a certain transmission ratio, which may lead to the following problems. When the radial space of the transmission is constant, the transmission ratio achieved by the gear transmission mechanism composed of a multi-stage external meshing gear set is relatively small. This will result in the need to increase the size and cost of the motor if the same torque needs to be output. Conversely, in the case where the transmission adopts a gear transmission mechanism composed of a multi-stage external meshing gear set, if a larger transmission ratio is achieved, the size of each stage of the driven wheels needs to be increased, which will result in a larger radial size of the transmission. Summary of the invention

[0004] This application is made in view of the defects of the above-mentioned technologies introduced in the background technology. One purpose of this application is to provide a new type of electric bridge drive system, which can realize an off-axis setting architecture and can achieve a larger transmission ratio while occupying a smaller radial space, correspondingly reducing the size of the motor and saving corresponding costs. Another purpose of this application is to provide a vehicle including the above-mentioned electric bridge drive system.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions.

[0006] The present application provides an electric bridge drive system, comprising two electric bridge drive units arranged side by side in an axial direction, each of the electric bridge drive units comprising a motor and a transmission.

[0007] The motor comprises a stator and a rotor,

[0008] The transmission includes a planetary row, a first gear set and a first output shaft, the planetary row includes a sun gear, a plurality of planetary gears, a planetary wheel carrier and a ring gear assembled together, the sun gear is coaxially arranged with the rotor and transmission connected, the ring gear is fixed relative to the stator, the first gear set includes a first driving wheel and a first driven wheel that are always meshed, the first driving wheel is installed on the planetary wheel carrier to be always transmission connected with the planetary wheel carrier, the first driven wheel is installed on the first output shaft to be always transmission connected with the first output shaft, and the first output shaft is eccentrically arranged with the rotor.

[0009] In an optional solution, the transmission of one electric axle drive unit and the transmission of another electric axle drive unit are adjacent to each other in the axial direction.

[0010] In another optional solution, the electric bridge drive unit further includes a housing, and the ring gear is fixed to the housing.

[0011] In another optional solution, the electric bridge drive unit further includes a plurality of bearings mounted on the housing, wherein the plurality of bearings support the planetary wheel carrier so that the planetary wheel carrier can rotate relative to the housing.

[0012] In another optional scheme, the transmission also includes a second gear set and a second output shaft, the second gear set includes a second driving wheel and a second driven wheel that are always meshed, the second driving wheel is installed on the first output shaft to be always drivingly connected to the first output shaft, the second driven wheel is installed on the second output shaft to be always drivingly connected to the second output shaft, and the second output shaft is set off-axis with the first output shaft and the rotor.

[0013] In another optional solution, in the axial direction, the planetary gear set and the second gear set are arranged overlappingly.

[0014] The present application also provides a vehicle, comprising the electric bridge drive system described in one of the above technical solutions.

[0015] In an optional solution, the first wheel and the second wheel are further included, wherein the first wheel and the second wheel are respectively connected to the first output shafts of the two electric bridge drive units of the electric bridge drive system.

[0016] The first wheel and the second wheel are both front wheels or the first wheel and the second wheel are both rear wheels.

[0017] The present application also provides a vehicle, comprising the electric bridge drive system described in one of the above technical solutions.

[0018] In an optional solution, the first wheel and the second wheel are further included, wherein the first wheel and the second wheel are respectively connected to the second output shafts of the two electric bridge drive units of the electric bridge drive system.

[0019] The first wheel and the second wheel are both front wheels or the first wheel and the second wheel are both rear wheels.

[0020] By adopting the above technical solution, the present application provides a novel electric bridge drive system and a vehicle including the electric bridge drive system. In the electric bridge drive system of the present application, two electric bridge drive units are arranged side by side in the axial direction, and each electric bridge drive unit includes a motor and a transmission. The motor includes a stator and a rotor. The transmission includes a planetary row, a first gear set and a first output shaft. The planetary row includes a sun gear, a plurality of planetary gears, a planetary wheel carrier and a ring gear assembled together, the sun gear is connected to the rotor to achieve a transmission connection, and the ring gear is fixed relative to the stator. The first gear set includes a first driving wheel and a first driven wheel that are always meshed, the first driving wheel is installed on the planetary wheel carrier to be always transmission-connected with the planetary wheel carrier, and the first driven wheel is installed on the first output shaft to be always transmission-connected with the first output shaft. In addition, the first output shaft is set off-axis with the rotor.

[0021] In this way, the torque from the rotor can be output to the outside via the first output shaft that is eccentrically arranged with the rotor, so that the electric bridge drive system realizes an architecture with dual motors and eccentrically arranged input and output ends. In addition, the transmission in each electric bridge drive unit includes a planetary gear to form a torque transmission path for transmitting torque to the outside. Therefore, compared with the electric bridge drive system in which the transmission is only composed of an external meshing gear set, a torque transmission path with a large transmission ratio can be realized in a relatively compact structure while occupying a small radial space, which correspondingly reduces the torque demand on the motor, can correspondingly reduce the size of the motor and save the cost of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram showing the topological structure of the electric bridge driving system according to the first embodiment of the present application.

[0023] Figure 2 is a schematic diagram showing a topological structure of an electric bridge drive system according to a second embodiment of the present application.

[0024] Description of Reference Numerals

[0025] EU bridge driver unit;

[0026] H housing;

[0027] EM motor; RO rotor; S1 rotor shaft; ST stator;

[0028] TM transmission; SG sun gear; PG planetary gear; PC planetary gear carrier; RG ring gear; S21 first output shaft; S22 second output shaft; G11 first driving wheel; G12 first driven wheel; G21 second driving wheel; G22 second driven wheel;

[0029] A is axial; R is radial. DETAILED DESCRIPTION

[0030] The exemplary embodiments of the present application are described below 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 feasible methods of the present application, nor to limit the scope of the present application.

[0031] In the present application, unless otherwise specified, "drive connection" refers to a connection between two components that can transmit torque, including direct connection and indirect connection.

[0032] In this application, unless otherwise specified, "axial" and "radial" refer to the axial and radial directions of the bridge drive unit (motor), respectively. "Axial side" refers to Figure 1 and Figure 2 The left side of the axis refers to Figure 1 and Figure 2 The “radially inner side” refers to the side close to the central axis of the bridge drive unit (motor), and the “radially outer side” refers to the side away from the central axis of the bridge drive unit (motor).

[0033] An electric bridge drive system and a vehicle including the electric bridge drive system according to a first embodiment of the present application will be described below in conjunction with the accompanying drawings.

[0034] (Electric bridge drive system and vehicle according to the first embodiment of the present application)

[0035] like Figure 1 As shown, the electric bridge drive system according to the first embodiment of the present application includes two electric bridge drive units EU integrated together. Each electric bridge drive unit EU includes a motor EM, a transmission TM and a housing H, and the motor EM and the transmission TM are both received and installed in the corresponding housing H. Figure 1As shown, the two electric bridge drive units EU are arranged side by side in the axial direction A. Furthermore, in the structural layout of the entire electric bridge drive system, one electric bridge drive unit EU is located as a whole on one axial side of the other electric bridge drive unit EU. In the above-mentioned one electric bridge drive unit EU, the transmission TM is located on the other axial side of the motor EM; in the above-mentioned other electric bridge drive unit EU, the transmission TM is located on one axial side of the motor EM. Thus, in the electric bridge drive system, the transmission TM of one electric bridge drive unit EU and the transmission TM of another electric bridge drive unit EU are adjacent to each other in the axial direction A, and the two transmissions TM are located between the two motors EM in the axial direction A. In this embodiment, the structures of the two electric bridge drive units EU are arranged basically symmetrically relative to the cross section of the electric bridge drive system at the axial center.

[0036] In this embodiment, if Figure 1 As shown, the motor EM is located inside the housing H, and includes a stator ST and a rotor RO located inside the stator ST and capable of rotating relative to the stator ST. Specifically, the stator ST is fixed to the housing H and includes an iron core and a winding. The iron core can be made of stacked silicon steel sheets and is formed with a plurality of slots for inserting and installing the winding. The winding can be inserted into the plurality of slots of the iron core and wound and installed on the iron core. In the rotor RO, the rotor shaft S1 is fixed to the rotor stack so that the rotor shaft S1 can rotate with the rotor stack. The rotor shaft S1 is formed to extend in a straight line along the axial direction A. In addition, the rotor shaft S1 is directly connected to the sun gear SG of the planetary row of the transmission TM to always be in transmission connection, so that the rotor shaft S1 and the sun gear SG can transmit torque in both directions. When the motor EM is supplied with electric energy by a battery, the motor EM can output torque to the outside as an electric motor; when the motor EM obtains torque from the outside, the motor EM can charge the battery as a generator.

[0037] In this embodiment, if Figure 1 As shown, the transmission TM can realize a torque transmission path with a large transmission ratio in a relatively compact structure. Specifically, the transmission TM includes a planetary gear, a first gear set and a first output shaft S21 assembled together. The planetary gear is coaxially arranged with the rotor shaft S1, and the first output shaft S21 is parallel to the rotor shaft S1 and eccentrically arranged. In one example, the first output shaft S21 can extend out of the housing H.

[0038] The planetary gear row includes a sun gear SG, a plurality of planetary gears PG, a planetary gear carrier PC and a ring gear RG assembled together. The sun gear SG is directly connected to the rotor shaft S1 of the motor EM to be always connected in transmission. The plurality of planetary gears PG are located radially outside the sun gear SG and are evenly distributed along the circumference. Each planetary gear PG is always meshed with the sun gear SG, so that each planetary gear PG can rotate around its own central axis and revolve around the sun gear SG as the sun gear SG rotates. The plurality of planetary gears PG are installed on the planetary gear carrier PC, and the first driving gear G11 of the first gear set is torsionally installed on the planetary gear carrier PC to be always connected in transmission. The revolution of the plurality of planetary gears PG can drive the planetary gear carrier PC to rotate, and the rotation of the planetary gear carrier PC can drive the plurality of planetary gears PG to revolve. The ring gear RG is located radially outside the plurality of planetary gears PG, and a track for the revolution of the plurality of planetary gears PG is formed between the ring gear RG and the sun gear SG, and the ring gear RG is always meshed with the plurality of planetary gears PG. In addition, the ring gear RG can be fixed to the housing H so that the ring gear RG cannot rotate relative to the housing H.

[0039] The first gear set includes a first driving wheel G11 and a first driven wheel G12 which are always in an external meshing state with each other. The first driving wheel G11 is torsionally mounted on the planetary wheel carrier PC of the planetary gear, and the first driven wheel G12 is torsionally mounted on the first output shaft S21. Thus, the planetary wheel carrier PC and the first output shaft S21 are always in transmission connection via the first gear set.

[0040] By adopting the above-mentioned transmission TM, the transmission path of the torque from the motor EM is as follows: motor EM (rotor shaft S1) → sun gear SG → planetary gear PG → planetary gear carrier PC → first driving wheel G11 → first driven wheel G12 → first output shaft S21. As a result, the torque of the motor EM can be output to the outside via the first output shaft S21 of the transmission TM. In this embodiment, a two-stage transmission consisting of a planetary gear and a first gear set is realized. Since the planetary gear with high power density can achieve a larger transmission ratio, the transmission ratio of the first gear set can be reduced under the same total transmission ratio requirement, thereby reducing the diameter of the first driven wheel G12, thereby reducing the radial size of the transmission.

[0041] In this embodiment, if Figure 1 As shown, most of the structures of the motor EM and the transmission TM are accommodated and installed in the internal space of the housing H. The housings H of the two electric bridge drive units EU can be assembled together through connectors. The housing H can be provided with a detachable body and end cover, which is conducive to the installation and maintenance of the motor EM and the transmission TM.

[0042] The following description includes two examples of vehicles using the electric axle drive system described above.

[0043] In one example, the vehicle according to the present application may include an electric bridge drive system having the above structure, wherein the first output shafts S21 of the two electric bridge drive units EU of the electric bridge drive system are respectively connected to the two front wheels of the vehicle. In this way, the motors EM of the two electric bridge drive units EU can independently drive the two front wheels to rotate.

[0044] In another example, the vehicle according to the present application may include an electric bridge drive system having the above structure, wherein the first output shafts S21 of the two electric bridge drive units EU of the electric bridge drive system are respectively connected to the two rear wheels of the vehicle. In this way, the motors EM of the two electric bridge drive units EU can independently drive the two rear wheels to rotate.

[0045] In the above-mentioned vehicles, since an electric bridge drive system according to the first embodiment of the present application is adopted, not only the transmission ratio is improved with a compact structure, thereby reducing the torque requirement for the output of the motor EM, but also the radial size of the entire electric bridge drive system and the space occupied are reduced.

[0046] The electric bridge driving system according to the second embodiment of the present application will be described below in conjunction with the accompanying drawings.

[0047] (Electric bridge drive system according to the second embodiment of the present application)

[0048] The structure of the electric bridge drive system according to the second embodiment of the present application is substantially the same as the structure of the electric bridge drive system according to the first embodiment of the present application, and the differences between the two are mainly described below.

[0049] In this embodiment, if Figure 2 As shown, the electric bridge drive system includes, in addition to the same components as those described in the first embodiment, a second gear set and a second output shaft S22, which are parallel to and offset from the first output shaft S21 and the rotor shaft S1. The second gear set includes a second driving wheel G21 and a second driven wheel G22 that are always in an external meshing state with each other. The second driving wheel G21 is torsionally mounted on the first output shaft S21, and the second driven wheel G22 is torsionally mounted on the second output shaft S22. As a result, the planetary wheel carrier PC is always in transmission connection with the second output shaft S22 via the first gear set, the first output shaft S21, and the second gear set.

[0050] It can be understood that in this embodiment, the first output shaft S21 can also be referred to as an intermediate shaft. In one example, the second output shaft S22 can extend out of the housing H.

[0051] By adopting the above-mentioned transmission TM, the transmission path of the torque from the motor EM is as follows: motor EM (rotor shaft S1) → sun gear SG → planetary gear PG → planetary gear carrier PC → first driving wheel G11 → first driven wheel G12 → first output shaft S21 → second driving wheel G21 → second driven wheel G22 → second output shaft S22. As a result, the torque of the motor EM can be output to the outside via the second output shaft S22 of the transmission TM. In this embodiment, a three-stage transmission consisting of a planetary gear, a first gear set and a second gear set is realized. Under the same radial size conditions, the three-stage transmission realizes a relatively larger transmission ratio, further reducing the torque input requirements for the motor EM, thereby further reducing the size of the motor EM and reducing the corresponding cost.

[0052] In addition, in order not to increase the axial dimension of the entire electric axle drive system compared to the first embodiment, in each electric axle drive unit EU, the planetary gear set and the second gear set are arranged overlapping in the axial direction A, that is, the planetary gear set and the second gear set at least partially overlap with each other when observed along the radial direction R.

[0053] The technical solution of the present application has been described in detail in the above specific embodiments, and supplementary explanations are given below.

[0054] i. In order to increase the transmission ratio of the torque transmission path of the electric axle drive system, planetary gears and external meshing gear sets can be added.

[0055] ii. In the above embodiments, if Figure 1 and Figure 2 As shown, the electric bridge drive unit EU may further include a plurality of bearings mounted on the housing H. These bearings are used not only to support the planetary wheel carrier PC so that the planetary wheel carrier PC can stably rotate relative to the housing H, but also to support the rotor shaft S1, the first output shaft S21, and the second output shaft S22 so that the rotor shaft S1, the first output shaft S21, and the second output shaft S22 can stably rotate relative to the housing H.

[0056] iii. In the above embodiments, in addition to outputting torque for driving to the transmission TM, the motor EM can also receive torque from the transmission TM to charge the battery.

[0057] iv. In the electric bridge drive system described in the above specific embodiment, the rotor shaft S1 of each motor EM is directly used as the input shaft of the transmission TM, but the present application is not limited thereto. An input shaft of the transmission TM independent of the rotor shaft S1 may be provided, and then the rotor shaft S1 and the input shaft of the transmission TM are connected together through, for example, a coupling.

[0058] v. The electric bridge drive system according to the present application can be applied to pure electric vehicles. If necessary, a vehicle can include more than two electric bridge drive systems according to the present application.

Claims

1. A bridge drive system, characterized in that: The invention comprises two electric bridge drive units (EU) arranged side by side in an axial direction (A), each of the electric bridge drive units (EU) comprising an electric motor (EM) and a transmission (TM), The electric machine (EM) comprises a stator (ST) and a rotor (RO), The transmission (TM) includes a planetary gear, a first gear set (G11, G12) and a first output shaft (S21). The planetary gear includes a sun gear (SG), a plurality of planetary gears (PG), a planetary gear carrier (PC) and a ring gear (RG) assembled together. The sun gear (SG) is coaxially arranged with the rotor (RO) and is transmission-connected. The ring gear (RG) is fixed relative to the stator (ST). The first gear set (G11, G12) includes a first driving wheel (G11) and a first driven wheel (G12) that are always meshed. The first driving wheel (G11) is installed on the planetary gear carrier (PC) to be transmission-connected with the planetary gear carrier (PC). The first driven wheel (G12) is installed on the first output shaft (S21) to be transmission-connected with the first output shaft (S21). The first output shaft (S21) is eccentrically arranged with the rotor (RO).

2. The electric bridge drive system according to claim 1, characterized in that: The transmission (TM) of one electric axle drive unit (EU) and the transmission (TM) of another electric axle drive unit (EU) are adjacent to each other in the axial direction (A).

3. The electric bridge drive system according to claim 1, characterized in that: The electric bridge drive unit (EU) further comprises a housing (H), and the ring gear (RG) is fixed to the housing (H).

4. The electric bridge drive system according to claim 3, characterized in that: The electric bridge drive unit (EU) further includes a plurality of bearings mounted on the housing (H), the plurality of bearings supporting the planetary wheel carrier (PC) so that the planetary wheel carrier (PC) can rotate relative to the housing (H).

5. The electric bridge drive system according to any one of claims 1 to 4, characterized in that: The transmission (TM) also includes a second gear set (G21, G22) and a second output shaft (S22), the second gear set (G21, G22) includes a second driving wheel (G21) and a second driven wheel (G22) that are always meshed, the second driving wheel (G21) is installed on the first output shaft (S21) to be always transmission-connected with the first output shaft (S21), the second driven wheel (G22) is installed on the second output shaft (S22) to be always transmission-connected with the second output shaft (S22), and the second output shaft (S22) is eccentrically arranged with the first output shaft (S21) and the rotor (RO).

6. The electric bridge drive system according to claim 5, characterized in that: In the axial direction (A), the planetary gear set and the second gear set (G21, G22) are arranged overlappingly.

7. A vehicle, characterized in that: The electric bridge drive system comprises the electric bridge drive system according to any one of claims 1 to 4.

8. The vehicle according to claim 7, characterized in that It also includes a first wheel and a second wheel, wherein the first wheel and the second wheel are respectively connected to the first output shafts (S21) of the two electric bridge drive units (EU) of the electric bridge drive system. The first wheel and the second wheel are both front wheels or the first wheel and the second wheel are both rear wheels.

9. A vehicle, characterized in that: Includes the electric bridge drive system as described in claim 5 or 6.

10. The vehicle according to claim 9, characterized in that The first wheel and the second wheel are respectively connected to the second output shafts (S22) of the two electric bridge drive units (EU) of the electric bridge drive system. The first wheel and the second wheel are both front wheels or the first wheel and the second wheel are both rear wheels.

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