A rack and pinion steering gear having an asymmetric seal and structural reinforcement arrangement

Abstract

The present application relates to the technical field of vehicle steering gear, and discloses a rack and pinion steering gear with asymmetric sealing and structure reinforcement layout, which comprises a shell, an accommodating cavity is formed in the interior of the shell, a gear shaft and a rack that are in meshing transmission are assembled in the accommodating cavity, the gear shaft is rotatably assembled in the accommodating cavity of the shell through a bearing, the tooth segment of the gear shaft is in meshing with the tooth profile of the rack, and the rotation of the gear shaft can drive the rack to make linear reciprocating motion along the axial direction of the shell;The shell is divided into a first side and a second side along the axial midpoint thereof, the first side is provided with a first sealing assembly, and the two sides of the steering gear adopt differentiated asymmetric sealing layout, the first side adopts a radial compression type first sealing assembly, and the second side adopts an axial compression type end face sealing assembly, so as to meet the requirements of asymmetric shell structure, installation arrangement and motion envelope avoidance, realize the comprehensive optimization of the sealing, protection, avoidance and structure reinforcement of the whole machine.

Description

Technical Field

[0001] This invention relates to the field of vehicle steering technology, specifically to a rack and pinion steering system with an asymmetric sealing and structurally reinforced layout. Background Technology

[0002] The core structure of a conventional passenger car rack and pinion steering system includes a steering pinion, a steering rack, a die-cast housing, a clearance compensation spring, a dust cover, and a tie rod ball joint. It can be combined with a hydraulic or electric power steering system to form a complete steering mechanism. During operation, the rotational motion of the steering pinion is converted into the horizontal linear reciprocating motion of the rack, which then drives the front wheels to deflect via the tie rod. It boasts advantages such as a short transmission chain, low loss, and low steering play. Existing passenger car steering systems mostly employ a nearly centrally symmetrical housing structure, paired with identical dust covers and sealing structures on both sides. The dust covers use a traditional radial clamping structure, radially pressed and fixed by clamps, relying on the cover's own expansion and contraction to adapt to the steering stroke. The overall arrangement is a left-right mirror image, suitable for the spacious interiors and small wheel sway angles of passenger cars.

[0003] However, in off-road vehicle applications such as ATVs and SSVs, the vehicles need to adapt to complex motion conditions such as large wheel steering angles, large suspension travel, and large vertical bounce at the wheel ends, while also needing to withstand high-frequency impact loads and harsh operating environments such as mud and water.

[0004] Under the above operating conditions, the steering system not only needs to meet the requirements of a large steering motion envelope, but also needs to have high impact resistance and long-term durability in its structure.

[0005] Furthermore, since the steering gear housing needs to be integrated with the vehicle chassis structure, the location of its mounting holes and the shape of the housing must be comprehensively considered: 1. Requires space for large swing angle movements; 2. The motion envelope of external transmission components; 3. Need for local structural reinforcement of the shell.

[0006] The aforementioned multiple constraints make it difficult for the traditional centrally symmetrical rack and pinion steering gear structure to simultaneously meet the requirements for large sway angle adaptability, structural strength under extreme impact conditions, and overall machine space layout.

[0007] Especially in traditional symmetrical structures, the shell is usually arranged in a mirror image. The structural reinforcement area and the installation arrangement are mutually constrained, making it difficult to effectively strengthen the local structure. At the same time, it limits the structural optimization space of the steering gear under large swing angle and high impact conditions.

[0008] Therefore, there is an urgent need to propose a new type of asymmetric steering gear structure that can achieve a comprehensive balance between large steering angle conditions, structural strength requirements, and spatial arrangement constraints. Summary of the Invention

[0009] This invention provides a novel asymmetric steering gear structure. Through the coordinated design of asymmetric shell layout, asymmetric sealing structure, and shell reinforcement structure, the comprehensive performance optimization of the steering gear under large sway angle conditions, extreme impact load conditions, and complex installation constraints is achieved. This solves the technical problem that existing symmetric steering gear structures cannot simultaneously achieve large sway angle adaptability, structural strength, and sealing reliability.

[0010] This invention provides the following technical solution: a rack and pinion steering gear with an asymmetric sealing and structural reinforcement layout, comprising a housing, an internal cavity for receiving the gear shaft and rack for meshing transmission, the gear shaft being rotatably mounted inside the cavity via bearings, the gear shaft teeth meshing with the rack teeth, and the rotation of the gear shaft driving the rack to perform linear reciprocating motion along the axial direction of the housing; the housing is divided into a first side and a second side along its axial midpoint, the first side being provided with a first sealing assembly, which adopts a radial compression sealing structure, and the second side being provided with a second sealing assembly, which adopts an axial compression end face sealing structure; wherein, the contour structure formed in the mounting area of ​​the second side is asymmetrical to the contour structure formed in the mounting area of ​​the first side, and located on the second side, the outer wall of the housing is integrally formed with an avoidance groove along the axial extension direction of the rack, the housing achieving motion envelope avoidance through the avoidance groove; the outer wall of the housing is integrally formed with a reinforcing base along the contour of the avoidance groove, the reinforcing base being used to strengthen the overall structural strength of the housing.

[0011] As a preferred embodiment of the present invention, a mounting post is pre-set on the second side of the housing, and the mounting post is arranged near the end of the housing to improve the rigidity of the installation connection.

[0012] As a preferred embodiment of the present invention, the reinforced substrate includes a thickened substrate and longitudinal reinforcing ribs disposed on the shell. The thickened substrate is integrally formed along the outer contour of the clearance groove, and the longitudinal reinforcing ribs extend along the axial direction of the rack. The thickened substrate and the longitudinal reinforcing ribs together constitute a reinforced structure, which is used to improve the structural strength and stiffness of the shell when subjected to impact loads and alternating loads under off-road conditions.

[0013] As a preferred embodiment of the present invention, an offset surface is provided on the second side of the housing; the offset surface is an end mounting reference surface offset relative to the central axis of the housing, used to provide an axial pressing mounting base for the second sealing assembly.

[0014] As a preferred embodiment of the present invention, the second sealing assembly includes a corrugated sleeve, the corrugated sleeve being formed with an end face pressing area adapted to the bias surface; a limiting member is provided on one side of the corrugated sleeve, located outside the bias surface and pressing against the end face pressing area, the limiting member pressing against the end face pressing area, so that the corrugated sleeve is fitted onto the bias surface and forms an end face seal.

[0015] Specifically, the corrugated sleeve is located on the left side of the rack, and its installation position along the axial direction of the rack is asymmetrical compared to the first sealing assembly located on the right side of the rack.

[0016] As a preferred embodiment of the present invention, the shell is made of aluminum alloy, and the thickened base and the longitudinal reinforcing rib are integrally cast with the shell.

[0017] The present invention has the following beneficial effects: 1. In this invention, the steering gear employs a differentiated asymmetric sealing layout on both sides. The first side uses a first sealing assembly, which forms a sealing structure by radially clamping the dustproof sleeve with a metal clamp. The corrugated equal-diameter structure is suitable for the steering gear's conventional reciprocating motion conditions, and has advantages such as simple structure, convenient assembly, and reliable sealing. The second side uses an end-face pressing type second sealing assembly, which forms a sealing fit through axial pressing to adapt to the asymmetric shell structure, installation structure layout, and large-angle motion conditions. Through the differentiated sealing structure design on both sides, a comprehensive balance is achieved in sealing reliability, structural strength, and motion adaptability.

[0018] 2. In this invention, an offset surface is provided on the housing. The large end of the corrugated sleeve is fixedly installed on this offset surface by a limiting member, while the small end is connected to the steering tie rod. During movement, the steering tie rod oscillates, causing the central axis of the corrugated sleeve to form a certain sway angle relative to the rack axis. Under extreme steering or large suspension bounce conditions, the corrugated sleeve can adaptively deform and release towards the side with relatively more space along the sway angle direction, thereby reducing the risk of local compression, tension, and structural interference, thus extending the service life of the seal and improving sealing reliability.

[0019] 3. In this invention, the housing adopts an asymmetrical shape with the axial midpoint as the dividing point. The second side is equipped with a relief groove, which extends along the rack axis and reserves a safety clearance to avoid the motion envelope of the drive shaft. This greatly reduces the risk of interference between the second side corrugated leather sleeve, housing and external moving parts, and is suitable for ATV and SSV off-road vehicles with large sway angles and large suspension travel conditions. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the asymmetric steering mechanism in this invention. Figure 2 This is a three-dimensional structural diagram of the asymmetric steering gear in this invention; Figure 3 This is an exploded view of the first sealing assembly in this invention; Figure 4 This is an exploded view of the second sealing assembly in this invention; Figure 5 This is a three-dimensional structural diagram of the shell in this invention; Figure 6 This is a comparison diagram of the asymmetric steering system of the present invention and the conventional centrally symmetrical steering system; Figure 7 This is a schematic diagram showing the relationship between the asymmetric steering gear and the outer boundary envelope space in this invention; Figure 8 This is a schematic diagram showing the maximum swing angle position of the steering transmission component in this invention.

[0021] In the figure: 1. Housing; 10. Receiving cavity; 11. Offset surface; 12. Clearance groove; 100. Gear shaft; 101. Rack; 120. Thickened base; 121. Longitudinal reinforcing rib; 2. First sealing assembly; 20. Dustproof sleeve; 21. Metal clamp; 200. Radial pressing area; 3. Second sealing assembly; 30. Corrugated sleeve; 31. Limiting element; 300. End face pressing area; 4. Steering transmission assembly; 40. First steering tie rod; 41. Second steering tie rod; 5. Mounting column. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that in the description of the embodiments of this application, the terms "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. For example, in this application, to correspond to the actual arrangement of the vehicle, the side of the drive shaft structure component closer to the steering gear is defined as the "right side," that is, the "first side" in this application; the opposite side is defined as the "left side," that is, the "second side" in this application; that is, divided by the axial midpoint of the housing 1, the first sealing component 2 and the second sealing component 3 are respectively provided on both sides of the housing 1, wherein the second sealing component 3 is located on the second side, and the first sealing component 2 is located on the first side. Compared with the assembly space on the second side, the assembly of each component is more compact in the assembly space on the first side.

[0024] like Figures 1 to 8 As shown, this application embodiment provides a rack and pinion steering gear with an asymmetric sealing and structurally reinforced layout, including a housing 1, which is the main load-bearing structure of the steering gear. The housing 1 is divided into an asymmetric shape along its axial midpoint, and a receiving cavity 10 is formed inside the housing 1. A gear shaft 100 and a rack 101 that mesh and drive each other are assembled inside the receiving cavity 10. The gear shaft 100 is rotatably mounted, and the rack 101 is slidable along the axial direction of the housing 1. A mounting post 5 is preset on the second side of the housing 1, and the mounting post 5 is arranged near the end of the housing 1. The mounting connection position is closer to the external load area to improve the installation rigidity of the housing 1 and reduce the local stress under impact load.

[0025] The first sealing component 2 and the second sealing component 3, which have completely different structures, are respectively assembled on both sides of the midpoint of the housing 1. The second sealing component 3 on the second side relies on axial pressure to fit against the end of the housing 1 to form an end face seal without radial outward protrusion, thereby reducing the radial space occupied on that side.

[0026] It should be noted that: the rack 101 is connected to the steering transmission assembly 4 at both ends. The wheel deflection is achieved by the linear push and pull of the rack 101. The steering transmission assembly 4 consists of a first steering tie rod 40 and a second steering tie rod 41. The first steering tie rod 40 and the second steering tie rod 41 are respectively fixedly connected to the two ends of the rack 101 to transmit the linear motion of the rack 101 to the wheel to complete the steering action. The first steering tie rod 40 is set in the first sealing assembly 2 and is connected to one end of the rack 101. The second steering tie rod 41 is set in the second sealing assembly 3 and is connected to the other end of the rack 101. The gear shaft 100 is rotatably assembled in the housing 1 receiving cavity 10 through bearings. The tooth segments of the gear shaft 100 mesh with the tooth profile of the rack 101. The torque input from the steering wheel drives the gear shaft 100 to rotate, which converts the rotational motion into the axial linear motion of the rack 101. like Figure 8 As shown in the figure, the horizontal dashed line is the initial position center line of the steering transmission assembly 4, and the inclined dashed line is the maximum swing angle of the first steering tie rod 40 and the second steering tie rod 41 in the steering transmission assembly 4. More specifically, the inclined dashed lines on both sides are the maximum swing angle positions of the first steering tie rod 40 and the second steering tie rod 41, respectively.

[0027] In practical applications, the overall operation of this rack and pinion steering system is as follows: Turning the steering wheel inputs torque to the gear shaft 100, causing it to rotate. The gear shaft 100 meshes and drives the rack 101 to slide back and forth along the axial direction of the housing 1. The rack 101 pushes and pulls the steering tie rods at both ends to drive the wheels to deflect. During the movement, the dustproof sleeve 20 on the first side adapts to the small displacement of the tie rod by its own corrugated expansion and contraction, and the clamp radially locks to block mud and sand. The corrugated sleeve 30 on the second side, located at the offset surface 11, undergoes large-angle adaptive deformation with the second steering tie rod 41. The axial limiting member 31 continuously presses the end face of the corrugated sleeve 30 to maintain the seal. At the same time, the clearance groove 12 on the housing 1 continuously isolates the drive shaft, and together with the thickened base 120 and longitudinal reinforcing ribs 121 on its back, it ensures the impact resistance and durability of the housing 1, so that the whole structure is suitable for the harsh working conditions of long-travel off-road vehicles such as ATVs and SSVs.

[0028] In one embodiment, the specific structure of the first sealing component 2 is further described, such as... Figure 3 and Figures 6-8 As shown, the first sealing component 2 is disposed on the first side of the housing 1, with ample assembly space. The first sealing component 2 includes a dustproof sleeve 20 of equal diameter and a metal clamp 21. The dustproof sleeve 20 is a sleeve of equal diameter, which is disposed on the first side of the housing 1 and located between the first steering tie rods 40 on the first side of the housing 1. A radial pressing area 200 is provided on the outer periphery of the dustproof sleeve 20. The metal clamp 21 is clamped on the outside of the radial pressing area 200, and the seal is achieved by radial clamping force. The first sealing component 2 adopts a clamp radial clamping structure composed of a dustproof sleeve 20 of equal diameter and a metal clamp 21. The dustproof sleeve 20 adopts a corrugated shape, which is simple in structure and easy to assemble. It is compatible with the small reciprocating movement of the rack 101 on this side and can maintain stable sealing performance during long-term use.

[0029] In one embodiment, the specific structure of the second sealing component 3 is further described, such as... Figure 4 and Figures 6-8 As shown, a bias surface 11 is provided on the second side of the housing 1, and the second sealing assembly 3 is assembled at the bias surface 11 and seals the second steering tie rod 41; The second sealing assembly 3 includes a corrugated sleeve 30, which is formed with an end face pressing area 300 adapted to the bias surface 11. A limiting member 31 is provided on one side of the corrugated sleeve 30, located outside the bias surface 11 and pressing against the end face pressing area 300. The limiting member 31 presses against the end face pressing area 300, so that the corrugated sleeve 30 is assembled on the bias surface 11 and forms an end face seal. The limiting member 31 is installed at the port of the bias surface 11 and presses the end face pressing area 300 along its axial direction, so that the corrugated sleeve 30 is tightly fitted to the bias surface 11 of the housing 1 to form a seal, eliminating the traditional radial clamp-type outward protrusion structure on the second side. The corrugated sleeve 30, which adopts a variable diameter structure, has its large end face pressing area 300 mounted on the offset surface 11 of the housing 1 via a limiting member 31, and its small end connected to the second steering tie rod 41. Under the constraint of the housing end face and the follow-up constraint of the second steering tie rod 41 at both ends of the corrugated sleeve 30, the swing of the second steering tie rod 41 causes the central axis of the corrugated sleeve 30 to change its swing angle relative to the axis of the rack 101.

[0030] The corrugated sleeve 30 is located on the left side of the rack 101, and compared with the first sealing component 2 located on the right side of the rack 101, the two are asymmetrically arranged in the axial direction of the rack 101. Under extreme steering or large suspension bounce conditions, the corrugated sleeve 30 can adaptively deform and release towards the side with relatively more space along the swing angle direction, thereby reducing the risk of local compression, tension and structural interference, avoiding cracking caused by long-term stress concentration, and thus improving sealing reliability and extending service life.

[0031] In one embodiment, to achieve superior active space avoidance, the structure of the housing 1 has been specifically improved in this application embodiment, such as... Figures 5-8 As shown, the second side mounting area forms an asymmetrical contour structure compared to the first side mounting area; the central axis of the corrugated sleeve is offset away from the external moving parts relative to the central axis of the rack, located on the second side, and the outer wall of the housing 1 is integrally formed with a relief groove 12 along the axial extension direction of the rack 101; and the central axis of the corrugated sleeve 30 is offset based on the central axis of the offset surface 11, so that the housing 1 can achieve motion envelope relief through the relief groove 12.

[0032] In one embodiment, to enhance the strength of the housing 1, a reinforcing base is integrally formed on the outer wall of the housing 1 along the contour of the clearance groove 12. The reinforcing base is used to strengthen the overall structural strength of the housing 1. The reinforcing base includes a thickened base 120 and longitudinal reinforcing ribs 121 disposed on the housing 1. The thickened base 120 is integrally formed along the outer contour of the clearance groove 12, and multiple longitudinal reinforcing ribs 121 extend along the axial direction of the rack 101. The thickened base 120 and the longitudinal reinforcing ribs 121 together constitute a reinforced structure, which is used to improve the structural strength and stiffness of the housing 1 when subjected to impact loads and alternating loads under off-road conditions.

[0033] The shell 1 adopts an integral casting structure of aluminum alloy. The thickened base 120 and the longitudinal reinforcing ribs 121 are integrally formed with the shell 1 body during the casting process, realizing the integrated design of the structure, thereby improving the overall rigidity and load transmission capacity of the shell.

[0034] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, and there are many other variations of different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0035] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A rack and pinion steering gear with an asymmetric sealing and structurally reinforced layout, characterized in that, The device includes a housing (1), and a receiving cavity (10) is provided inside the housing (1). A gear shaft (100) and a rack (101) that mesh with each other are assembled inside the receiving cavity (10). The gear shaft (100) is rotatably assembled inside the receiving cavity (10) of the housing (1) through a bearing. The tooth segment of the gear shaft (100) meshes with the tooth profile of the rack (101). The rotation of the gear shaft (100) can drive the rack (101) to make linear reciprocating motion along the axial direction of the housing (1). The housing (1) is divided into a first side and a second side along the midpoint of its own axis. The first side is provided with a first sealing assembly (2), which adopts a radial compression sealing structure. The second side is provided with a second sealing assembly (3), which adopts an axial compression end face sealing structure. Among them, the contour structure formed in the second side mounting area is asymmetrical with the contour structure formed in the first side mounting area. Located on the second side, the outer wall of the housing (1) is integrally formed with a relief groove (12) along the axial extension direction of the rack (101). The housing (1) achieves motion envelope relief through the relief groove (12). The outer wall of the shell (1) is integrally formed with a reinforcing base along the contour of the clearance groove (12), and the reinforcing base is used to strengthen the overall structural strength of the shell (1).

2. A rack and pinion steering gear with an asymmetric sealing and structurally reinforced layout according to claim 1, characterized in that, The housing (1) has a mounting post (5) pre-set on the second side, and the mounting post (5) is arranged near the end of the housing (1).

3. A rack and pinion steering gear with an asymmetric sealing and structurally reinforced layout according to claim 1, characterized in that, The reinforced base includes a thickened base (120) and longitudinal reinforcing ribs (121) disposed on the shell (1). The thickened base (120) is integrally formed along the outer contour of the clearance groove (12). A plurality of longitudinal reinforcing ribs (121) extend along the axial direction of the rack (101). The thickened base (120) and the longitudinal reinforcing ribs (121) together constitute a reinforced structure to improve the structural strength and stiffness of the shell (1) under impact load and alternating load under off-road conditions.

4. A rack and pinion steering gear with an asymmetric sealing and structurally reinforced layout according to claim 1, characterized in that, An offset surface (11) is provided on the second side of the housing (1); The offset surface (11) is an end mounting reference surface offset relative to the central axis of the housing (1), used to provide an axial clamping mounting base for the second sealing assembly (3).

5. A rack and pinion steering gear with an asymmetric sealing and structurally reinforced layout according to claim 4, characterized in that, The second sealing assembly (3) includes a corrugated sleeve (30) having an end face pressing area (300) adapted to the bias surface (11). One side of the corrugated sleeve (30) is provided with a limiting member (31) located outside the bias surface (11) and pressing against the end face pressing area (300). The limiting member (31) presses against the end face pressing area (300), so that the corrugated sleeve (30) is assembled on the bias surface (11) and forms an end face seal.

6. A rack and pinion steering gear with an asymmetric sealing and structurally reinforced layout according to claim 5, characterized in that, The corrugated sleeve (30) is located on the left side of the rack (101), and compared with the first sealing assembly (2) located on the right side of the rack (101), the two are asymmetrically arranged in the axial direction of the rack (101).

7. A rack and pinion steering gear with an asymmetric sealing and structurally reinforced layout according to claim 3, characterized in that, The shell (1) is made of aluminum alloy, and the thickened base (120) and the longitudinal reinforcing rib (121) are integrally cast with the shell (1).

Images