Steering gear and ball screw for steering gear

Abstract

The ball screw for the steering gear comprises a rod body, a first through hole is formed in the rod body in the axial direction, the first through hole penetrates through one end, used for being connected with a ball cup, of the rod body, and the rod body is further provided with a second through hole. One end of the second through hole penetrates through one end of the first through hole away from the ball cup to form a first opening, and the other end of the second through hole extends to the surface of the body to form a second opening. When the nut is driven by the motor to drive the rod body to move through the ball, extruded airflow in the shell enters the first through hole from the second opening in the surface of the rod body and flows out of the first opening, or the extruded airflow flows in from the first opening and flows out of the second opening, and compared with a gap between the nut and the roller path, the gap between the nut and the roller path is smaller. The ventilation effect of the first through hole and the second through hole is better, so that airflow circulation in the left cavity and the right cavity is smooth, the stability of the air pressure in the sealing cavity of the shell is facilitated, and the situation that the air pressure difference causes large pressure to the dustproof cover and the clamp is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile steering gears, in particular to a steering gear and a ball screw for the steering gear. Background Art

[0002] The primary function of a car's power steering system is to assist the driver in reducing steering effort, making driving more comfortable. A quiet driving environment can also help drivers relax and avoid premature fatigue. The power steering system is equipped with telescopic dust covers at both ends. These covers expand and contract during operation. Due to their sealed structure, low or high pressure can form inside the covers, hindering the operation of the power steering system. In conventional steering systems, the input shaft rotates during operation, driving the pinion. The pinion meshes with the rack portion of the ball screw, causing the ball screw to move linearly. This in turn drives the inner and outer tie rods, rotating the tires and completing the steering operation.

[0003] However, this structure may cause uneven air pressure in the sealed cavity of the shell during operation, resulting in an air pressure difference. The airflow at the left and right ends of the shell mainly passes through the gap between the nut and the screw raceway or between the nut steel balls. Due to the small gap, the air pressure on one side is always higher during the movement of the screw, which causes greater pressure on the dust cover and clamp, accelerates the aging of the parts, and affects the life of the parts. At the same time, it will also affect the noise, vibration and harshness (NVH) of the entire steering gear, affecting the quality of the product to a certain extent. Utility Model Content

[0004] In response to the above technical problems, the utility model proposes a steering gear and a ball screw for the steering gear. Compared with the gap between the nut and the raceway, the first through hole and the second through hole have better ventilation effect, so that the air flow in the left and right cavities flows smoothly, thereby helping to stabilize the air pressure inside the sealed cavity of the shell.

[0005] The technical solution adopted by the utility model is as follows: A ball screw for a steering gear includes a rod body, a first through hole is provided inside the rod body along the axial direction, the first through hole passes through one end of the rod body for connection with the ball head seat, the rod body is also provided with a second through hole, one end of the second through hole passes through the end of the first through hole away from the ball head seat to form a first opening, and the other end of the second through hole extends to the surface of the body to form a second opening.

[0006] Optionally, the outer peripheral wall of the rod body is provided with a spiral track for cooperating with a nut, and the spiral track is located between the first opening and the second opening.

[0007] Optionally, the rod body includes a first transmission section and a second transmission section connected to the first transmission section, the outer peripheral wall of the first transmission section is provided with the spiral track, and the second transmission section is provided with a rack for cooperating with a gear.

[0008] The utility model also discloses a steering gear, comprising a nut, a gear and the ball screw for the steering gear described above, wherein the nut cooperates with the spiral track on the outer peripheral wall of the first transmission section, the gear cooperates with the rack on the surface of the second transmission section, and the nut is located between the first opening and the second opening.

[0009] Optionally, a ball head seat is further included, which includes a connecting block and a seat body, the connecting block cooperates with the first opening, the connecting block is provided with a third through hole, one end of the third through hole is connected to the first through hole, and the other end of the third through hole extends to the surface of the seat body to form a third opening.

[0010] Optionally, a groove cooperating with the spherical pull rod is provided at one end of the seat away from the connecting block.

[0011] Optionally, it further includes a shell and a dust cover, the rod body is arranged inside the shell, one end of the dust cover is connected to the shell, and the other end of the dust cover is connected to the spherical pull rod.

[0012] Optionally, the dust cover is a corrugated telescopic structure.

[0013] The beneficial effect of the present utility model is that when the nut is driven by the motor to move the rod body through the ball bearing, the squeezed air flow in the shell enters the first through hole from the second opening on the surface of the rod body and flows out from the first opening, or the squeezed air flow flows in from the first opening and flows out from the second opening. Compared with the gap between the nut and the raceway, the ventilation effect of the first through hole and the second through hole is better, so that the air flow in the left and right cavities flows smoothly, which helps to stabilize the air pressure inside the sealed cavity of the shell and prevents the pressure difference from causing greater pressure on the dust cover and the clamp. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic structural diagram of a ball screw for a steering gear according to an embodiment of the present invention;

[0015] Figure 2 A schematic diagram of a steering device according to an embodiment of the present invention;

[0016] Figure 3 This is a schematic diagram of the third through hole of the steering gear proposed in an embodiment of the present utility model.

[0017] The marks in the accompanying drawings are: 1. rod body; 11. first transmission section; 111. spiral track; 12. second transmission section; 121. rack; 2. first through hole; 21. first opening; 3. second through hole; 31. second opening; 4. nut; 5. ball head seat; 51. connecting block; 52. seat body; 6. third through hole; 7. spherical pull rod; 8. shell; 9. dust cover. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below with reference to the accompanying drawings and examples.

[0019] like Figures 1 to 3 As shown, this embodiment discloses a ball screw for a steering gear, comprising a rod body 1, wherein the rod body 1 has a first through hole 2 formed in the axial direction thereof. The first through hole 2 penetrates one end of the rod body 1 for connection with the ball seat 5. The rod body 1 also has a second through hole 3. One end of the second through hole 3 penetrates the end of the first through hole 2 away from the ball seat 5 to form a first opening 21, and the other end of the second through hole 3 extends to the surface of the body to form a second opening 31. When the nut 4 is driven by the motor to move the rod body 1 through the ball bearing, the compressed air in the housing 8 enters the first through hole 2 through the second opening 31 on the surface of the rod body 1 and flows out through the first opening 21, or the compressed air flows in through the first opening 21 and flows out through the second opening 31. Compared with the gap between the nut 4 and the raceway, the first through hole 2 and the second through hole 3 provide better ventilation, allowing smooth airflow in the left and right cavities, thereby facilitating the stabilization of the air pressure inside the sealed cavity of the housing 8 and preventing the pressure difference from causing a large pressure on the dust cover 9 and the clamp.

[0020] like Figure 1 As shown, the outer peripheral wall of the rod body 1 is provided with a spiral track 111 for cooperating with the nut 4, and the spiral track 111 is located between the first opening 21 and the second opening 31. The outer peripheral wall of the spiral track 111 is sleeved with a nut 4, and the nut 4 drives the rod body 1 to move left and right. The spiral track 111 is located between the first opening 21 and the second opening 31, that is, the nut 4 is located between the first opening 21 and the second opening 31, so that the airflow in the left and right cavities separated by the nut 4 can maintain a steady flow inside the shell 8 through the first opening 21 and the second opening 31. The rod body 1 includes a first transmission section 11 and a second transmission section 12 connected to the first transmission section 11. The outer peripheral wall of the first transmission section 11 is provided with the spiral track 111, and the second transmission section 12 is provided with a rack 121 for cooperating with the gear.

[0021] like Figure 2 and 3 As shown, this embodiment also discloses a steering gear, including a nut 4, a gear, and a ball screw for the steering gear. The nut 4 cooperates with the spiral track 111 on the outer peripheral wall of the first transmission section 11, and the gear cooperates with the rack 121 on the surface of the second transmission section 12. The nut 4 is located between the first opening 21 and the second opening 31. The second opening 31 is located on the left side of the nut 4, and the first opening 21 is located on the right side of the nut 4. When the rod body 1 moves to the left, the airflow on the left side enters through the second opening 31 and flows out through the first opening 21. When the rod body 1 moves to the right, the airflow on the right side enters through the first opening 21 and flows out through the second opening 31.

[0022] like Figure 2 As shown, the ball head seat 5 is also included. The ball head seat 5 includes a connecting block 51 and a seat body 52. ​​The connecting block 51 cooperates with the first opening 21. The connecting block 51 is provided with a third through hole 6. One end of the third through hole 6 is connected to the first through hole 2, and the other end of the third through hole 6 extends to the surface of the seat body 52 to form a third opening. Air flows out of or into the third through hole 6 on the ball head seat 5.

[0023] like Figure 2 and 3 As shown, the end of the base body 52 away from the connecting block 51 is provided with a groove that mates with the spherical pull rod 7. It also includes a housing 8 and a dust cover 9. The rod body 1 is disposed within the housing 8. One end of the dust cover 9 is connected to the housing 8, and the other end of the dust cover 9 is connected to the spherical pull rod 7. The dust covers 9 are located at both ends of the housing 8, forming a sealed cavity within the housing 8. The dust cover 9 has a bellows telescopic structure, which provides space for the dust cover 9 to expand and contract when the pull rod moves left and right.

[0024] It is understandable that the specific embodiments described above are only used to explain the relevant utility model, rather than to limit the utility model. It should also be noted that, for the convenience of description, only the parts related to the utility model are shown in the accompanying drawings. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not have contradictions or conflicts. Any equivalent structural transformation made using the contents of the description and drawings of this utility model, directly or indirectly used in other related technical fields, are also included in the protection scope of this utility model.

Claims

1. A ball screw for a steering gear, characterized in that: It includes a rod body, a first through hole is provided inside the rod body along the axial direction, the first through hole passes through one end of the rod body for connection with the ball head seat, the rod body is also provided with a second through hole, one end of the second through hole passes through the end of the first through hole away from the ball head seat to form a first opening, and the other end of the second through hole extends to the surface of the body to form a second opening.

2. The ball screw for a steering gear according to claim 1, characterized in that: A spiral track for cooperating with a nut is provided on a peripheral wall of the rod body, and the spiral track is located between the first opening and the second opening.

3. The ball screw for a steering gear according to claim 2, characterized in that: The rod body includes a first transmission section and a second transmission section connected to the first transmission section. The outer peripheral wall of the first transmission section is provided with the spiral track, and the second transmission section is provided with a rack for cooperating with a gear.

4. A steering gear, characterized in that: It includes a nut, a gear and the ball screw for the steering gear as described in claim 3, the nut cooperates with the spiral track on the outer peripheral wall of the first transmission section, the gear cooperates with the rack on the surface of the second transmission section, and the nut is located between the first opening and the second opening.

5. The steering gear according to claim 4, characterized in that: It also includes a ball head seat, which includes a connecting block and a seat body. The connecting block cooperates with the first opening. The connecting block is provided with a third through hole. One end of the third through hole is connected to the first through hole, and the other end of the third through hole extends to the surface of the seat body to form a third opening.

6. The steering gear according to claim 5, characterized in that: One end of the seat body away from the connecting block is provided with a groove which cooperates with the spherical pull rod.

7. The steering gear according to claim 4, characterized in that: It also includes a shell and a dust cover. The rod body is arranged inside the shell. One end of the dust cover is connected to the shell, and the other end of the dust cover is connected to the spherical pull rod.

8. The steering gear according to claim 7, characterized in that: The dust cover is a corrugated telescopic structure.

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