WO2022061848A1

WO2022061848A1 - Bushing for fork and fork assembly

Info

Publication number: WO2022061848A1
Application number: PCT/CN2020/118257
Authority: WO
Inventors: 冯晓崇
Original assignee: 舍弗勒技术股份两合公司; 冯晓崇
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2022-03-31
Also published as: CN115698555A; DE112020007640T5

Abstract

A bushing for a fork, the bushing being sleeved at an end portion of a fork shaft (FS) so as to support the fork shaft (FS). The bushing comprises: a main body (10), which is tubular; and a positioning part (20), which is disposed at an axial end portion of the main body (10), an inner peripheral wall of the positioning part (20) partially protruding toward a radial inner side or being recessed toward a radial outer side to thus form a positioning region, and the positioning region being used to shape-lockedly match with a positioning ring (S11) located on the fork shaft (FS) so as to define the axial position of the bushing on the fork shaft (FS). Further provided is a fork assembly.

Description

Fork bushing and fork assembly

technical field

The present invention relates to the field of shift forks, and in particular to a bush for a fork shaft and a fork assembly including the bush.

Background technique

In a multi-speed transmission, for example, a shift fork is often required to effect a shift.

Figure 1 shows a possible fork assembly F, which includes a fork shaft FS and a fork FF fixed to the fork shaft FS. During the shifting process, the shift fork shaft FS can drive the shift fork FF to reciprocate along the axial direction. Both ends of the fork shaft FS are each provided with a bushing B to support the fork shaft FS.

2 is an exploded schematic view of FIG. 1 , the cross section of the fork shaft FS is rectangular, and the cross section of the inner peripheral wall of the bushing B is also rectangular. The axial center of the bushing B is provided with a bushing pin hole B0 which penetrates in the radial direction. Correspondingly, the shifting fork shaft FS is provided with a shaft pin hole S0. After the bushing B is sleeved on the shifting fork shaft FS, a positioning pin is used. P passes through the bushing pin hole B0 and the shaft pin hole S0 to axially position the bushing B and the fork shaft FS.

However, in the process of pressing the positioning pin P into the bushing pin hole B0 and the shaft pin hole S0, it is easy to press out the excess material such as burrs in the holes. For example, usually the bushing B is a plastic part, and the shift fork shaft FS For metal parts, during the process of installing the positioning pin P, plastic chips and metal chips will be generated. This would lead to, for example, a reduction in cleanliness within the transmission.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome or at least alleviate the above-mentioned deficiencies of the prior art, and to provide a bush for a shift fork with a simple structure and good installation effect, and a shift fork assembly including the bush.

According to a first aspect of the present invention, there is provided a bushing for a shift fork, which is sleeved on an end of a shift fork shaft to support the shift fork shaft, wherein the bushing comprises:

the body, in the form of a tube; and

The positioning part is arranged at the axial end of the main body, and the inner peripheral wall of the positioning part is partially convex radially inward or concave radially outward to form a positioning area, and the positioning area is used for connecting with the The locating ring of the fork shaft is form-fittingly fitted to define the axial position of the bushing on the fork shaft.

In at least one embodiment, the positioning portion includes a plurality of elastic claws, the plurality of elastic claws are distributed in a circumferential direction of the main body, and the elastic claws include:

a claw body connected to the main body and extending in the axial direction of the bushing; and

The claw head protrudes from the inner peripheral wall of the claw body and is used for extending into the concave positioning ring located on the fork shaft.

In at least one embodiment, an axial end of the claw head close to the body forms a claw head guide,

In the axial region where the claw head guide portion is located, the closer the claw head is to the main body, the further the inner peripheral wall of the claw head extends radially outward of the bushing.

In at least one embodiment, the positioning portion further includes a plurality of fastening claws, the fastening claws and the elastic clamping claws are spaced apart, and the inner diameter of the cylindrical surface where the inner peripheral wall of the fastening claws is located is equal to or is smaller than the outer diameter of the axial region of the fork shaft in which the bushing is mounted.

In at least one embodiment, the inner peripheral wall of the bushing partially protrudes radially inward to form an interference zone, and the inner diameter of the cylinder where the inner peripheral wall of the interference zone is located is smaller than the diameter of the fork shaft for the fork shaft. The outer diameter of the axial region where the bushing is installed.

In at least one embodiment, the interference areas are multiple, and the interference areas are spaced apart in the circumferential direction of the bushing.

In at least one embodiment, the interference zone includes a plurality of strip-shaped protrusions extending along the axial direction.

In at least one embodiment, the interference region extends from the main body to the positioning portion in the axial direction, and corresponds to the fastening claw in the circumferential direction.

According to a second aspect of the present invention, a shift fork assembly is provided, which includes a shift fork shaft and a bushing sleeved on at least one end portion of the shift fork shaft in the axial direction, wherein the bushing is The bush for a shift fork of the present invention.

In at least one embodiment, at least one end of the shift fork shaft forms a bushing mounting portion, the bushing is mounted on the bushing mounting portion, and the positioning ring is recessed in an annular shape at the bushing mounting portion in the form of grooves or annular projections.

In at least one embodiment, an outer diameter of the bushing mounting portion is smaller than an outer diameter of a shaft main body of the shift fork shaft located in an axial middle portion, so as to form between the bushing mounting portion and the axle main body a shaft shoulder against which the bushing abuts.

The bushing according to the present invention is simple in structure, low in manufacturing cost, and easy to assemble with the shifting fork shaft.

The shift fork assembly according to the present invention can realize the axial positioning of the bushing relative to the shift fork shaft without using the positioning pin, and the shrapnel falling off the components is not easily generated during the installation process.

Description of drawings

Figure 1 is a schematic diagram of one possible fork assembly.

FIG. 2 is an exploded schematic view of some components of FIG. 1 .

3 is a schematic diagram of a shift fork assembly according to one embodiment of the present invention.

FIG. 4 is an exploded schematic view of some components of FIG. 3 .

5 is a schematic diagram of a partial structure of a shift fork shaft of a shift fork assembly according to an embodiment of the present invention.

6 is a schematic diagram of a bushing of a shift fork assembly according to one embodiment of the present invention.

7 to 9 are schematic diagrams of cross-sections of a bushing and a shift fork shaft of a shift fork assembly according to an embodiment of the present invention during assembly.

Description of reference numbers:

F fork assembly; FF fork; FS fork shaft;

P locating pin; S0 shaft pin hole;

S1 bushing mounting part; S11 locating ring; S12 shoulder; S1a shaft guide; Sm shaft body;

B bushing; B0 bushing pin hole; Br interference area;

10 Main body; 10a Chamfer of main body;

20 positioning part; 21 elastic claw; 210 claw body; 211 claw head; 211a claw head guide part; 22 fastening claw;

A axial; R radial.

detailed description

Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present invention, and are not used to exhaust all possible ways of the present invention, nor to limit the scope of the present invention.

3 to 9, the shift fork assembly F and the bushing B according to the present invention are introduced. Unless otherwise specified, in the figures, A represents the axial direction of the fork assembly, which is consistent with the axial direction of the bushing in the fork assembly; R represents the radial direction of the fork assembly, and the radial direction R is consistent with the axial direction of the fork assembly. The radial alignment of the bushing in the .

3 and 4 , the shift fork assembly F includes a shift fork shaft FS, a shift fork FF and a bushing B.

The shift fork FF is fixed on the shift fork shaft FS and can reciprocate along the axis A along the shift fork shaft FS. The bushing B is sleeved on at least one end of the fork shaft FS (in this embodiment, both ends of the fork shaft FS are sleeved with the bushing B). In both the radial direction R and the axial direction A, the bushing B is fixed relative to the shift fork shaft FS, so that the bushing B can follow the shift fork shaft FS to move in the axial direction A and provide support for the shift fork shaft FS.

Preferably, the material of manufacture of the bushing B includes plastic.

4 , 5 and 7 , the structure for mounting the bush B of the fork shaft FS is first described.

The middle part of the fork shaft FS in the axial direction A is referred to as the shaft main body Sm. Both ends of the fork shaft FS, which are located on both sides of the shaft body Sm, are formed as bushing mounting portions S1, and the bushings B are sleeved on the outer periphery of the bushing mounting portion S1. Hereinafter, for convenience, in the axial direction A, the side where the shaft body Sm is located is referred to as the inner side of the fork shaft FS, and the side where the bushing mounting portion S1 is located is referred to as the outer side of the fork shaft FS.

The diameter of the bushing mounting portion S1 is smaller than the diameter of the shaft main body Sm, so that a shoulder S12 is formed at the boundary between the bushing mounting portion S1 and the shaft main body Sm. One end of the bushing B can abut against the shaft shoulder S12 to obtain an axial limit.

A positioning ring S11 is formed on the outer periphery of the bushing mounting portion S1. The positioning ring S11 is used to cooperate with the positioning portion 20 located on the bushing B to provide an axial limit for the bushing B.

In this embodiment, the positioning ring S11 is a concave portion of the peripheral wall of the bushing mounting portion S1, or in other words, the positioning ring S11 is an annular groove. In the axial direction A, the positioning ring S11 is located in a region of the bushing mounting portion S1 near the outer end, but not at the outermost end.

The outermost end of the fork shaft FS forms a shaft guide portion S1a, and the outer diameter of the shaft guide portion S1a increases as it goes inward in the axial direction. In other words, the shaft guide portion S1a is a chamfered or rounded end of the fork shaft FS. Horn. The provision of the shaft guide portion S1a makes the process of inserting the bushing B into the fork shaft FS more convenient.

Next, the bushing B will be described with reference to FIGS. 6 and 7 .

The bushing B is in the shape of a short tube, which includes a main body 10 and a positioning portion 20 located at the end of the main body 10 . The positioning portion 20 is used to cooperate with the positioning ring S11 located at the bushing installation portion S1 to provide the bushing B on the fork shaft. Axial positioning on FS. Preferably, the positioning portion 20 can also provide radial positioning for the bushing B. As shown in FIG.

Preferably, the inner circumference of the end of the main body 10 facing the axially inner side of the fork shaft FS is formed with a chamfer 10a to facilitate the assembly of the bushing B and the fork shaft FS.

In this embodiment, the positioning portion 20 includes a plurality of elastic claws 21 and a plurality of fastening claws 22, and the elastic claws 21 and the fastening claws 22 are arranged at intervals in the circumferential direction, that is, adjacent elastic claws 21 are tightened The fixing claws 22 are spaced apart, and the adjacent fastening claws 22 are spaced apart by the elastic claws 21 .

The elastic jaws 21 are mainly used to provide axial positioning for the bushing B. The elastic claw 21 includes a claw body 210 and a claw head 211 .

The claw body 210 is in the shape of a strip, which is connected with the main body 10 and extends along the axial direction A. As shown in FIG. The inner diameter of the cylindrical surface on which the inner walls of the plurality of claw bodies 210 in the circumferential direction are located is approximately equal to (or preferably slightly larger than) the outer diameter of the bushing mounting portion S1 .

The claw head 211 is located at the end of the claw body 210 away from the main body 10 , and in this embodiment, the claw head 211 protrudes radially inward from the inner peripheral wall of the claw body 210 , or the claw head 211 is radially opposite to the claw body 210 Extend inward. When the bushing B is installed on the fork shaft FS, the claw head 211 protrudes into the groove of the positioning ring S11 to provide axial positioning for the bushing B and prevent the bushing B from falling off the fork shaft FS.

Preferably, the end portion of the claw head 211 for facing the axially inner side of the fork shaft FS forms a claw head guide portion 211a. In the axial region where the claw head guide portion 211a is located, the inner peripheral wall of the claw head 211 extends radially outward of the bush B as it goes inward in the axial direction. In other words, the claw head guide portion 211 a is a chamfered or rounded corner of the end of the claw head 211 . The provision of the claw head guide portion 211a makes the process of the elastic claw 21 extending into the positioning ring S11 more smoothly by virtue of elastic deformation.

Preferably, in order to make the elastic deformation and recovery of the elastic jaw 21 easier during the installation process with the fork shaft FS, the claw body 210 has a smaller wall thickness. For example, the thickness of the claw body 210 in the radial direction R is smaller than the thickness of the main body 10 in the radial direction R, and preferably, the inner peripheral wall of the claw body 210 and the inner peripheral wall of the main body 10 are on the same cylindrical surface, and the claw body 210 The outer diameter is smaller than the outer diameter of the main body 10 .

The fastening claw 22 is used to strengthen the structural strength of the bushing B. The inner diameter of the cylindrical surface on which the fastening claw 22 is located is equal to or slightly smaller than the outer diameter of the bushing mounting portion S1. Preferably, the thickness of the fastening claw 22 in the radial direction R is equal to the thickness of the main body 10 in the radial direction R, and preferably, the inner peripheral wall of the fastening claw 22 and the inner peripheral wall of the main body 10 are on the same cylindrical surface, and the fastening The outer peripheral wall of the claw 22 and the outer peripheral wall of the main body 10 are on the same cylindrical surface.

Preferably, in the axial direction A, the lengths of the fastening claw 22 and the elastic clamping claw 21 are equal.

Preferably, the inner peripheral wall of the bushing B partially protrudes radially inward to form an interference region Br, and the inner diameter of the cylinder where the inner peripheral wall of the interference region Br is located is smaller than the outer diameter of the bushing mounting portion S1 . So that the bushing B and the bushing mounting part S1 achieve an interference fit at least in the interference area Br.

Preferably, in the axial direction A, the interference area Br extends from the main body 10 to the positioning portion 20; in the circumferential direction, the interference area Br is located in the area where the fastening claw 22 is located, that is, the inner peripheral wall of the fastening claw 22 is oversized The area Br covers and the interference area Br on the inner circumference of each fastening claw 22 extends all the way along the axial direction A and penetrates the main body 10 , while the circumferential area where the elastic claw 21 is located does not have the interference area Br.

Each of the interference regions Br includes, for example, a plurality of strip-shaped protrusions extending along the axial direction A. As shown in FIG.

The above-mentioned method of setting the interference zones Br at intervals in the circumferential direction not only ensures the tight fit between the bushing B and the shift fork shaft FS in the radial direction, but also prevents the bushing B from being subjected to too much interference, such as cracking, etc. damage.

Next, referring to FIGS. 7 to 9 , the assembling process of the bushing B and the fork shaft FS will be described.

First, referring to FIG. 7 , the bushing B and the axis of the fork shaft FS are centered, and the bushing B is prepared to be put on the fork shaft FS so that the main body 10 faces the fork shaft FS.

8, the bushing B is gradually inserted into the bushing mounting portion S1 until the claw head guide portion 211a of the elastic jaw 21 contacts the shaft guide portion S1a at the end of the bushing mounting portion S1.

Finally, referring to FIG. 9 , continue to apply force along the axial direction A to make the elastic jaws 21 open radially outward, then the elastic jaws 21 are reset, and the jaws 211 extend into the grooves of the positioning ring S11 . The end face abuts the shoulder S12.

It is worth noting that, in other possible implementations, the positioning ring S11 may also be an annular protrusion located on the peripheral wall of the bushing installation portion S1. Correspondingly, for example, the inner peripheral wall of the elastic claw 21 may have a concave portion. The positioning ring S11 can extend into the concave part of the inner circumference of the elastic claw, so as to realize the axial positioning of the bushing B.

In this case, preferably, the bushing B is installed on the fork shaft FS with the elastic pawls 21 facing inwards and the main body 10 facing outwards, so as to avoid interference between the protruding positioning ring S11 and the main body 10 .

Some beneficial effects of the above-mentioned embodiments of the present invention are briefly described below.

(i) The bushing B according to the present invention is simple in structure, low in production cost, and easy to assemble with the fork shaft FS.

(ii) The shift fork assembly according to the present invention can realize the axial positioning of the bushing B relative to the shift fork shaft FS without using the positioning pin, and the installation process is not easy to generate debris from the components.

It should be understood that the above-mentioned embodiments are only exemplary, and are not intended to limit the present invention. Those skilled in the art can make various modifications and changes to the above-described embodiments under the teachings of the present invention without departing from the scope of the present invention. E.g,

(i) The fastening claw 22 can also be omitted, and the radial positioning between the bushing B and the fork shaft FS can be realized only by the main body 10 and the elastic clamping claw 21 .

(ii) Although in the illustrated embodiment, the outer peripheral wall of the bushing mounting portion S1 and the inner peripheral wall of the bushing B are both cylindrical, this is not required, and in other possible embodiments, the bushing is installed The cross-sections of the portion S1 and the bushing B may not be circular.

Claims

A bushing for a shift fork, which is used to be sleeved on the end of a shift fork shaft (FS) to support the shift fork shaft (FS), characterized in that the bushing comprises:

a body (10), in the form of a tube; and

The positioning portion (20) is arranged at the axial end portion of the main body (10), and the inner peripheral wall of the positioning portion (20) is partially convex radially inward or concave radially outward to form a positioning area, so The locating area is used for form-locking cooperation with a locating ring (S11) located on the fork shaft (FS) to define the axial position of the bush on the fork shaft (FS).
The bushing for a shift fork according to claim 1, wherein the positioning portion (20) comprises a plurality of elastic claws (21), and the plurality of elastic claws (21) are located on the main body (10). ) are spaced apart in the circumferential direction, and the elastic jaws (21) include:

a claw body (210) connected to the main body (10) and extending along the axial direction (A) of the bushing; and

The claw head (211) protrudes from the inner peripheral wall of the claw body (210), and is used for extending into the concave positioning ring (S11) located on the fork shaft (FS).
The bushing for a shift fork according to claim 2, characterized in that an axial end portion of the claw head (211) close to the main body (10) forms a claw head guide portion (211a),

In the axial region where the claw head guide portion (211a) is located, the closer to the main body (10), the more the inner peripheral wall of the claw head (211) extends radially outward of the bushing.
The bushing for a shift fork according to claim 2, characterized in that, the positioning portion (20) further comprises a plurality of fastening claws (22), the fastening claws (22) and the elastic clamping claws ( 21) Spaced apart, the inner diameter of the cylindrical surface where the inner peripheral wall of the fastening claw (22) is located is equal to or smaller than the outer diameter of the axial region of the fork shaft (FS) for installing the bushing.
The bushing for a shift fork according to claim 4, characterized in that the inner peripheral wall of the bushing partially protrudes radially inward to form an interference region (Br), and the interference region (Br) has The inner diameter of the cylinder on which the inner peripheral wall is located is smaller than the outer diameter of the axial region of the fork shaft (FS) where the bushing is installed.
The bushing for a shift fork according to claim 5, characterized in that the interference regions (Br) are provided at multiple locations, and the interference regions (Br) are spaced apart in the circumferential direction of the bushing. set up.
The bushing for a shift fork according to claim 5, characterized in that, the interference region (Br) comprises a plurality of strip-shaped protrusions extending in the axial direction.
The bushing for a shift fork according to claim 5, characterized in that the interference region (Br) extends from the main body (10) to the positioning portion (20) in the axial direction, and is circumferentially aligned with the positioning portion (20). The fastening claws (22) correspond.
A shift fork assembly, comprising a shift fork shaft (FS) and a bushing (B) sleeved on at least one end of the fork shaft (FS) in the axial direction (A), characterized in that the The bushing (B) is the bushing for a shift fork according to any one of claims 1 to 8 .
The shift fork assembly according to claim 9, wherein at least one end of the shift fork shaft (FS) forms a bushing mounting portion (S1), and the bushing (B) is mounted on the bushing An installation part (S1), the positioning ring (S11) is formed in the form of an annular groove or an annular protrusion in the bushing installation part (S1).
The shift fork assembly according to claim 10, wherein the outer diameter of the bushing mounting portion (S1) is smaller than the outer diameter of the shaft main body (Sm) located in the axial middle of the shift fork shaft (FS) , so that a shoulder (S12) is formed between the bushing mounting portion (S1) and the shaft main body (Sm), and the bushing (B) abuts against the shoulder (S12).