Roller bearing, in particular for a vehicle steering system or for a vehicle wheel hub assembly

Patent metadata

Field	Value
Publication number	US-9926974-B2
Application number	US-201615185202-A
Country	US
Kind code	B2
Filing date	Jun 17, 2016
Priority date	Jun 19, 2015
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A roller bearing including an outer ring, at least one inner ring and a plurality of rolling bodies inserted between the outer ring and the inner ring. The outer ring presents an osculation of between 0.51 and 0.56 and the inner ring presents an annular race having a bottom surface delimited by an annular relief ( 16 ) including a cylindrical section ( 18 ) with a greater diameter than that of the bottom surface ( 12 ), a first convex curved section ( 19 ) having a pre-established radius of curvature (R 1 ) and which connects with continuity the annular bottom surface ( 12 ) of the first annular race with the cylindrical section ( 18 ), a second convex curved section ( 20 ) which connects with continuity with the cylindrical section ( 18 ) and a third concave curved section ( 21 ) that connects with continuity with the second section ( 20 ).

First claim

The invention claimed is:

1. A roller bearing for a steering system or a vehicle wheel hub assembly comprising:
at least one first ring;
at least one first annular race formed in the first ring;
at least one second ring;
a second annular race formed in the second ring, wherein the second annular race is positioned facing the at least one first annular race; and
a plurality of rolling bodies inserted between the first ring and the second ring that enable the rings to rotate relatively around an axis of rotation, wherein the rolling bodies collectively create at least one annular band of rolling bodies that engage with the at least one first annular race and the second annular race;
wherein a surface comprising the first annular race includes:
an annular bottom surface having a concave annular surface, the annular bottom surface delimited by a first end and a second end;
a first section having a convex annular surface with a first radius of curvature, the first section delimited by a first end and a second end;
a lateral surface delimited by a first end and a second end;
a cylindrical section having a constant radial dimension from the axis of rotation, the cylindrical section delimited by a first end and a second end;
a second section having a convex annular surface with a second radius of curvature, the second section delimited by a first end and a second end;
a third section having a concave annular surface with a third radius of curvature, the third section delimited by a first end and a second end;
the annular bottom surface arranged having the first end located proximate one end of the first ring and the second end located proximate a central section of the first annular race,
the first section being located between the annular bottom surface and the lateral surface with the first end of the first section being continuous with the second end of the annular bottom surface,
the lateral surface being located between the first section and the cylindrical section with the first end of the lateral surface being continuous with the second end of the first section,
the cylindrical section having a constant diameter across the section, the cylindrical section being located between the lateral surface and the second section with the first end of the cylindrical section being continuous with the second end of the lateral surface,
the second section being located between the cylindrical section and the second section with the first end of the second section being continuous with the second end of the cylindrical section,
the third section arranged having the first end continuous with the second section and the second end located proximate a second end of the first ring, and
a bend having a concave annular surface, the bend formed on each side of a junction between the first end of the third section and the second end of the second section,
the diameter of the cylindrical section being greater than a smallest diameter of the annular bottom surface, wherein the cylindrical section provides an axial retention shoulder for the rolling bodies.

2. The roller bearing according to claim 1 , wherein the cylindrical section presents a minimum axial extension at least smaller than that of the first section.

3. The roller bearing according to claim 1 , wherein the value of the second radius of curvature and the value of the third radius of curvature are equal to or lower than the value of the first radius of curvature.

4. The roller bearing according to claim 1 , wherein the rolling bodies are balls having a radius,
wherein the second race is delimited by a concave annular bottom surface having a radius of curvature,
wherein a ratio between the radius of curvature of the annular bottom surface of the second race and the diameter of the balls is between 0.51 and 0.56,
wherein radius of curvature of the annular bottom surface is greater than the radius of the balls by such an amount to create an osculation between the annular bottom surface of the second race and the balls.

5. The roller bearing according to claim 1 , wherein the value of the first radius of curvature is greater than 12 mm.

6. The roller bearing according to claim 1 , wherein the at least one first annular race and the second annular race defines a first pair of annular races, the roller bearing further comprising a second pair of first and second annular races,
wherein the rolling bodies are balls and are housed in two bands of rolling bodies arranged adjacently, the rolling bodies engaging the first pair of first and second annular races and the second pair of first and second annular races, the first pair of first and second annular races and the second pair of first and second annular races being arranged adjacently to one another,
wherein the second annular race of the first pair and the second annular race of the second pair are delimited each by annular surface, each of the second races comprising a concave bottom having a radius of curvature that is greater than the radius of the balls such that the second ring presents an osculation between the annular bottom surfaces of the second races and the balls, defined as a ratio between the radius of curvature of the annular concave bottom surfaces of the second races and the diameter of the balls between 0.51 and 0.56.

7. The roller bearing according to claim 6 , wherein the at least one first ring is a pair of inner rings and the second ring is an outer ring; the first annular races being formed on a radially external lateral surface of the inner rings and the second annular races being formed on a radially internal lateral surface of the outer ring.

8. A wheel hub assembly including a roller bearing, the roller bearing comprising:
at least one first ring;
at least one first annular race formed in the first ring;
at least one second ring;
a second annular race formed in the second ring, wherein the second annular race is positioned facing the at least one first annular race; and
a plurality of rolling bodies inserted between the first ring and the second ring that enable the rings to rotate relatively around an axis of rotation, wherein the rolling bodies collectively create at least one annular band of rolling bodies that engage with the at least one first annular race and the second annular race;
wherein a surface comprising the first annular race includes:
an annular bottom surface having a concave annular surface, the annular bottom surface delimited by a first end and a second end;
a first section having a convex annular surface with a first radius of curvature, the first section delimited by a first end and a second end;
a lateral surface delimited by a first end and a second end;
a cylindrical section having a constant radial dimension from the axis of rotation, the cylindrical section delimited by a first end and a second end;
a second section having a convex annular surface with a second radius of curvature, the second section delimited by a first end and a second end;
a third section having a concave annular surface with a third radius of curvature, the third section delimited by a first end and a second end;
the annular bottom surface arranged having the first end located proximate one end of the first ring and the second end located proximate a central section of the first annular race,
the first section being located between the annular bottom surface and the lateral surface with the first end of the first section being continuous with the second end of the annular bottom surface,
the lateral surface being located between the first section and the cylindrical section with the first end of the lateral surface being continuous with the second end of the first section,
the cylindrical section having a

Assignees

• Ciulla Luca
• Finetti William
• Lamboglia Francesco
• Rainone Gerardo
• Sguotti Laura
• Skf Ab

Inventors

• Ciulla Luca
• Finetti William
• Lamboglia Francesco
• Rainone Gerardo
• Sguotti Laura

Classifications

• F16C2326/24

  Steering systems, e.g. steering rods or columns · CPC title

• F16C33/585

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

• B60B27/0005

  with ball bearings · CPC title

• F16C2326/02

  Wheel hubs or castors · CPC title

• F16C33/583

  Details of specific parts of races · CPC title