Double-gear type electric power steering gear assembly

Abstract

The utility model provides a double-gear type electric power steering gear assembly. Comprising a steering gear shell provided with a tubular sleeve and a pressing cylinder, a steering shaft rotatably arranged in the tubular sleeve in a penetrating mode, a steering wheel shaft with a steering gear penetrating through the tubular sleeve and meshed with a first rack on the steering shaft, and a power-assisted wheel shaft with a power-assisted gear penetrating through the tubular sleeve and meshed with a second rack on the steering shaft. The compressing structure is arranged in the compressing cylinder and used for compressing the outer wall of the steering shaft on the back side of the racks, and the planes where the first rack and the second rack are located form an acute angle, so that the stress uniformity of the steering shaft during compressing can be improved, the stability is improved, and noise is reduced; the pressing structure comprises a pressing block axially and movably arranged in a pressing cylinder, an O-shaped ring contained in an annular groove in the outer wall of the pressing block, an adjusting bolt in threaded connection with the inner wall of the pressing cylinder, and a spiral spring tightly extruded between the adjusting bolt and the pressing block, so that the pressing force can be adjusted by screwing and rotating the adjusting bolt; and parts of the pressing structure can be reduced, the structure is simplified, and the assembling risk is reduced.

Description

Technical Field

[0001] This utility model relates to the field of automotive steering technology, specifically to a dual-gear electric power steering assembly. Background Technology

[0002] A steering gear is a car component that transmits the driver's steering wheel input to the tires to change or maintain the vehicle's direction. Traditional steering gears are mostly purely mechanical, requiring considerable effort to turn the steering wheel. To address this issue, steering gears have emerged that use a power assist motor to provide assistance, reducing the force required to turn the steering wheel. Common power assist motors are mostly located on the steering column or the steering gear housing. For example, Chinese patent CN210707598U discloses a steering gear with the power assist motor mounted on the steering column. However, in this design, the power assist motor is too close to the steering wheel, making it easier to transmit vibrations to the steering wheel, affecting usability. In terms of comfort, for example, Chinese patent CN115214761A discloses a steering gear in which the power assist motor is mounted on the steering gear housing. In this design, the power assist motor is closer to the output end, resulting in higher transmission efficiency, less impact of motor torque fluctuations on steering wheel feel, and better quietness. However, in this design, the meshing rack of the steering column end and the power assist motor is located on the same side of the steering shaft. When the steering shaft is pressed, it is easy to make it biased towards one side of the inner wall of the steering gear housing, resulting in unilateral force, relatively poor stability, and higher overall noise. At the same time, the rack pressing structure of this steering gear has many components and a complex structure, which poses a risk of misassembly or omission during assembly. Utility Model Content

[0003] The purpose of this invention is to overcome one or more shortcomings in the prior art and provide a dual-gear electric power steering assembly.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is a dual-gear electric power steering assembly, comprising:

[0005] A steering gear housing having a tubular sleeve and a clamping cylinder, the clamping cylinder being connected alongside the tubular sleeve;

[0006] A steering shaft that is rotatably inserted inside a tubular sleeve has a first rack and a second rack spaced apart on its outer wall;

[0007] The steering wheel axle is connected to the bottom of the steering column, and the steering gear on it passes through the tubular sleeve and meshes with the first rack;

[0008] The power steering wheel shaft is connected to the output end of the power steering motor, and the power steering gear on it passes through the tubular sleeve and meshes with the second rack.

[0009] A clamping structure is provided inside the clamping cylinder, which is used to clamp the outer wall of the steering shaft on the back side of the first rack and the back side of the second rack;

[0010] The first plane on the steering shaft where the first rack is mounted and the second plane on which the second rack is mounted form an angle, which is an acute angle. The clamping structure includes a pressure block, an O-ring, an adjusting bolt, and a coil spring. The pressure block is a cylindrical component that is axially movable inside the clamping cylinder. The end of the pressure block facing the steering shaft has an end groove that fits against the outer wall of the steering shaft. The outer wall of the pressure block has an annular groove that accommodates the O-ring. The O-ring is squeezed between the inner wall of the annular groove and the inner wall of the clamping cylinder to form a buffer gap. The adjusting bolt is threaded to the inner wall of the clamping cylinder and is located on the side of the pressure block away from the steering shaft. The coil spring is squeezed between the adjusting bolt and the pressure block. Tightening the adjusting bolt can adjust the clamping force applied by the coil spring to the pressure block, thereby changing the clamping effect on the steering shaft.

[0011] Preferably, the angle between the first plane and the second plane is 35 to 45 degrees.

[0012] More preferably, the angle between the first plane and the second plane is 41.5 degrees.

[0013] Preferably, the end of the adjusting bolt protrudes from the edge of the clamping cylinder to form a connecting end, and the clamping structure further includes a locking nut threadedly connected to the connecting end. The locking nut abuts against the edge of the clamping cylinder to prevent the adjusting bolt from loosening.

[0014] Preferably, there are two annular grooves spaced apart along the axial direction of the pressure block, and each annular groove contains an O-ring.

[0015] Preferably, the adjusting bolt is fitted to the end face of the pressure block on the opposite side, the end face of the adjusting bolt facing the pressure block is provided with a first blind hole to accommodate one end of the helical spring, and the end face of the pressure block facing the adjusting bolt is provided with a second blind hole to accommodate the other end of the helical spring.

[0016] More preferably, the bottom wall of the second blind hole is provided with a through hole that communicates with the end groove.

[0017] Preferably, the first rack and the second rack are inclined relative to the cross-section of the steering shaft, and the first rack and the second rack are inclined in opposite directions but at the same angle.

[0018] Preferably, the booster wheel shaft is connected to the output end of the booster motor via a worm gear reducer, and the booster motor is a symmetrical six-phase motor.

[0019] Preferably, a sensor for detecting the rotation angle and torque of the steering wheel shaft is sleeved on the steering wheel shaft, and the sensor is electrically connected to the dual redundant controller at the tail of the power assist motor.

[0020] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:

[0021] 1. By making the first plane on which the first rack is set on the steering shaft and the second plane on which the second rack is set at an angle, and the angle being an acute angle, the steering shaft can be pressed on opposite sides, improving the uniformity of the force on the steering shaft, avoiding the phenomenon of unilateral force caused by the steering shaft being biased towards the inner wall of the steering gear housing, improving the stability of use, and reducing the overall noise.

[0022] 2. By making the clamping structure include a clamping block, an O-ring, an adjusting bolt, and a coil spring, the clamping block is a cylindrical component that can be axially moved and set inside the clamping cylinder. An end groove that fits against the outer wall of the steering shaft is provided at the end of the clamping block facing the steering shaft. An annular groove for accommodating the O-ring is provided on the outer wall of the clamping block. The O-ring is squeezed between the inner wall of the annular groove and the inner wall of the clamping cylinder to form a buffer gap. The adjusting bolt is threaded to the inner wall of the clamping cylinder and is located on the side of the clamping block away from the steering shaft. The coil spring is squeezed between the adjusting bolt and the clamping block. This allows the clamping force applied to the clamping block by the coil spring to be adjusted by turning the adjusting bolt, thereby changing the clamping effect on the steering shaft. It also reduces the number of components in the clamping structure and simplifies the structure, thereby significantly reducing the risk of misassembly and omission during assembly. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention.

[0024] Figure 2 yes Figure 1 Enlarged cross-sectional view along the AA direction.

[0025] Figure 3 , Figure 4 yes Figure 1 A 3D schematic diagram with components such as the steering gear housing and telescopic protective cover removed.

[0026] Figure 5 yes Figure 3 A 3D schematic diagram with the worm gear housing and dual redundant controller hidden.

[0027] Figure 6 yes Figure 3 A radial schematic diagram of the central steering shaft, with the viewpoint directed towards the first rack.

[0028] Figure 7 yes Figure 3 A radial schematic diagram of the central steering shaft, with the viewpoint directed towards the second rack.

[0029] Figure 8 yes Figure 3 Enlarged axial diagram of the steering shaft.

[0030] The components are as follows: 10. Steering gear housing; 11. Tubular sleeve; 12. Clamping cylinder; 13. Clamp; 14. Telescopic protective cover; 20. Steering shaft; 21. First rack; 211. First plane; 22. Second rack; 221. Second plane; 23. Steering ball joint tie rod; 30. Steering wheel axle; 31. Steering gear; 32. Sensor; 40. Power steering wheel axle; 41. Power steering gear; 50. Clamping structure; 51. Clamping block; 511. End groove; 512. Annular groove; 513. Second blind hole; 514. Through hole; 52. O-ring; 53. Adjusting bolt; 531. Connecting end; 532. First blind hole; 54. Helical spring; 55. Locking nut; 61. Worm gear reduction mechanism; 62. Power steering motor; 63. Worm gear housing; 64. Dual redundant controller. Detailed Implementation

[0031] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art.

[0032] like Figures 1 to 8As shown, the dual-gear electric power steering assembly provided by this utility model includes: a steering gear housing 10, a steering shaft 20, a steering wheel axle 30, a power steering wheel axle 40, and a clamping structure 50. The steering gear housing 10 has a tubular sleeve 11 and a clamping cylinder 12, with two clamping cylinders 12 connected sideways to the tubular sleeve 11 and spaced apart. The steering shaft 20 is rotatably inserted into the tubular sleeve 11, with a first rack 21 and a second rack 22 spaced apart on its outer wall. Both ends of the shaft are connected to steering ball joint rods 23. The two ends of the tubular sleeve 11 are clamped by clamps 13 to provide telescopic protective covers 14 that enclose the steering ball joint rods 23. The steering wheel axle 30 is connected to the steering gear housing 10, a steering shaft 20, a steering wheel axle 30, a power steering wheel axle 40, and a clamping structure 50. At the bottom of the column, a steering gear 31 is provided on the steering wheel shaft 30. The steering gear 31 passes through the side wall of the tubular sleeve 11 and meshes with the first rack 21. The assist wheel shaft 40 is connected to the output end of the assist motor. An assist gear 41 is provided on the assist wheel shaft 40. The assist gear 41 passes through the side wall of the tubular sleeve 11 and meshes with the second rack 22. There are two clamping structures 50, which are respectively provided in two clamping cylinders 12. These two clamping structures 50 are used to clamp the outer wall of the steering shaft 20 on the opposite side of the first rack 21 and the opposite side of the second rack 22, respectively. The first plane 211 on the steering shaft 20 where the first rack 21 is provided and the second plane 221 on the second rack 22 are provided form an angle, and this angle... The angle is acute. Preferably, the included angle between the first plane 211 and the second plane 221 is 35 to 45 degrees. In this embodiment, the included angle is 41.5 degrees. This arrangement allows for pressing of the steering shaft 20 on opposite sides, improving the uniformity of force on the steering shaft 20, avoiding unilateral force caused by the steering shaft 20 being biased towards the inner wall of the tubular sleeve 11 of the steering gear housing 10, improving operational stability, and reducing overall noise. The pressing structure 50 includes a pressing block 51, an O-ring 52, an adjusting bolt 53, and a coil spring 54. The pressing block 51 is a cylindrical component that is axially movable inside the pressing cylinder 12. The end of the pressing block 51 facing the steering shaft 20 is provided with a joint with the outer wall of the steering shaft 20. The fitting end groove 511 and the outer wall of the pressure block 51 are provided with an annular groove 512 to accommodate the O-ring 52. The O-ring 52 is squeezed between the inner wall of the annular groove 512 and the inner wall of the pressure cylinder 12 to form a buffer gap. The adjusting bolt 53 is threaded to the inner wall of the pressure cylinder 12 and is located on the side of the pressure block 51 away from the steering shaft 20. The coil spring 54 is squeezed between the adjusting bolt 53 and the pressure block 51. Tightening the adjusting bolt 53 can adjust the clamping force applied by the coil spring 54 to the pressure block 51, thereby changing the clamping effect on the steering shaft 20. This setting can also reduce the number of parts of the clamping structure 50 and simplify its structure, thereby greatly reducing the risk of misassembly and omission during assembly.

[0033] To improve the anti-loosening effect, in this embodiment, the end of the adjusting bolt 53 protrudes from the edge of the clamping cylinder 12 to form a connecting end 531. The clamping structure 50 also includes a locking nut 55 sleeved on the connecting end 531 and threadedly connected to the connecting end 531. The locking nut 55 abuts against the edge of the clamping cylinder 12 to prevent the adjusting bolt 53 from loosening.

[0034] To further enhance the buffering effect, the annular groove 512 is further provided in two rows and spaced apart along the axial direction of the pressure block 51, and each annular groove 512 is provided with an O-ring 52.

[0035] In this embodiment, the adjusting bolt 53 is in contact with the end face of the pressure block 51 on the opposite side. Specifically, the end face of the adjusting bolt 53 facing the pressure block 51 is provided with a first blind hole 532 to accommodate one end of the coil spring 54, and the end face of the pressure block 51 facing the adjusting bolt 53 is provided with a second blind hole 513 to accommodate the other end of the coil spring 54. Further, the bottom wall center of the second blind hole 513 is provided with a through hole 514 that communicates with the end groove 511.

[0036] In this embodiment, the first rack 21 and the second rack 22 are inclined relative to the cross-section of the steering shaft 20, and the inclination directions of the first rack 21 and the second rack 22 are opposite, while the inclination angles are the same, in order to improve stability. At the same time, the power steering wheel shaft 40 is connected to the output end of the power steering motor 62 through the worm gear reduction mechanism 61. The worm gear reduction mechanism 61 is provided with a worm gear housing 63 on its outer side. The power steering motor 62 is a symmetrical six-phase motor, and its tail is provided with a dual-redundant controller 64. A sensor 32 for detecting the rotation angle and torque of the steering wheel shaft 30 is sleeved on the steering wheel shaft 30. The sensor 32 is electrically connected to the dual-redundant controller 64.

[0037] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A dual-gear electric power steering assembly, comprising: A steering gear housing having a tubular sleeve and a clamping cylinder, the clamping cylinder being connected alongside the tubular sleeve; A steering shaft that is rotatably inserted inside a tubular sleeve has a first rack and a second rack spaced apart on its outer wall; The steering wheel axle is connected to the bottom of the steering column, and the steering gear on it passes through the tubular sleeve and meshes with the first rack; The power steering wheel shaft is connected to the output end of the power steering motor, and the power steering gear on it passes through the tubular sleeve and meshes with the second rack. A clamping structure is provided inside the clamping cylinder, which is used to clamp the outer wall of the steering shaft on the back side of the first rack and the back side of the second rack; Its features are: The first plane on the steering shaft where the first rack is mounted and the second plane on which the second rack is mounted form an angle, which is an acute angle. The clamping structure includes a pressure block, an O-ring, an adjusting bolt, and a coil spring. The pressure block is a cylindrical component that is axially movable inside the clamping cylinder. The end of the pressure block facing the steering shaft has an end groove that fits against the outer wall of the steering shaft. The outer wall of the pressure block has an annular groove that accommodates the O-ring. The O-ring is squeezed between the inner wall of the annular groove and the inner wall of the clamping cylinder to form a buffer gap. The adjusting bolt is threaded to the inner wall of the clamping cylinder and is located on the side of the pressure block away from the steering shaft. The coil spring is squeezed between the adjusting bolt and the pressure block. Tightening the adjusting bolt can adjust the clamping force applied by the coil spring to the pressure block, thereby changing the clamping effect on the steering shaft.

2. The dual-gear electric power steering assembly according to claim 1, characterized in that: The angle between the first plane and the second plane is 35 to 45 degrees.

3. The dual-gear electric power steering assembly according to claim 2, characterized in that: The angle between the first plane and the second plane is 41.5 degrees.

4. The dual-gear electric power steering assembly according to claim 1, characterized in that: The end of the adjusting bolt protrudes from the edge of the clamping cylinder to form a connecting end. The clamping structure also includes a locking nut that is threadedly connected to the connecting end. The locking nut abuts against the edge of the clamping cylinder to prevent the adjusting bolt from loosening.

5. The dual-gear electric power steering assembly according to claim 1, characterized in that: The annular groove has two channels and is spaced apart along the axial direction of the pressure block, and each annular groove is provided with an O-ring.

6. The dual-gear electric power steering assembly according to claim 1, characterized in that: The adjusting bolt is fitted to the end face of the pressure block on the opposite side. The end face of the adjusting bolt facing the pressure block is provided with a first blind hole to accommodate one end of the helical spring, and the end face of the pressure block facing the adjusting bolt is provided with a second blind hole to accommodate the other end of the helical spring.

7. The dual-gear electric power steering assembly according to claim 6, characterized in that: The bottom wall of the second blind hole has a through hole at its center that communicates with the end groove.

8. The dual-gear electric power steering assembly according to claim 1, characterized in that: The first rack and the second rack are inclined relative to the cross-section of the steering shaft, and the first rack and the second rack are inclined in opposite directions but at the same angle.

9. The dual-gear electric power steering assembly according to claim 1, characterized in that: The booster wheel shaft is connected to the output end of the booster motor via a worm gear reducer mechanism. The booster motor is a symmetrical six-phase motor.

10. The dual-gear electric power steering assembly according to claim 1, characterized in that: A sensor for detecting the rotation angle and torque of the steering wheel shaft is fitted on the steering wheel shaft, and the sensor is electrically connected to the dual redundant controller at the tail of the power assist motor.

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