Bearing arrangement

Abstract

A wheel bearing arrangement for a vehicle, comprising at least one roller bearing, wherein at least one of the roller bearings is a ball bearing, which includes an inner ring and an outer ring, wherein both rings have raceways for balls being located between the rings. To ensure a sufficient lifetime of the roller bearings and to minimize the friction in the bearing, the at least one of the rings of the bearing arrangement is made from a ball bearing steel produced by a powder metallurgical process using a powder metallurgy component including 0.5 to 2.0 weight-% C, a maximum of 0.035 weight-% S, 3.0 to 5.0 weight-% Cr, 1.0 to 4.0 weight-% V, 1.0 to 12.0 weight-% W and 2.0 to 12.0 weight-% Mo, wherein at least one raceway has a radius and the balls have a diameter which fulfills the equation: radius/diameter>0.53.

Claims

1. A wheel bearing arrangement for supporting a wheel of a vehicle, comprising a first roller bearing and a second roller bearing both positioned proximate to the wheel, wherein the first roller bearing comprises a first inner raceway, a first outer raceway, and a first set of balls having a first diameter (D.sub.B) therebetween, the second roller bearing comprises a second inner raceway, a second outer raceway, and a second set of balls having a second diameter (D.sub.2B) therebetween, the first inner and outer raceways are configured to have substantially the same first raceway radius (r.sub.I/O), the second inner and outer raceways are configured to have substantially the same second raceway radius (r.sub.2I/2O), wherein at least one of the inner and outer raceways of each of the first and second roller bearings is made from a ball bearing steel produced by a powder metallurgical process using a powder metallurgy component including: 0.5 to 2.0 weight-% C, a maximum of 0.035 weight-% S, 3.0 to 5.0 weight-% Cr, 1.0 to 4.0 weight-% V, 1.0 to 12.0 weight-% W and 2.0 to 12.0 weight-% Mo, wherein the first raceway radius and the first diameter of the first set of balls fulfil the equation:
0.545 (zero point five four five)>r.sub.I/O/D.sub.B>0.54 (zero point five four) wherein the second raceway radius and the second diameter of the second set of balls fulfil the equation:
0.535 (zero point five three five)>r.sub.2I/2O/D.sub.2B>0.53 (zero point five three), and wherein the first roller bearing is arranged closer to the wheel than the second roller bearing.

2. The wheel bearing arrangement according to claim 1, wherein the powder metallurgy component includes: 1.3 to 1.4 weight-% C, a maximum of 0.035 weight-% S, 3.50 to 4.25 weight-% Cr, 1.75 to 2.20 weight-% V, 5.75 to 6.50 weight-% W and 10.0 to 11.0 weight-% Mo.

3. The wheel bearing arrangement according to claim 1, wherein the powder metallurgy component further comprises 5.0 to 12.0 weight-% Co.

4. The wheel bearing arrangement according to claim 1, wherein both of the inner and outer raceways of the first and second roller bearings are made from the ball bearing steel produced by the powder metallurgical process.

5. The wheel bearing arrangement according to claim 1, wherein a surface of the raceways has a hardness between 65 HRC and 70 HRC.

6. The wheel bearing arrangement according to claim 1, wherein the first and second roller bearings are arranged adjacent to another to support one of a wheel shaft or a hub, wherein the first and second roller bearings are angular contact ball bearings (ACBB).

7. The wheel bearing arrangement according to claim 6, wherein the contact angles of the first and second roller bearings are different.

8. The wheel bearing arrangement according to claim 6, wherein the first roller bearing comprises a first inner ring and the second roller bearing comprises a second inner ring, the first and second inner rings of the first and second roller bearings are made as a one-piece element.

9. The wheel bearing arrangement according claim 6, wherein the first roller bearing comprises a first outer ring and the second roller bearing comprises a second outer ring, the first and second outer rings of the first and second roller bearings are made as a one-piece element.

10. The wheel bearing arrangement according to claim 1, wherein the first and second set of balls of the first and second roller bearings are made of ceramic material.

11. The wheel bearing arrangement according to claim 1, wherein the wheel bearing arrangement is a component within a Formula 1 racing car.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The drawings show an embodiment of the bearing arrangement according to the invention.

(2) FIG. 1 shows a cross sectional view of a wheel bearing arrangement according to an embodiment of the invention and

(3) FIG. 2 shows an enlarged view of a region of a ball bearing which is a part of the wheel bearing arrangement.

DETAILED DESCRIPTION OF THE INVENTION

(4) In FIG. 1 a wheel bearing arrangement 1 is shown by which a wheel 9 is supported; the wheel 9 has a shaft 10 which is supported in two roller bearings 2 and 3 which are both designed as angular contact ball bearings ACBB. The ball bearing 2 which is arranged adjacent to the wheel 9 is the outboard bearing; the ball bearing 3 which is arranged remote from the wheel 9 is the inboard bearing.

(5) Both ball bearings 2, 3 have respective inner rings 4 and outer rings 5. Between the rings 4, 5 balls 8 made from ceramics are arranged. The inner ring 4 and the outer ring 5 have raceways 6 and 7 respectively for the balls 8 (see FIG. 2).

(6) In FIG. 2 the geometrical relations between the raceways of the bearing rings and the balls are depicted. The balls 8 have a diameter DB. The radius of the raceway of the inner ring 4 is denoted with r.sub.I. The radius of the raceway of the outer ring 5 is denoted with r.sub.O.

(7) The ratio between the radius of the raceway of the inner or outer ring and the diameter of the balls is the osculation between ring and ball and is according to the invention:
r.sub.I/O/D.sub.B>0.53.

(8) In a specific embodiment of the invention the osculation between the raceway of the inner ring 4 and the balls 8 and the osculation between the raceway of the outer ring 5 and the balls 8 are substantial equal, but there are differences between the two bearings 2 and 3. Therefore, since the diameter of the balls 8 in ball bearing 2 are the same, the radius of the raceway of the inner ring 4 of ball bearing 2 and the radius of the raceway of the outer ring 5 of ball bearing 2 are substantially equal, and, since the diameter of the balls 8 in ball bearing 3 are the same, the radius of the raceway of the inner ring 4 of ball bearing 3 and the radius of the raceway of the outer ring 5 of ball bearing 3 are substantially equal. The outboard bearing 2 has an osculation of r.sub.I/O/D.sub.B>0.54, while the inboard bearing 3 has a smaller osculation of r.sub.2I/2O/D.sub.2B>0.53.

(9) The mentioned ratio of osculation of the outboard bearing 2 is preferably between 0.54 and 0.545; the mentioned ratio of osculation of the inboard bearing 3 is preferably between 0.53 and 0.535.

(10) All mentioned ratios for the osculation remain preferably below 0.55.