GB2091821A

GB2091821A - A rolling bearing unit

Info

Publication number: GB2091821A
Application number: GB8202126A
Authority: GB
Original assignee: SKF Nova AB
Current assignee: SKF Nova AB
Priority date: 1981-01-27
Filing date: 1982-01-26
Publication date: 1982-08-04
Also published as: FR2498705A1; GB2091821B; SE436110B; JPS57144103A; IT1149487B; IT8220657V0; DE3202136A1; IT8219315A0; FR2498705B1; DE8201634U1; SE8100491L; DE3202136C2

Abstract

A rolling bearing unit, for fitting a wheel to a vehicle, comprises relatively rotatable radially inner and outer members one of which (24) is to be secured to the vehicle and has a radially extending flange (25). The flange (25) has four separate bolt holes (27) lying at the four corners of a rectangle for securing that one member to the vehicle. The diagonals of the rectangle intersect at an angle (2 alpha ) of 60 DEG +/- 5 DEG and at a point lying on the axis of that one member. <IMAGE>

Description

SPECIFICATION A rolling bearing unit This invention relates to a rolling bearing unit for fitting a wheel, driven or non-driven, to a vehicle.

There is known a rolling bearing unit which can be attached directly to a part of a vehcile, such as the suspension, and a wheel is attached to another part of the unit to allow the wheel to rotate. An example of such a unit is described in USA patent Specification No. 3757883. The unit described with reference to Figure 1 of USA patent Specification No. 3757883 comprises an inner member 1 having a radially outwardly extending flange 2 and an outer member 3 having a radially outwardly extending flange 4.

Flange 2 has bolt holes 6 and flange 4 has bolt holes 7 all arranged on a common pitch diameter 5. The inner and outer members 1 and 3 are arranged for relative rotational movement by means of a double row angular contact ball bearing 8.

The inner member 1 is intended to be secured to a wheel by bolts 9 extending through bolt holes 6 and outer member 3 is intended to be secured to a part of a vehicle by bolts extending through bolt holes 7.

The flange 4 of the outer member 3 has three bolt holes 7 arranged at 900 one to another and a further pair of bolt holes 12 for securing a brake calliper housing to the flange. When the unit is connected to a vehicle, two of the bolt holes 7 are arranged on a vertical line and the third bolt hole 7 is arranged to one side of the vertical line.

Another known rolling bearing unit has four bolt holes in the flange of the member for attachment to the vehicle, the bolt holes being arranged at 90" to each other. When this unit is connected to a vehicle, two of the bolt holes are arranged on a vertical line and the other two on a horizontal line.

When a wheel is fitted to a vehicle using a known rolling bearing unit, the bolts through the member attaching the unit to the vehicle can be subject to quite large loads particularly when cornering and when the unit is subject to shock loads.

As an improvement upon the known rolling bearing units, the invention provides a rolling bearing unitforfitting a wheel to a vehicle, the bearing unit comprising relatively rotatable radially inner and outer members one of which is to be secured to the vehicle and has a radially extending flange, which flange has four separate bolt holes lying at the four corners of a rectangular for securing that one member to the vehicle, the diagonals of which rectangle intersect at an angle of 60 + 5 and at a point lying on the axis of that one member.

The invention also includes a vehicle having a wheel fitted to the vehicle by a rolling bearing unit constructed according to the invention, a radius intersecting the axis of the bearing and passing through any one bolt hole forming an angle of 30 + 21/2 to a line vertical with respect to the vehicle.

Calculations show that by attaching a rolling bearing according to the invention to the vehicle in that way, the strength of the unit and the member to which it is attached (e.g. the steering knuckle housing) can be utilized to a maximum. Thus an optimum weight and a low cost for the unit and suspension can be achieved.

The flange may be an annularflange and be thinner between each two circumferentially adjacent bolt holes than at and adjacent to the bolt holes.

The outer periphery of the flange may touch an envelope circle radially outwardly from each bolt hole and lie in from the envelope circle elsewhere.

Embodiments of the invention will now be described by way of example, reference being made to the accompanying drawings, of which: Figure 'shows a rolling bearing unit according to the invention in longitudinal section, and Figure 2 shows an axial view of the outer race ring ofthe rolling bearing unit shown in Figure 1.

The rolling bearing unit shown in Figure 1 comprises an inner member 20 which provides the outer race 21 for a constant velocity joint and has a radially outwardly extending flange 22 with a plurality of bolt holes 23. An outer race ring or member 24, having a radially outwardly extending flange 25, is disposed around the inner member 20 and to one side of the flange 22. A double-row angular contact ball bearing 26 provides balls rolling on raceways of the inner and outer members 20 and 24 and allows the two members 20 and 24 to rotate relative one to the other. The inner member 20 is adapted to be connected to a driven wheel and the outer member 24 is adapted to be connected to a part of a vehicle.

Figure 2 shows the outer race ring or member 24, the flange 25 of which is drawn to show four different embodiments A, B, C and D. The flange 25 has four bolt holes 27 disposed on the same pitch circle diameter. The bolt holes 27 are so arranged that they lie at the four corners of a rectangle, one at each corner, the diagonals of the rectangle intersecting at an angle of 60 f 5 and at a point lying on the axis of the outer race ring 24. When the unit is attached to a vehicle by means of bolts extending through the bolt holes 27, a radius R intersecting the axis of the bearing and passing through any one bolt hole forms an angle a of 300+ 21/2" to a line L vertical with respect to the vehicle.With the vehicle, for example, a motor car, disposed with its wheels on a horizontal plane, the line L extends vertically.

With the bolt holes 27 arranged as described and illustrated, the flange 25 can be designed so as to save on material and thus reduce weight.

In embodiment A, the top left hand sector of Figure 2, the portion of the annularflange 25 between the outer rim or periphery 28 and the broken line 29 has been made thinner than the portion lying radially inwardly of the broken line 29 and at and adjacent to the bolt hole 27. Similarly, in embodiment B, the top right hand sector of Figure 2, the portion of the annular flange 25 between the outer rim or periphery 28 and the broken lines 30 has been made thinner than the portion lying radially inwardly of the broken lines 30 and at and adjacent to the bolt hole 27. In use of the unit, the flange 25 is not subjected to large forces radially outside the broken lines 29 and 30 so that the flange can be made thinner there.

In embodiment C, the bottom left hand sector of Figure 2, the outer rim or periphery 31 of the flange 25 lies in from the envelope circle 32 between circumferentially adjacent bolt holes 27, and touches the envelope circle radially outwardly from the bolt holes.

Similarly, in embodiment D, the bottom right hand sector of Figure 2, the outer rim or periphery 33 of the flange 25 lies in from the envelope circle 32 between circumferentially adjacent bolt holes 27, and touches the envelope circle radially outwardly from the bolt holes. By shaping the flange 25 in this way, much space is saved which can be used for arranging, for example, a brake block housing.

The present invention provides a rolling bearing unit which can be utilized to an optimum and can be made as light as possible by removing all unnecessary material. Ease of manufacture and ease of assembly are provided for by the unit being symmetrical.

Claims

1. A rolling bearing unitforfitting a wheel to a vehicle, the bearing unit comprising relatively rotatable radially inner and outer members one of which is to be secured to the vehicle and has a radially extending flange, which flange has four separate bolt holes lying atthe four corners of a rectangle for securing that one member to the vehicle, the diagonals of which rectangle intersect at an angle of 60 f 5 and at a point lying on the axis of that one member.

2. A rolling bearing unit as claimed in Claim 1, wherein the flange is an annular flange and is thinner between each two circumferentially adjacent bolt holes than at and adjacent to the bolt holes.

3. A rolling bearing unit as claimed in Claim 1, wherein the outer periphery of the flange touches an envelope circle radially outwardly from each bolt hole and lies in from the envelope circle elsewhere.

4. A rolling bearing unit substantially as herein described with reference to and as shown in Figure 1 and any one of the four possible constructions described with reference to and as shown in Figure 2 ofthe accompanying drawings.

5. A vehicle having a wheel fitted to the vehicle by a rolling bearing unit as claimed in any preceding claim, a radius intersecting the axis of the bearing and passing through any one bolt hole forming an angle of 30 + 21/2 to a line vertical with respect to the vehicle.