Ball Bearing Rings

The present invention relates, in general, to ball bearings adapted to cope with high radial loading and more particularly to the outer ring of such a bearing and a method of making same.

It is known to provide a full complement of balls in the grooved raceways of the inner and outer metallic rings of bearings by splitting and expanding the outer ring and assembling the balls between the raceways without a cage. In order to split the outer ring, it is known from U.S. Pat. No. 2,702,216 to score the outer ring on its outer periphery. From U.S. Pat. No. 3,858,288 it is known to provide a radial passage at least partly through the thickness of the ring or a score in one end face of the ring. Such measures produce a weakened or relieved zone such that when the ring is exposed to sufficient force it fractures along an axial plane defined by said zone. During fabrication, the adapted outer ring would be formed in conventional manner, hardened by heat treatment and then fractured in a jig to ensure the ring is not distorted prior to final assembly.

Problems arise in the fabrication of split bearing rings by conventional methods. Particularly, unless the ring cracks cleanly there is a danger that small loose metallic particles could be created which could become detached and enter the bearing surfaces with adverse effects. A general object of the present invention is to provide an improved bearing ring adapted to be fractured and an improved method of making such a ring.

In one aspect the present invention provides a method of making a split bearing ring which allows a full complement of balls to be assembled within a raceway in the inner bore of the ring, said method comprising making a continuous bearing ring with the raceway, providing at least one notch in the ring which extends from one side face thereof to terminate in the bore adjacent the raceway and exposing the ring to force in order to cause the ring to crack or fracture along a plane containing the notch. A pair of notches, each as aforesaid, may be provided in opposite side faces of the ring in alignment on the axial plane where separation is to occur.

The or each notch can be inclined to the axis of the ring to intersect the inner bore land but not encroach on the bearing surface defined by the grooved raceway. Since the notch is usually small it is desirable to provide a mark on the ring to identify the position of the notch. The identifiying means or mark may be a small recess or indent in a side face of the ring aligned with the notch. Alternatively, a score line in an exterior surface of the ring can be used. This score line may then supplement the notch or notches in providing a defined weakened zone whereat a separation over a clean axial plane occurs when the ring is fractured. To fracture the ring, force can be applied to compass the ring in a jig inwardly from its outer periphery. The force can be produced hydraulically or pneumatically.

A bearing ring constructed in accordance with the invention is characterised by the presence of at least one notch extending from one side face of the ring to terminate in the inner bore land thereof adjacent to the conventional raceway therein. The notch can be V-shaped and preferably tapers in depth to decrease inwardly from the side face.

The invention may be understood more readily, and various other aspects and features of the invention may become apparent from consideration of the following description.

Embodiments of the invention will now be described, by way of examples only, with reference to the accompanying drawings, wherein:

FIG. 1 is a side view of a bearing ring constructed in accordance with the invention;

FIG. 2 is a cross-sectional view of the bearing ring shown in FIG. 1;

FIG. 3 is a side view of another bearing ring constructed in accordance with the invention; and

FIG. 4 is a cross-sectional view of the bearing ring shown in FIG. 3.

As shown in FIGS. 1 and 2 an integral bearing ring 1 has a raceway or track 11 of elliptical form on its inner peripheral bore 16 for contacting a plurality of balls (not shown). The ring 1 is provided with a single angled notch 13 of V-shaped profiled extending from a side face 14 of the ring 1. The inner end of the notch 13 terminates adjacent the raceway 11 but without intersecting the latter. The notch 13 also tapers in depth as shown in FIG. 2 and the radially innermost surface 15 extends at an angle .alpha. of approximately 30.degree. to the land surface of the inner bore 16 of the ring 1. A small recess or indent 18 is provided in the side face 14 in registry with the notch 13 to permit the position of the latter to be more easily identified. Conveniently the notch 13 and indent 18 can be created by treating the ring 1 in a press.

The ring 1 illustrated in FIGS. 3 and 4 is the same as that described and illustrated in FIGS. 1 and 2 except that the ring 1 is also provided with shaped grooves 12 open towards both side faces 14 of the ring 1. The grooves 12 serve to receive shields (not shown) as is known.

As described previously, the provision of the notch 13 permits the ring 1 to be fractured reliably along a defined axial plane. Normally the fracturing operation would be performed in a jig wherein a movable pressure plate is driven by hydraulic or pneumatic pressure and exposes the ring 1 to an inwardly directed compressive force sufficient to cause fracturing along a regular defined plane denoted P--P in FIGS. 1 and 3 containing the notch 13. It is possible to provide further relief, say a score across the outer periphery 20 of the ring 1 in alignment with the notch 13, in which case the identification recess 18 can be dispensed with. It is also possible to provide a pair of aligned notches 13 on the opposite side faces of the ring in mirror image to one another. It has been found the the notch or notches 13 enables fracturing to occur reliably with good precision without the formation of loose metal particles or pieces.