Electric power steering gear and steering nut thereof

Abstract

The utility model discloses an electric power steering gear and a steering nut thereof, and relates to the technical field of automobile steering, the electric power steering gear comprises a body, a first convex ring and a second convex ring, one side of the peripheral wall of the body is provided with a rack meshed with sector teeth of a rocker arm shaft, the first convex ring is coaxially arranged on the peripheral wall of one end of the body, and the second convex ring is coaxially arranged on the peripheral wall of the other end of the body. The diameter of the first convex ring is the same as that of the second convex ring, and the free end of the rack protrudes out of the outer wall face of the first convex ring and the outer wall face of the second convex ring. The first convex ring and the second convex ring are used for abutting against the inner wall of the shell, the free end, namely the end meshed with the rocker arm shaft, of the rack protrudes out of the first convex ring and the second convex ring, the strength of the rack can be improved, and convenience can be improved when the rack and the rocker arm shaft are meshed and assembled. And interference of the first convex ring and the second convex ring on the rack during assembly is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of automobile steering, specifically relates to electric power steering gear and steering nut thereof. BACKGROUND

[0002] The steering nut is a very important part of the automobile steering gear and is connected with the valve assembly. The steering gear mainly comprises a screw rod, a nut, a steering gear shell and a plurality of small steel balls. The so-called circulating ball refers to the small steel balls which are placed in the closed pipeline between the nut and the screw rod and serve to convert the sliding friction between the nut and the screw rod into rolling friction with smaller resistance. When the screw rod fixed together with the steering column rotates, the screw rod drives the nut to move up and down. The prior art discloses a steering nut of an automobile power steering gear in Chinese patent CN201220348937.4, which comprises a nut body and a steering rack provided on the nut body. The end of the steering rack is flush with the nut body. When the end of the steering rack is engaged with the rocker shaft, the nut body is prone to interfering with the rocker shaft, and improvement is urgently needed. SUMMARY

[0003] In view of the above technical problems, the utility model provides an electric power steering gear and a steering nut thereof. The free end of the rack, i.e. the end engaged with the rocker shaft, protrudes from the first and second convex rings, thereby increasing the strength of the rack and the convenience of assembling the rack and the rocker shaft, and avoiding interference between the first and second convex rings and the rack during assembly.

[0004] The utility model adopts the following technical scheme: a steering nut, comprising a body, a first convex ring and a second convex ring, the body is equipped with the rack that is engaged with the fan tooth of rocker axle on one side of outer wall, the first convex ring is coaxial and is equipped with on one end of outer wall of body, the second convex ring is coaxial and is equipped with on the other end of outer wall of body, the diameter of first convex ring is same with the diameter of second convex ring, the free end of rack protrudes from the outer wall surface of first convex ring and the outer wall surface of second convex ring.

[0005] Optionally, the diameter of the first convex ring and the diameter of the second convex ring are both greater than the diameter of the body.

[0006] Optionally, the root of the rack protrudes from the body to form a reinforcing rib, and a groove is formed between the reinforcing rib, the first convex ring and the second convex ring.

[0007] Optionally, the outer peripheral wall of the first convex ring and the outer peripheral wall of the second convex ring are respectively provided with annular grooves, wear-resistant rings are installed in the annular grooves, and the wear-resistant rings protrude from the annular grooves.

[0008] Optionally, the inner peripheral wall of the body is provided with a flat groove for installing a ball return device and an inner raceway for rolling of the ball.

[0009] An electric power steering gear comprises a worm wheel, a steering screw, a rocker shaft and the steering nut as described above, the worm wheel and the body are sleeved on the outer peripheral wall of the steering screw, and the rocker shaft is engaged with the rack.

[0010] Optionally, the steering screw is provided with a first eccentric bearing at one end and a second eccentric bearing at the other end, the worm wheel and the steering nut are arranged between the first eccentric bearing and the second eccentric bearing, the first eccentric bearing is provided with a first adjusting hole, the second eccentric bearing is provided with a second adjusting hole, and the first adjusting hole and the second adjusting hole are arranged on the same axis.

[0011] Optionally, one side of the second eccentric bearing facing the steering nut is provided with a sealing plate, one end of the sealing plate is in interference fit with the inner ring of the second eccentric bearing, and the other end of the sealing plate is press-fitted with the inner wall of the outer ring of the second eccentric bearing through chamfering.

[0012] The electric power steering gear has the advantages that the first convex ring and the second convex ring are used for abutting against the inner wall of the shell, the free end of the rack, i.e. the end protruding from the first convex ring and the second convex ring and engaged with the rocker shaft, can increase the strength of the rack and the convenience of assembling the rack and the rocker shaft, and the interference of the first convex ring and the second convex ring on the rack during assembly is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A structural schematic view of the steering nut is provided for the embodiment of the utility model;

[0014] Figure 2 A schematic view of the electric power steering gear is provided for the embodiment of the utility model;

[0015] Figure 3 A schematic view of the second eccentric bearing is provided for the embodiment of the utility model.

[0016] The marks in the drawings are as follows: 1, body; 2, first convex ring; 3, second convex ring; 4, rack; 5, reinforcing rib; 6, annular groove; 7, flat groove; 8, inner raceway; 9, worm wheel; 10, steering screw; 11, rocker shaft; 12, first eccentric bearing; 13, second eccentric bearing; 14, sealing plate. DETAILED DESCRIPTION

[0017] The application will be further described in detail below with reference to the drawings and embodiments.

[0018] As Figure 1As shown in the figure, the embodiment discloses a steering nut, which comprises a body 1, a first convex ring 2 and a second convex ring 3, the body 1 is provided with a rack 4 on one side of the outer wall, the rack 4 is engaged with the fan teeth of a rocker shaft 11, the first convex ring 2 is coaxially arranged on the outer wall of one end of the body 1, the second convex ring 3 is coaxially arranged on the outer wall of the other end of the body 1, the diameter of the first convex ring 2 is the same as that of the second convex ring 3, and the free end of the rack 4 protrudes from the outer wall surface of the first convex ring 2 and the outer wall surface of the second convex ring 3. The first convex ring 2 and the second convex ring 3 are respectively used for abutting against the inner wall of a housing, the free end of the rack 4, that is, the end engaged with the rocker shaft 11, protrudes from the first convex ring 2 and the second convex ring 3, that is, the strength of the rack 4 itself can be increased, and the convenience of the engagement assembly of the rack 4 and the rocker shaft 11 can be increased, and the interference of the first convex ring 2 and the second convex ring 3 to the rack 4 during assembly is avoided.

[0019] In the embodiment, as shown in the figure, Figure 1 the diameter of the first convex ring 2 and the diameter of the second convex ring 3 are both greater than the diameter of the body 1. The effect of weight reduction is achieved. The root of the rack 4 protrudes from the body 1 to form a reinforcing rib 5, and a groove is formed between the reinforcing rib 5, the first convex ring 2 and the second convex ring 3. The reinforcing rib 5 increases the engagement strength of the rack 4, and the groove achieves the effect of weight reduction, thereby reducing the overall weight of the steering nut.

[0020] As shown in the figure, Figure 1 the outer wall of the first convex ring 2 and the outer wall of the second convex ring 3 are respectively provided with annular grooves 6, wear-resistant rings are installed in the annular grooves 6, and the wear-resistant rings protrude from the annular grooves 6. When the steering nut abuts against the inner wall of the housing and reciprocates on the inner wall of the housing under the driving of a steering screw 10, the wear-resistant rings directly move with the housing, thereby increasing the wear resistance of the steering nut. The material of the wear-resistant ring can be rubber. The inner wall of the body 1 is provided with a flat groove 7 for installing a ball returning device and an inner raceway 8 for rolling of the ball.

[0021] As shown in the figure, Figure 2As shown, the embodiment also discloses an electric power steering gear, comprising a worm wheel 9, a steering screw 10, a rocker shaft 11 and the steering nut described above, the worm wheel 9 and the body 1 are sleeved on the outer wall of the steering screw 10, and the rocker shaft 11 is engaged with the rack 4. One end of the steering screw 10 is provided with a first eccentric bearing 12, and the other end of the steering screw 10 is provided with a second eccentric bearing 13, the worm wheel 9 and the steering nut are arranged between the first eccentric bearing 12 and the second eccentric bearing 13, the first eccentric bearing 12 is provided with a first adjusting hole, the second eccentric bearing 13 is provided with a second adjusting hole, and the first adjusting hole and the second adjusting hole are arranged on the same axis. At the beginning of assembly, the small diameter of the first eccentric bearing 12 and the small diameter of the second eccentric bearing 13 are both towards the top of the shell, and the first eccentric bearing 12 and the second eccentric bearing 13 are rotated synchronously, so that the steering nut abuts against the inner wall of the shell, and then the radial gap between the steering nut and the shell is adjusted,

[0022] In the embodiment, as shown, Figure 3 As shown, one side of the second eccentric bearing 13 towards the steering nut is provided with a sealing plate 14, one end of the sealing plate 14 is interference-fitted with the inner ring of the second eccentric bearing 13, and the other end of the sealing plate 14 is press-fitted with the inner wall of the outer ring of the second eccentric bearing 13 through chamfering. The iron filings generated by the meshing friction between the worm wheel 9 and the worm and the steering nut and the steering screw 10 will enter the second eccentric bearing 13, causing the steel balls in the second eccentric bearing 13 to be stuck, and then affecting the normal operation of the steering gear. The setting of the sealing plate 14 can prevent the iron filings from entering the inside of the second eccentric bearing 13, prolonging the service life of the second eccentric bearing 13. The first adjusting hole is arranged on the outer ring of the first eccentric shaft, and the second adjusting hole is arranged on the outer ring of the second eccentric bearing 13.

[0023] It can be understood that the specific embodiments described above are only used to explain the related utility model, and are not limited to the utility model. In addition, it should be noted that only the parts related to the utility model are shown in the drawings for convenience of description. The multiple technical solutions in the same embodiment and the multiple technical solutions of different embodiments can be arranged and combined to form new technical solutions without contradiction or conflict. Any equivalent structural transformation, direct or indirect application in other related technical fields, is also included in the protection scope of the utility model.

Claims

1. A turnbuckle, characterized in that, The application relates to a steering nut comprising a body, a first convex ring and a second convex ring, wherein a rack meshing with a fan tooth of a rocker shaft is arranged on one side of the outer wall of the body, the first convex ring is coaxially arranged on the outer wall of one end of the body, the second convex ring is coaxially arranged on the outer wall of the other end of the body, the diameter of the first convex ring is the same as that of the second convex ring, and the free end of the rack protrudes from the outer wall surface of the first convex ring and the outer wall surface of the second convex ring.

2. The turnbuckle nut of claim 1, wherein, The diameter of the first convex ring and the diameter of the second convex ring are both larger than the diameter of the body.

3. The turnbuckle nut of claim 2, wherein, The root of the rack protrudes from the body to form a reinforcing rib, and a groove is formed among the reinforcing rib, the first convex ring and the second convex ring.

4. The turnbuckle nut of claim 2, wherein, The outer wall of the first convex ring and the outer wall of the second convex ring are respectively provided with annular grooves, wear-resistant rings are arranged in the annular grooves, and the wear-resistant rings protrude from the annular grooves.

5. The turnbuckle nut of claim 1, wherein, The inner wall of the body is provided with a flat groove for mounting a ball returning device and an inner raceway for ball rolling.

6. An electric power assisted steering gear characterised in that The application further relates to a steering nut comprising a worm wheel, a steering screw, a rocker shaft and the steering nut of any one of claims 1-5, wherein the worm wheel and the body are both sleeved on the outer wall of the steering screw, and the rocker shaft is meshed with the rack.

7. The electric power assisted steering gear of claim 6, wherein One end of the steering screw is provided with a first eccentric bearing, the other end of the steering screw is provided with a second eccentric bearing, the worm wheel and the steering nut are arranged between the first eccentric bearing and the second eccentric bearing, the first eccentric bearing is provided with a first adjusting hole, the second eccentric bearing is provided with a second adjusting hole, and the first adjusting hole and the second adjusting hole are arranged on the same axis.

8. The electric power assisted steering gear of claim 7, wherein One side of the second eccentric bearing facing the steering nut is provided with a sealing plate, one end of the sealing plate is in interference fit with the inner ring of the second eccentric bearing, and the other end of the sealing plate is press-fitted with the inner wall of the outer ring of the second eccentric bearing through chamfering.

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