GB2168115A

GB2168115A - Tapered roller bearings

Info

Publication number: GB2168115A
Application number: GB08530370A
Authority: GB
Inventors: Alan John Wright
Original assignee: Timken Co
Current assignee: Timken Co
Priority date: 1984-12-11
Filing date: 1985-12-10
Publication date: 1986-06-11
Also published as: GB2168115B; GB8431252D0; GB8530370D0

Abstract

A two-row tapered roller bearing assembly in which the outer races 4, 5 are located and spaced by a shoulder member in the form of a cylindrical split ring 14 lodged permanently in a groove 15 in the bearing housing 2. The shoulder member has a width in the axial direction in the range 13-50mm and is machined to a high tolerance, typically +/-0,025mm. This construction allows bearings to be accurately set without the need for a difficult machining operation within the housing bore. <IMAGE>

Description

SPECIFICATION Tapered roller bearing assembly The invention relates to a multi-row tapered roller bearing assembly, particularly for motor vehicle road-wheels.

In order to avoid the time and expense of bearing adjustment, it is the practice for highvolume applications to use pre-set assemblies.

In one form the inner races, rollers and outer races are pre-assembled as a unit which is fitted into the bearing housing bore.

An alternative bearing assembly is known as SET-RIGHT (registered trade mark). For this, the bearing housing bore is machined to leave an inwardly projecting annular shoulder. The shoulder provides the location and spacing from the bearing outer races. For accurate setting of the bearing, the shoulder must be machined to extremely high tolerance-typically +0,025mm. Clearly, such tolerances are difficult to achieve when machining within a bore.

The present invention seeks to provide an improved bearing assembly which reduces the difficult machining requirements.

According to the invention there is provided a multi-row tapered roller bearing assembly for a motor-vehicle road-wheel, the assembly comprising tapered roller bearings mounted in a housing, the outer races being located and spaced by a shoulder member in the form of a cylindrical split ring lodged permanently in a groove in the housing.

The shoulder member requires to be substantial, and can range from 13-50mm in width. Whatever the width, the split ring can be ground to the necessary tolerance of 0,025mm without undue difficulty or expense.

Also required is machining of the groove to accommodate the split ring. However, the invention utilises the realisation that the width of the groove is not as critical as the width of the ring. The width of the groove will not affect the bearing setting-it is merely sufficient that the ring lodges in the groove and is prevented thereby from sliding from the housing. A tolerance of +0,13mm is sufficient for the groove.

Thus, use of the invention avoids difficult high-tolerance machining. Moreover, the housing can be through-bored.

The ring is substantial and to all intents and purposes is non-deformable and once in place it is non-removable. It is found convenient to allow a reasonably wide gap of 10-20mm at the split in the ring. In this way it is possible to assist removal of the bearing outer races, when replacement is required, by first pulling one out and then driving the other out from the same side by means of a tool applied at the ring gap.

In order that the invention may be better understood an embodiment thereof will now be described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a partial section of a known two-row tapered roller bearing assembly; Figures 2 and 3 are views similar to Fig. 1 showing examples of the bearing assembly of the invention; Figure 4 is an elevation of the split ring used in the bearing of Fig. 2; Figure 5 is a view on the lines V-V of Fig.

4; Figure 6 is a sectional view of a tool useable to insert the split ring during manufacture of the bearing assembly; and Figure 7 is a diagrammatic side view showing how the tool of Fig. 6 is used.

Referring to Fig. 1 there is shown a tworow tapered roller bearing assembly for rotatably mounting a shaft 1 in the bore of housing 2. Typically, the bore diameter is in the range 100-200mm. The end of the shaft is formed of reduced diameter, thereby defining a shoulder 3 against which the bearings locate. Each bearing comprises a separate outer race 4, 5 and inner race 6, 7 between which is mounted in the usual manner respective sets of roller members 8, 9. Each set of roller members incorporates a respective cage 10, 11. The two inner races are in abutting relationship and are fixed in place by locking ring 12 which is threadedly engaged on a threaded end portion of shaft 1. The outer races, on the other hand, are spaced from one another by a central shoulder 13 which is integral with the housing.As mentioned previously, in SET RIGHT applications the width of this shoulder has to be machined to an accuracy of + 0,025mm.

Referring now to Figs. 2 and 3, it will be seen that the shoulder 13 has been replaced by an annular split ring 14 which is located in an annular groove 15 formed in the housing.

The arrangements shown in Figs. 2 and 3 are the same, with the exception that, in the Fig.

3 arrangement, the rectangular section of the split ring of Fig. 2 is given a chamfer on its two outer edges which, when used with a correspondingly-shaped groove 15 is an aid to accurate location of the ring within the groove.

Fig. 4 and 5 show the manner in which the split ring used in the bearing arrangement of Fig. 2 is constructed. The ring is of heavy section in order to give adequate (90%) support to the outer races and can be made of any suitable axial length to suit the application, typically in the range 13-50mm. The ring is formed with a gap 19 at the split which is preferably in the range 10-20mm wide. Once in place, it is to be noted that the ring is not removable (except by causing damage either to itself or the housing), and therefore can be considered to be semi-integral with the housing.

Figs. 7 and 8 show a tool used to fit the ring during manufacture, together with the method of use of the tool. The tool comprises a sleeve 16 having a tapered bore 17 and a stepped portion 18 at its smaller end by which the tool may be located against the housing (see Fig. 8). The ring is fitted by applying a press load in direction P which pushes the ring through the sleeve whilst simultaneously reducing the diameter of the ring sufficiently to allow it to enter the bore of the housing. Letters A, B and C in Fig. 8 illustrate the sequence of events, with letter C indicating the final position of the ring located in the groove 15.

Claims

1. A multi-row tapered roller bearing assembly for a motor-vehicle road-wheel, the assembly comprising tapered roller bearings mounted in a housing, the outer races being located and spaced by a shoulder member in the form of a cylindrical split ring lodged permanently in a groove in the housing.

2. A bearing assembly as claimed in claim 1 wherein said shoulder member has a width in the axial direction within the range of 1 3-50mm.

3. A bearing assembly as claimed in either one of claims 1 or 2 wherein the split ring is ground during manufacture to provide a high tolerance in the axial direction.

4. A bearing assembly as claimed in claim 3 wherein the aforesaid tolerance is + 0,025mm.

5. A bearing assembly as claimed in either one of claims 3 or 4 wherein the groove in the housing is machined during manufacture to a lesser tolerance than that of the split ring.

6. A bearing assembly as claimed in claim 5 wherein the groove is machined to a tolerance of +0,13mm.

7. A bearing assembly as claimed in any one of the preceding claims wherein the ring is of substantial construction such that, once in place in the groove, it is substantially nonremovable.

8. A bearing assembly as claimed in any one of the preceding claims wherein there exists a reasonably wide gap at the split in the ring, such as to enable a tool to be inserted.

9. A bearing assembly as claimed in any one of the preceding claims wherein the split ring is of rectangular section.

10. A bearing assembly as claimed in any one of claims 1 to 8 wherein the outer perimeter edges of the split ring are chamfered to give the ring a part-conical section.

11. A bearing assembly substantially as hereinbefore described with reference to the accompanying drawings.