Hydraulic power-assisted steering gear with through shaft rotary valve

Abstract

The invention relates to the technical field of welding robots, in particular to a through shaft rotary valve hydraulic power-assisted steering gear. Comprising a shell, a rack piston, a screw rod shaft, a valve body, a plane needle roller thrust bearing, a plane bearing gasket, a threaded cover, an input shaft, a rocker arm shaft, a first gasket, a plane thrust bearing, a second gasket, an eccentric bearing, an oil return channel, an oil inlet channel, an upper cavity communicating oil channel and a lower cavity communicating oil channel, and the oil return channel, the oil inlet channel, the upper cavity communicating oil channel and the lower cavity communicating oil channel are formed in the screw rod shaft. One end of the steering gear valve element composed of the screw shaft and the input shaft is supported at the bottom of a cylinder hole of the shell through a first gasket, a plane thrust bearing and a second gasket, and the other end of the steering gear valve element is supported on the threaded cover through a plane needle roller thrust bearing and a plane bearing gasket. The two ends of the steering gear valve element are supported by the bearings, the overall rigidity is better in the loaded state, transmission is smoother, the requirement for the comfort of driving control hand power is met, and the driving experience is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of commercial vehicle steering, in particular to a through-shaft valve hydraulic power steering gear. BACKGROUND

[0002] In recent years, with the development of high performance requirements of vehicles, in order to meet the safety and driving comfort requirements of heavy commercial vehicles, a through-shaft valve hydraulic power steering gear is developed. In order to realize the precise control of the steering angle and the lane keeping function, the steering gear must not have any steering gap.

[0003] However, the existing through-shaft structure adjusts the gap by repeatedly adjusting a plurality of different thickness gaskets, which requires high machining precision and consistency of the parts, and the assembly and adjustment efficiency is low. Therefore, a through-shaft valve hydraulic power steering gear which can simply and efficiently adjust the steering gap is needed to ensure the precise control of the steering gap and to meet the safety and driving comfort requirements of heavy commercial vehicles. SUMMARY

[0004] The present application aims to provide a through-shaft valve hydraulic power steering gear to solve the problems in the background art.

[0005] To achieve the above-mentioned purpose, the present application provides a through-shaft valve hydraulic power steering gear, which comprises a housing, a rack piston, a screw shaft, a valve body, a flat thrust needle bearing, a flat bearing washer, a threaded cover, an input shaft, a rocker shaft, a first gasket, a flat thrust bearing, a second gasket, and an eccentric bearing, and oil return channels, oil inlet channels, upper cavity oil channels, and lower oil channels are opened in the screw shaft. The valve body is fixed to the housing by a screw, one end of the steering gear spool composed of the screw shaft and the input shaft is supported at the bottom of the cylinder hole of the housing through the first gasket, the flat thrust bearing, and the second gasket, and the other end is supported on the threaded cover through the flat thrust needle bearing and the flat bearing washer, the threaded cover is fixed on the valve body by threads, a torsion bar is arranged inside the steering gear spool to connect the screw shaft and the input shaft, a steel ball is arranged in the rolling channel to transmit power between the rack piston and the screw shaft, the rack piston and the rocker shaft are connected by tooth engagement, and the corresponding parts are sealed by oil seals, and the eccentric bearing cooperates with the rocker shaft.

[0006] As a further improvement of the present technical solution, the axial gap of the steering gear spool is adjusted by pre-tightening the threaded cover, and the threaded cover is riveted and fixed to the valve body to prevent loosening.

[0007] As a further improvement of the present technical solution, the rocker shaft is a straight tooth structure, and the meshing gap of the rack piston is eliminated by rotating the eccentric bearing.

[0008] As a further improvement of the technical solution, one end of the torsion bar is fixedly connected with the screw shaft, and the other end is fixedly connected with the input shaft.

[0009] As a further improvement of the technical solution, the rack piston is provided with circulating steel balls in the raceway of the screw shaft, and a circulating ball transmission mechanism is formed.

[0010] As a further improvement of the technical solution, the connecting screws of the valve body and the shell are uniformly distributed along the circumference of the valve body.

[0011] As a further improvement of the technical solution, the flat bearing washer is located between the flat thrust needle bearing and the threaded cap.

[0012] As a further improvement of the technical solution, the first gasket, the flat thrust bearing and the second gasket are sequentially arranged from bottom to top.

[0013] As a further improvement of the technical solution, the inner thread of the threaded cap and the threaded surface of the valve body are both provided with a lubricating coating.

[0014] Compared with the prior art, the beneficial effects of the present application are: 1. In the through shaft rotary valve hydraulic power steering gear, the valve core of the steering gear is supported by bearings at both ends, and the overall rigidity is better under load, the transmission is smoother, the comfort of the driving control force is met, and the driving experience is improved.

[0015] 2. In the through shaft rotary valve hydraulic power steering gear, the adjustment of the axial gap of the valve core of the steering gear is realized by the pre-tightening of the threaded cap, which is simple to operate and does not require repeated adjustment of multiple gaskets, and the meshing gap between the rocker shaft and the rack piston can be eliminated by rotating the eccentric bearing, so that the adjustment process is convenient and efficient, and the assembly production efficiency is improved.

[0016] 3. In the through shaft rotary valve hydraulic power steering gear, the dimensional accuracy of some parts is relatively low, which reduces the production cost and is more suitable for mass production, and can meet the production needs of heavy commercial vehicles.

[0017] 4. In the through shaft rotary valve hydraulic power steering gear, the steering gap is effectively eliminated, the accuracy of the steering angle control is improved, which is beneficial to realize the lane keeping function and improve the safety of driving. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the overall structure of the present application; Figure 2 is a schematic diagram of the structure of the present application.

[0019] The meanings of the various reference numbers in the drawings are as follows: 1. housing; 2. rack piston; 3. screw shaft; 4. valve body; 5. flat thrust needle bearing; 6. flat bearing washer; 7. threaded cap; 8. input shaft; 9. oil return passage; 10. oil inlet passage; 11. passage to upper chamber; 12. rocker shaft; 13. passage to lower chamber; 14. first washer; 15. flat thrust bearing; 16. second washer; 17. eccentric bearing. DETAILED DESCRIPTION

[0020] The technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without any creative work fall within the protection scope of the present application.

[0021] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0022] In addition, the terms "first", "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly and specifically limited. Embodiment one

[0023] Please refer to Figure 1 and Figure 2The application relates to a hydraulic power steering gear with a through shaft rotary valve, which comprises a shell 1, a rack piston 2, a screw shaft 3, a valve body 4, a plane thrust needle bearing 5, a plane bearing washer 6, a threaded cover 7, an input shaft 8, a rocker shaft 12, a first washer 14, a plane thrust bearing 15, a second washer 16 and an eccentric bearing 17, and oil return channels 9, oil inlet channels 10, upper cavity oil channels 11 and lower oil channels 13 formed in the screw shaft 3, wherein the valve body 4 is fixed to the shell 1 by means of screws, one end of a steering gear valve core composed of the screw shaft 3 and the input shaft 8 is supported at the bottom of a cylinder hole of the shell 1 through the first washer 14, the plane thrust bearing 15 and the second washer 16, and the other end is supported on the threaded cover 7 through the plane thrust needle bearing 5 and the plane bearing washer 6, the threaded cover 7 is fixed to the valve body 4 by means of threads, a torsion bar is arranged inside the steering gear valve core to connect the screw shaft 3 and the input shaft 8, the rack piston 2 and the screw shaft 3 are driven through steel balls in a rolling track, the rack piston 2 and the rocker shaft 12 are driven through tooth engagement, corresponding parts are provided with oil seal, and the eccentric bearing 17 is matched with the rocker shaft 12. The axial gap of the steering gear valve core is adjusted by pre-tightening of the threaded cover 7, and the threaded cover 7 and the valve body 4 are riveted and fixed to prevent loosening. The rocker shaft 12 is of a straight-tooth structure, the meshing gap of the rack piston 2 is eliminated by rotating the eccentric bearing 17. One end of the torsion bar is fixedly connected with the screw shaft 3, and the other end is fixedly connected with the input shaft 8. Circulating steel balls are arranged in the rolling track between the rack piston 2 and the screw shaft 3, and a circulating ball transmission mechanism is formed. The connecting screws of the valve body 4 and the shell 1 are uniformly distributed along the circumference of the valve body 4. The plane bearing washer 6 is located between the plane thrust needle bearing 5 and the threaded cover 7. The first washer 14, the plane thrust bearing 15 and the second washer 16 are sequentially arranged from bottom to top. The internal threads of the threaded cover 7 and the threaded surface of the valve body 4 are both provided with a lubricating coating.

[0024] During implementation, the driver rotates the steering wheel in the required direction, the input shaft 8 connected with the steering wheel is rotated, the screw shaft 3 is relatively rotated with the input shaft 8 to open the steering gear rotary valve, during continuous rotation of the rotary valve, one end of the valve core is supported at the bottom of the cylinder hole of the shell 1 through the first washer 14, the plane thrust bearing 15 and the second washer 16, the other end is supported on the threaded cover 7 through the plane thrust needle bearing 5 and the plane bearing washer 6, and the threaded cover 7 is fixed to the valve body 4 by means of threads, the opening of the steering gear rotary valve is realized through the oil inlet channels 10, the upper cavity oil channels 11, the lower oil channels 13 and the oil return channels 9 arranged on the screw shaft 3 to distribute high and low hydraulic oils, a high and low pressure difference is formed on both sides of the rack piston 2 to push the rack piston 2 to move linearly left and right, the transmission between the rack piston 2 and the screw shaft 3 is realized through the steel balls in the rolling track, the linear movement of the rack piston 2 left and right drives the rocker shaft 12 to move circularly through tooth engagement, and finally the steering of the vehicle is realized through the connecting rod mechanism of the whole vehicle.

[0025] In summary, the working principle of the present application is as follows: the driver turns the steering wheel in the required direction, the input shaft 8 associated with the steering wheel is turned, the relative rotation of the screw shaft 3 and the input shaft 8 opens the steering valve, in the continuous rotation process of the valve, one end of the valve core is supported on the bottom of the cylinder hole of the shell 1 through the first gasket 14, the plane thrust bearing 15 and the second gasket 16, the other end is supported on the threaded cover 7 through the plane thrust needle bearing 5 and the plane bearing washer 6, and the threaded cover 7 is fixed on the valve body 4 through the thread, the opening of the steering valve is realized by the distribution of high and low hydraulic oil through the oil inlet 10, the upper cavity oil passage 11, the lower oil passage 13, the oil return passage 9 provided on the screw shaft 3, a high and low pressure difference is formed on both sides of the rack piston 2, so as to push the rack piston 2 to move linearly left and right, the transmission between the rack piston 2 and the screw shaft 3 is transmitted through the steel ball in the rolling groove, the linear motion of the rack piston 2 left and right will drive the rocker shaft 12 to make circular motion through the meshing of the teeth, and finally the steering of the vehicle is realized through the linkage mechanism of the whole vehicle.

[0026] The basic principle, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above-mentioned embodiments, the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application, and are not used to limit the present application, various changes and improvements of the present application can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A hydraulic power steering gear with a through-axis rotary valve, characterized in that: The invention comprises a housing (1), a rack piston (2), a screw shaft (3), a valve body (4), a plane thrust needle bearing (5), a plane bearing washer (6), a threaded cover (7), an input shaft (8), a rocker shaft (12), a first gasket (14), a plane thrust bearing (15), a second gasket (16) and an eccentric bearing (17), as well as an oil return passage (9), an oil inlet passage (10), an upper chamber oil passage (11) and a lower chamber oil passage (13) provided on the screw shaft (3), wherein the valve body (4) is fixed to the housing (1) by screws, and one end of the steering valve core composed of the screw shaft (3) and the input shaft (8) is connected to the steering valve core by the first gasket (14). ), a plane thrust bearing (15), and a second gasket (16) are supported on the bottom of the cylinder hole of the housing (1), and the other end is supported on the threaded cover (7) through a plane thrust needle bearing (5) and a plane bearing washer (6), and the threaded cover (7) is fixed to the valve body (4) through a thread, and a torsion bar is provided inside the steering valve core to connect the screw shaft (3) and the input shaft (8), the rack piston (2) and the screw shaft (3) are driven by the steel balls in the raceway, the rack piston (2) and the rocker shaft (12) are driven by teeth meshing, and oil seals are provided at the corresponding parts, and the eccentric bearing (17) is matched with the rocker shaft (12).

2. The through-shaft rotary valve hydraulic power steering gear according to claim 1, characterized in that: The axial clearance of the steering gear valve core is adjusted by pre-tightening the threaded cover (7), and the threaded cover (7) and the valve body (4) are riveted and fixed to prevent loosening.

3. The hydraulic power steering gear with a through-axis rotary valve according to claim 1, characterized in that: The rocker arm shaft (12) is a straight tooth structure, and the meshing clearance of the rack piston (2) is eliminated by rotating the eccentric bearing (17).

4. The through-shaft rotary valve hydraulic power steering device according to claim 1, characterized in that: One end of the torsion bar is fixedly connected to the screw shaft (3), and the other end is fixedly connected to the input shaft (8).

5. The through-shaft rotary valve hydraulic power steering gear according to claim 1, characterized in that: Circulating steel balls are provided in the rolling paths of the rack piston (2) and the screw shaft (3), forming a circulating ball transmission mechanism.

6. The through-shaft rotary valve hydraulic power steering gear according to claim 1, characterized in that: The connecting screws between the valve body (4) and the housing (1) are evenly distributed along the circumference of the valve body (4).

7. The hydraulic power steering gear with a through-axis rotary valve according to claim 1, characterized in that: The plane bearing washer (6) is located between the plane thrust needle roller bearing (5) and the threaded cover (7).

8. The through-shaft rotary valve hydraulic power steering device according to claim 1, characterized in that: The first gasket (14), the plane thrust bearing (15), and the second gasket (16) are arranged in sequence from bottom to top.

9. The through-shaft rotary valve hydraulic power steering device according to claim 1, characterized in that: The internal threads of the threaded cover (7) and the threaded surfaces of the valve body (4) are both provided with a lubricating coating.

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