CN119428122A - Electric bridge drive system and vehicle - Google Patents

Abstract

The application provides a bridge driving system and a vehicle. Two bridge drive units arranged coaxially are included in the bridge drive system of the present application. A coaxially arranged motor and transmission are included in each bridge drive unit. Further, the transmission includes two planetary rows, and at least a portion of the transmission overlaps the motor in an axial direction of the bridge drive system. In this way, the overall axial dimension of the bridge drive system can be reduced, the space occupied by the whole bridge drive system can be saved, and the structural layout of the vehicle comprising the bridge drive system is facilitated. In addition, since the power source of the transmission in each bridge drive unit transmits torque to the outside via two planetary rows, a torque transmission path having a large gear ratio can be realized in a relatively compact configuration, thereby reducing the torque demand on the motor and correspondingly saving the cost of the motor.

Description

Bridge driving system and vehicle

Technical Field

The present application relates to the field of vehicles, and more particularly, to a bridge drive system for a vehicle and a vehicle including the same.

Background

Currently, bridge drive systems can be used for electric-only vehicles and hybrid vehicles for driving the vehicle. In a typical bridge drive system, two motors are included as power sources, arranged coaxially, which can improve vehicle dynamics (e.g., acceleration time from launch to 100 km/h). Further, in the above-described bridge drive system, the transmissions are provided for the respective two motors, so that the motors can drive the wheels of the vehicle via the respective transmissions. However, with a sufficiently large gear ratio of the transmission, the bridge drive system is relatively large in axial dimension and occupies a relatively large space, which adversely affects the overall layout of the vehicle comprising the bridge drive system.

Disclosure of Invention

The present application has been made in view of the drawbacks of the above-mentioned techniques. It is an object of the present application to provide a novel bridge drive system that is capable of increasing the gear ratio while reducing the axial dimension of the bridge drive system. It is another object of the present application to provide a vehicle comprising the above-described bridge drive system.

In order to achieve the above object, the present application adopts the following technical scheme.

The present application provides a bridge drive system comprising two bridge drive units coaxially arranged, each bridge drive unit comprising a motor and a transmission coaxially arranged with the motor, at least a part of the transmission overlapping the motor in an axial direction of the bridge drive system,

The motor includes a rotor and a stator, the transmission includes a first planetary row including a first sun gear, a plurality of first planetary gears, a first carrier, and a first ring gear assembled together, the first sun gear being connected with the rotor to achieve a drive coupling, the first ring gear being fixed relative to the stator, and a second planetary row including a second sun gear, a plurality of second planetary gears, a second carrier, and a second ring gear assembled together, the second sun gear being connected with the first carrier to achieve a drive coupling, the second ring gear being fixed relative to the stator, thereby enabling torque from the rotor to be output to the outside via the second carrier.

In an alternative, the transmission is located at one axial end of the motor for one of the two bridge drive units and at the other axial end of the motor for the other of the two bridge drive units.

In another alternative, the stator includes a core and a winding including a protruding portion protruding from the core, the first row of planets is located radially inward of the protruding portion, and at least a portion of the first row of planets overlaps the protruding portion in the axial direction.

In another alternative, the second planetary row is offset from the motor in the axial direction.

In another alternative, the first row of planets is located within the rotor and the first planet carrier extends from the rotor in the axial direction.

In another alternative, the stator includes a core and a winding including a protruding portion protruding from the core, the second planetary row is located radially inward of the protruding portion, and at least a portion of the second planetary row overlaps the protruding portion in the axial direction.

In another alternative, the bridge drive unit includes a housing, and the ring gear is fixed to the housing.

In another alternative, the bridge drive unit includes a plurality of bearings mounted to the housing for supporting the first and second planetary carriers such that the first and second planetary carriers are rotatable relative to the housing.

The application also provides a vehicle comprising the bridge driving system according to any one of the technical schemes.

In an alternative, the vehicle further comprises a first wheel and a second wheel, wherein the first wheel and the second wheel are respectively in transmission connection with two bridge driving units of the bridge driving system,

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

By adopting the technical scheme, the application provides a novel bridge driving system and a vehicle comprising the same. Two bridge drive units arranged coaxially are included in the bridge drive system of the present application. A coaxially arranged motor and transmission are included in each bridge drive unit. Further, at least a portion of the transmission overlaps the motor in an axial direction of the bridge drive system. The transmission includes a first planetary row and a second planetary row. The first planet row comprises a first sun gear, a plurality of first planet gears, a first planet carrier and a first gear ring which are assembled together, the first sun gear is connected with a rotor of the motor to realize transmission connection, and the first gear ring is fixed relative to the stator. The second planet row comprises a second sun gear, a plurality of second planet gears, a second planet carrier and a second gear ring which are assembled together, the second sun gear is connected with the first planet carrier to realize transmission connection, and the second gear ring is fixed relative to the stator. Thereby, torque from the rotor is enabled to be output to the outside via the second carrier.

In this way, on the one hand, since at least a part of the transmission overlaps the motor in the axial direction of the bridge drive system in each bridge drive unit, the axial dimension of the whole bridge drive system can be reduced, the space occupied by the whole bridge drive system can be saved, and the structural layout of the vehicle comprising the bridge drive system can be facilitated. On the other hand, since the power source of the transmission in each bridge drive unit transmits torque to the outside via two planetary rows, a torque transmission path having a large gear ratio can be realized in a relatively compact configuration, thereby reducing the torque demand on the motor, and accordingly saving the cost of the motor.

Drawings

Fig. 1 is a schematic diagram showing the topology of a bridge drive system according to a first embodiment of the present application.

Fig. 2 is a schematic diagram showing the topology of a bridge drive system according to a second embodiment of the present application.

Description of the reference numerals

EU bridge driving unit, H shell;

EM motor, RO rotor, S1 rotor shaft, ST stator, IC iron core, WI winding;

TM speed changer, SG1 first sun gear, PG1 first planetary gear, PC1 first planetary gear carrier, RG1 first gear ring, SG2 second sun gear, PG2 second planetary gear, PC2 second planetary gear carrier, RG2 second gear ring and S2 output shaft;

The A axial direction and the R radial direction.

Detailed Description

Exemplary embodiments of the present application are described below with reference to the accompanying drawings. It should be understood that these specific illustrations are for the purpose of illustrating how one skilled in the art may practice the application, and are not intended to be exhaustive of all of the possible ways of practicing the application, nor to limit the scope of the application.

In the present application, unless otherwise stated, "drive coupled" refers to a connection where two components are capable of transmitting torque, including direct and indirect connections.

In the present application, "axial" and "radial" refer to the axial direction and the radial direction of the bridge drive unit (motor), respectively, unless otherwise specified. "axial one side" refers to the left side in fig. 1 and 2, and "axial other side" refers to the right side in fig. 1 and 2. "radially inward" refers to the side that is closer to the central axis of the bridge drive unit (motor), and "radially outward" refers to the side that is farther from the central axis of the bridge drive unit (motor).

A bridge drive system according to a first embodiment of the present application and a vehicle including the same will be described below with reference to the drawings.

(Bridge drive System and vehicle according to first embodiment of the application)

As shown in fig. 1, the bridge driving system according to the first embodiment of the present application includes two bridge driving units EU integrated together. Each bridge drive unit EU includes a motor EM, a transmission TM, and a housing H, each of which is accommodated and mounted in the corresponding housing H. As shown in fig. 1, two bridge drive units EU are coaxially arranged side by side, and in each bridge drive unit EU, the motor EM is coaxially arranged with the transmission TM. Further, in the structural layout of the entire bridge drive system, one bridge drive unit EU is located entirely on one axial side of the other bridge drive unit EU. In the one bridge drive unit EU, the transmission TM is located at one axial end portion of the motor EM, and in the other bridge drive unit EU, the transmission TM is located at the other axial end portion of the motor EM. In the present embodiment, the structures of the two bridge drive units EU are arranged substantially line-symmetrically with respect to the center line of the bridge drive system at the axial center.

In the present embodiment, as shown in fig. 1, the motor EM includes a stator ST and a rotor RO located inside the stator ST and rotatable with respect to the stator ST. Specifically, the stator ST includes an iron core IC, which may be made of a laminate of silicon steel sheets and formed with a plurality of slots for insertion and installation of the winding WI, and a winding WI, which is inserted into the plurality of slots of the iron core IC and wound and installed on the iron core IC. A portion of the winding WI can protrude from both axial ends of the core IC, thereby forming protruding portions. In the rotor RO, the rotor shaft S1 is fixed with the rotor laminated body so that the rotor shaft S1 can rotate together with the rotor laminated body. The rotor shaft S1 is formed to extend linearly along the axial direction a. In addition, the rotor shaft S1 is directly connected to the first sun gear SG1 of the first planetary row of the transmission TM for a constant drive coupling, so that the rotor shaft S1 and the first sun gear SG1 can transmit torque in both directions. When the motor EM is supplied with electric power from the battery, the motor EM can output torque as a motor to the outside, and when the motor EM obtains torque from the outside, the motor EM can charge the battery as a generator EM.

In this embodiment, as shown in fig. 1, the transmission TM can realize a torque transmission path having a large gear ratio in a relatively compact structure. Specifically, the transmission TM includes a first planetary row, a second planetary row, and an output shaft S2 assembled together.

The first row of planet gears includes a first sun gear SG1, a plurality of first planet gears PG1, a first carrier PC1, and a first ring gear RG1 assembled together. The first sun gear SG1 is directly connected to the rotor shaft S1 of the electric machine EM for a constant drive connection. The plurality of first planetary gears PG1 are located at the radial outer side of the first sun gear SG1 and are uniformly distributed along the circumferential direction, each first planetary gear PG1 is always in tooth engagement with the first sun gear SG1, so that each first planetary gear PG1 can rotate around the respective central axis and revolve around the first sun gear SG1 along with the rotation of the first sun gear SG1, the plurality of first planetary gears PG1 are mounted on the first planetary gear carrier PC1, and the first planetary gear carrier PC1 and the second sun gear SG2 of the second planetary gear are directly connected together to be always in transmission connection. The plurality of first planetary gears PG1 revolve to drive the first carrier PC1 to rotate, and the rotation of the first carrier PC1 drives the plurality of first planetary gears PG1 to revolve. The first ring gear RG1 is located radially outside the plurality of first planetary gears PG1, a track through which the plurality of first planetary gears PG1 revolve is formed between the first ring gear RG1 and the first sun gear SG1, and the first ring gear RG1 is always in tooth engagement with the plurality of first planetary gears PG 1. In addition, the first ring gear RG1 may be fixed with the housing H such that the first ring gear RG1 cannot rotate with respect to the housing H.

The second planetary row includes a second sun gear SG2, a plurality of second planet gears PG2, a second planet carrier PC2, and a second ring gear RG2 assembled together. As described above, the second sun gear SG2 is always in driving engagement with the first carrier PC 1. The plurality of second planetary gears PG2 are located radially outside the second sun gear SG2 and are uniformly distributed along the circumferential direction, and each of the second planetary gears PG2 is always tooth-engaged with the second sun gear SG2, so that each of the second planetary gears PG2 can perform rotation about the respective central axis and revolution about the second sun gear SG2 as the second sun gear SG2 rotates. The plurality of second planetary gears PG2 are mounted on the second planet gear carrier PC2. The plurality of second planetary gears PG2 revolve to drive the second planet carrier PC2 to rotate, and the rotation of the second planet carrier PC2 can drive the plurality of second planetary gears PG2 to revolve. The second planet carrier PC2 is directly connected to the output shaft S2 for a constant drive coupling. The second ring gear RG2 is located radially outside the plurality of second planetary gears PG2, a track for revolution of the plurality of second planetary gears PG2 is formed between the second ring gear RG2 and the second sun gear SG2, and the second ring gear RG2 is always tooth-engaged with the plurality of second planetary gears PG 2. In addition, the second ring gear RG2 may be fixed with the housing H such that the second ring gear RG2 cannot rotate with respect to the housing H.

By using the above-described transmission TM, the transmission path of the torque from the motor EM is such that the motor EM (rotor shaft S1) →the first sun gear SG1→the first planetary gear pg1→the first carrier PC1→the second sun gear SG2→the second planetary gear pg2→the second carrier PC2→the output shaft S2. Thereby, the torque of the motor EM can be output to the outside via the transmission TM.

In order to reduce the axial size of the bridge drive system, in the present embodiment, as shown in fig. 1, the first row of planets is located radially inward of the protruding portion of the winding WI of the stator ST, and a part of the structure of the first row of planets overlaps with the protruding portion in the axial direction a. That is, the protruding portion of the winding WI and a portion of the first row of satellites are shielded from each other as viewed in a radial direction R perpendicular to the axial direction a. Further, the second planetary row is completely offset from the motor EM in the axial direction a. In this way, the second planetary row can have a larger radial dimension, which is beneficial to constructing a transmission TM capable of realizing a larger transmission ratio and transmitting larger torque.

In the present embodiment, as shown in fig. 1, most of the structures of both the motor EM and the transmission TM are accommodated and mounted in the internal space of the housing H. The housings H of the two bridge drive units EU can be assembled with each other by means of connectors. The housing H may be provided with a removable body and end caps, which facilitate installation and maintenance of the motor EM and the transmission TM.

It will be appreciated that the output shaft S2 may not be part of the bridge drive system of the present application and may be detachably connected to the second planet carrier PC2.

Two examples of a vehicle including the above-described bridge drive system are described below.

In one example, the vehicle according to the present application may include one bridge drive system having the above-described structure, and the output shafts S2 of the two bridge drive units EU of the bridge drive system are respectively drivingly coupled to the two front wheels of the vehicle. In this way, the motors EM of the two bridge drive units EU can drive the two front wheels to rotate independently, respectively.

In another example, the vehicle according to the present application may include one bridge drive system having the above-described structure, and the output shafts S2 of the two bridge drive units EU of the bridge drive system are respectively drivingly coupled to the two rear wheels of the vehicle. Thus, the motors EM of the two bridge drive units EU can drive the two rear wheels independently, respectively.

In the above-described vehicles, since one bridge drive system according to the first embodiment of the present application is employed, not only is the gear ratio increased in a compact structure, thereby reducing the torque demand on the output of the motor EM, but also the axial size and occupied space of the entire bridge drive system are reduced.

A bridge drive system according to a second embodiment of the present application will be described below with reference to the drawings.

(Bridge drive System according to second embodiment of the application)

The structure of the bridge driving system according to the second embodiment of the present application is substantially the same as that of the bridge driving system according to the first embodiment of the present application, and differences between the two are mainly described below.

In the present embodiment, as shown in fig. 2, the rotor shaft S1 is formed in a hollow configuration. The first planetary row having a smaller radial dimension can be constructed without the first planetary row being required to transmit excessive torque. In addition to the first planet carrier PC1, the first planet row is entirely located in the rotor shaft S1, and a part of the first planet carrier PC1 is located in the rotor shaft S1 and another part protrudes from the rotor shaft S1. The second planetary row is located radially inward of the protruding portion of the winding WI of the stator ST, and a portion of the second planetary row overlaps the protruding portion. In this way, the axial size of the entire bridge drive system and the space taken up can be further reduced as compared with the first embodiment.

It will be appreciated that the electric machine EM may comprise a rotor shaft and a rotor support connecting the rotor shaft and the rotor stack, in which case the rotor shaft need not be a hollow shaft, and the first row of planets may be located radially inward of the rotor RO or the outer periphery (axially extending portion) of the rotor support as a whole.

The technical scheme of the application is explained in detail in the above specific embodiments, and supplementary explanation is made below.

I. in order to reduce the axial dimensions and the space taken up by the entire bridge drive system, the specific solutions described in the above embodiments do not have to be adopted, but only at least a part of the transmission TM overlaps the motor EM in the axial direction a of the bridge drive system.

In the above embodiment, as shown in fig. 1 and 2, the bridge drive unit EU may further include a plurality of bearings mounted to the housing H. These bearings are used not only to support the first carrier PC1 and the second carrier PC2 so that the first carrier PC1 and the second carrier PC2 can rotate stably with respect to the housing H, but also to support the rotor shaft S1 so that the rotor shaft S1 can rotate stably with respect to the housing H.

In the above embodiment, the motor EM is able to receive torque from the transmission TM for charging the battery, in addition to outputting torque for driving to the transmission TM.

In the bridge drive system described in the above specific embodiment, the rotor shaft S1 of each motor EM directly serves as the input shaft of the transmission TM, but the present application is not limited thereto. An input shaft of the transmission TM may be provided separately from the rotor shaft S1, and then the rotor shaft S1 and the input shaft of the transmission TM are rigidly connected together by, for example, a coupling.

The bridge drive system according to the application can be applied to electric-only vehicles as well as hybrid vehicles. If desired, the vehicle may include more than two bridge drive systems according to the present application.

Claims (10)

1. An electric bridge drive system, characterized in that it comprises two coaxially arranged electric bridge drive units (EU), each electric bridge drive unit (EU) comprises an electric motor (EM) and a transmission (TM), the transmission (TM) is coaxially arranged with the electric motor (EM), at least a part of the transmission (TM) overlaps with the electric motor (EM) in the axial direction (A) of the electric bridge drive system, The motor (EM) includes a rotor (RO) and a stator (ST), and the transmission (TM) includes a first planetary row and a second planetary row, the first planetary row includes a first sun gear (SG1) assembled together, a plurality of first planetary gears (PG1), a first planetary gear carrier (PC1) and a first ring gear (RG1), the first sun gear (SG1) is connected to the rotor (RO) to achieve transmission connection, the first ring gear (RG1) is fixed relative to the stator (ST), the second planetary row includes a second sun gear (SG2) assembled together, a plurality of second planetary gears (PG2), a second planetary gear carrier (PC2) and a second ring gear (RG2), the second sun gear (SG2) is connected to the first planetary gear carrier (PC1) to achieve transmission connection, and the second ring gear (RG2) is fixed relative to the stator (ST), so that the torque from the rotor (RO) can be output to the outside via the second planetary gear carrier (PC2). 2. The electric bridge drive system according to claim 1, characterized in that: For one of the two electric bridge drive units (EU), the transmission (TM) is located at one axial end of the electric motor (EM); and For the other one of the two electric axle drive units (EU), the transmission (TM) is located at the other axial end of the electric machine (EM). 3. The electric bridge drive system according to claim 1 or 2, characterized in that the stator (ST) includes an iron core (IC) and a winding (WI), the winding (WI) includes an extended portion extending from the iron core (IC), the first planetary row is located radially inside the extended portion, and at least a portion of the first planetary row overlaps with the extended portion in the axial direction (A). 4 . The electric bridge drive system according to claim 3 , wherein the second planetary gear is offset from the electric motor (EM) in the axial direction (A). 5. The electric bridge drive system according to claim 1 or 2, characterized in that: The first planet row is located in the rotor (RO) and the first planet wheel carrier (PC1) extends from the rotor (RO) along the axial direction (A). 6. The electric bridge drive system according to claim 5 is characterized in that the stator (ST) includes an iron core (IC) and a winding (WI), the winding (WI) includes an extended portion extending from the iron core (IC), the second planetary row is located radially inside the extended portion, and at least a portion of the second planetary row overlaps with the extended portion in the axial direction (A). 7. The electric bridge drive system according to claim 1 or 2, characterized in that the electric bridge drive unit (EU) comprises a housing (H), and the ring gear is fixed to the housing (H). 8. The electric bridge drive system according to claim 7 is characterized in that the electric bridge drive unit (EU) includes a plurality of bearings installed on the housing (H), and the plurality of bearings are used to support the first planetary wheel carrier (PC1) and the second planetary wheel carrier (PC2), so that the first planetary wheel carrier (PC1) and the second planetary wheel carrier (PC2) can rotate relative to the housing (H). 9. A vehicle, characterized by comprising the electric bridge drive system according to any one of claims 1 to 8. 10. The vehicle according to claim 9, further comprising a first wheel and a second wheel, wherein the first wheel and the second wheel are respectively connected to two electric bridge drive units (EU) of the electric bridge drive system in a transmission manner. The first wheel and the second wheel are both front wheels or the first wheel and the second wheel are both rear wheels.