JPH0645693Y2 - Strut thrust bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a strut thrust bearing incorporated in a strut assembly of a strut suspension (McPherson type) in an automobile.

<Prior Art> Generally, strut suspensions are mainly used for automobiles, especially for front wheels of small front-wheel drive passenger cars.

The strut assembly of the strut type suspension comprises a combination of a shock absorber and a suspension spring whose upper end is fixed to a vehicle body side attachment member and whose lower end is attached to the axle side.

In the above suspension, when the strut assembly is rotated by the operation of the steering wheel, the piston rod of the shock absorber may or may not rotate.
In either case, a strut thrust bearing is required between the vehicle body side and the suspension spring or between the suspension spring and the support member for fixing the upper end of the piston rod in order to allow the assembly to rotate smoothly.

Conventionally, rolling bearings using balls or needles have been used as bearings in this portion.

In these rolling bearings, the inner peripheral surface of the lower race ring is fitted to the outer peripheral surface of the cylindrical protruding portion formed on the upper spring seat of the strut assembly, and the lower surface of the lower race ring is formed into a flat portion continuous with the outer peripheral surface of the cylindrical protruding portion of the seat. The seat is seated, and the outer surface of the lower track ring is assembled on the seat by caulking with the tongue piece that is erected on the flat surface of the seat.

However, since the upper spring seat in which the bearing is incorporated is usually made of sheet metal, the flatness of the seat flat portion on which the bearing is seated and the seat cylinder to which the inner diameter surface of the bearing lower race ring is fitted. There is a problem that it is difficult to manufacture the roundness of the protruding portion with high accuracy, and as a result, the bearing is subjected to a one-sided contact phenomenon, which causes uneven wear, seizure and the like due to the one-sided contact phenomenon.

Further, since a dust seal made of a rubber elastic body is mounted on the outer diameter side of the bearing to prevent dust and the like from entering the rolling surface of the bearing, the dust seal is interposed between the relative rotating surfaces. There is also a problem that the friction coefficient is increased and smooth relative rotation is hindered.

In order to solve the above-mentioned problems, in recent years, metal upper and lower races made of synthetic resin are fitted into the lower case, and the upper and lower cases are elastically mounted and combined,
A strut thrust bearing has been proposed in which a sealing portion is formed on the elastic mounting portion by a labyrinth action.

FIGS. 3 to 5 show one example thereof. FIG. 3 is a sectional view of a strut assembly incorporating the strut thrust bearing, and FIG. 4 shows the upper spring seat fitted with the bearing. FIG. 5 is a plan view showing the state, and FIG. 5 is a sectional view taken along line XX in FIG.

In the figure, B is a strut thrust bearing, and the bearing B is made of synthetic resin and has upper and lower cases 1 and 2 and upper and lower cases 1 and 2.
It is composed of metal bearing rings 3 and 4 which are respectively fitted and held therein, and a plurality of rolling elements 5 arranged between the upper and lower bearing rings 3 and 4.

The upper case 1 has a base portion 1a having an annular groove 1b on its lower surface.
And the outside of the base portion 1a, the outside hanging on the inner peripheral edge, and the inner annular hanging portion 1
Equipped with d and 1g.

On the inner peripheral surface of the lower end of the outer annular hanging portion 1d and the outer peripheral surface of the lower end of the inner annular hanging portion 1g, annular engaging protrusions 1h and 1i are formed, respectively.

The lower case 2 has a base 2a having an annular groove 2b on its upper surface.
And the outer and inner annular protrusions 2 protruding to the outer and inner peripheral edges of the base 2a
Equipped with d and 2g.

Annular engagement protrusions 2h and 2i are formed on the upper inner peripheral surface of the outer annular protrusion 2d and the upper outer peripheral surface of the inner annular protrusion 2g, respectively.

The upper and lower cases 1 and 2 are annular concave grooves on the lower surface of the upper case 1.
The lower bearing ring 3 is attached to 1b, and the annular groove 2b is formed on the upper surface of the lower case 2.
The upper race 4 is fitted into each of them, and the rolling element 5 is arranged between the races 3 and 4, and the annular engaging protrusions 1h and 1i of the outer ring 1d and 1g of the outer ring of the upper case 1 are arranged. Is elastically attached (snap fit) to the annular engaging protrusions 2h and 2i of the inner annular protrusions 2d and 2g outside the lower case 2 to form a strut thrust bearing.

The strut thrust bearing B having such a structure is
The inner peripheral surface of the lower case 2 is fitted to the cylindrical protrusion 6a formed on the upper spring seat 6, and the lower surface of the lower case 2 can be seated on the flat surface portion 6b of the seat 6 and the flat surface portion.
It is crimped and fixed by a tongue piece 6c that is erected on 6b.

On the lower surface of the seat 6, there is a spring seating portion having a concave arc shape.
6d is formed, and the upper end of the suspension spring 7 is seated on the seat 6d.

<Problems to be Solved by the Invention> The strut thrust bearing configured as described above is made of synthetic resin in view of the poor flatness accuracy of the flat surface portion 6b of the upper spring seat 6 which is a problem of the above-described conventional technology. Can be absorbed by the elastic deformation of the elastic mounting portion, and the sealing portion formed on the elastic mounting portion by the labyrinth action does not require a dust seal made of a rubber elastic body separately, which prevents smooth relative movement due to the dust seal. Although it has the advantage of being able to solve it, it cannot absorb the poor circularity accuracy of the cylindrical protrusion 6a formed on the flat surface portion 6b of the sheet 6, so Distortion or radial deviation between the cases 1 and 2, and thus deviations in the raceway surfaces of the upper and lower case rings 3 and 4 arranged between the upper and lower cases 1 and 2 may hinder smooth relative rotation. The problem is still unsolved.

<Means for Solving Problems> The inventors of the present invention have noticed that all the above-mentioned problems are caused by the accuracy of the upper spring seat, and the above-mentioned problems can be solved by integrating the bearing and the upper spring seat. It succeeded in solving the problem.

That is, the strut thrust bearing of the present invention is (1)
The synthetic resin upper case has a base portion having an annular groove on the lower surface, an outer annular hanging portion that hangs on the outer peripheral edge of the base portion with an annular gap, and an inner peripheral side wall surface of the annular groove. (2) The lower case made of synthetic resin has an annular concave portion on its upper surface. An outer annular protrusion that is continuous with a base portion having a groove and a cylindrical surface portion that serves as an outer peripheral side wall surface of the annular groove and that has an outer annular shoulder portion that projects at the outer peripheral edge of the base portion, and an inner annular shoulder portion that projects at the inner peripheral edge portion. An annular protrusion is provided, and an outer taper that hangs down on the lower surface of the lower case in a continuous manner with the shoulder portion, an inner taper surface portion and an outer taper that hangs continuously with the outer taper surface portion and an inner taper surface portion. A cylindrical portion having and an arcuate concave sp formed on the lower surface of the cylindrical portion That comprises a ring seat,
(3) The upper race is fitted in the annular groove on the lower surface of the upper case, and the lower race is fitted in the annular groove on the upper surface of the lower case. (4) The upper and lower cases are A rolling element is held between the upper and lower races, and the outer ring of the upper case and the inner ring hanging part are elastically attached to the outer ring of the lower case and the inner ring projection, and are combined (1) The suspension spring fixed to the receiving member fixed to the vehicle body side in the upper case, and the suspension spring seated on the lower spring seat is seated on the arc concave spring seat portion on the lower surface of the lower case. It is incorporated between the receiving member and the suspension spring.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS.
It will be described in detail with reference to the drawings.

In the drawing, A is a strut thrust bearing, and the bearing A is made of synthetic resin, and upper and lower cases 1 and 2 and metallic upper and lower bearing rings 3 fitted and held in the upper and lower cases 1 and 2, respectively. ,
4 and a plurality of rolling elements 5 arranged between the upper and lower races 3, 4.

The upper case 1 has a base portion 1a having an annular groove 1b on its lower surface.
And an outer annular hanging portion 1d that hangs on the outer peripheral edge of the base portion 1a with the annular concave groove 1b and an annular gap 1c therebetween, a cylindrical surface portion 1e that is an inner peripheral side wall surface of the annular concave groove 1b, the cylindrical surface portion 1e, and an annular shape. An inner annular hanging portion 1g that is continuous with a step portion 1f and hangs down to the inner peripheral edge of the base portion 1a
It has and.

On the inner peripheral surface of the lower end of the outer annular hanging portion 1d and the outer peripheral surface of the lower end of the inner annular hanging portion 1g, annular engaging protrusions 1h and 1i are formed, respectively.

The lower case 2 has a base 2a having an annular groove 2b on its upper surface.
And an outer annular protrusion 2d that is continuous with the cylindrical surface portion 2e that is the outer peripheral side wall surface of the annular groove 2b and that projects with an outer annular shoulder 2j on the outer peripheral edge of the base 2a and an inner annular shoulder 2k that projects on the inner peripheral edge. And an inner taper surface portion 2 which is provided with an inner annular protrusion 2g which is slanted downwardly from the shoulder 2J, 2k.
It is provided with a cylindrical portion 2q having inner and inner cylindrical surfaces 2o and 2p and a circular arc concave spring seat portion 2r formed on the lower surface of the cylindrical portion 2q.

Annular engagement protrusions 2h and 2i are formed on the upper inner peripheral surface of the outer annular protrusion 2d and the upper outer peripheral surface of the inner annular protrusion 2g, respectively.

The upper and lower cases 1 and 2 are annular concave grooves on the lower surface of the upper case 1.
The upper race 3 is fitted to the cylindrical surface portion 1e by abutting on the cylindrical portion 1b,
The lower bearing ring 4 is provided in the annular groove 2b of the lower case 2 with a cylindrical surface portion.
The rolling element 5 is disposed between the upper and lower races 3 and 4 while abutting on and fitted to the 2e, and the outer ring 1 and the inner ring hanging portion 1 of the upper case 1 are arranged.
Strut thrust bearings, in which the annular engaging protrusions 1h and 1i of d and 1g are elastically attached (snap fit) to the outside of the lower case 2 and the annular engaging protrusions 2h and 2i of the inner annular protrusions 2d and 2g. Is configured.

In this way, by combining the upper and lower cases 1 and 2, a sealing portion by a labyrinth action is formed in the elastic mounting portion.

The strut thrust bearing A configured as described above is fixed to the receiving member 8a fixed to the vehicle body 8 side in the upper case 1, and one end of the strut thrust bearing A is fixed to the shock seat 9 on the spring seat 2r on the lower surface of the lower case 2. The other end of the suspension spring 7 seated on the lower spring seat 10 is seated, and the bearing A is assembled between the receiving member 8a and the suspension spring 7.

The piston rod 9a of the shock absorber 9 has a threaded portion 9b at the tip of the piston rod 9a fitted into a hole of the support member 11, and is fixed to the support member 11 by a nut 9c.

Reference numeral 12 is a rubber elastic body, and the support member 11 is fixed to the inside and a cap 13 fixed to the vehicle body 8 on the outside.
Is crowned and fixed.

In this embodiment, the strut assembly is of a type in which the piston rod does not rotate, and is a dual path type (input separation type) in which the upper surface of the strut thrust bearing and the upper end of the piston rod are fixed to separate members. However, the present invention is also applicable to a type in which the piston rod rotates and a single-pass type strut assembly in which the upper surface of the strut thrust bearing and the upper end of the piston rod are fixed to the same receiving member.

<Effects of the Invention> As described above, the strut thrust bearing of the present invention has the following effects due to the above configuration.

That is, the spring seat which was necessary for the strut assembly using the conventional strut thrust bearing is not necessary, and due to the poor dimensional accuracy of the spring seat, which has been a problem in the past, the occurrence of strain between the lower cases, A smooth relative rotation can be performed without causing a radial deviation, and thus a deviation of the orbits of the upper and lower bearing rings arranged between the upper and lower cases.

Further, there is no problem such as galling of the bearing portion or generation of abnormal noise due to intrusion of the rust powder into the bearing portion due to rusting of the spring seat itself.

Further, the number of parts is reduced, and not only the cost but also the workability at the time of assembly is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a strut thrust bearing of the present invention in which the upper end of a suspension spring is seated, and FIG. 2 is a sectional view showing an embodiment of a strut assembly using the strut thrust bearing of the present invention. 3 and 4 are sectional views showing a strut assembly incorporating a conventional strut thrust bearing, FIG. 4 is a plan view showing a state in which the conventional strut thrust bearing is fitted and fixed to a spring seat, and FIG. 5 is It is a XX sectional view of FIG. A: Strut thrust bearing, 1 ... Upper case, 2 ...
… Lower case, 2r …… Spring seat, 3 …… Upper race, 4 …… Lower race, 5 …… Rolling element, 7 …… Suspension spring.

Claims (1)

[Scope of utility model registration request] (1) An upper case 1 made of synthetic resin has a base 1a having an annular groove 1b on its lower surface, and an outer peripheral portion of the base 1a which hangs apart from the annular groove 1b and an annular gap 1c. Circular hanging part 1d
And a cylindrical surface portion 1e which is an inner peripheral side wall surface of the annular groove 1b, and an inner annular hanging portion 1g which is continuous with the cylindrical surface portion 1e with an annular step portion 1f and hangs down to the inner peripheral edge of the base portion 1a. (2) The lower case 2 made of synthetic resin has an annular groove 2b on its upper surface.
An outer annular projection 2d that is continuous with a base 2a having a base 2a and a cylindrical surface 2e that is the outer peripheral side wall surface of the annular groove 2b, and projects with an outer annular shoulder 2j on the outer peripheral edge of the base 2a and an inner annular shoulder on the inner peripheral edge. Part 2k
And an inner taper surface portion 2m and an inner taper surface portion 2m, 2n which is provided on the lower surface of the lower case so as to hang down obliquely in succession to the shoulder portions 2j and 2k, respectively. , 2n, the outer and inner cylindrical surfaces 2o, 2P
A cylindrical portion 2q having a circular arc concave surface spring seating portion 2r formed on the lower surface of the cylindrical portion 2q, and (3) the upper bearing ring 3 is fitted in the annular concave groove 1b on the lower surface of the upper case 1. And the lower race 4 is fitted in the annular groove 2b on the upper surface of the lower case 2. (4) The upper and lower cases 1 and 2 are between the upper and lower races 3 and 4. The rolling member 5 is held, and the inner annular hanging part outside the upper case 1
1d and 1g are elastically mounted on the inner annular projections 2d and 2g outside the lower case 2 and combined, and the above-mentioned configurations (1) to (4) are provided. The suspension spring 7 fixed on the lower spring seat 10 is seated on the arc-shaped concave spring seat portion 2r on the lower surface of the lower case 2. Strut thrust bearing built in between.