WO2019017261A1

WO2019017261A1 - Sliding bearing

Info

Publication number: WO2019017261A1
Application number: PCT/JP2018/026243
Authority: WO
Inventors: 関根　敏彦; 勝紀斉藤; 和彦明田; 淳大内
Original assignee: オイレス工業株式会社
Priority date: 2017-07-20
Filing date: 2018-07-11
Publication date: 2019-01-24
Also published as: JP2019019952A

Abstract

Provided is a sliding bearing that is capable of reducing generation of abnormal noise caused by rattling of a shaft member while suppressing torque generated by sliding with the shaft member. A rack bush 1 is housed in a cylindrical housing 2 in a state where movement in an O-axis direction is restricted, is mounted to the back surface 41 (the surface on the opposite side of a rack gear 40) side of a rack bar 4, and supports a load applied to the rack bar 4 while permitting movement of the rack bar 4 in the O-axis direction. The rack bush 1 is provided with: a cylindrical bush body 10 that has a clearance from the rack bar 4; a through-slit 102 that penetrates both end surfaces of the bush body 10 in the axis direction on the rack gear 40 side of the rack bar 4; and a pair of support surfaces 11 that touches and supports the rack bar 4 so as to pinch the rack bar 4 in the vertical direction V (the width direction of through-slit 102).

Description

Sliding bearing

The present invention relates to a slide bearing for supporting a load applied to a shaft member, and more particularly to a slide bearing suitable for a rack bush used in a rack and pinion type steering mechanism.

The rack-and-pinion type steering mechanism engages the rotational movement of the pinion gear with the linear movement of the rack gear by meshing between the pinion gear formed at the tip of the shaft that rotates in conjunction with the steering wheel and the rack gear formed on the rack bar. Convert to Thereby, the direction of the tire connected to the tie rod interlocked with the rack bar is changed.

Patent Document 1 discloses a rack and pinion type steering mechanism provided with a rack bush. In this steering mechanism, the rack bush is mounted on the rear side of the rack gear surface of the rack bar and supports the rack bar when it is loaded while allowing linear movement of the rack bar. In addition, the rack bush has through slits penetrating both end faces formed along the axial direction on the rack gear side of the rack bar, and therefore, it is easy to reduce the diameter compared to a cylindrical bush without a through slit. Assembling work of the rack bush to the housing which accommodates the rack bush together with the rack bar becomes easy and smooth.

JP, 2013-79024, A

In the rack bush described in Patent Document 1, the inner circumferential surface is in contact with the outer circumferential surface of the rack bar over the entire circumference. Therefore, torque is generated by the sliding between the rack bar and the rack bush, which affects the steering operation. In order to reduce this influence, it is preferable to have a clearance for the entire circumference of the rack bar so as to be noncontact with the rack bar.

However, in the rack-and-pinion type steering mechanism, when the rotational movement of the pinion gear is converted into the linear movement of the rack gear, the rack gear is pulled up and down by the pinion gear, and vertical rattling occurs in the rack bar. For this reason, in the rack bush having a clearance with respect to the entire circumference of the rack bar, the rack bar may abut against the rack bar to generate noise due to the rattling of the rack bar in the vertical direction.

This problem is not limited to the rack bush used in the rack and pinion type steering mechanism. In a slide bearing for supporting a load applied to a shaft member, when it has a clearance with respect to the entire circumference of the shaft member, it is generated due to rattling of the shaft member.

The present invention has been made in view of the above circumstances, and an object thereof is a sliding bearing capable of reducing the generation of abnormal noise due to rattling of a shaft member while suppressing torque due to sliding with the shaft member. It is to provide.

In order to solve the above-mentioned subject, in the present invention, while forming the penetration slit which penetrates the both end faces of a bearing body along with the axial direction in the cylindrical bearing main body in which a shaft member is inserted, the width direction of this penetration slit A pair of support surfaces that contact and support the shaft member in a sandwiching manner are provided radially inward from the inner peripheral surface of the bearing body.

For example, the present invention
A slide bearing for supporting a shaft member,
A cylindrical bearing body into which the shaft member is inserted;
Through slits penetrating both axial end faces of the bearing body;
And a pair of support surfaces formed radially inward of the inner peripheral surface of the bearing main body and in contact with and supporting the shaft member so as to sandwich the shaft member in the width direction of the through slit.

In the present invention, since the shaft member is supported by being in contact with and held in the width direction of the through slit by the pair of support surfaces, rattling of the shaft member in the width direction of the through slit is suppressed, and Abutment can be prevented, whereby generation of abnormal noise can be prevented. Further, since the pair of support surfaces are formed radially inward of the inner peripheral surface of the bearing main body, the contact with the shaft member inserted into the bearing main body can be made to be only the support surface. The torque due to the sliding between the member and the slide bearing can be suppressed. Therefore, according to the present invention, it is possible to reduce the generation of abnormal noise due to rattling of the shaft member while suppressing the torque due to the sliding with the shaft member.

FIG. 1 is a top partial cross-sectional view of a rack and pinion type steering mechanism in which a rack bush 1 according to an embodiment of the present invention is used. FIG. 2 is a side partial cross-sectional view of the rack and pinion type steering mechanism shown in FIG. 3A, 3B, 3C, and 3D are a front view, a top view, a left side view, and a right side view of the rack bush 1, respectively. FIGS. 4A and 4B are a cross-sectional view taken along the line AA and a cross-sectional view taken along the line AA of the rack bush 1 shown in FIG. 3C.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a top partial cross-sectional view of a rack and pinion type steering mechanism in which a rack bush 1 according to an embodiment of the present invention is used. FIG. 2 is a side cross-sectional view of the rack and pinion type steering mechanism shown in FIG.

As shown, the rack-and-pinion type steering mechanism comprises a pinion gear 30 formed at the tip of the shaft 3 which rotates in conjunction with a steering wheel (not shown) and a rack gear 40 formed on the rack bar 4. By meshing, the rotational movement R of the pinion gear 30 is converted into a linear movement L in the direction of the axis O of the rack gear 40 (perpendicular to the vehicle traveling direction G and in the horizontal direction). Thereby, the direction of the tire (not shown) connected to the tie rod (not shown) interlocked with the rack bar 4 is changed.

Here, the rack bush 1 is accommodated in the cylindrical housing 2 in a state in which the movement in the direction of the axis O is restricted, and is mounted on the rear surface 41 of the rack bar 4 (surface opposite to the rack gear 40) 41 Thus, the load applied to the rack bar 4 is supported while permitting the movement of the rack bar 4 in the axial O direction.

3A, 3B, 3C, and 3D are a front view, a top view, a left side view, and a right side view of the rack bush 1, respectively. 4 (A) and 4 (B) are an AA cross sectional view and a BB cross section of the rack bush 1 shown in FIG. 3 (C).

The rack bush 1 is formed of a synthetic resin having good sliding characteristics such as polyacetal resin, polyamide resin, polyethylene resin, and a pair of support portions 13 each having a cylindrical bush main body 10 and a support surface 11 as illustrated. And have.

The bush main body 10 has a pair of slits 101 provided for each support portion 13, a through slit 102, and a flange 103.

The pair of slits 101 is formed along the axis O direction from one end face 104 a to the other end face 104 b in the vertical direction V of the bush main body 10 (the width direction of the through slit 102). The corresponding support surface 11 of the support portion 13 is disposed radially inward.

The through slit 102 penetrates both

end faces

104a and 104b of the bush main body 10 along the axis O direction on the rack gear 40 side of the rack bar 4 (see FIG. 2). It is expandable in the direction. The width H1 of the through slit 102 is larger than the width H2 of the rack gear 40 of the rack bar 4 (see FIG. 2). This prevents the edge 1020 of the through slit 102 from coming into contact with the gear surface of the rack gear 40.

The flange 103 is formed on the outer peripheral surface 105 of the bush main body 10 on the other end surface 104 b side of the bush main body 10, and is inserted into an annular groove 21 formed in the circumferential direction on the inner peripheral surface 20 of the housing 2. Thereby, the movement of the rack bush 1 accommodated in the housing 2 in the direction of the axis O is restricted (see FIG. 1).

Projections 106 for alignment are formed on the flange 103, and the projections 106 are inserted into the guide grooves 22 formed in the axial O direction on the inner circumferential surface 20 of the housing 2, whereby the through slits 102 are formed. Is positioned on the rack gear 40 side of the rack bar 4 and the rack bush 1 is correctly positioned so that the width direction thereof coincides with the vertical direction V (see FIG. 1).

Further, the bush main body 10 has the inner circumferential surface 109 disposed on the back surface 41 side of the rack bar 4 and has a first inner diameter portion 107 having an inner diameter r1 larger than the outer diameter r3 of the rack bar 4 and the first inner diameter portion 107 A second inner diameter portion 108 is disposed on the rack gear 40 side of the rack bar 4 and has an inner diameter r2 larger than the inner diameter r1 of the first inner diameter portion 107. Thus, the inner circumferential surface 109 of the bush main body 10 has a clearance with respect to the rack bar 4 over the entire circumference. Further, by making the inner diameter r2 of the second inner diameter portion 108 larger than the inner diameter r1 of the first inner diameter portion 107, the bush main body 10 is the rack bar 4 due to the back and forth movement of the rack bush 1 (vehicle traveling direction G). The possibility of contact with the rack gear 40 is reduced (see FIG. 2).

The pair of support portions 13 contacts and supports the rack bar 4 so as to sandwich the rack bar 4 in the vertical direction V by the respective support surfaces 11 (see FIG. 2). As described above, the support portion 13 has the support surface 11 disposed radially inward in the corresponding slit 101, and is connected to the bush main body 10 by the arm 12 extending in the axial O direction. The arm 12 and the support portion 13 are disposed on the inner side (axis O side) of the bush main body 10 than the outer peripheral surface 105 of the bush main body 10. Therefore, when the rack bush 1 is accommodated in the housing 2, a gap g is formed between the outer peripheral surface 14 of the arm 12 and the outer peripheral surface 15 of the support portion 13 and the inner peripheral surface 20 of the housing 2 (see FIG. 2) Thus, the support surface 11 can move in the vertical direction V and the circumferential direction C while abutting the rack bar 4.

Further, the pair of support portions 13 respectively arrange the support surface 11 on the circle 110 set so as to be flush with the rack bar 4, and thereby contact the rack bar 4 with certainty. It is being done. Furthermore, each of the pair of support portions 13 has the support surface 11 disposed on the rack gear 40 side of the rack bar 4 with respect to the vertical line D including the axial center O and parallel to the width direction of the through slit 102, Thereby, rattling of the front and rear (vehicle traveling direction G) of the rack bush 1 is suppressed, and the possibility that the bush main body 10 contacts the rack gear 40 of the rack bar 4 is reduced (see FIG. 2).

Heretofore, an embodiment of the present invention has been described.

In the present embodiment, the rack bush 1 is mounted on the rack bar 4 so that the width direction of the through slit 102 coincides with the vertical direction V of the rack bar 4, so the rack bush 1 supports the pair of support portions 13. The rack bar 4 is in contact with and supported by the surface 11 so as to be sandwiched from the vertical direction V. Therefore, rattling in the vertical direction V of the rack bar 4 can be suppressed, and contact with the rack bar 4 due to this rattling can be prevented, whereby generation of abnormal noise can be prevented. Further, since the inner diameter having the clearance to the rack bar 4 (the inner diameter r1 of the first inner diameter portion 107 and the inner diameter r2 of the second inner diameter portion 108) and the contact with the rack bar 4 is only the support surface 11, the rack bar The torque caused by the sliding of the rack bush 4 and the rack bush 1 can be reduced to reduce the influence on the steering operation. Therefore, it is possible to reduce the generation of abnormal noise while suppressing the influence on the steering operation.

Further, in the present embodiment, the support portion 13 arranges the support surface 11 radially inward in the corresponding slit 101, and is connected to the bush main body 10 by the arm 12 extending in the axial O direction. There is. Since the support surface 11 can move in the vertical direction V and the circumferential direction C while abutting the rack bar 4 by the elastic deformation in the width direction of the through slit 102 of the arm 12 and the circumferential direction of the bush main body 10 The pair of support surfaces 11 can be reliably contacted by the rack bar 4.

Further, in the present embodiment, on the rack gear 40 side of the rack bar 4, the through slits 102 penetrating the both end faces 104 a and 104 b of the bush main body 10 are provided along the axis O direction. The main body 10 can be expanded and contracted in the radial direction, and the mounting operation to the housing 2 can be facilitated.

Further, in the present embodiment, the pair of support surfaces 11 supporting the rack bar 4 in the vertical direction V includes the axial center O, and the rack bar 4 of the rack bar 4 with respect to the vertical line D parallel to the width direction of the through slit 102. Since it is disposed on the rack gear 40 side, rattling of the front and rear (vehicle traveling direction G) of the rack bush 1 can be suppressed, and the possibility of the bush main body 10 coming into contact with the rack gear 40 of the rack bar 4 can be reduced. Therefore, the generation of abnormal noise can be further reduced.

Further, in the present embodiment, the bush main body 10 has the inner diameter r2 of the second inner diameter portion 108 disposed on the rack gear 40 side of the rack bar 4 as the first inner diameter portion 107 disposed on the back surface 41 side of the rack bar 4. Since the diameter is larger than the inner diameter r1, the possibility of the bush main body 10 coming into contact with the rack gear 40 of the rack bar 4 can be reduced by the back and forth movement of the rack bush 1 (vehicle traveling direction G). Sound generation can be further reduced.

The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the invention.

For example, in the above embodiment, the support surface 11 is disposed radially inward in the corresponding slit 101, and is connected to the bush main body 10 by the arm 12 extending in the axial O direction. However, the present invention is not limited to this. The support surface 11 may be connected to the bush main body 10 by any method as long as it can move in the vertical direction V while abutting the rack bar 4. For example, by interposing an elastic body such as rubber or thermoplastic elastomer between the support surface 11 and the inner circumferential surface 109 of the bush main body 10, the support surface 11 is in contact with the rack bar 4 in the vertical direction V It may be movable. Alternatively, a gap is provided between the support portion 13 and the inner circumferential surface 20 of the housing 2 so that the support portion 13 can move in the gap, so that the support surface 11 contacts the rack bar 4 in the vertical direction. It may be movable to V.

Further, the present invention is not limited to the rack bush used in the rack and pinion type steering mechanism. It is widely applicable to a sliding bearing that supports a shaft member.

1: Rack bush, 2: housing, 3: shaft, 4: rack bar, 10: bush main body, 11: support surface, 12: arm, 13: support portion, 14: outer peripheral surface of arm 12, 15: support portion 13 Outer circumferential surface of 20, inner circumferential surface of housing 2, 21: annular groove of housing 2, 22: guide groove of housing 2, 30: pinion gear, 40: rack gear, 101: slit, 102: penetrating slit, 103: flange 104a, 104b: end face of the bush main body 105, 105: outer peripheral surface of the bush main body 106, 106: projection of the flange 103, 107: first inner diameter of the bush main 10, 108: second inner diameter of the bush main 10, 109: inner circumferential surface of the bush main body 10, 1020: an edge of the through slit 102

Claims

A slide bearing for supporting a shaft member,
A cylindrical bearing body into which the shaft member is inserted;
Through slits penetrating both axial end faces of the bearing body;
A slide bearing comprising: a pair of support surfaces which are formed radially inward from the inner peripheral surface of the bearing body and abut against and support the shaft member so as to sandwich the shaft member from the width direction of the through slit. .
The sliding bearing according to claim 1, wherein
The slide bearing, wherein the support surface is movable while being in contact with the shaft member.
A sliding bearing according to claim 1 or 2, wherein
The bearing body is
A pair of slits provided corresponding to each of the pair of support surfaces and formed in the axial direction from one end face to the other end face;
And an elastically deformable arm provided corresponding to each of the pair of support surfaces,
The support surface is
A slide bearing, which is disposed in the corresponding slit and connected to the bearing main body by the corresponding arm.
The sliding bearing according to claim 3, wherein
The arm is
A slide bearing, wherein the slide bearing is disposed on the inner side of the bearing body than the outer peripheral surface of the bearing body.
The sliding bearing according to claim 3, wherein
The slide bearing is
Housed in a cylindrical housing with restricted axial movement,
The arm is
A slide bearing characterized by having a gap in the radial direction from the inner circumferential surface of the housing.
The sliding bearing according to claim 1 or 2, wherein
The apparatus further comprises a pair of support portions each having the support surface formed thereon,
The pair of support portions is
A slide bearing, wherein the slide bearing is disposed on the inner side of the bearing body than the outer peripheral surface of the bearing body.
The sliding bearing according to claim 1 or 2, wherein
The apparatus further comprises a pair of support portions each having the support surface formed thereon,
The slide bearing is
Housed in a cylindrical housing with restricted axial movement,
The pair of support portions is
A slide bearing characterized by having a gap in the radial direction from the inner circumferential surface of the housing.
A sliding bearing according to any one of the preceding claims, wherein
The pair of support surfaces is
A slide bearing characterized in that it is disposed on the through slit side with respect to a straight line including an axial center and parallel to the width direction of the through slit.
A sliding bearing according to any one of the preceding claims, wherein
The shaft member is
A rack bar with a rack and pinion type steering mechanism,
The sliding bearing is
A slide bearing, wherein the through slit is attached to the rack bar so as to axially penetrate both end surfaces of the bush main body on the rack gear side of the rack bar.
The slide bearing according to claim 9, wherein
The pair of support surfaces is
A slide bearing characterized in that it is disposed on the rack gear side of the rack bar with respect to a straight line including an axial center and parallel to the width direction of the through slit.
A sliding bearing according to claim 9 or 10, wherein
The bearing body is
A first inner diameter portion disposed on the back side opposite to the rack gear of the rack bar;
A slide bearing disposed on the rack gear side of the rack bar from the first inner diameter portion, and having a second inner diameter portion larger in diameter than the first inner diameter portion.
A plain bearing according to any one of claims 9 to 11, wherein
The width of the through slit is
A slide bearing characterized by being larger than the width of the rack gear of the rack bar.