Bridge drive system

Abstract

The application provides a kind of bridge driving system, comprising: motor (5), motor (5) includes stator (51) and rotor (52), stator (51) includes stator core (511) and winding (512), in the axial direction of motor (5), the part of winding (512) protruding from stator core (511) forms end winding (E);First planetary gear assembly (1), first planetary gear assembly (1) is connected to the output shaft of motor (5), and is located on the one side of the axial direction of motor (5);Second planetary gear assembly (2), second planetary gear assembly (2) is connected to the output shaft of motor (5), and is located on the other side of the axial direction of motor (5), wherein at least a part of first planetary gear assembly (1) and at least a part of second planetary gear assembly (2) are located on the radial inner side of end winding (E).

Description

Technical Field

[0001] This application belongs to the field of vehicle technology, and in particular relates to an electric axle drive system. Background Technology

[0002] CN207510397U discloses an integrated high-speed drive device with an integrated parking system, wherein the power output by the motor is transmitted to the differential through a multi-stage gear.

[0003] If a higher torque is required, the gear ratio needs to be increased, which leads to an increase in gear diameter and center distance of the gear set, thus increasing the radial dimension of the drive unit. Since the first-stage gear set cannot utilize the radially inner space of the end windings of the motor stator, the axial length of the drive unit is relatively large.

[0004] CN112810433A discloses a parallel shaft electric drive axle with a planetary gear set, wherein the power output by the motor is transmitted to the differential through a planetary gear set and a gear set.

[0005] However, because planetary gear sets need to withstand a large torque, their diameter is also large. As a result, planetary gear sets cannot utilize the radial inner space of the end windings of the motor stator, leading to an increase in the axial length of the gearbox and wasting the radial inner space of the end windings.

[0006] Because the differential needs to avoid the larger driven gears or planetary gears of the first-stage gear set, the axial dimension of the electric bridge is relatively long. Utility Model Content

[0007] This application aims to propose an electric bridge drive system with a compact structure.

[0008] This application provides an electric bridge drive system, comprising:

[0009] An electric motor, the electric motor including a stator and a rotor, the stator including a stator core and windings, wherein, in the axial direction of the electric motor, a portion of the windings protruding from the stator core forms an end winding;

[0010] A first planetary gear assembly is connected to the output shaft of the motor and is located on one axial side of the motor;

[0011] The second planetary gear assembly is connected to the output shaft of the motor and is located on the other side of the motor's axial direction.

[0012] At least a portion of the first planetary gear assembly and at least a portion of the second planetary gear assembly are located radially inside the end winding.

[0013] In at least one possible implementation, at least a portion of the first planetary gear assembly and at least a portion of the second planetary gear assembly occupy the same axial space as the end winding.

[0014] In at least one possible implementation, the planetary gears of the first planetary gear assembly and / or the planetary gears of the second planetary gear assembly are stepped gears, the stepped gears comprising a major diameter gear and a minor diameter gear arranged coaxially, the major diameter gear having a diameter greater than the minor diameter gear, and the minor diameter gear being located at least partially radially inside the end winding and occupying the same axial space as the end winding.

[0015] In at least one possible implementation, the minor diameter gear is located entirely radially inside the end winding, and the minor diameter gear is entirely within the axial space occupied by the end winding.

[0016] In at least one possible implementation, the major diameter gear of the first planetary gear assembly meshes with the sun gear of the first planetary gear assembly, and the minor diameter gear of the first planetary gear assembly meshes with the ring gear of the first planetary gear assembly.

[0017] The major diameter gear of the second planetary gear assembly meshes with the sun gear of the second planetary gear assembly, and the minor diameter gear of the second planetary gear assembly meshes with the ring gear of the second planetary gear assembly.

[0018] The small-diameter gear is closer to the end winding than the large-diameter gear, and the gear ring is at least partially located radially inside the end winding and occupies the same axial space as the end winding.

[0019] In at least one possible implementation, the output shaft of the motor is connected to the sun gear of the first planetary gear assembly and the sun gear of the second planetary gear assembly, and the first planetary gear assembly and the second planetary gear assembly have the same transmission ratio.

[0020] In at least one possible implementation, the electric bridge drive system further includes a first cylindrical gear set, a second cylindrical gear set, and a differential, the differential including a differential housing and two half-shafts, the two half-shafts being parallel to the output shaft of the motor.

[0021] The first cylindrical gear set is disposed between the first planetary gear assembly and the differential, and transmits the power output from the first planetary gear assembly to the differential housing through the first cylindrical gear set.

[0022] The second cylindrical gear set is disposed between the second planetary gear assembly and the differential, and transmits the power output from the second planetary gear assembly to the differential housing through the second cylindrical gear set.

[0023] In at least one possible implementation, the first cylindrical gear set and the second cylindrical gear set have the same transmission ratio.

[0024] In at least one possible implementation, the first cylindrical gear set is located on one axial side of the first planetary gear assembly, and the second cylindrical gear set is located on the other axial side of the second planetary gear assembly.

[0025] In at least one possible implementation, the electric bridge drive system further includes a differential located at the midpoint of the motor's axial direction.

[0026] In at least one possible implementation, the electric bridge drive system further includes a differential located on one side of the motor at an axially offset intermediate position, at least a portion of which occupies the same axial space as the first planetary gear assembly or the second planetary gear assembly.

[0027] In at least one possible implementation, the gears of the first planetary gear assembly and the second planetary gear assembly are helical gears, and the helical gears of the first planetary gear assembly and the second planetary gear assembly have opposite directions of rotation.

[0028] By adopting the above technical solution, by placing at least a portion of the first planetary gear assembly and at least a portion of the second planetary gear assembly on the radially inner side of the end winding, the space on the radially inner side of the end winding is fully utilized, making the structure of the electric bridge drive system compact. Attached Figure Description

[0029] Figure 1 A schematic diagram of the structure of an electric bridge drive system according to a first embodiment of this application is shown.

[0030] Figure 2 A schematic diagram of the structure of an electric bridge drive system according to a second embodiment of this application is shown.

[0031] Figure 3 A schematic diagram of the structure of an electric bridge drive system according to a third embodiment of this application is shown.

[0032] Explanation of reference numerals in the attached figures

[0033] 1. First planetary gear assembly; 11. First ring gear; 12. First planetary gear; 13. First planetary carrier; 14. First sun gear.

[0034] 2. Second planetary gear assembly; 21. Second ring gear; 22. Second planetary gear; 23. Second planetary carrier; 24. Second sun gear.

[0035] 3 First cylindrical gear set 31 First gear 32 Second gear

[0036] 4. Second cylindrical gear set 41, Third gear 42, Fourth gear

[0037] 5. Motor 51. Stator 511. Stator core 512. Winding 52. Rotor

[0038] 6 Differential 61 Differential housing 62 Half shaft

[0039] E end winding

[0040] Axial direction R Radial direction Detailed Implementation

[0041] To more clearly illustrate the above-mentioned objectives, features, and advantages of this application, specific embodiments of this application are described in detail in conjunction with the accompanying drawings in this section. Besides the embodiments described in this section, this application can also be implemented in other different ways. Those skilled in the art can make corresponding improvements, modifications, and substitutions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed in this section. The scope of protection of this application should be determined by the claims.

[0042] (First Implementation)

[0043] like Figure 1 As shown, the first embodiment of this application proposes an electric axle drive system that can be used in pure electric vehicles or hybrid vehicles.

[0044] The electric bridge drive system may include a motor 5, a first planetary gear assembly 1, a second planetary gear assembly 2, a first cylindrical gear set 3, a second cylindrical gear set 4, and a differential 6.

[0045] The motor 5 includes a stator 51 and a rotor 52. The stator 51 can be fixedly connected to the housing of the motor 5, and the rotor 52 can be rotatably connected to the housing of the motor 5 relative to the stator 51. The rotor 52 can be disposed radially inside the stator 51. The stator 51 includes a stator core 511 and a winding 512. The winding 512 is connected to the stator core 511. In the axial direction A of the motor 5, the portion of the winding 512 that protrudes from the end face of the stator core 511 can be referred to as the end winding E.

[0046] The differential 6 includes a differential housing 61 and two half-shafts 62. The two half-shafts 62 can be parallel to (but not on the same axis as) the output shaft of the motor 5, so this electric axle drive system can be called an offset (offset shaft) electric axle drive system. The two half-shafts 62 are used to output power to the wheels of the vehicle.

[0047] Optionally, the differential 6 can be located at the middle position on the axial direction A of the motor 5.

[0048] The output shaft of motor 5 can extend from both axial ends of the housing of motor 5, and the first planetary gear assembly 1 is located on one axial side of motor 5. Figure 1 (Left side of the motor 5), the second planetary gear assembly 2 can be located on the other side of the axial direction of the motor 5. Figure 1 (The right side of the middle).

[0049] The first planetary gear assembly 1 includes a first ring gear 11, a plurality of first planetary gears 12, a first planet carrier 13, and a first sun gear 14. The first ring gear 11 can be fixedly connected to the housing of the motor 5 and / or the housing of the electric bridge drive system. The first sun gear 14 can be connected to the output shaft of the motor 5. The plurality of first planetary gears 12 are rotatably connected to the first planet carrier 13 relative to the first planet carrier 13. The first planet carrier 13 is rotatably connected to the housing of the motor 5 and / or the housing of the electric bridge drive system. In the radial direction R of the first planetary gear assembly 1, the first planetary gears 12 are located between the first ring gear 11 and the first sun gear 14, and the first planetary gears 12 mesh with both the first ring gear 11 and the first sun gear 14.

[0050] The second planetary gear assembly 2 includes a second ring gear 21, a plurality of second planetary gears 22, a second planetary carrier 23, and a second sun gear 24. The second ring gear 21 can be fixedly connected to the housing of the motor 5 and / or the housing of the electric bridge drive system. The second sun gear 24 can be connected to the output shaft of the motor 5. The plurality of second planetary gears 22 are rotatably connected to the second planetary carrier 23 relative to the second planetary carrier 23. The second planetary carrier 23 is rotatably connected to the housing of the motor 5 and / or the housing of the electric bridge drive system. In the radial direction R of the second planetary gear assembly 2, the second planetary gears 22 are located between the second ring gear 21 and the second sun gear 24, and the second planetary gears 22 mesh with both the second ring gear 21 and the second sun gear 24.

[0051] The first planetary gear assembly 1 and the second planetary gear assembly 2 have the same transmission ratio.

[0052] At least a portion of the first planetary gear assembly 1 and at least a portion of the second planetary gear assembly 2 are located radially inside the end winding E, and the at least a portion of the first planetary gear assembly 1 and at least a portion of the second planetary gear assembly 2 occupy the same axial space as the end winding E. Viewed radially R, the end winding E can block at least a portion of the first planetary gear assembly 1 and at least a portion of the second planetary gear assembly 2.

[0053] It is understood that the first planetary gear assembly 1 and the second planetary gear assembly 2, located on both sides of the axial direction of the motor 5, simultaneously transmit torque. The torque borne by the first planetary gear assembly 1 and the second planetary gear assembly 2 is (T0×i1) / 2. Here, T0 represents the torque output by the output shaft of the motor 5, and i1 represents the transmission ratio of the first planetary gear assembly 1 or the second planetary gear assembly 2. Since the torque borne by the first planetary gear assembly 1 and the second planetary gear assembly 2 is relatively small, the gear diameters used in the first planetary gear assembly 1 and the second planetary gear assembly 2 can be smaller. This not only reduces the radial dimension of the transmission mechanism but also helps to arrange at least a portion of the first planetary gear assembly 1 and at least a portion of the second planetary gear assembly 2 radially inside the end winding E. By fully utilizing the space on the radially inner side of the end winding E, the structure of the electric bridge drive system becomes compact.

[0054] Furthermore, since the torque borne by the first planetary gear assembly 1 and the second planetary gear assembly 2 is relatively small, the width of the gears used in the first planetary gear assembly 1 and the second planetary gear assembly 2 can be smaller, which also helps to reduce the axial dimension of the electric bridge drive system.

[0055] Optionally, the gears of the first planetary gear assembly 1 and the second planetary gear assembly 2 can be helical gears. Helical gears have a larger overlap ratio than spur gears, transmit larger torque, have smoother transmission, and better NVH performance.

[0056] Furthermore, the helical gears of the first planetary gear assembly 1 and the second planetary gear assembly 2 have opposite directions of rotation. The axial forces generated by the helical gears of the first planetary gear assembly 1 and the second planetary gear assembly 2 can cancel each other out, thereby reducing the load on the bearings of the planetary gear assemblies (e.g., the bearings supporting the first planetary carrier 13 and the second planetary carrier 23), allowing for the selection of smaller bearings and reducing bearing costs.

[0057] The first cylindrical gear set 3 can be disposed between the first planetary gear assembly 1 and the differential 6. The first planetary gear assembly 1 can be connected to the differential housing 61 through the first cylindrical gear set 3, so that the power of the output shaft of the motor 5 can be transmitted to the differential 6 through the two-stage transmission of the first planetary gear assembly 1 and the first cylindrical gear set 3.

[0058] The second cylindrical gear set 4 can be disposed between the second planetary gear assembly 2 and the differential 6. The second planetary gear assembly 2 can be connected to the differential housing 61 through the second cylindrical gear set 4, so that the power of the output shaft of the motor 5 can be transmitted to the differential 6 through the two stages of transmission of the second planetary gear assembly 2 and the second cylindrical gear set 4.

[0059] The first cylindrical gear set 3 may include a first gear 31 and a second gear 32. The first gear 31 may be fixedly connected to the first planetary carrier 13, and the second gear 32 may be fixedly connected to the differential housing 61. The first gear 31 and the second gear 32 mesh. Thus, the power output from the first planetary gear assembly 1 is transmitted to the differential housing 61 through the first cylindrical gear set 3.

[0060] The second cylindrical gear set 4 may include a third gear 41 and a fourth gear 42. The third gear 41 may be fixedly connected to the second planetary carrier 23, and the fourth gear 42 may be fixedly connected to the differential housing 61. The third gear 41 and the fourth gear 42 mesh. Thus, the power output from the second planetary gear assembly 2 is transmitted to the differential housing 61 through the second cylindrical gear set 4.

[0061] The transmission ratio of the first cylindrical gear set 3 and the second cylindrical gear set 4 can be the same.

[0062] The first cylindrical gear set 3 is located on one axial side of the first planetary gear assembly 1. Figure 1 (Left side of the middle), the second cylindrical gear set 4 is located on the other side of the axial direction of the second planetary gear assembly 2 ( Figure 1 (The right side of the middle).

[0063] The power output by motor 5 can be transmitted to differential housing 61 via two sets of two-stage reduction gears on both sides of its axis, and then transmitted to the wheels on both sides of the vehicle via differential 6. In this way, the power transmission through two sets of two-stage reduction gears can reduce the torque borne by each set of two-stage reduction gears, thus reducing the gear size of each set of two-stage reduction gears and making the structure of the electric axle drive system compact.

[0064] It can be understood that the torque borne by the first cylindrical gear set 3 and the second cylindrical gear set 4 is (T0×i1×i2) / 2, where T0 represents the torque output by the output shaft of the motor 5, i1 represents the transmission ratio of the first planetary gear assembly 1 or the second planetary gear assembly 2, and i2 represents the transmission ratio of the first cylindrical gear set 3 or the second cylindrical gear set 4.

[0065] The first cylindrical gear set 3 and the second cylindrical gear set 4 each bear relatively small torques. Therefore, under the same transmission ratio, the gear diameters used in the first cylindrical gear set 3 and the second cylindrical gear set 4 can be smaller, and the center distance of the gear assembly can be smaller. This can reduce the radial dimension of the transmission mechanism and make the structure of the electric bridge drive system more compact.

[0066] (Second Implementation)

[0067] The bridge drive system of the second embodiment of this application has most of the same structure as the bridge drive system of the first embodiment. The same reference numerals are used for the same or similar components in the two embodiments, and the specific structure will not be described again.

[0068] The main difference between the electric bridge drive system of the second embodiment and the electric bridge drive system of the first embodiment lies in the different structures of the first planetary gear assembly 1 and the second planetary gear assembly 2. In the second embodiment, the first planetary gear 12 of the first planetary gear assembly 1 and / or the second planetary gear 22 of the second planetary gear assembly 2 are stepped gears.

[0069] like Figure 2 As shown, the second embodiment of this application proposes an electric bridge drive system, which includes a motor 5, a first planetary gear assembly 1, a second planetary gear assembly 2, a first cylindrical gear set 3, a second cylindrical gear set 4, and a differential 6.

[0070] Specifically, the first planetary gear 12 may include a first major diameter gear 122 and a first minor diameter gear 121 arranged coaxially, with the diameter of the first major diameter gear 122 being larger than the diameter of the first minor diameter gear 121. The first major diameter gear 122 meshes with the first sun gear 14, and the first minor diameter gear 121 meshes with the first ring gear 11.

[0071] The first minor diameter gear 121 is closer to the end winding E than the first major diameter gear 122. At least a portion of the first minor diameter gear 121 and at least a portion of the first gear ring 11 are located radially inside the end winding E. At least a portion of the first minor diameter gear 121 and at least a portion of the first gear ring 11 occupy the same axial space as the end winding E.

[0072] The second planetary gear 22 may include a second major diameter gear 222 and a second minor diameter gear 221 arranged coaxially, wherein the diameter of the second major diameter gear 222 is larger than the diameter of the second minor diameter gear 221. The second major diameter gear 222 meshes with the second sun gear 24, and the second minor diameter gear 221 meshes with the second ring gear 21.

[0073] The second minor diameter gear 221 is closer to the end winding E than the second major diameter gear 222. At least a portion of the second minor diameter gear 221 and at least a portion of the second gear ring 21 are located radially inside the end winding E. At least a portion of the second minor diameter gear 221 and at least a portion of the second gear ring 21 occupy the same axial space as the end winding E.

[0074] For example, the small-diameter gears (first small-diameter gear 121 and second small-diameter gear 221) can be located entirely within the radially inner side of the end winding E, and the small-diameter gears (first small-diameter gear 121 and second small-diameter gear 221) can be located entirely within the axial space occupied by the end winding E. In this way, the small-diameter gears do not need to occupy additional space in the radial direction R or the axial direction A, making full use of the space within the radially inner side of the end winding E.

[0075] Compared to the first embodiment of the electric bridge drive system, the second embodiment of this application sets the first planetary gear 12 as a stepped gear, thereby increasing the transmission ratio of the first planetary gear assembly 1; and sets the second planetary gear 22 as a stepped gear, thereby increasing the transmission ratio of the second planetary gear assembly 2.

[0076] (Third implementation method)

[0077] The bridge drive system of the third embodiment of this application has most of the same structure as the bridge drive system of the second embodiment. The same reference numerals are used for the same or similar components in the two embodiments, and the specific structure will not be described again.

[0078] The main difference between the electric bridge drive system of the third embodiment and the electric bridge drive system of the second embodiment lies in the different installation positions of the differential 6.

[0079] like Figure 3 As shown, the third embodiment of this application proposes an electric bridge drive system, which includes a motor 5, a first planetary gear assembly 1, a second planetary gear assembly 2, a first cylindrical gear set 3, a second cylindrical gear set 4, and a differential 6.

[0080] The differential 6 can be located on one side of the motor 5 at a position offset from the middle along the axial direction A. The lengths of the two half-shafts of the differential 6 can be different. At least a portion of the differential 6 occupies the same axial space as the first planetary gear assembly 1 or the second planetary gear assembly 2. Viewed along at least one radial direction R, the differential 6 and the first planetary gear assembly 1 or the second planetary gear assembly 2 are at least partially overlapped. The differential 6 can be located at the end of the motor 5. At least a portion of the differential 6 and at least a portion of the motor 5 can occupy the same radial space. Viewed along the axial direction A, the differential 6 and the motor 5 are at least partially overlapped. For example, at least a portion of the differential 6 can be located at the end of the stator 51 of the motor 5. Viewed along the axial direction A, the differential 6 and the stator core 511 can be partially overlapped. The differential 6 and the winding 512 may or may not overlap. In this way, the differential 6 can occupy less radial space, further reducing the center distance between the two gears in the first cylindrical gear set 3 and the center distance between the two gears in the second cylindrical gear set 4, making the electric bridge drive system more compact in the radial direction.

[0081] It should be understood that at least some aspects or features of the above-described implementation methods, embodiments, or examples can be appropriately combined.

[0082] It is understood that, in this application, when the number of parts or components is not specifically limited, the number can be one or more, where multiple refers to two or more. For cases where the number of parts or components shown in the drawings and / or described in the specification is, for example, two, three, four, etc., this specific number is generally exemplary and not restrictive, and can be understood as multiple, i.e., two or more; however, this does not mean that this application excludes the case of one.

[0083] In this application, unless otherwise expressly stated or limited, terms such as "installation," "assembly," "connection," "linking," "joining," "linking," "abutment," "communication," "connection," "conduction," "fixing," and "fastening" should be interpreted broadly, for example, they can be direct or indirect. For instance, regarding connection, 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; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly stated or limited. For instance, regarding communication / conduction, it can be direct communication / conduction or indirect communication / conduction through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0084] In this application, unless otherwise expressly stated or limited, a component being disposed / installed / located / enclosed / placed within, inside, or incorporated in another component can be either of the following two situations: a portion or a majority of the one component is located within the other component; or the one component is completely enclosed within the other component.

[0085] Although the present application has been described in detail using the above embodiments, it will be apparent to those skilled in the art that the present application is not limited to the embodiments described herein. The present application can be modified and implemented as alternative embodiments without departing from the spirit and scope of the present application as defined by the claims. Therefore, the description in this specification is for illustrative purposes only and does not have any limiting meaning for the present application.

Claims

1. An electric bridge drive system, characterized in that, include: An electric motor, the electric motor including a stator and a rotor, the stator including a stator core and windings, wherein, in the axial direction of the electric motor, a portion of the windings protruding from the stator core forms an end winding; A first planetary gear assembly is connected to the output shaft of the motor and is located on one axial side of the motor; The second planetary gear assembly is connected to the output shaft of the motor and is located on the other side of the motor's axial direction. At least a portion of the first planetary gear assembly and at least a portion of the second planetary gear assembly are located radially inside the end winding.

2. The bridge drive system according to claim 1, characterized in that, At least a portion of the first planetary gear assembly and at least a portion of the second planetary gear assembly occupy the same axial space as the end winding.

3. The bridge drive system according to claim 1, characterized in that, The planetary gears of the first planetary gear assembly and / or the planetary gears of the second planetary gear assembly are stepped gears. The stepped gears include a major diameter gear and a minor diameter gear arranged coaxially. The diameter of the major diameter gear is larger than the diameter of the minor diameter gear. The minor diameter gear is located at least partially radially inside the end winding and occupies the same axial space as the end winding.

4. The bridge drive system according to claim 3, characterized in that, The minor diameter gear is located entirely within the radial interior of the end winding, and the minor diameter gear is entirely within the axial space occupied by the end winding.

5. The bridge drive system according to claim 3, characterized in that, The major diameter gear of the first planetary gear assembly meshes with the sun gear of the first planetary gear assembly, and the minor diameter gear of the first planetary gear assembly meshes with the ring gear of the first planetary gear assembly. The major diameter gear of the second planetary gear assembly meshes with the sun gear of the second planetary gear assembly, and the minor diameter gear of the second planetary gear assembly meshes with the ring gear of the second planetary gear assembly. The small-diameter gear is closer to the end winding than the large-diameter gear, and the gear ring is at least partially located radially inside the end winding and occupies the same axial space as the end winding.

6. The bridge drive system according to claim 1, characterized in that, The output shaft of the motor is connected to the sun gear of the first planetary gear assembly and the sun gear of the second planetary gear assembly, and the first planetary gear assembly and the second planetary gear assembly have the same transmission ratio.

7. The bridge drive system according to claim 1, characterized in that, The electric bridge drive system also includes a first cylindrical gear set, a second cylindrical gear set, and a differential. The differential includes a differential housing and two half-shafts, which are parallel to the output shaft of the motor. The first cylindrical gear set is disposed between the first planetary gear assembly and the differential, and transmits the power output from the first planetary gear assembly to the differential housing through the first cylindrical gear set. The second cylindrical gear set is disposed between the second planetary gear assembly and the differential, and transmits the power output from the second planetary gear assembly to the differential housing through the second cylindrical gear set.

8. The bridge drive system according to claim 1, characterized in that, The electric bridge drive system also includes a differential, which is located at the midpoint of the motor's axial direction.

9. The bridge drive system according to claim 1, characterized in that, The electric bridge drive system also includes a differential located on one side of the motor at an axially offset midpoint, and at least a portion of the differential occupies the same axial space as the first planetary gear assembly or the second planetary gear assembly.

10. The bridge drive system according to claim 1, characterized in that, The gears of the first planetary gear assembly and the second planetary gear assembly are helical gears, and the helical gears of the first planetary gear assembly and the second planetary gear assembly have opposite directions of rotation.

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