GB2250786A

GB2250786A - Mounting a ring on a shaft or in the bore of a housing

Info

Publication number: GB2250786A
Application number: GB9122547A
Authority: GB
Inventors: Klaus Kispert; Robert Stolz
Original assignee: SKF GmbH
Current assignee: SKF GmbH
Priority date: 1990-10-27
Filing date: 1991-10-24
Publication date: 1992-06-17
Anticipated expiration: 2011-10-24
Also published as: GB2250786B; DE4034238A1; ITTO910739A0; IT1250500B; ITTO910739A1; GB9122547D0

Description

22507,36 MOUNTING A RING ON A SHAFT OR IN THE BORE OF A HOUSING 5. The

present invention relates to mounting a ring for example, a bearing ring on a shaft or in the bore of a housing.

Bearing rings are known to be mounted on a shaft with an interference fit, the seating surfaces of the ring and the shaft both being cylindrical in shape. The shaft may have a radial abutment surface such as a shoulder or flange adjacent to the seating surface. In some circumstances, when the ring is mounted abutting the abutment surface, there is no room to provide means to locate the ring in the other direction. In the event of high radial loads being applied, the ring may move axially along the shaft and come off.

The invention in one aspect provides a shaft having a radial abutment surface and a seating surface adjacent to the abutment surface, and a ring for mounting on the seating surface of the shaft and abutting the abutment surface, the ring having a seating surface in its bore, the two seating surfaces being an interference fit with each other, one being of cylindrical shape and the other being in the form of a truncated cone to provide a tighter fit of the ring at that end adjacent to or abutting the abutment surface than at the other end.

In another aspect the invention provides a housing having a bore with a radial abutment surface and a seating surface adjacent to the abutment surface, and a ring for mounting on the seating surface in the bore and abutting the abutment surface, the ring having a seating surface on its outer circumferential surface, the two seating surfaces being an interference fit with other, one being of cylindrical shape and the other bei-n^g in the form of a truncated cone to provide a tighter fit of the ring at that end adjacent to or abutting the' abutment surface than at the other end.

1 Preferably, the surface of the ring which is radially opposed to the seating surface of the ring is shaped such that, when the ring is mounted, that surface is cylindrical in shape.

The invention thus provides features which allow a ring to be mounted on a shaft or in the bore of a housing which, despite high radial loads being applied, will remain in place and provide a cylindrical surface radially opposed to the seating surface of the ring.

In a further aspect, the invention provides an assembly comprising a ring mounted in the bore of a housing or on a shaft and adjacent to or abutting a radial abutment surface of the housing or shaft, the ring being an interference fit in the bore or on the shaft which is tighter nearer the abutment surface.

In the accompanying drawings:

Figure 1 shows a shaft with a cylindrical journal and a ring with a seating surface in the form of a truncated cone; Figure 2 shows a shaft with a journal having a seating surface in the form of a truncated cone and a ring with a cylindrical bore; Figure 3 shows a shaft with a cylindrical journal and a ring which has radially opposed surfaces both in the form of truncated cones; Figure 4 shows a shaft with a journal having a seating surface in the form of a truncated cone and a ring with a cylindrical bore and a radially outer circumferential surface in the form of a truncated cone; and Figure 5 shows a pinion supported for rotation by means of a cylindrical roller bearing.

Figure 1 shows a shaft 10 having a shoulder 12 providing a radial abutment surface 14, and a journal 16 having a cylindrical seating surface 18. A ring 20 has a cylindrical outer circumferential surface 22 and a seating surface 24 in its bore in the form of a truncated cone. The seating surfaces 18 and 24 are an interference fit with each other. The end of the ring 20 having the smaller diameter bore is intended to abut the abutment surface 14. The inclination of the conical seating surface 24 is greatly exaggerated in the drawing in the interests of clarity and in practice is approximately 0.01Omm.

When the ring 20 has been driven along the journal 16 to abut the surface 14 of the shoulder 12, there is a tighter fit of the ring at the end abutting the shoulder than at the other end.

It has been found that, when the ring is subject to high radial loads, it tends to move in the direction of greater pressure, that is towards the shoulder. Thus it does not come off the journal.

Figure 2 shows a shaft 26 having a shoulder 28 providing a radial abutment surface 30, and a journal 32 having a seating surface 34 in the form of a truncated cone (greatly exaggerated in the drawing in the interests of clarity). The end of the journal having the larger diameter is adjacent to the shoulder 28. A ring 36 has a cylindrical outer circumferential surface 38 and a cylindrical seating surface 40 in its bore.

The seating surfaces 34 and 40 are an interference fit with each other.

When the ring 36 has been driven along the journal 32 to abut the surface 30 of the shoulder 28, there is a tighter fit of the ring at the end abutting the shoulder than at the other end.

When the rings 20 and 36 are mounted on the respective journals 16 and 32 of Figures 1 and 2, the outer cylindrical surfaces 22 and 38 in each case is deformed and assumes the shape of a truncated cone.

This is unsuitable for the raceway of a cylindrical roller bearing.

Figure 3 shows the same shaft 20 as in Figure 1, with the shoulder 12, abutment surface 14 and journal 16 with the cylindrical seating surface 18.

Instead of the ring 20, there is a radially inner ring 42 of a cylindrical roller bearing having a seating surface 44 in its bore and an outer circumferential surface 46 both in the form of a truncated cone providing a ring having a uniform wall thickness. The ring 42 also has a radial annular flange 48 at its smaller diameter end.

When the ring 42 has been driven along the journal 16, there is a tighter fit of the ring at the end abutting the shoulder than at the other end, and the outer circumferential surface is deformed and assumes a cylindrical shape.

Figure 4 shows the same shaft 26 as in Figure 2 with the shoulder 28, abutment surface 30 and journal 32 with its seating surface 34 in the form of a truncated cone. Instead of the ring 36, there is a radially inner ring 50 of a cylindrical roller bearing having a cylindrical seating surface 52 in its bore and an outer circumferential surface 54 having the form of a truncated cone. The ring 50 also has a radial annular flange 56 at its smaller diameter end.

The inclination of the outer circumferential surface 54 of the ring 50 is the same as, but in the opposite direction to, that of the seating surface 34 of the journal 32. When the ring 50 has been driven along the journal 32, there is a tight fit of the ring at the end abutting the shoulder 28 than at the other end, and the outer circumferential surface 54 is deformed and assumes a cylindrical shape.

Figure 5 shows a pinion 58 having a journal 60 and which is supported for rotation by means of a cylindrical roller bearing 62. The bearing comprises an inner ring 64 having a single radial annular flange 66, an outer ring 68 having two radial annular flanges 70 and a single row of rollers 72. The journal 60 has a cylindrical seating surface 74.

The cylindrical journal 60 is so short that, although there is space to mount the bearing 62 as an interference fit abutting the shoulder of the pinion, there is no space available to fit means to locate the bearing at the other end to the shoulder. Accordingly, the bearing inner ring 64 is of the same design as the ring 42 shown in Figure 3, in which the seating surface in the bore of the ring and the outer circumferent'lal raceway surface each have the form of a truncated cone before the ring is mounted on the journal. When mounted, the bearing inner ring 64 is a tighter fit in region A than in region B. Although the specific description and drawings only relate to rings mounted on shafts, the same principle can be employed for rings mounted in the bores of housings.

Claims

1. A shaft having a radial abutment surface and a seating surface adjacent to the abutment surface, and a ring for mounting on the seating surface of the shaft and abutting the abutment surface, the ring having a seating surface in its bore, the two seating surfaces being an interference fit with each other, one being of cylindrical shape and the other being in the form of a truncated cone to provide a tighter fit of the ring at that end adjacent to or abutting the abutment surface than at the other end.

is

2. A housing having a bore with a radial abutment surface and a seating surface adjacent to the abutment surface, and a ring for mounting on the seating surface in the bore and abutting the abutment surface, the ring having a seating surface on its outer circumferential surface, the two seating surfaces being an interference fit with other, one being of cylindrical shape and the other being in the form of a truncated cone to provide a tighter fit of the ring at that end adjacent to or abutting the abutment surface than at the other end.

3. An arrangement as claimed in Claim 1 or 2, wherein the surface of the ring which is radially opposed to the seating surface of the ring is shaped such that, when the ring is mounted, that surface is cylindrical in shape.

4. A method of mounting a ring on a shaft, comprising the steps of:

i) providing a shaft with a radialabutment surface and a seating surface adjacent to the abutment surface; ii) providing a ring having a seating surface in its bore, the two seating surfaces being an interference fit with each other, one being of cylindrial shape and the other being in the form of a truncated cone; iii) driving the"ring up on the shaft to abut the abutment surface such that the conical seating surface provides a tighter fit at that end of the ring abutting the abutment surface than at the other end.

5. A method of mounting a ring in the bore of a housing, comprising the steps of:

i) providing a housing with a bore having a radial abutment surface and a seating surface adjacent to the abutment surface; ii) providing a ring having a seating surface on its outer circumferential surface, the two seating surfaces being an interference fit with each other, one being of cylindrical shape and the other being in the form of a truncated cone; iii) driving the ring along the bore to abut the abutment surface such that the conical surface provides a tighter fit at that end of the ring abutting the abutment surface than at the other end.

6. An assembly comprising a ring mounted in the bore of a housing or on a shaft and adjacent to or abutting a radial abutment surface of the housing or shaft, the ring being an interference fit in the bore of on the shaft which is tighter nearer the abutment surface.

7. An assembly for mounting a bearing ring on a shaft or in the bore of a housing, which is located axially only in one direction by appropriate means, characterised in that one seating surface is formed slightly conically and the other seating surface is formed cylindrically, so that in the region near to the axial location a tighter fit is provided for the bearing ring to be located than in the opposing region.

8. Bearing rings according to Claim 7, characterised in that the circumferential surface of the journal and the bore surface of the housing accommodating the bearing ring are cylindrically formed, and the bore surface of the inner ring and the bearing circumferential surface of the outer ring are respectively of conical shape.

9. Bearing rings according to Claim 8, characterised in that the bearing surface remote from the conical seating surface of the bearing ring is disposed parallel to the seating surface.

10. Bearing rings according to Claim 7, characterised in that the circumferential surface of the journal and the bore surface of the housing accommodating the bearing ring are of conical shape, and the bore surface and the circumferential surface of the bearing ring are respectively cylindrically formed.

11. Bearing rings according to Claim 10, characterised in that the bearing surface of the bearing ring remote from the seating surface is arranged with the same but oppositely directed inclination as the conical seating surface.

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12. A ring mounted on a shaft or in a bore of a housing substantially as herein described with reference to and as shown in the accompanying drawings.

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