Bearing rolling including a low friction sealing device, in particular for a hub bearing unit

Patent metadata

Field	Value
Publication number	US-9925830-B2
Application number	US-201615164194-A
Country	US
Kind code	B2
Filing date	May 25, 2016
Priority date	May 29, 2015
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A rolling bearing providing an outer ring, an inner ring, and a plurality of rolling bodies disposed between the inner ring and the outer ring, and a sealing device held by the outer ring and consisting of a first and second annular shield and an elastomeric sealing element held by one of the shields. The second shield extends axially and radially to protrude on the outside of the outer ring and cooperates with a radially outer lateral surface of the outer ring, to delimit a radial annular gap therewith. An annular tooth is formed on the radially outer lateral surface of the outer ring in front of the radial gap to shield the radial gap in axial direction. An annular groove formed in a position immediately adjacent to the annular tooth and on the side opposite to the second shield.

First claim

The invention claimed is:

1. A rolling bearing for a vehicle wheel bearing unit, comprising:
an outer bearing ring,
an inner bearing ring,
a plurality of rolling bodies interposed between the inner ring and the outer ring, and a sealing device; the sealing device having a first annular shield, the first annular shield being a single component and constructed from a rigid material, and held by the outer ring radially on the inside, a second annular shield, held by the inner ring radially on the outside, the second shield extending axially and radially to protrude on the outside of the outer ring and cooperating with a radially outer lateral surface of the outer ring, to delimit a radial annular gap therewith; and an elastomeric sealing element held by one of the shields and provided with at least one first annular lip cooperating with the other shield to define a labyrinth seal therewith; wherein the sealing device further provides, in combination:
an annular tooth formed from the radially outer radially outer surface of the outer bearing in front of and extend beyond the radial gap to shield the radial gap in an axial direction; and
a first annular groove formed from the radially outer lateral surface of the outer bearing ring, in position immediately adjacent to the annular tooth and on the side opposite to the second shield; the first annular groove being adapted to define a first collector for possible external contaminants.

2. The rolling bearing according to claim 1 , wherein the annular tooth radially extends to protrude with respect to an end portion of the outer ring facing towards the second shield, the annular tooth having a radially outer terminal end, which radially extends to protrude with respect to a bottom wall of the first annular groove and beyond the radial gap substantially until it is flush with a radially outer edge of an annular frontal rim of the second shield; and the first annular groove extends in depth within the outer ring, according to a radial direction, up to the radial gap.

3. The rolling bearing according to claim 2 , wherein the annular tooth has in radial section a substantially saw-tooth shaped profile, having a first side that faces towards the second shield and defined by a flat annular surface perpendicular to the radially outer lateral surface of the outer ring; and a second side that faces the second shield on the opposite side that is delimited by a concave curved annular surface which slopes towards the bottom wall of the first annular groove, to which it joins.

4. The rolling bearing according to claim 2 , wherein the first annular groove has an asymmetric profile in radial section having a first side arranged towards the second shield that is delimited by an annular, curved and concave surface and by a first portion of the bottom wall, joined to the surface of the annular tooth; and a second side arranged on the side opposite to the second shield that is delimited by a second portion of the bottom wall and by a conical surface facing towards the second shield and that joins on one side to the second portion of the bottom wall, while on the other side it extends in radial direction substantially to the radially outer terminal end of the annular tooth to end with an annular edge at a portion of the outer ring having diameter greater than that of the end portion.

5. The rolling bearing according to claim 1 , wherein the sealing device further provides a second annular groove formed on a portion of a radially outer lateral surface of the outer ring delimiting an end portion of the outer ring facing towards the second shield; the second annular groove being arranged immediately adjacent to the annular tooth on the side of the second shield and on the opposite side to the first annular groove and being adapted to define a second collector for external contaminants.

6. The rolling bearing according to claim 5 , wherein the second annular groove has a substantially semicircular symmetric profile in radial section.

7. The rolling bearing according to claim 5 , wherein the second shield is shaped in radial section as a C facing towards the outer ring and provides a first radially inner sleeve portion, the second shield is keyed on the inner ring, a second radially outer sleeve portion, parallel to and facing the first sleeve portion, and a flange portion that radially connects the first and second sleeve portions, which both axially extend to protrude from the flange portion towards the outer ring; the second sleeve portion extends radially on the outside of the end portion of the outer ring and axially along the stretch of the radially outer lateral surface of the outer ring delimiting the end portion, with which it defines the radial gap; the second sleeve portion ending on the side opposite to the flange portion with a free end, which axially and radially extends to protrude on the outside over the second annular groove, preferably substantially to the middle line of the second annular groove, to define a frontal annular rim of the second shield facing towards the annular tooth and arranged facing it and axially distanced from it to define an axial gap with the annular tooth; a radially outer edge of the front annular rim being arranged substantially flush with a radially outer terminal end of the annular tooth.

8. The rolling bearing according to claim 7 , wherein the flange portion of the second shield is axially external to the outer ring and is provided with a double L fold substantially at a sleeve-shaped journaling portion of the first shield; the first annular lip cooperating with the double L fold with a free end thereof to define the labyrinth seal with the flange portion.

9. The rolling bearing according to claim 1 , wherein the second shield is shaped in radial section substantially as a C facing towards the outer ring, which is stationary; and the inner ring has an end portion opposite to the outer ring that axially extends to protrude from the outer ring, the end portion of the inner ring being provided with a flange and the inner ring rotating; the second shield having an intermediate flange portion that radially connects a first and a second sleeve portion, which extend to protrude axially from the flange portion; the flange of the inner ring and the flange portion of the second shield being shaped to delimit there between an annular channel that rotates, adapted to work as rotating collector for external contaminants.

10. A wheel hub unit comprising:
a rolling bearing having an outer ring,
an inner ring,
a plurality of rolling bodies interposed between the inner ring and the outer ring, and a sealing device; the sealing device having a first annular shield, the first annular shield being a single component and constructed from a rigid material, and held by the outer ring radially on the inside, a second annular shield, held by the inner ring radially on the outside, the second shield extending axially and radially to protrude on the outside of the outer ring and cooperating with a radially outer lateral surface of the outer ring, to delimit a radial annular gap therewith; and an elastomeric sealing element held by one of the shields and provided with at least one first annular lip cooperating with the other shield to define a labyrinth seal therewith; wherein the sealing device further provides, in combination:
an annular tooth formed from the radially outer radially outer surface of the outer bearing in front of and extend beyond the radial gap to shield the radial gap in an axial direction; and
a first annular groove formed from the radially outer lateral surface of the outer ring, in position immediately adjacent to the annular tooth and on the side opposite to the second s

Assignees

• Barberis Giorgio
• Morello Fausto
• Skf Ab

Inventors

• Barberis Giorgio
• Morello Fausto

Classifications

• F16C2326/02

  Wheel hubs or castors · CPC title

• F16C33/586

  outside the space between the races, e.g. end faces or bore of inner ring · CPC title

• F16C33/7883

  mounted to the inner race and of generally L-shape, the two sealing rings defining a sealing with box-shaped cross-section · CPC title

• B60B35/18 Primary

  Arrangement of bearings · CPC title

• F16C33/7826

  of the opposing surface cooperating with the seal, e.g. a shoulder surface of a bearing ring · CPC title