Wheel hub assembly with optimized raceways

Patent metadata

Field	Value
Publication number	US-11788578-B2
Application number	US-202217711190-A
Country	US
Kind code	B2
Filing date	Apr 1, 2022
Priority date	Apr 12, 2021
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

A bearing unit for a wheel hub assembly for motor vehicles, having a first raceway which is a radially outer and axially outer raceway and a second raceway which is a radially outer and axially inner raceway, a third raceway which is a radially inner and axially outer raceway and a fourth raceway which is a radially inner and axially inner raceway; an axially outer row and an axially inner row of rolling bodied, interposed, respectively, between the first raceway and the third raceway and between the second raceway and the fourth raceway; at least one raceway is provided with a first raceway portion and a second raceway portion, the raceway portions being tangential to the rolling body of the row of rolling bodies at two different contact angles the first contact angle of the first raceway being smaller than the second contact angle of the second raceway portion.

First claim

We claim:

1. A bearing unit for a wheel hub assembly for motor vehicles, the bearing unit having a rotation axis (X) and comprising:
two radially outer raceways, comprising a first raceway which is a radially outer and axially outer raceway and a second raceway which is a radially outer and axially inner raceway,
two radially inner raceways, comprising a third raceway which is a radially inner and axially outer raceway and a fourth raceway which is a radially inner and axially inner raceway,
two rows of rolling bodies, comprising an axially outer row and an axially inner row, interposed, respectively, between the first raceway and the third raceway and between the second raceway and the fourth raceway and in axially symmetrical positions relative to a plane of axial symmetry (Z) of the bearing unit,
wherein at least one of the raceways comprises a first raceway portion and a second raceway portion, both of the raceway portions being tangential to the rolling body of the row of rolling bodies or to the rolling body of the row of rolling bodies plus an axial clearance at two different contact angles comprising a first contact angle (CAO′) and a second contact angle (CAO″), the first contact angle (CAO′) of the first raceway portion being smaller than the second contact angle (CAO″) of the second raceway portion,
wherein the axial clearance of the second raceway portion with respect to the rolling body of the row of rolling bodies comprises a value between 5μ and 20μ.

2. The bearing unit of claim 1 , wherein a center (C′) of the first raceway portion and a center (C″) of the second raceway portion do not coincide.

3. The bearing unit of claim 2 , wherein both an axial distance and a radial distance between the center (C′) of the first raceway portion and the center (C″) of the second raceway portion lie within a range of 0.01 mm to 0.5 mm.

4. The bearing unit of claim 1 , wherein the first contact angle (CAO′) of the first raceway portion comprises a value between 5° and 30°.

5. The bearing unit of claim 1 , wherein the second contact angle (CAO″) of the second raceway portion comprises a value between 30° and 60°.

6. The bearing unit of claim 1 , wherein an osculation of the first raceway portion is different from an osculation of the second raceway portion.

7. The bearing unit of claim 1 , wherein an osculation (OOI′, OOE′, OIE′, OII′) of the first raceway portion is different from an osculation (OOI″, OOE″, OIE″, OII″) of the second raceway portion, wherein OOI′≠OOI″, OOE′≠OOE″, OIE′≠OIE″, and OII′≠OII″;
wherein:
OOI′ is a ratio between a radius of curvature of the first raceway portion of the radially inner and axially outer raceway and an outer diameter DSO of the balls in the axially outer row of rolling bodies;
OOI″ is a ratio between a radius of curvature of the second raceway portion of the radially inner and axially outer raceway and the outer diameter DSO of the balls in the axially outer row of rolling bodies;
OOE′ is ratio between a radius of curvature of the first raceway portion of the radially outer and axially outer raceway and the outer diameter DSO of the balls in the axially outer row of balls;
OOE″ is a ratio between a radius of curvature of the second raceway portion of the radially outer and axially outer raceway and the outer diameter DSO of the balls in the axially outer row of balls;
OIE′ is a ratio between a radius of curvature of the first raceway portion of the radially outer and axially inner raceway and the outer diameter DSI of the balls in the axially inner row of balls;
OIE″ is a ratio between a radius of curvature of the second raceway portion of the radially outer and axially inner raceway and the outer diameter DSI of the balls in the axially inner row of balls;
OII′ is a ratio between a radius of curvature of the first raceway portion of the radially inner and axially inner raceway and the outer diameter DSI of the balls in the axially inner row of balls; and
OII″ is a ratio between a radius of curvature of a second raceway portion of the radially inner and axially inner raceway and the outer diameter DSI of the balls in the axially inner row of balls.

8. The bearing unit of claim 7 , wherein the values of the osculation of the first raceway portion of the radially inner and axially outer raceway (OOI′) and the first portion of the radially inner and axially inner raceway (OII′) are greater than 0.5175, and the values of the osculation of the first raceway portion of the radially outer and axially outer raceway (OOE′) and first raceway portion of the radially outer and axially inner raceway (OIE′) is greater than 0.53.

9. The bearing unit of claim 7 , wherein the values of the osculation of the second raceway portion of the radially inner and axially outer raceway (OOI″) and the second portion of the radially inner and axially inner raceway (OII″) is less than 0.5175 and the values of the osculation of the second raceway portion of the radially outer and axially outer raceway (OOE″) and the second raceway portion of the radially outer and axially inner raceway (OIE″) is less than 0.53.

10. A wheel hub assembly for motor vehicles, the assembly comprising:
a wheel hub; and
a bearing unit having a rotation axis (X) and comprising:
two radially outer raceways, comprising a first raceway which is a radially outer and axially outer raceway and a second raceway which is a radially outer and axially inner raceway,
two radially inner raceways, comprising a third raceway which is a radially inner and axially outer raceway and a fourth raceway which is a radially inner and axially inner raceway, wherein at least one of the two radially inner raceways is formed on the wheel hub,
two rows of rolling bodies, comprising an axially outer row and an axially inner row, interposed, respectively, between the first raceway and the third raceway and between the second raceway and the fourth raceway and in axially symmetrical positions relative to a plane of axial symmetry (Z) of the bearing unit,
wherein at least one of the raceways comprises a first raceway portion and a second raceway portion, both of the raceway portions being tangential to the rolling body of the row of rolling bodies or to the rolling body of the row of rolling bodies plus an axial clearance at two different contact angles comprising a first contact angle (CAO′) and a second contact angle (CAO″), the first contact angle (CAO′) of the first raceway portion being smaller than the second contact angle (CAO″) of the second raceway portion,
wherein the axial clearance of the second raceway portion with respect to the rolling body of the row of rolling bodies comprises a value between 5μ and 20μ.

11. The wheel hub assembly of claim 10 , wherein a center (C′) of the first raceway portion and a center (C″) of the second raceway portion do not coincide.

12. The wheel hub assembly of claim 11 , wherein both an axial distance and a radial distance between the center (C′) of the first raceway portion and the center (C″) of the second raceway portion lie within a range of 0.01 mm to 0.5 mm.

13. The wheel hub assembly claim 10 , wherein the first contact angle (CAO′) of the first raceway portion comprises a value between 5° and 30°.

14. The wheel hub assembly of claim 10 , wherein the second contact angle (CAO″) of the second raceway portion comprises a value between 30° and 60°.

15. The wheel hub assembly of claim 10 , wherein an osculation of the first raceway portion is different from an osculation of the second raceway portion.

16. The wheel hub assembly of claim 10 , wherein an osculation (OOI′, OOE′, OIE′

Assignees

• Skf Ab

Inventors

• Ferrero Alessandro
• Bogliacino Fabio
• Bertola Maurizio

Classifications

• F16C33/585 Primary

  of raceways, e.g. ribs to guide the rollers · CPC title

• B60B27/0005

  with ball bearings · CPC title

• B60B27/0094

  one or more of the bearing races are formed by the hub · CPC title

• F16C19/186 Primary

  with three raceways provided integrally on parts other than race rings, e.g. third generation hubs · CPC title

• F16C2326/02

  Wheel hubs or castors · CPC title