JPH1113767A - Synthetic resin thrust bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust bearing to prevent entrance of dust from the outer peripheral surface side to a slide surface, maintain a smooth steering force during steering operation for a long period without reducing the slide characteristics due to entrance of dust and besides prevent the uncomfortable noise. SOLUTION: A synthetic resin thrust bearing 1 comprises a lower case 2 made of synthetic resin; a lower case 2 made of synthetic resin; an upper case 3 made of synthetic resin rotatably combined with the lower case 2; an annular bearing body 5 made of synthetic resin arranged in an annular space 4 between the upper and lower cases 2 and 3; and an annular body 7 arranged relatively slidably supported at the upper and lower cases 2 and 3 to close a labyrinth 6 on the outer peripheral side under an own weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin thrust bearing, and more particularly to a synthetic resin thrust bearing suitable for being incorporated in a strut type suspension (MacPherso type) in a four-wheeled vehicle.

[0002]

A strut type suspension generally used for a front wheel of a four-wheeled vehicle has a structure in which a coil spring is combined with a strut assembly having a hydraulic shock absorber built in an outer cylinder integrated with a main shaft. It is.

[0003] The suspension includes a type in which the piston rod of the assembly rotates when the strut assembly rotates together with the coil spring by a steering operation, and a type in which the piston rod does not rotate. A bearing is used between the mounting member of the vehicle body and the upper spring seat of the coil spring so as to allow the rotation smoothly.

Conventionally, a roller bearing or a sliding bearing made of synthetic resin using a ball has been used for the bearing at this point. The present applicant has disclosed the latter sliding bearing made of synthetic resin as disclosed in Japanese Utility Model Publication No. 3-39614. As a synthetic resin thrust bearing.

[0005] The synthetic resin thrust bearing according to this proposal is:
It is possible to eliminate the disadvantage that the steering force is increased due to a dust seal made of a rubber elastic body mounted around the sliding surface between the sliding surfaces for the purpose of preventing dust and the like from entering the sliding surface, Further, it is possible to prevent dust and the like from entering the sliding surface as much as possible, and to obtain a stable and smooth steering force.

[0006] The strut-type suspension is mounted on a portion where dust, muddy water, etc. act directly while the vehicle is running. Therefore, the operating environment of the thrust bearing incorporated in the strut-type suspension is extremely severe, and it is actually fair. The synthetic resin thrust bearing proposed in Japanese Patent Application Laid-Open No. 3-39614 is obtained by simply elastically mounting a case (upper case) on a bearing body (lower case) on the outer peripheral side. There is still a risk that dust, muddy water and the like may enter the sliding surface from the elastic mounting portion.

Moreover, in the proposed synthetic resin thrust bearing, sliding friction occurs between the case and the bearing body at the elastic mounting portion during steering, and there is a possibility that unpleasant noise due to the sliding friction may be generated. .

The present invention has been made in view of the above-mentioned points, and can prevent dust and the like from entering the sliding surface from the outer peripheral surface side. It is an object of the present invention to provide a synthetic resin thrust bearing that can maintain a smooth steering force during steering operation for a long period of time without deteriorating characteristics and that does not generate unpleasant noise.

[0009]

SUMMARY OF THE INVENTION A synthetic resin thrust bearing according to the present invention comprises: a synthetic resin lower case; a synthetic resin upper case rotatably combined with the lower case; An annular bearing body made of synthetic resin disposed in the annular space, and an outer peripheral side and an inner peripheral side of the annular space are respectively formed on an outer peripheral side and an inner peripheral side formed between the upper and lower cases. The labyrinth is sealed from the outside, and an annular body that closes the labyrinth by its own weight is slidably supported by the upper and lower cases in the labyrinth on the outer peripheral side.

In the above-mentioned synthetic resin thrust bearing of the present invention, the lower case has a disk-shaped lower case base having an insertion hole in the center and an annular step radially outward with respect to the insertion hole. A first inner annular protruding portion arranged and protruding from the upper surface of the lower case base portion; a locking portion formed radially inward with respect to an outer peripheral surface of the lower case base portion; A first outer annular protrusion that is arranged radially inward with respect to the upper surface of the lower case base and protrudes from the upper surface of the lower case base.
The upper case has a disk-shaped upper case base having an insertion hole in a central portion, an annular hanging portion that hangs down from the lower surface of the upper case base and has a tip facing an annular step of the lower case, An inner annular lip hanging down from the lower surface of the upper case base so as to form a narrow inner annular recess radially outward with respect to the hanging part in cooperation with the annular hanging part; An outer annular lip hanging down from the lower surface of the upper case base portion so as to form a wide intermediate annular recess in cooperation with the inner annular lip radially outward with respect to the outer annular lip. An outer annular hanging portion hanging down from a lower surface of the upper case base portion and a radially inner surface of the outer annular hanging portion so as to radially outwardly cooperate with the outer annular lip portion to form an outer annular concave portion. With the locking part The first inner annular projection is disposed in the narrow inner annular recess of the upper case so as to form a labyrinth on the inner peripheral side, and the first outer annular projection is located on the outer peripheral side. Is formed in the outer annular concave portion of the upper case so as to form the labyrinth, and the intermediate annular concave portion forms an annular space in which the bearing body is disposed.

Further, in the synthetic resin thrust bearing of the present invention, the lower case has a narrow inner annular portion radially outward with respect to the first inner annular projection in cooperation with the first inner annular projection. A second inner annular protrusion protruding from an upper surface of the lower case base portion to form a recess is further provided, and the inner annular lip portion of the upper case forms an inner labyrinth. So that it is located in the inner annular recess of the lower case.

Further, the lower case cooperates with the first outer annular projection to form a narrow outer annular recess radially inward with respect to the first outer annular projection. It further includes a second outer annular protrusion protruding from the upper surface of the lower case base, and the outer annular lip of the upper case includes:
It is arranged in the outer annular recess of the lower case so as to form a labyrinth on the outer peripheral side. Here, the second outer annular protrusion is provided on the upper surface of the lower case base so as to form an intermediate annular recess in the lower case in cooperation with the second inner annular protrusion. An annular space in which the bearing body is disposed is formed by the intermediate annular recess of the case.

In the present invention, the bearing body is slidably in contact with at least one of the lower surface and the upper surface of the upper and lower case base portions, and in a preferred example, both the lower surface and the upper surface of the upper and lower case base portions. In the case where only one of the lower surface and the upper surface of the upper and lower case base portions is slidably contacted, a bearing body may be integrally fixed to the other upper or lower case base portion.

The annular body in the present invention is made of a synthetic resin or metal plate-like ring or a circular or elliptical ring in cross section.

The synthetic resin constituting the upper and lower cases in the synthetic resin last bearing of the present invention is preferably excellent in sliding characteristics such as wear resistance, impact resistance and creep resistance and mechanical characteristics. The synthetic resin constituting the bearing body disposed between the upper and lower cases preferably has a self-lubricating property, for example, polyacetal resin, polyamide resin, polybutylene terephthalate (PBT).
Polyester resins such as polyester resin and polyethylene and polypropylene are preferably used, and polycarbonate resin and the like may also be used.

For the upper and lower cases, the same synthetic resin as the synthetic resin constituting the bearing body can be used. In particular, the upper and lower cases have a good combination of the synthetic resin used for the bearing body and the friction characteristics. It is desirable that the synthetic resin be relatively rigid. The following table shows an example of the desirable combination.

[0017]

[Table] Bearing pieces Upper and lower cases Friction coefficient Wear amount (mm) Polyacetal Polyamide 0.05 0.020 Polyamide Polyacetal 0.04 0.021 Polyethylene Polyacetal 0.04 0.038 Polyacetal PBT 0.07 0.045 Polyacetal Polyacetal 0.06 0.025 Polyacetal steel (steel) 0.11 0.095

In the table, the friction characteristics are the results obtained under the following test conditions.

[Test conditions] Thrust load 350 kg / cm ² Oscillation angle ± 35 degrees Oscillation speed 60 cpm Lubrication method Apply grease to the sliding surface at startup

The amount of abrasion indicates the amount of dimensional change (mm) of the bearing piece after one million cycles of the above test.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention and embodiments of the present invention will be described in more detail with reference to the preferred embodiments shown in the drawings. The present invention is not limited to these embodiments.

[0022]

1 and 2, a synthetic resin thrust bearing 1 of this embodiment comprises a lower case 2 made of a synthetic resin, an upper case 3 made of a synthetic resin rotatably combined with the lower case 2, and an upper case 3 made of a synthetic resin. In order to close an annular labyrinth 6 on the outer peripheral side, which will be described later, by its own weight, an annular bearing body 5 made of synthetic resin disposed in an annular space 4 between the lower case 2 and the lower case 2 and 3 is closed. And an annular body 7 supported and arranged so as to be freely slidable.

The lower case 2 is provided with a disc-shaped lower case base 12 having an insertion hole 11 in the center and an annular step 13 disposed radially outward with respect to the insertion hole 11 through the lower case 13. An inner annular protrusion 15 protruding from the upper surface 14 of the base 12 and an annular step formed radially inward with respect to the outer peripheral surface 16 of the lower case base 12 and having a flat surface. A locking portion 17, an outer annular projection 18 disposed radially inward with respect to the locking portion 17 and protruding from the upper surface 14 of the lower case base portion 12, and a diameter relative to the inner annular projection 15. The lower case base portion 1 is formed so as to cooperate with the inner annular protrusion 15 to form a narrow inner annular recess 19 outward in the direction.
A narrow outer annular recess 21 is formed radially inward of the inner annular projection 20 protruding from the upper surface 14 of the second annular projection 18 in cooperation with the outer annular projection 18. And at the same time radially outward with respect to the inner annular projection 20, in cooperation with the inner annular projection 20, a wide intermediate annular recess 22.
An outer annular projection 23 projecting from the upper surface 14 of the lower case base portion 12 and an insertion hole 24 communicating with the insertion hole 11 and concentric with the insertion hole 11 are defined by the inner peripheral surface so as to form Thus, the lower case base portion 12 includes the cylindrical portion 26 protruding from the lower surface 25 of the lower case base portion 12.

The upper case 3 has a disc-shaped upper case base 32 having an insertion hole 31 having the same diameter and concentricity with the insertion hole 11 at the center, and a distal end 34 which hangs down from a lower surface 33 of the upper case base 32. An annular hanging portion 35 facing the annular step portion 13 of the lower case 2, and a narrow inner annular recess 36 cooperating with the annular hanging portion 35 radially outward with respect to the annular hanging portion 35.
The inner annular lip 37 hanging from the lower surface 33 of the upper case base portion 32 so as to form a radially outer portion of the inner annular lip 37 in cooperation with the inner annular lip 37 so as to form a wide intermediate portion. An outer annular lip 39 hanging from the lower surface 33 of the upper case base 32 and cooperating with the outer annular lip 39 radially outward with respect to the outer annular lip 39 so as to form an annular recess 38. The lower surface 3 of the upper case base portion 32 is formed so as to form the outer annular concave portion 40.
The outer annular hanging part 41 includes an outer annular hanging part 41 and an engaging part 42 formed on a radially inner surface of the outer annular hanging part 41 and having an inwardly inclined annular inclined surface. Annular hanging part 3
The inner peripheral surface of 5 communicates with the insertion hole 31 and defines an insertion hole 43 having the same diameter and concentricity as the insertion hole 31.

In the synthetic resin thrust bearing 1, the outer annular projection 18 of the lower case 2 is disposed in the outer annular recess 40 of the upper case so as to form the outer labyrinth 6. The projecting portion 23 is arranged on the outer peripheral side of the intermediate annular concave portion 38 of the upper case, and the outer annular lip portion 39 of the upper case 3 is arranged in the outer annular concave portion 21 of the lower case 2.

As described above, the labyrinth 6 on the outer peripheral side is
On the inner peripheral side, it communicates with the annular space 4 formed by the intermediate annular concave portions 22 and 38, and on the outer peripheral side, the outer annular hanging portion 4
1 extends to the annular opening 51 between the inner peripheral surface of the first case 1 and the outer peripheral surface of the lower case base portion 12, and seals the annular space 4 to the outside by labyrinth action.

On the other hand, in the synthetic resin thrust bearing 1,
The inner annular projection 15 of the lower case 2 is disposed in the inner annular recess 36 of the upper case 3 so as to form the labyrinth 55 on the inner peripheral side, and the inner annular projection 20 of the lower case 2 is 3, the inner annular lip portion 37 of the upper case 3
The lower case 2 is arranged in the inner annular recess 19.

Thus, the inner labyrinth 55
Is open to the annular space 4 on the outer peripheral side, and extends to the annular opening 56 between the distal end 34 of the annular hanging portion 35 and the flat surface of the annular step portion 13 on the inner peripheral side. Sealed to the outside by labyrinth action.

In this example, the bearing body 5 is formed separately from the upper and lower cases 3 and 2, and slidably contacts the lower surface 33 and the upper surface 14 of the upper and lower base portions 32 and 12, respectively. It has an upper surface 61 and a lower surface 62. On the upper surface 61, a plurality of radially extending grooves 63 and an annular groove 64 communicating with the grooves 63 are formed as a lubricating grease reservoir. Similarly, a plurality of radially extending grooves 65 and an annular groove 66 communicating with the grooves 65 are formed as a lubricating grease reservoir.

In this embodiment, the annular body 7 is formed of a metal plate-shaped ring, and its outer peripheral side is seated on a locking portion 42 formed of an annular inclined surface, and is slidable relative to the upper case 3. It is supported, and its inner peripheral side is seated on the flat surface of the locking portion 17 formed of an annular step, and is supported by the lower case 2 so as to be relatively slidable.

The annular space 4 and the labyrinths 6 and 55 are filled with lubricating grease as required.

The synthetic resin thrust bearing 1 is, for example, shown in FIG.
Spring support 7 of strut assembly 71 as shown in FIG.
It is used by being mounted via a seat 74 between the vehicle body 2 and the vehicle body side mounting member 73. In this case, the outer peripheral surface of the piston rod 75 of the strut assembly 71 is
The inner peripheral surfaces of the lower case base portion 12 and the cylindrical portion 26 that define the first and the second case 24 and the inner peripheral surfaces of the upper case base portion 32 and the annular hanging portion 35 that define the insertion holes 31 and 43 are formed in a bearing gap (clearance). ) So that the insertion hole 1
1 and 24 and the insertion holes 31 and 43. In FIG. 3, reference numeral 76 denotes a coil spring, 77 denotes a bump stopper (rubber) disposed on the lower surface of the spring receiver 72 so as to surround the outer peripheral surface of the piston rod 75, and 78 denotes struts.

In the synthetic resin thrust bearing 1 used for the strut assembly 71, the thrust load of the vehicle body is supported by the bearing body 5, and the smooth rotation of the spring receiver 72 with respect to the vehicle body-side mounting member 73 is allowed.

In the synthetic resin thrust bearing 1, the annular body 7 is slidably supported by the upper and lower cases 3 and 2 so that the labyrinth 6 on the outer peripheral side is closed by its own weight at the annular opening 51 side. Since it is arranged on the side of the annular opening 51, it is possible to prevent dust and the like from entering the labyrinth 6 by the annular body 7, thus preventing dust and the like from entering the sliding surface of the bearing body 5. In addition, since the annular body 7 is simply placed and supported on the upper and lower cases 3 and 2, there is almost no unpleasant noise in sliding.

In the above, the inner annular projection 20, the outer annular projection 23, and the cylindrical section 2 are attached to the lower case base 12.
6, the synthetic resin thrust bearing 1 may be configured by omitting at least one of them. For example, the inner annular projecting portion 20, the outer annular projecting portion 23, and the cylindrical portion are provided. FIG. 4 shows a synthetic resin thrust bearing 1 without 26. In the synthetic resin thrust bearing 1 shown in FIG. 4, a plurality of projections 81 are provided on the lower surface 25 of the lower case base 12, and the projections 81 are formed in through holes 82 formed in the spring receiver 72. The lower case 2 is fitted so that it cannot rotate relative to the spring receiver 72.

Further, as shown in FIG. 4, the annular body 7 may be formed of a ring having a circular cross section. In this case, the locking portion 17 is inclined outward like the locking portion 42. It is good to comprise from the annular inclined surface which did.

[0037]

As described above, according to the present invention, it is possible to prevent dust and the like from entering the sliding surface from the outer peripheral surface side, and to reduce the sliding characteristics of the bearing caused by the dust and the like. Thus, it is possible to provide a synthetic resin thrust bearing that can maintain a smooth steering force at the time of steering operation for a long period of time and can prevent generation of unpleasant noise.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a preferred embodiment of the present invention.

FIG. 2 is a plan view of the bearing body of the embodiment shown in FIG.

FIG. 3 is an explanatory view of an example in which the embodiment shown in FIG. 1 is used for a strut assembly.

FIG. 4 is a cross-sectional view of another preferred embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Synthetic resin thrust bearing 2 Lower case 3 Upper case 4 Annular space 5 Bearing body 6 Labyrinth 7 Annular body

Claims (10)

[Claims] 1. A lower case made of a synthetic resin, an upper case made of a synthetic resin rotatably combined with the lower case, and an annular bearing made of a synthetic resin disposed in an annular space between the upper and lower cases. And an outer peripheral side and an inner peripheral side of the annular space are sealed from the outside by labyrinths on an outer peripheral side and an inner peripheral side formed between an upper case and a lower case. A synthetic resin thrust bearing in which an annular body that closes the labyrinth by its own weight is slidably supported by the upper and lower cases on the side labyrinth. The lower case is provided with a disc-shaped lower case base having an insertion hole in the center and an annular step radially outward with respect to the insertion hole to form the lower case base. A first inner annular protruding portion protruding from the upper surface, and a locking portion formed radially inward with respect to the outer peripheral surface of the lower case base portion;
A first outer annular projecting portion disposed radially inward with respect to the locking portion and projecting from the upper surface of the lower case base portion; and the upper case has an insertion hole in the center. A disk-shaped upper case base portion, an annular hanging portion that hangs down from the lower surface of the upper case base portion and has a tip facing the annular step portion of the lower case, and radially outward with respect to the annular hanging portion. An inner annular lip portion hanging down from the lower surface of the upper case base portion so as to form a narrow inner annular recess in cooperation with the annular hanging portion; An outer annular lip hanging down from a lower surface of the upper case base so as to form a wide intermediate annular recess in cooperation with the annular lip; and an outer annular lip radially outward with respect to the outer annular lip. To form an outer annular recess in cooperation with the An outer annular hanging portion hanging from a lower surface of the upper case base portion, and a locking portion formed on a radially inner surface of the outer annular hanging portion. Is formed in the narrow inner annular recess of the upper case so as to form a labyrinth on the side, and the first outer annular protrusion is formed in the outer annular recess of the upper case so as to form a labyrinth on the outer peripheral side. Claim 1 which is arranged
The synthetic resin thrust bearing according to 1. 3. The synthetic resin thrust bearing according to claim 2, wherein the intermediate annular recess forms an annular space in which the bearing body is disposed. 4. A lower case, wherein the lower case cooperates with the first inner annular protrusion to form a narrow inner annular recess radially outward with respect to the first inner annular protrusion. The upper case further includes a second inner annular protrusion protruding from an upper surface of the case base, and the inner annular lip of the upper case has an inner annular recess of the lower case so as to form an inner labyrinth. The synthetic resin thrust bearing according to claim 2, wherein the thrust bearing is disposed at a location. 5. The lower case, radially inward with respect to the first outer annular protrusion, cooperates with the first outer annular protrusion to form a narrow outer annular recess. The lower case base further includes a second outer annular protrusion protruding from an upper surface of the lower case base, and the outer annular lip of the upper case has an outer annular recess of the lower case so as to form an outer labyrinth. The synthetic resin thrust bearing according to any one of claims 2 to 4, wherein the thrust bearing is disposed at a location. 6. The second outer annular projection is formed on the upper surface of the lower case base so as to form an intermediate annular recess in the lower case in cooperation with the second inner annular projection. The synthetic resin thrust bearing according to claim 5, as long as it depends on claim 4. 7. The synthetic resin thrust bearing according to claim 6, wherein an annular space in which the bearing body is disposed is formed by the intermediate annular recess of the lower case. 8. The synthetic resin thrust bearing according to claim 1, wherein the bearing body is slidably in contact with at least one of the lower surface and the upper surface of the upper and lower case bases. 9. The synthetic resin thrust bearing according to claim 1, wherein the annular body is formed of a synthetic resin or metal plate ring. 10. The synthetic resin thrust bearing according to claim 1, wherein the annular body is made of a synthetic resin or metal ring having a circular or elliptical cross section.