WO1993001423A1

WO1993001423A1 - Semicircular bushing for axial plain bearing

Info

Publication number: WO1993001423A1
Application number: PCT/EP1992/001576
Authority: WO
Inventors: Yves Serre; Eric Proust
Original assignee: Federal-Mogul S.A.
Priority date: 1991-07-13
Filing date: 1992-07-11
Publication date: 1993-01-21
Also published as: DE4123231A1; DE4123231C2

Abstract

A curved semicircular bushing (2) that forms the bearing surface of an axial plain bearing is outwardly enlarged at its apex area and narrows down to its base line, forming an angle of approximately 45°. In addition, the semicircular bushing (2) has at its ends lateral enlargements (8) that extend in a prefered embodiment up to the outer radius of the vertex of the bushing. Since the inner (4) and outer (6) outer edges of the semicircular bushing (2) have the same shape, the outer edge (6) of one semicircular bushing and the inner edge (4) of the following semicircular bushing are formed at the same time by a single cutting line when the semi-circular bushings (2) are punched out. The lost surface during punching of these semicircular bushings does not exceed therefore 10 % of the surface of the composite material used for producing the plain bearings.

Description

Thrust washer for axial plain bearings

DESCRIPTION

The invention relates to an arcuate thrust washer half ring for axial sliding bearing surfaces according to the preamble of claim 1. The invention further relates to a method for producing such half rings.

Thrust washer half rings generally have circular inner and outer contours. Two such thrust washer half rings are put together to produce an axial plain bearing track. The thrust washer half-rings must have sufficient contact surfaces on the adjoining dividing joint edges of the half-rings for firmly connecting the segments.

Furthermore, suitable devices for fixing the thrust washer half rings must be present in order to prevent rotation of the parts by the shaft moving in the slide bearing track.

Such thrust washer half rings are known from German Offenlegungsschrift 24 33 929 (Glycometallwerke) and British Patent 1,589,322. Both documents provide information as to what a material-saving arrangement of the thrust washer half rings can look like when punching out from a band-shaped plain bearing composite material.

In order to achieve maximum material utilization, both the ends of the inner edges of the thrust washer half rings are trimmed and cutouts on the outer edge of the thrust washer half rings are accepted in order to minimize the scrap when punching out the thrust washer parts. These measures are limited by the requirement that the ends of the thrust washer half rings must have a sufficient width for the joint to the adjacent thrust washer half ring. In spite of this, even when such incisions and recesses are provided, material losses of around 30% of the required area of the plain bearing composite material are incurred.

The object of the invention is to propose thrust washer half rings which, with high utilization of the bearing material band from which they are punched out, perform at least a corresponding bearing function in comparison to half circular rings with approximately the same surface area. This object is achieved in terms of the device by the characterizing features of claim 1.

Compared to a circular ring with a corresponding surface, the half ring according to the invention is widened outwards in the apex region, while it is made narrower at angles of approximately 45 degrees to the baseline. The side widenings at the ends, which in the preferred embodiment again extend to approximately the outer radius of the apex of the ring, compensate for the reduction in width in the intermediate transition area, so that a full ring composed of two half rings according to the invention each has sufficiently wide contact surfaces offset by 90 degrees, while surface reductions can take place in the intermediate areas, which lead to the overall shape which can be produced with little waste.

Due to the same shape of the inner and outer peripheral edge, in a preferred embodiment, when a thrust washer half ring is punched out with a single cutting line, the outer edge of the one half ring and the inner edge of the subsequent half rings are simultaneously formed. This is in contrast to previously known procedures such as those in the abovementioned documents are shown. In known methods, the outer edge of the first segment is formed by a first cut and the inner edge of the second segment by a subsequent, second step. When the thrust washer half-ring according to the invention is punched out, a flat loss of the plain bearing composite material does not occur between two successive segments, as was previously the case. The loss surface when punching out the thrust washer half ring according to the invention is therefore limited to a maximum of 10% of the surface area used for the plain bearing composite material, which essentially only occur on the outer edge of the material strip.

The thrust washer half ring can also be provided in a known manner with grooves in the surface, which serve to supply the lubricant between the thrust washer half ring and the supported axle. These grooves can be designed in such a way that they are always arranged in the same place in the case of successive thrust washer half rings and can be embossed in the starting material as a continuous depression.

Furthermore, the parting line edges on the ring ends can be provided with chamfered recesses which also serve to supply lubricant.

The thrust washer half ring can be provided with a recess, which serves as a registration mark for the precise fitting of the thrust washer half ring into the holder.

The thrust washer half-rings according to the invention also offer the advantage that the length of the joint edge which prevents rotation of the thrust washer half-rings can be made longer than in the case of known thrust washer half-rings according to GB-PS 1 589 322. The thrust washer half rings according to the invention can be positioned in the counterbore of the engine block housing with at least three fastening points or two fastening elbows or a combination of both.

Fitting marks or starting points for welding or for attaching the rings as flanges to radial bearings or other markings can be applied at any point on the thrust washer half ring.

Indentations, such as for lubricant grooves, can be stamped into the flat plain bearing composite material immediately before the thrust washer half-ring is punched out. The embossing of the grooves does not have to correspond exactly to the outer and inner circumferential edges of the thrust washer half rings, but can continue on the preceding and following half ring.

When punching out the thrust washer half rings, an inner and an outer contour of the thrust washer half ring are produced in a single cut.

The chamfered recess in the area of the joint edge of the thrust washer half-ring can be produced immediately before or during punching out of the thrust washer half-rings, both from the coated and from the carrier material side of the flat plain bearing composite material.

A preferred embodiment of the thrust washer half ring according to the invention is shown below.

Show it:

Figure 1: Top view of a thrust washer segment Figure 2: Top view of the blank arrangement for thrust washer segments according to Figure 1;

Figure 3: Top view of the blank arrangement of known thrust washer segments.

Figure 4: Top view of three thrust washer segments

FIG. 1 shows a preferred embodiment of the thrust washer half ring 2 according to the invention with the features described in detail below. The thrust washer half ring 2 has a concave inner contour 4 and a convex outer contour 6, each with the same course. The uniform course of the inner contour 4 and the outer contour 6 necessitates outward protruding lateral projections 8 and a parting edge 10 at each end of a thrust washer half ring. Furthermore, the thrust washer half-ring 2 has a groove 12 for lubricant and residual recesses 14 in the groove 12 of the adjacent thrust washer half-ring in each end region, as shown in particular in FIG. 4. Further recesses 16 as a passage for lubricants are provided in the region of the joint edge 10 by chamfering.

FIG. 2 shows the blank arrangement of thrust washer half rings according to the invention. It can be seen from the figure that, due to the inner and outer contours running in parallel, adjacent thrust washer half rings can be punched out essentially without loss.

FIG. 3, on the other hand, shows the cutting arrangement of conventional thrust washer half rings according to GB-PS 1 589 322. The cutting arrangement shows that between the punching of the outer circumferential edge of the first thrust washer half ring and the subsequent punching of the inner circumferential edge of the second thrust washer half ring shot piece from the band-shaped plain bearing composite material.

However, it is not only the processing effort for the thrust washer half-rings that is simplified, but also the stability of the thrust washer half-ring 2 according to the invention is significantly improved compared to a conventional thrust washer segment. From Figures 2 and 3 it can be seen that the length 18 of the joint edge in Figure 2 is significantly greater than the length 18 • of the joint edge in Figure 3. Thus, the thrust washer half ring according to the invention has a much wider contact surface to the opposite thrust washer half ring than before .

The dimension of the thrust washer half rings shown in FIG. 2 differs from the thrust washer half rings shown in FIG. 3 in that the maximum radius of the outer circumferential contour 22 is larger than the outer radius 22 in conventional thrust washer half rings, while the radius 24, 24 'of the inner circumferential edge is unchanged. Furthermore, the thrust washer half-ring shown in FIG. 2 has a greater width with approximately the same area in the apex area (20) than the thrust washer half-ring shown in FIG. 3 in the crown area 20 '. This is due to the different radius of the inner and outer contours 22 ^' , 24' of the thrust washer half ring shown in FIG. 3.

Claims

PATENT CLAIMS

1. Arc-shaped thrust washer half ring as part of two axial sliding bearing surfaces to be formed from two such rings with a convex outer contour and a concave inner contour and a dividing joint edge at each end of the half ring, the connecting line of the dividing joint edge forming an imaginary base line of the half ring, characterized in that that the width of the half ring (2), measured in a direction substantially perpendicular to its outer contour (6), decreases from the apex of the half ring (2) over the center of its base line to the ends of the half ring (2) the ends of the convex outer contour and the concave inner contour (4) form angles of less than 90 degrees with the base line, and that the ends of the half-ring (2) are provided with outward-facing side widenings (8).

2. Half ring according to claim 1, characterized in that the angles between the ends of the convex outer contour (6) or the concave inner contour (4) to the base line are 70 degrees and less preferably about 60 degrees.

3. Half ring according to claim 1 or 2, characterized gekenn¬ characterized in that the lateral widenings (8) in a direction perpendicular to the base line on the one hand by the parting line edge (10) or the base line itself and on the other hand by an essentially Chen transverse edge parallel to the baseline are limited, this transverse edge runs through the intersection, which is formed by the convex outer contour (6) and a normal to the baseline, which in turn is at the intersection of the baseline with the concave inner contour (4) on the baseline.

4. Half ring according to at least one of claims 1 to

3, characterized in that the circumferential limits of the lateral widenings (8) lie approximately on an arc around the center of the base line with the radius of the apex of the convex outer contour (6).

5. Half ring according to at least one of claims 1 to

4, characterized in that the convex outer contour (6) and the concave inner contour (4) have a quasi-parabolic course.

6. Half-ring according to claim 4 or 5, characterized gekenn¬ characterized in that the concave inner contour (4) and at least parts of the joint edges (10) on the one hand and the convex outer contour (6) and the transverse edges of the lateral extension (8) have congruent line courses.

7. Half ring according to claim 6, characterized in that notches or approaches are provided on the concave outer contour, for example for positioning purposes, which correspond in the direction perpendicular to the baseline congruent, complementary approaches or notches in the concave inner contour.

8. Half ring according to at least one of claims 1 to 7, characterized in that its surface contains at least one semi-circular line around the center of the base line.

9. Half-ring according to at least one of claims 1 to 8, characterized in that the length of the dividing joint edge (10) corresponds to at least about half the width of the half-ring at the apex above the base line, measured at right angles to the outer contour (6) of the half-ring.

10. A method for producing arcuate thrust washer half-rings according to one of claims 6 to 9, in which the half-rings are punched out in succession in the same orientation with a corresponding punching tool from a band of suitable plain bearing material, characterized in that the half rings rings are punched out directly adjacent to one another with a tool which has only one or more cutting edges with an identical contour.

11. The method according to claim 10, characterized in that prior to the punching out of the half rings, if necessary, the recesses exceeding the half ring boundaries (12) for lubricant supply are stamped into the alloy side of the bearing material.

12. The method according to claim 10 or 11, characterized gekenn¬ characterized in that before or during the punching of the half-rings bevels along the (provided) cut lines are embossed in the Lagermaterial¬ strips.