Method for manufacturing bearing bushings
23 Nov, 2021

One type of independent plain bearing is the bush bearing, often called a bushing or bush. It’s a mechanical component that reduces friction between rotating shafts and stationary supporting parts by providing a bearing surface for rotary applications.

BACKGROUND OF THE INVENTION

The current invention is for a bearing bush with a seam and an incorporated structure suited for use in, for example, a turntable in a microwave oven for supporting a thrust load as well as a radial load.

The invention pertains to a bearing bush with at least one internal annular groove for fitting a sealing ring at least one bush end, as well as a method of making such a bearing bush.

Bearing bushes are used in a variety of applications, including door hinges, roller bearing systems, pedal and clutch bearings, and so on. The bearing bush may be covered on the inside with a bearing substance having good sliding characteristics and minimal wear.

The bearing’s sliding and wear characteristics, on the other hand, maybe harmed if foreign material penetrates the bearing. If no extra precautions are taken, dirt, moisture, and particles abraded from neighboring components have a direct effect on the bush’s bearing function, and the latter may need to be replaced after only a short service life.

Furthermore, in the case of lubricated bearing bushes, the lubrication may escape from the bush, resulting in deterioration of the sliding characteristics over time.

To address this, bushes have been designed that have a groove cut into one or both ends, into which a specially shaped, generally stepped sealing ring is fitted to prevent dirt and other foreign objects from entering the bearing.

The downside of such bushes is that they require a particular minimum thickness to mill in such a sealing member accommodating groove. This is a time-consuming and costly procedure. Milled grooves feature a rectangular cross-section, necessitating the use of specially designed sealing rings to fit in the milled grooves.

Also read: Bushing Guide For Buyers – Bushing Types And Sizes

SUMMARY OF THE INVENTION

The major goal of the current invention is to provide a bearing bush that eliminates the above-mentioned drawbacks of previous bearing bushes.

The invention is to offer a bearing bush with an internal groove into which a standard sealing device can be inserted and kept, regardless of the customary thin wall thickness. The invention also has the goal of providing a suitable production technique.

This is accomplished with a bearing bush in which the groove has a curved shape and is positioned inside an annular bead that projects outwards from the bush body.

A simple upsetting procedure can make an annular bead without the use of complex internal milling tools. Because the upsetting process is quick and cost-effective, the overall manufacturing costs for the bearing bush may be significantly lowered.

The bush end to be reshaped to form the annular bead is widened in a parallel manner, the widened bush portion is reshaped inwards at its end, such that the end face forms an angle of between 10° and 80° with the longitudinal axis of the bush, and the bush is upset to form the annular bead while maintaining the orientation of the end face.

BRIEF DESCRIPTION OF THE DRAWINGS

With the aid of the drawings, exemplary embodiments are explained in greater detail below, in which:

A shrub having a bead at the front end is depicted in perspective in FIG. 1.

FIG. 2 depicts a cross-section of the bush depicted in FIG. 1 along lines II-II.

FIGS. 3a to d are vertical section schematic representations of the reshaping process carried out by a reshaping device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 depicts bush 1 with a cylindrical bush body 6 and a longitudinally extending wall at the front end of which produces an annular bead 2 that extends radially outwards from the bush body 6. The wall thickness of bush 1 is consistent throughout, including bead 2. The end face 3 is angled in relation to the longitudinal axis 5, which may be seen in greater detail in

FIG. 2. A groove 7 is made within bead 2 into which an O-ring 4 is inserted as a sealing member.

FIG. 2 depicts a cross-section of the bush depicted in FIG. 1. The bush 1’s end face 3 creates a 45° angle with the longitudinal axis 5 in the embodiment depicted here.

The advantage of this tilted end face 3 is that the O-ring can be easily installed. The sealing component has a circular cross-section that is conformed to the circular curvature and size of groove 7, allowing it to fit securely against the inside groove wall of bead 2 in full conforming contact.

The radius R depicted is the same as the radius of the sealing member and represents the curvature of the groove 7.

The shape of bead 2 is chosen so that, taking into consideration the radius R, the O-ring 4 has a lower internal diameter DD than the internal diameter DB of the bush body, allowing the O-ring 4 to be compressed and its sealing action to unfold when a bearing shaft or the like is inserted.

FIG. 3a shows a schematic representation of the reshaping process as it begins with the use of an appropriate device. The first front dies 11 functions as a limiter, preventing the bush from deflecting outwards in an uncontrolled manner.

The distance between the internal wall of die 11 and the region 20b of the mandrel 10 is 10 in accordance with bush 1a’s bearing wall thickness. A wider, equally cylindrical section 8 is formed, as shown in FIG. 3b.

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