Miniaturized and expandable electric drive assembly and vehicle

Abstract

The miniaturized and expandable electric drive assembly comprises a motor shaft and an input shaft which are coaxially and fixedly arranged on a shell through bearings, a single-row planetary gear is arranged between the motor shaft and the input shaft, a planet carrier of the single-row planetary gear is in transmission connection with the input shaft, and the single-row planetary gear is in transmission connection with the input shaft. A gear ring of the single-row planet gear is fixedly arranged on the shell, a sun gear of the single-row planet gear is fixedly connected with the motor shaft, a planet gear connected to the planet carrier is arranged between the sun gear and the gear ring, the input shaft is connected with a differential mechanism assembly through a parallel cylindrical gear, and the differential mechanism assembly is connected with the single-row planet gear. And the differential mechanism assembly is connected with a whole vehicle half shaft. The invention has the advantages of small volume, low cost, wide speed ratio adjusting range and high expandability.

Description

Technical Field

[0001] The present invention relates to the technical field of electric drive assemblies, and specifically discloses a miniaturized and expandable electric drive assembly and a vehicle. Background Art

[0002] In the context of fierce competition in the new energy industry, electric drive systems are facing unprecedented technical challenges. With the rapid development of the electric vehicle market, the performance requirements of electric drive products are constantly increasing, especially in key parameters such as weight, output torque and reliability. In order to meet these stringent performance indicators, electric drive assemblies are showing a trend of miniaturization and integration.

[0003] At present, there are two typical technical paths for the design of electric drive assemblies: 1. Traditional three-axis single-speed parallel shaft reducer structure. This structure adopts the configuration of input shaft, intermediate shaft and differential. However, this design has significant engineering defects: first, the space occupied in the X and Z directions of the whole vehicle is large, which seriously squeezes the effective space of the driving cabin; second, due to the large overall size of the electric drive, the weight of the whole machine increases, the manufacturing cost remains high, and then affects the cruising range of the whole vehicle. More importantly, the output torque capacity of this structure is strongly related to the input-output center distance. The slight difference in the center distance will cause the electric drive assembly tooling to be incompatible, which seriously restricts the scalability of the electric drive system and makes the initial manufacturing investment continue to be high. 2. Coaxial planetary gear reducer structure Compared with the traditional three-axis structure, the coaxial planetary gear reducer has a significant improvement in the space occupied by the whole vehicle, which can effectively reduce the space requirements in the X and Z directions. But this technical solution also has key problems: due to the complex manufacturing process of the planetary gear and the high cost, it is usually only used in high-end models. What's more troublesome is that the structure consists of a sun gear, planetary gears and a ring gear, involving many parts, making speed ratio adjustment extremely difficult, which greatly limits the versatility of the system.

[0004] Faced with the above technical bottlenecks, the electric drive assembly urgently needs an innovative design solution that can simultaneously solve the problems of space occupancy, weight, cost and scalability. Summary of the invention

[0005] The purpose of the present invention is to provide a miniaturized and scalable electric drive assembly and vehicle, which adopts a two-stage reduction scheme, with the high-speed stage being a single-row planetary gear reduction and the low-speed stage being a parallel cylindrical gear reduction, and has the advantages of small size, low cost, wide speed ratio adjustment range, and high scalability.

[0006] To achieve the above-mentioned purpose, the present invention discloses a miniaturized and expandable electric drive assembly, including a motor shaft and an input shaft coaxially fixed to a housing through bearings, a single-row planetary gear is arranged between the motor shaft and the input shaft, the planet carrier of the single-row planetary gear is drivingly connected to the input shaft, the ring gear of the single-row planetary gear is fixedly arranged on the housing, the sun gear of the single-row planetary gear is fixedly connected to the motor shaft, a planetary gear connected to the planet carrier is arranged between the sun gear and the ring gear, the input shaft is connected to a differential assembly through parallel cylindrical gears, and the differential assembly is connected to the half shafts of the whole vehicle.

[0007] In a preferred embodiment of the present invention, the planet carrier is provided with a planet shaft which is fitted with an interference fit therewith, and the planet shaft is connected to the planet gear through radial support of a needle bearing.

[0008] In a preferred embodiment of the present invention, a bearing is provided on the planet carrier.

[0009] In a preferred embodiment of the present invention, the number of the planetary gears is 3 or 4.

[0010] In a preferred embodiment of the present invention, the sun gear and the motor shaft are an integrated structure.

[0011] In a preferred embodiment of the present invention, the parallel cylindrical gear includes external teeth processed on the outer circumferential surface of the input shaft and a reduction gear capable of meshing with the external teeth for transmission.

[0012] In a preferred embodiment of the present invention, the center of the input shaft is provided with a first oil passage extending axially therethrough, the second oil passage is connected to the first oil passage, and the planetary carrier is provided with a third oil passage for guiding the first oil passage to the needle bearing.

[0013] In a preferred embodiment of the present invention, an oil guide ring is provided at the oil inlet end of the first oil passage, and a circular ring with a hole for controlling the amount of oil flowing from the first oil passage into the second oil passage is provided at the oil inlet end of the second oil passage.

[0014] In a preferred embodiment of the present invention, the speed ratio of the single-row planetary gear is between 3 and 4, the speed ratio of the parallel cylindrical gear is between 3 and 5, and the total speed ratio is between 9 and 20.

[0015] The present invention also discloses a vehicle, which includes a miniaturized and expandable electric drive assembly.

[0016] The beneficial effects of the present invention are: the present invention has achieved a creative breakthrough in miniaturization. Through innovative design, the present invention achieves a significant reduction of the input-output distance by more than 50 mm compared with the traditional solution, which means that the power density can be greatly improved. The compact layout not only significantly reduces the overall volume of the electric drive assembly, but also provides greater spatial flexibility for vehicle design.

[0017] Secondly, the present invention demonstrates outstanding technical advantages in speed ratio adjustment. Through the carefully designed secondary parallel shaft structure, the overall speed ratio range can be flexibly adjusted to cover a wide range of 9 to 20. This flexibility provides more accurate power matching for different working conditions and vehicle models.

[0018] Furthermore, the present invention breaks through the scalability bottleneck of traditional electric drive assemblies. In the process of adjusting the speed ratio, the center distance remains unchanged, which means that there is almost no additional modification cost for the existing production line. More importantly, when a speed ratio range of 4 to 7 is required, the planetary reduction stage can be directly removed. The whole process will not have any substantial impact on the existing production line, reflecting the high modularity and versatility of the design.

[0019] Finally, in terms of cost control, the present invention has significant advantages. Since the speed ratio adjustment only involves the second-stage gear, the planetary gear can be shared among multiple models with different speed ratios, thereby achieving effective cost sharing. This design concept not only reduces the manufacturing cost of a single vehicle, but also provides an economic basis for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a miniaturized and scalable electric drive assembly;

[0021] Figure 2 A transmission diagram of a miniaturized and scalable electric drive assembly;

[0022] Figure 3 A schematic diagram of an input shaft of a miniaturized and scalable electric drive assembly;

[0023] Figure 4 A schematic diagram of an oil passage of a miniaturized and scalable electric drive assembly;

[0024] Figure 5 An intentional rendering of a miniaturized and scalable electric drive assembly. DETAILED DESCRIPTION

[0025] The technical solution of the present invention (including the preferred technical solution) is further described in detail below by means of the accompanying drawings and by listing some optional embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] like Figure 1-4 As shown, the miniaturized and scalable electric drive assembly proposed in the present invention is an innovative solution designed to address key technical challenges such as space occupancy, weight control and cost optimization faced by electric drive systems of new energy vehicles.

[0027] The core innovation of the electric drive assembly of the present invention lies in its unique multi-stage reduction structure design. Through the sophisticated planetary gear system and parallel cylindrical gear configuration, it achieves miniaturization and high scalability that are difficult to achieve with traditional electric drive assemblies. In terms of overall structure, the electric drive assembly adopts a layout in which the motor shaft 4 is coaxially fixed with the input shaft 1, and a single-row planetary gear system is embedded therebetween, forming a compact and efficient power transmission path.

[0028] The planetary gear system consists of a sun gear, a ring gear 3, a planetary gear 6 and a planetary carrier 2, wherein the sun gear and the motor shaft 4 are of an integrated structure, which realizes direct power transmission. The planetary carrier 2 is connected with the input shaft 1 by an internal spline, which ensures the accuracy and stability of the transmission. In order to improve the load-bearing capacity and operating stability of the system, 3-4 planetary gears 6 are used in the design, and the planetary shaft 7 is radially supported by a needle bearing, which significantly improves the reliability of the system.

[0029] In terms of bearing layout, the present invention adopts a multi-point precise positioning strategy. The motor shaft 4, the input shaft 1 and the planetary carrier 2 are respectively equipped with special bearing systems, and axial fixation is achieved through retaining rings and pressure plates. This design not only ensures the precise positioning of each component, but also provides good structural stability for the entire electric drive assembly. Specifically, two bearings are arranged on the motor shaft 4: a first bearing 16 and a second bearing 17, a third bearing 15 is installed on the planetary carrier 2, and a fourth bearing 14 is arranged on the input shaft 1, forming a multi-point supported bearing system. Among them, the first bearing 16 is axially fixed to the housing through the bearing pressure plate 5 and the first retaining ring 13, the third bearing 15 of the planetary carrier 2 is axially fixed through the second retaining ring 12, and the fourth bearing 14 of the input shaft 1 is axially fixed to the housing through the third retaining ring 11 and the pressure plate 10.

[0030] The lubrication system is the key to ensure the long-term stable operation of the electric drive assembly. The present invention designs a set of efficient oil circulation paths, which are transported from the oil pan through the oil pump, enter the inner hole of the input shaft 1 (the first oil channel) through the housing oil channel, and then connect through the second oil channel, and drain to the needle bearing through the third oil channel on the planetary carrier 2, and finally reach the bearing on the motor shaft 4. In order to accurately control the oil flow rate, a circular ring with a hole is pressed into the inner hole of the motor shaft 4, and cooperates with an oil guide ring to ensure the accuracy and reliability of the lubrication system. The oil guide ring is set at the oil inlet end of the first oil channel, and the circular ring with a hole is set at the oil inlet end of the second oil channel, which is used to control the amount of oil flowing from the first oil channel into the second oil channel.

[0031] Speed ​​ratio adjustment is another outstanding feature of the present invention. Through the well-designed single-row planetary gears and parallel cylindrical gears, the system can achieve flexible speed ratio adjustment between 9-20. The speed ratio of the single-row planetary gears is controlled between 3-4, and the speed ratio of the parallel cylindrical gears is controlled between 3-5, ensuring the stability of the overall performance. More importantly, the center distance remains unchanged during the speed ratio adjustment, which means that there is almost no modification cost for the existing production line. If a speed ratio range of 4-7 is required, the planetary reduction stage can even be directly removed, reflecting the high modularity of the design.

[0032] In terms of processing technology, the invention particularly emphasizes the precise assembly sequence: first, the gear processing of the input shaft 1 is completed, then the splines of the planetary carrier 2 are press-fitted, and finally the through holes on the planetary carrier 2 that match the planetary shaft 7 are finely processed using the inner hole of the input shaft 1 as the positioning reference. This strict processing sequence ensures the processing accuracy and assembly quality of the system.

[0033] From the perspective of the power transmission path, the present invention forms an efficient power transmission chain: motor shaft 4->sun gear->planetary gear 6->planetary shaft 7->planet carrier 2->input shaft 1->reduction gear 8->differential assembly 9->vehicle half shaft. Each link is carefully designed to minimize energy loss. Among them, the reduction gear 8 is connected to the differential assembly 9 by bolts, and the ring gear 3 is fixed to the housing by splines.

[0034] like Figure 5 As shown in the figure, compared with the traditional three-axis single-speed electric drive assembly, the present invention achieves a reduction of more than 50mm in the input-output distance (A0-A1>50), which means that the power density is greatly improved. More importantly, since the speed ratio can be changed by adjusting only the second-stage gear, the planetary gear can be shared among multiple models with different speed ratios, thereby effectively amortizing the cost and reducing the overall manufacturing cost.

[0035] The miniaturized and expandable electric drive assembly provided by the present invention not only has significant technological innovations, but also demonstrates great economic and engineering value in practical applications, providing a forward-looking solution for the development of electric drive systems for new energy vehicles.

[0036] The present invention further discloses a vehicle including the above electric drive assembly, which provides important technical support for the development of new energy vehicle technology.

[0037] Those skilled in the art will readily appreciate that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, replacements, improvements, etc. made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A miniaturized and expandable electric drive assembly, characterized in that: The invention comprises a motor shaft (4) and an input shaft (1) which are coaxially fixedly arranged on a housing through a bearing, a single-row planetary gear is arranged between the motor shaft (4) and the input shaft (1), a planet carrier (2) of the single-row planetary gear is drivingly connected to the input shaft (1), a ring gear (3) of the single-row planetary gear is fixedly arranged on the housing, a sun gear of the single-row planetary gear is fixedly connected to the motor shaft (4), a planetary gear (6) connected to the planet carrier (2) is arranged between the sun gear and the ring gear (3), the input shaft (1) is connected to a differential assembly (9) through parallel cylindrical gears, and the differential assembly (9) is connected to the half shaft of the whole vehicle.

2. The miniaturized and scalable electric drive assembly according to claim 1, characterized in that: The planetary carrier (2) is provided with a planetary shaft (7) which is fitted with the planetary carrier in an interference fit, and the planetary shaft (7) is connected to the planetary gear (6) through radial support of a needle bearing.

3. The miniaturized and expandable electric drive assembly according to claim 1, characterized in that: The planet carrier (2) is provided with a bearing (15).

4. The miniaturized and scalable electric drive assembly according to claim 1, characterized in that: The number of the planetary gears (6) is 3 or 4.

5. The miniaturized and expandable electric drive assembly according to claim 1, characterized in that: The sun gear and the motor shaft (4) are an integrated structure.

6. The miniaturized and scalable electric drive assembly according to claim 1, characterized in that: The parallel cylindrical gear comprises external teeth machined on the outer peripheral surface of the input shaft (1) and a reduction gear (8) capable of meshing with the external teeth for transmission.

7. The miniaturized and expandable electric drive assembly according to claim 2, characterized in that: The center of the input shaft (1) is provided with a first oil passage penetrating along its axial direction, the second oil passage is connected to the first oil passage, and the planet carrier (2) is provided with a third oil passage for guiding the first oil passage to the needle roller bearing.

8. The miniaturized and expandable electric drive assembly according to claim 7, characterized in that: An oil guide ring is arranged at the oil inlet end of the first oil passage, and a circular ring with a hole for controlling the amount of oil flowing from the first oil passage into the second oil passage is arranged at the oil inlet end of the second oil passage.

9. The miniaturized and scalable electric drive assembly according to claim 1, characterized in that: The speed ratio of the single-row planetary gear is between 3 and 4, the speed ratio of the parallel cylindrical gear is between 3 and 5, and the total speed ratio is between 9 and 20.

10. A vehicle, characterized in that: Comprising a miniaturized and expandable electric drive assembly as described in any one of claims 1-9.

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