Wheel edge driving mechanism

Abstract

The utility model relates to the technical field of vehicle power transmission, in particular to a wheel edge driving mechanism which comprises an input shaft, an output shaft and a transmission shaft arranged between the input shaft and the output shaft. The input shaft is in transmission connection with the transmission shaft, the input shaft and the transmission shaft are in two-gear transmission connection with different transmission ratios, the transmission shaft and the output shaft are in transmission connection through a planet row, and the output shaft is connected to a driving wheel. Therefore, the power of the motor is transmitted to the driving wheel through the input shaft, the transmission shaft and the output shaft in sequence. The input shaft and the transmission shaft are arranged to be in two-gear transmission connection, the transmission ratio can be switched, and therefore high-rotating-speed low torque or low-rotating-speed high torque can be output according to needs so as to adapt to various using working conditions of electric automobiles, and the requirement for large torque of medium and heavy trucks can be met through a motor with small power.

Description

Technical Field

[0001] This utility model relates to the field of vehicle power transmission technology, specifically to a wheel-side drive mechanism. Background Technology

[0002] Existing wheel-side drive mechanisms for electric vehicles typically employ planetary gear sets for gear shifting. However, relying solely on planetary gear sets results in a limited range of gear ratios, making them unsuitable for the diverse operating conditions of electric vehicles, especially for electric motor-driven medium and heavy-duty trucks. Medium and heavy-duty trucks, due to their large load capacity and complex operating conditions, require high torque for heavy-load uphill driving and high speeds for high-speed driving on straight roads. Particularly during unloaded high-speed driving, the torque requirement is lower, but the high speed requirement is still necessary. This high torque demand from medium and heavy-duty trucks also necessitates higher motor power. High-power motors are larger, heavier, and more expensive, while low-power motors struggle to meet the high torque requirements. Therefore, current transmission mechanisms with a single gear ratio cannot simultaneously meet the diverse operating conditions and reduce the cost of wheel-side drive mechanisms. Summary of the Invention

[0003] The purpose of this utility model is to provide a wheel-side drive mechanism that achieves high torque output and high speed output through multi-speed transmission to adapt to various working conditions.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows: a wheel-side drive mechanism, comprising an input shaft, an output shaft, and a transmission shaft disposed between the input shaft and the output shaft. The input shaft is connected to the output end of a drive motor, and the input shaft is drivenly connected to the transmission shaft with two different transmission ratios. The transmission shaft and the output shaft are connected by a planetary gear set. The output shaft is connected to a drive wheel, so that the power of the motor is transmitted to the drive wheel sequentially through the input shaft, the transmission shaft, and the output shaft.

[0005] In one embodiment, the input shaft is provided with a first gear and a second gear, and the transmission shaft is provided with a third gear and a fourth gear. The first gear meshes with the third gear to form a first gear transmission structure with a first transmission ratio, and the second gear meshes with the fourth gear to form a second gear transmission structure with a second transmission ratio. Thus, the input shaft and the transmission shaft form the two-gear transmission connection. A gear switching structure is also provided so that the input shaft and the transmission shaft form a transmission connection with either the first gear transmission structure or the second gear transmission structure.

[0006] In one embodiment, the gear shifting structure is a clutch or synchronizer disposed on the input shaft.

[0007] In one embodiment, the first gear and the second gear are rotatably connected to the input shaft, and the first gear and the second gear rotate synchronously with the input shaft by means of the clutch or the synchronizer, and the third gear and the fourth gear are fixedly connected to the drive shaft.

[0008] In one embodiment, the first gear transmission structure is a reduction transmission with a transmission ratio greater than 1, and the second gear transmission structure is a speed-increasing transmission with a transmission ratio less than 1.

[0009] In one embodiment, the planetary gear set is an NW composite planetary gear set, including a sun gear disposed on the drive shaft. The sun gear and a first planet gear form an external meshing gear pair. The first planet gear is coaxially connected to a second planet gear, and the first planet gear and the second planet gear are synchronously connected. The second planet gear and an internal gear ring form an internal meshing gear pair. The internal gear ring is fixedly disposed. The planet carrier of the second planet gear is coaxially rotatably connected to the output shaft.

[0010] In one embodiment, the wheel-side drive mechanism is for medium- and heavy-duty electric trucks, and the output shaft is connected to the drive wheel of the medium- and heavy-duty electric truck.

[0011] The beneficial effects of this utility model are as follows: by setting the input shaft and drive shaft to a two-speed transmission connection, the transmission ratio can be switched, thereby outputting high speed and low torque or low speed and high torque as needed to adapt to various operating conditions of electric vehicles. It can also meet the high torque requirements of medium and heavy-duty trucks with a smaller power motor. In addition, setting the transmission ratio of the two-speed transmission between the input shaft and drive shaft to a reduction transmission greater than 1 and a speed-increasing transmission less than 1 respectively can more reliably increase the torque of the drive wheel or increase the speed of the drive wheel. Combined with the NW composite planetary gear set, the transmission ratio adjustment range of the wheel-side drive mechanism is increased. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of an embodiment of the present utility model.

[0013] The components are: 1. Input shaft, 2. Output shaft, 3. Drive shaft, 4. Planetary gear set, 41. Sun gear, 42. First planetary gear, 43. Second planetary gear, 43. Planetary carrier, 44. Internal gear ring, 51. First gear, 52. Second gear, 53. Third gear, 54. Fourth gear, and 6. Synchronizer. Detailed Implementation

[0014] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0015] See Figure 1 As shown, this utility model discloses a wheel-side drive mechanism for medium and heavy-duty electric trucks. The wheel-side drive mechanism includes an input shaft 1, an output shaft 2, and a transmission shaft 3 disposed between the input shaft 1 and the output shaft 2. The input shaft 1 is connected to the output end of a drive motor EM. The input shaft 1 is driven by the transmission shaft 3, and the two are connected by two gears with different transmission ratios. The transmission shaft 3 and the output shaft 2 are connected by a planetary gear set 4 (the area inside the dotted box in the figure is the planetary gear set 4). The output shaft 2 is connected to the drive wheel of the medium and heavy-duty electric truck. Thus, the power of the motor is transmitted sequentially through the input shaft 1, the transmission shaft 3, and the output shaft 2 to the drive wheel, providing power to the drive wheel.

[0016] To achieve a two-speed transmission connection between input shaft 1 and transmission shaft 3, this embodiment employs two sets of gear transmission structures with different transmission ratios and a synchronizer 6. Specifically, input shaft 1 is equipped with a first gear 51 and a second gear 52, while transmission shaft 3 is equipped with a third gear 53 and a fourth gear 54. The first gear 51 and the third gear 53 mesh to form a first-speed transmission structure with a first transmission ratio, and the second gear 52 and the fourth gear 54 mesh to form a second-speed transmission structure with a second transmission ratio, thus forming a two-speed transmission connection between input shaft 1 and transmission shaft 3. The synchronizer 6 is configured as a gear switching structure, serving to switch the transmission gear between input shaft 1 and transmission shaft 3, allowing input shaft 1 and transmission shaft 3 to form a transmission connection using either the first-speed or second-speed transmission structure, i.e., transmission at either the first or second transmission ratio. In this embodiment, the first-speed transmission structure is a deceleration transmission with a transmission ratio greater than 1, and the second-speed transmission structure is a speed-increasing transmission with a transmission ratio less than 1.

[0017] The first gear 51 and the second gear 52 are rotatably connected to the input shaft 1. The first gear 51 and the second gear 52 rotate synchronously with the input shaft 1 by means of a synchronizer 6. The third gear 53 and the fourth gear 54 are fixedly connected to the drive shaft 3. Since the drive shaft 3 is closer to the drive wheels than the input shaft 1, when the vehicle travels over uneven roads, the drive wheels experience greater undulations. These undulations are transmitted sequentially to the output shaft 2, the planetary gear set 4, the drive shaft 3, the gear transmission structure between the input shaft 1 and the drive shaft 3, and finally to the input shaft 1. Because the drive shaft 3 is closer to the drive wheels than the input shaft 1, the input shaft 1 experiences less vibration. By placing the first gear 51, the second gear 52, and the synchronizer 6 on the input shaft 1, the vibration of the first gear 51, the second gear 52, and the synchronizer 6 can be reduced, preventing the synchronizer 6 from affecting the transmission due to vibration during gear shifting or transmission, thus improving the reliability of the transmission. Of course, in other embodiments, it is also feasible to fix the first gear 51 and the second gear 52 to the input shaft 1, and to rotatably connect the third gear 53 and the fourth gear 54 to the transmission shaft 3. In this case, the synchronizer 6 should be set on the transmission shaft 3.

[0018] In other embodiments, a clutch can be used instead of a synchronizer, thereby forming a gear shifting structure to switch gears.

[0019] Planetary gear set 4 is an NW composite planetary gear set, including a sun gear 41 disposed on the drive shaft 3. The sun gear 41 and the first planet gear 42 form an external meshing gear pair. The first planet gear 42 is coaxially connected to a second planet gear 43, and the first planet gear 42 and the second planet gear 43 are connected and rotate synchronously. The second planet gear 43 and the internal gear ring 44 form an internal meshing gear pair. The internal gear ring 44 is fixedly disposed. The planet carrier 430 of the second planet gear 43 is coaxially rotatably connected to the output shaft 2. In this embodiment, the planet carrier 430 of the second planet gear 43 and the output shaft 2 are integrally connected, that is, the rotating shaft part of the planet carrier 430 forms the output shaft 2. In other embodiments, the planet carrier 430 and the output shaft 2 can also be separately connected.

[0020] In this embodiment, the planetary gear set 4 adopts an NW composite planetary gear set. Compared with a single-row planetary gear set, the NW composite planetary gear set can increase the transmission ratio range through the synchronously rotating first and second planetary gears. More specifically, the pitch circle diameters and number of teeth of the first planetary gear 42 and the second planetary gear 43 are different, thereby increasing the reduction ratio of the planetary gear set 4. Of course, in other embodiments, it is also feasible to use a single-row planetary gear set 4.

[0021] Besides gear transmission, other transmission methods that can change the transmission ratio can be used between input shaft 1 and transmission shaft 3 to form a two-speed transmission connection, such as belt transmission structure.

[0022] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that the remaining undescribed parts are prior art, and that all changes in form and detail made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims fall within the protection scope of the present invention.

Claims

1. A wheel-side drive mechanism, characterized in that: It includes an input shaft, an output shaft, and a transmission shaft disposed between the input shaft and the output shaft. The input shaft is connected to the output end of a drive motor. The input shaft is driven by the transmission shaft, and the two are connected by two gears with different transmission ratios. The transmission shaft and the output shaft are connected by a planetary gear set. The output shaft is connected to a drive wheel, so that the power of the motor is transmitted to the drive wheel in sequence through the input shaft, the transmission shaft, and the output shaft.

2. The wheel-side drive mechanism according to claim 1, characterized in that: The input shaft is provided with a first gear and a second gear, and the transmission shaft is provided with a third gear and a fourth gear. The first gear meshes with the third gear to form a first gear transmission structure with a first transmission ratio, and the second gear meshes with the fourth gear to form a second gear transmission structure with a second transmission ratio. Thus, the input shaft and the transmission shaft form the two-gear transmission connection. A gear switching structure is also provided so that the input shaft and the transmission shaft form a transmission connection with either the first gear transmission structure or the second gear transmission structure.

3. The wheel-side drive mechanism according to claim 2, characterized in that: The gear shifting structure is a clutch or synchronizer located on the input shaft.

4. The wheel-side drive mechanism according to claim 3, characterized in that: The first gear and the second gear are rotatably connected to the input shaft, and the first gear and the second gear rotate synchronously with the input shaft by means of the clutch or the synchronizer. The third gear and the fourth gear are fixedly connected to the transmission shaft.

5. The wheel-side drive mechanism according to claim 2, characterized in that: The first gear transmission structure is a reduction transmission with a transmission ratio greater than 1, and the second gear transmission structure is a speed-increasing transmission with a transmission ratio less than 1.

6. The wheel-side drive mechanism according to claim 1, characterized in that: The planetary gear set is an NW composite planetary gear set, including a sun gear disposed on the drive shaft. The sun gear and the first planet gear form an external meshing gear pair. The first planet gear is coaxially connected to a second planet gear, and the first planet gear and the second planet gear are synchronously connected. The second planet gear and the internal gear ring form an internal meshing gear pair. The internal gear ring is fixedly disposed. The planet carrier of the second planet gear is coaxially rotatably connected to the output shaft.

7. The wheel-side drive mechanism according to claim 1, characterized in that: This wheel-side drive mechanism is used in medium and heavy-duty electric trucks, and the output shaft is connected to the drive wheel of the medium and heavy-duty electric truck.

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