An electric ATV drive shaft assembly

Abstract

This utility model relates to the field of drive shaft assembly technology and discloses an electric ATV drive shaft assembly, including a drive shaft installed in the vehicle chassis. One end of the drive shaft is provided with an input universal joint for connecting to the gearbox, and the other end of the drive shaft is provided with an output universal joint for connecting to the reducer. The drive shaft includes a long shaft tube, which is connected to a short shaft tube via a connecting shaft. The long shaft tube and the short shaft tube form a two-section clearance structure between the long shaft tube and the vehicle chassis via the connecting shaft, thereby reducing the rotation diameter of the drive shaft. A splined shaft with a protective structure is provided between the short shaft tube and the input universal joint, dividing the drive shaft into two parts: a long shaft tube and a short shaft tube. By setting a two-section clearance structure on the drive shaft, the drive shaft can maximize the avoidance of chassis structures such as the battery pack within a limited space.

Description

Technical Field

[0001] This utility model relates to the field of drive shaft assembly technology, specifically to an electric ATV drive shaft assembly. Background Technology

[0002] In electric all-terrain vehicles, when a single motor achieves four-wheel drive via a transfer case, the driveshaft needs to transmit high torque within a limited space. Traditional connecting shafts, lacking proper clearance design, are prone to dynamic interference with the frame, battery pack, or suspension components. Especially under off-road conditions, torsional deformation of the vehicle body may cause the driveshaft to collide with surrounding structures, affecting reliability.

[0003] Due to the compact chassis of electric all-terrain vehicles and the fact that the transmission system generally adopts a high-speed design, when the drive shaft bends and deforms between the yield torque and the breaking torque, it is very easy to interfere with surrounding components, which in turn increases the risk of battery pack impact and seriously affects the overall structure of the chassis.

[0004] In traditional drive shaft design, bending deformation of the shaft tube is usually considered the main failure mode, resulting in increased oscillation amplitude, specifically as follows: Figure 4 As shown, this could cause a significant impact on the chassis, posing a risk of damaging core components such as the battery pack. In particular, the area near the electronic components, i.e. the end away from the wheel hub, is prone to secondary damage during a collision, potentially leading to problems such as fire.

[0005] Therefore, since it does not meet the existing requirements, we propose an electric ATV drive shaft assembly. Utility Model Content

[0006] This utility model provides an electric ATV drive shaft assembly with a clean fracture surface and precise and controllable fracture location, which effectively avoids the risk of secondary damage caused by random fracture and solves the problems mentioned in the background art.

[0007] This utility model provides the following technical solution: an electric ATV drive shaft assembly, including a drive shaft disposed in the vehicle chassis, one end of the drive shaft being provided with an input universal joint for connecting to a gearbox, and the other end of the drive shaft being provided with an output universal joint for connecting to a reducer. The drive shaft includes a long shaft tube, and the long shaft tube is connected to a short shaft tube via a connecting shaft. The long shaft tube and the short shaft tube form a two-section clearance structure between the long shaft tube and the vehicle chassis via the connecting shaft, so as to reduce the rotation diameter of the drive shaft through the two-section clearance structure. A spline shaft with a protective structure is disposed between the short shaft tube and the input universal joint.

[0008] Specifically, the input universal joint, the short shaft tube, the connecting shaft, the long shaft tube, and the output universal joint are coaxially connected in sequence along the power transmission direction.

[0009] Specifically, the protective structure on the splined shaft is used to passively separate the transmission main shaft from the input universal joint when the output torque of the transmission system is greater than the load-bearing torque of the transmission main shaft.

[0010] More specifically, the splined shaft includes a shaft body with splines, and the short shaft tube is connected to the input universal joint through the splines on the shaft body. An overload protection structure is preset on the side of the shaft body near the short shaft tube. The breaking torque of the overload protection structure is less than the maximum torque of the transmission main shaft. When the output torque of the transmission system is greater than the breaking torque of the overload protection structure, the short shaft tube is separated from the input universal joint through the shaft body.

[0011] More specifically, the diameter of the overload protection structure is smaller than that of the shaft, and the breaking torque of the overload protection structure is less than the withstand torque of other surrounding components of the vehicle chassis.

[0012] Specifically, the connecting shaft is located between the short shaft tube and the long shaft tube, and the outer diameter of the connecting shaft changes in a stepped manner from its center to both sides of the axial direction, forming a stepped clearance structure.

[0013] More specifically, at least a portion of the outer diameter of the connecting shaft is smaller than the outer diameters of the short shaft tube and the long shaft tube.

[0014] Specifically, the input universal joint is a three-pin housing universal joint, which has the characteristics of strong load-bearing capacity and compact structure. It allows adjacent drive shafts to form a large angle, which can improve the turning maneuverability of the vehicle.

[0015] Specifically, the output universal joint is a fixed ball cage type universal joint. The fixed ball cage type universal joint can overcome the non-uniform speed problem of ordinary cross shaft type universal joints, and is particularly suitable for use in steering drive axles.

[0016] This utility model has the following beneficial effects:

[0017] 1. In this utility model, the transmission main shaft is divided into two parts, a long shaft tube and a short shaft tube, by means of a connecting shaft without affecting the length of the original transmission main shaft. This allows for the installation of a two-section clearance structure on the transmission main shaft, thereby maximizing the clearance of the transmission main shaft from chassis structures such as battery packs within a limited space.

[0018] 2. In this utility model, the connecting shaft, which is set to change in a stepped manner from its center to both sides of the axial direction, forms a stepped clearance structure with the long shaft tube and the short shaft tube, thereby reducing the bending deformation of the transmission main shaft between the yield torque and the breaking torque.

[0019] 3. In this utility model, by setting a splined shaft with a protective structure, the transmission main shaft can break at the preset protective structure when it breaks due to overload, so as to transform the unpredictable and dangerous random failure mode of traditional transmission shafts into a predictable and controllable safety event.

[0020] 4. In this utility model, by setting an overload protection structure on the shaft, when the transmission main shaft breaks due to overload, it can break along the overload protection structure of the shaft, thereby making the spline shaft have the characteristics of precise control and neat fracture surface, which can effectively avoid the risk of secondary damage caused by random fracture. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of an electric ATV drive shaft assembly according to the present invention.

[0022] Figure 2 This is an exploded view of an electric ATV drive shaft assembly according to this utility model;

[0023] Figure 3 This is a partial half-sectional structural diagram of an electric ATV drive shaft assembly according to the present invention.

[0024] Figure 4 This is a schematic diagram of the rotation diameter of a traditional drive shaft.

[0025] In the diagram: 1. Drive shaft; 10. Long shaft tube; 11. Connecting shaft; 12. Short shaft tube; 2. Input universal joint; 3. Output universal joint; 4. Splined shaft; 40. Shaft body; 41. Overload protection structure. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] like Figures 1-4As shown, an electric ATV driveshaft assembly includes a drive shaft 1 mounted in the vehicle chassis. One end of the drive shaft 1 is provided with an input universal joint 2 for connecting to a gearbox, and the other end of the drive shaft 1 is provided with an output universal joint 3 for connecting to a reducer. The drive shaft 1 is installed in the power transmission system of the electric all-terrain vehicle. Specifically, one end of the drive shaft 1 is connected to the gearbox in the engine unit through the input universal joint 2, and the other end of the drive shaft 1 is connected to the reducer in the tire through the output universal joint 3. The drive shaft 1 rotates with high torque within the limited space of the vehicle chassis.

[0028] In this implementation, the input universal joint 2 adopts a three-pin housing type universal joint. The three-pin housing type universal joint has the characteristics of strong load-bearing capacity and compact structure. It allows adjacent drive shafts to form a large angle, which can improve the turning maneuverability of the car.

[0029] In this implementation, the output universal joint 3 adopts a fixed ball cage type universal joint. The fixed ball cage type universal joint can overcome the non-uniform speed problem of ordinary cross shaft type universal joints, and is particularly suitable for use in steering drive axles.

[0030] It should be noted that the input universal joint 2 and output universal joint 3 can be replaced with different joint types and functions as needed.

[0031] like Figures 1-3 As shown, the transmission main shaft 1 includes a long shaft tube 10, which is connected to a short shaft tube 12 via a connecting shaft 11. The input universal joint 2, the short shaft tube 12, the connecting shaft 11, the long shaft tube 10, and the output universal joint 3 are coaxially connected in sequence along the power transmission direction. The long shaft tube 10 and the short shaft tube 12 are connected along the same straight line via the connecting shaft 11 to form the transmission main shaft 1. The two ends of the transmission main shaft 1, that is, the two opposite ends between the long shaft tube 10 and the short shaft tube 12, are respectively connected to the input universal joint 2 and the output universal joint 3. The input end of the input universal joint 2 is connected to the output shaft of the gearbox, and the output end of the output universal joint 3 is also connected to the input shaft of the rear axle reducer via a spline.

[0032] like Figures 1-2 As shown, in some embodiments, the long shaft tube 10 and the short shaft tube 12 form a two-section clearance structure between the connecting shaft 11 and the vehicle chassis. The specific details of the two-section clearance structure are as follows:

[0033] The connecting shaft 11 is located between the short shaft tube 12 and the long shaft tube 10. The outer diameter of the connecting shaft 11 changes in a stepped manner from its center to both sides of the axial direction, forming a stepped clearance structure. The stepped clearance structure can be set in the area with a small gap on the transmission main shaft 1. Its outer diameter changes in a gradient along the axial direction, ensuring that the chassis structure such as the battery pack is maximized to avoid the chassis structure in a limited space.

[0034] At least a portion of the outer diameter of the connecting shaft 11 is smaller than the outer diameter of the short shaft tube 12 and the long shaft tube 10. By changing the diameter of the connecting shaft 11, the short shaft tube 12 and the long shaft tube 10 are divided into two parts when they undergo bending deformation between the yield torque and the breaking torque, so as to reduce the rotational diameter of the entire transmission main shaft 1.

[0035] The rotation diameter of the transmission main shaft 1 is reduced by the two-stage clearance structure. The two-stage clearance structure can reduce the deformation of the transmission main shaft 1 during bending deformation between the yield torque and the breaking torque, so as to avoid interference with the surrounding components in the chassis and thus avoid the problem of impact on the battery pack.

[0036] It should be noted that the deformation of the transmission spindle 1 can also be reduced by setting connecting shafts 11 of different materials and diameters at the junction between the short shaft tube 12 and the long shaft tube 10 on the transmission spindle 1, thereby reducing the rotation diameter.

[0037] like Figures 1-3 As shown, in some embodiments, a splined shaft 4 with a protective structure is provided between the short shaft tube 12 and the input universal joint 2. The splined shaft 4 and the protective structure are as follows:

[0038] The protective structure on the spline shaft 4 is used to passively separate the transmission main shaft 1 from the input universal joint 2 when the output torque of the transmission system is greater than the load-bearing torque of the transmission main shaft 1. When the transmission system reaches the critical load, the spline shaft 4 can achieve controllable fracture, effectively avoiding secondary damage to the chassis structure.

[0039] The splined shaft 4 includes a shaft body 40 with splines. A short shaft tube 12 is connected to an input universal joint 2 via the splines on the shaft body 40. An overload protection structure 41 is pre-set on the side of the shaft body 40 near the short shaft tube 12. The breaking torque of the overload protection structure 41 is less than the maximum torque of the transmission main shaft 1. When the output torque of the transmission system is greater than the breaking torque of the overload protection structure 41, the short shaft tube 12 separates from the input universal joint 2 via the shaft body 40. By setting an overload protection structure 41 on the shaft body 40 with a breaking torque less than the maximum torque of the transmission main shaft 1, the transmission main shaft 1 can achieve controlled fracture at a predetermined position, that is, at the overload protection structure 41 on the shaft body 40, under overload conditions. This splined shaft 4 has the characteristics of precise control and neat fracture surface, which can effectively avoid the risk of secondary damage caused by random fracture.

[0040] The diameter of the overload protection structure 41 is smaller than that of the shaft 40, the breaking torque of the shaft 40 is less than the peak torque of the motor, and the breaking torque of the overload protection structure 41 is less than the withstand torque of other surrounding components of the vehicle chassis.

[0041] Taking a shaft 40 made of 20CrMnTi and a motor with a peak torque of 1600-1900 N·m as an example, according to the material mechanics shear strength formula: τ=T / (πd 3 / 16), where T is the torque, d is the diameter, and τ is the shear stress; considering the shear strength of shaft 40, the minimum diameter of shaft 40 should be 15.45 mm, and the failure torque is 900~1100 N·m.

[0042] Moreover, in this embodiment, the breaking torque of the shaft 40 is less than the peak torque of the motor, which is 1600-1900 N·m, thus effectively protecting the motor and the gearbox. It is also set to be lower than the measured withstand torque of the battery pack mounting bracket of the vehicle chassis. This means that when an overload occurs, the drive shaft will break at this preset position without transmitting excessive impact force to other components of the vehicle chassis, thereby achieving active protection of the core components.

[0043] In summary, in this utility model, the stepped clearance structure composed of the short shaft tube 12 and the long shaft tube 10 with a two-section structure serves as a physical safety barrier. Moreover, in the event of a breakage of the protective structure on the spline shaft 4, it also provides greater swing margin for the two broken parts. Together with the spline shaft 4 with the protective structure, it forms a "double insurance" to ensure the safety of the vehicle chassis.

Claims

1. An electric ATV driveshaft assembly, comprising a drive shaft (1) disposed in a vehicle chassis, wherein one end of the drive shaft (1) is provided with an input universal joint (2) for connecting a gearbox, and the other end of the drive shaft (1) is provided with an output universal joint (3) for connecting a reducer, characterized in that: The transmission main shaft (1) includes a long shaft tube (10), and the long shaft tube (10) is connected to a short shaft tube (12) through a connecting shaft (11). The long shaft tube (10) and the short shaft tube (12) form a two-section clearance structure between the long shaft tube (10) and the vehicle chassis through the connecting shaft (11), so as to reduce the rotation diameter of the transmission main shaft (1) through the two-section clearance structure. A splined shaft (4) with a protective structure is provided between the short shaft tube (12) and the input universal joint (2).

2. The electric ATV drive shaft assembly according to claim 1, characterized in that: The protective structure on the spline shaft (4) is used to passively separate the transmission main shaft (1) from the input universal joint (2) when the output torque of the transmission system is greater than the bearing torque of the transmission main shaft (1).

3. The electric ATV drive shaft assembly according to claim 1, characterized in that: The connecting shaft (11) is located between the short shaft tube (12) and the long shaft tube (10). The outer diameter of the connecting shaft (11) changes in a stepped manner from its center to both sides of the axial direction, forming a stepped clearance structure.

4. The electric ATV drive shaft assembly according to claim 1, characterized in that: The input universal joint (2), the short shaft tube (12), the connecting shaft (11), the long shaft tube (10), and the output universal joint (3) are coaxially connected in sequence along the power transmission direction.

5. The electric ATV drive shaft assembly according to claim 2, characterized in that: The splined shaft (4) specifically includes a shaft body (40) with splines. The short shaft tube (12) is connected to the input universal joint (2) through the splines on the shaft body (40). An overload protection structure (41) is preset on the side of the shaft body (40) near the short shaft tube (12). The breaking torque of the overload protection structure (41) is less than the maximum torque of the transmission main shaft (1). When the output torque of the transmission system is greater than the breaking torque of the overload protection structure (41), the short shaft tube (12) is separated from the input universal joint (2) through the shaft body (40).

6. The electric ATV drive shaft assembly according to claim 5, characterized in that: The diameter of the overload protection structure (41) is smaller than that of the shaft (40).

7. The electric ATV drive shaft assembly according to claim 3, characterized in that: At least a portion of the outer diameter of the connecting shaft (11) is smaller than the outer diameter of the short shaft tube (12) and the long shaft tube (10).

8. The electric ATV drive shaft assembly according to claim 1, characterized in that: The input universal joint (2) is a three-pin type universal joint.

9. The electric ATV drive shaft assembly according to claim 1, characterized in that: The output universal joint (3) is a fixed ball cage type universal joint.

10. An electric ATV drive shaft assembly according to claim 6, characterized in that: The destructive torque of the overload protection structure (41) is less than the withstand torque of other surrounding components of the vehicle chassis.

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