Rolling bearing, in particular vehicle hub bearing unit, having a sealing cover

Patent metadata

Field	Value
Publication number	US-9505267-B2
Application number	US-201514830852-A
Country	US
Kind code	B2
Filing date	Aug 20, 2015
Priority date	Aug 26, 2014
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A rolling bearing constituting a vehicle hub bearing unit, including an outer ring, an inner ring, a plurality of rolling bodies interposed between the inner and outer rings, and a cover driven with axial and radial interference on a first end of the outer ring, which it fluid-tightly closes; wherein the cover is formed by a plastic made body, made of a synthetic plastic material, and by a cylindrical metal sleeve co-molded with the plastic made body; between the cover and the outer ring there being arranged an annular sealing element housed with axial clearance in a seat of the outer ring made at least in part on the radially inner surface of the outer ring; a sealant being arranged between the metal sleeve and the plastic body.

First claim

The invention claimed is:

1. A rolling bearing, in particular a vehicle hub bearing unit, comprising:
an outer ring, stationary in use;
an inner ring, rotating in use about a common symmetry axis of the inner ring and the outer ring;
a plurality of rolling bodies interposed between the inner and outer rings; and
a sensor bearing element, in the shape of a closing and sealing cover, which fluid-tightly closes a first open annular end of the outer ring,
wherein the sensor bearing element is mounted integral with the outer ring, driven in axial abutment and radial interference on the first end of the outer ring, and being formed by a plastic made body, made of a synthetic plastic material, and by a cylindrical metal sleeve, co-molded with the plastic made body, which metal sleeve defines at least one radially outer, radial coupling lateral surface of the sensor bearing element with a radially inner lateral surface of the outer ring;
wherein between the sensor bearing element and the outer ring there being arranged an annular sealing element housed in a seat obtained on the outer ring, there being present in the bearing:
a first passage of possible leakage of fluid along the radially inner, radial coupling lateral surface of the outer ring and the radially outer, radial coupling lateral surface of the sensor bearing element, and along respective axial coupling surfaces in abutment between the sensor bearing element and the outer ring defined by an axial shoulder frontal surface of the sensor bearing element delimited by the plastic made body and by a frontal surface of the first end of the outer ring, and
a second passage of possible leakage of fluid along a first contact interface between the cylindrical metal sleeve and the plastic made body and along a second contact interface between the axial shoulder coupling surfaces between the plastic made body of the sensor bearing element and the outer ring,
a sealant is arranged to close the second passage of possible leakage of fluid,

wherein:
i) the housing seat for the annular sealing element is made so as to allow a free deformation in axial direction of the annular sealing element, without any axial contact between annular sealing element and sensor bearing element;
ii) the housing seat for the annular sealing element is made at least in part at the radially inner lateral surface of the outer ring and its radial dimensions are such to ensure a radial sealing action between the outer ring and the metal sleeve of the sensor bearing element, the annular sealing element being radially interference fitted between the housing seat and the radially outer, radial coupling lateral surface of the sensor bearing element;
iii) so that the annular sealing element cuts off only the first passage of possible leakage of fluid.

2. A rolling bearing according to claim 1 , wherein the second path of possible leakage is closed by the sealant, wherein the sealant is poured between the cylindrical metal sleeve and the plastic made body of the sensor bearing element.

3. A rolling bearing according to claim 2 , wherein, in combination:
the cylindrical metal sleeve is delimited between a radially outer cylindrical lateral surface thereof defining the at least one radial coupling lateral surface of the sensor bearing element and a radially inner cylindrical lateral surface thereof defining the first contact interface between cylindrical metal sleeve and plastic made body;
the cylindrical metal sleeve is provided with: a distal end from the outer ring, radially folded outwards in an L-shape, which is completely embedded in a first flange-shaped portion of the plastic made body, such a first portion of the plastic made body delimiting the axial shoulder frontal surface of the sensor bearing element; and a vicinal end to the outer ring, opposite to the distal end and radially folded inwards as an L, which defines a metal frontal end of the sensor bearing element towards the outer ring and which has a radially inner edge embedded in a second sleeve-shaped portion of the plastic made body; the second portion of the plastic made body extending parallel to the metal sleeve and in contact with the radially inner lateral surface of the metal sleeve; the first and the second portion of the plastic made body being made integrally in one piece with each other and with a bottom wall of the plastic made body arranged facing the first open end of the outer ring; and
the sealant forms an annular cordon arranged between a portion of the radially outer cylindrical lateral surface of the metal sleeve immediately adjacent to the distal end of the metal sleeve and a base of the first flange-shaped portion of the plastic made body.

4. A rolling bearing according to claim 2 , wherein:
a housing seat for the annular sealing element is obtained in part on the extension of a stretch of the frontal surface of the first end of the outer ring and in part on the extension of a stretch of the inner lateral surface of the outer ring immediately adjacent to the first end of the outer ring;
the housing seat is delimited by a pair of annular flat surfaces arranged obliquely to the rotation axis and converging with, and joined to, each other, one facing the radially outer lateral surface of the metal sleeve and the other facing the axial shoulder frontal surface of the sensor bearing element delimited by the plastic made body, respectively;
the annular sealing element consists of an elastically deformable o-ring inserted radially by interference between the oblique first annular flat surface of the housing seat and the radially outer lateral surface of the metal sleeve; and
a predetermined axial clearance is present between the annular sealing element and the axial shoulder frontal surface of the sensor bearing element delimited by the plastic made body.

5. A rolling bearing according to claim 2 , wherein:
the housing seat for the annular sealing element is obtained only on the radially inner lateral surface of the outer ring;
the housing seat is defined by an annular groove delimited by an annular bottom wall facing the radially outer cylindrical lateral surface of the metal sleeve defining the at least one radial coupling lateral surface of the sensor bearing element, and by a pair of opposite end faces facing each other and parallel to the front surface of the first end of the outer ring;
the annular sealing element consists of an elastically deformable o-ring radially interference fitted between the annular bottom wall of the annular groove and the radially outer lateral surface of the metal sleeve; and
a predetermined axial clearance is present between the annular sealing element and both end faces of the annular groove facing each other.

6. A rolling bearing according to claim 1 , wherein the second path of possible leakage is closed by the sealant, wherein the sealant is poured between the cylindrical metal sleeve and the plastic made body of the sensor bearing element during a step of manufacturing of the sensor bearing element.

7. A rolling bearing according to claim 1 , wherein the inner ring is equipped on a side thereof opposite to the sensor bearing element with a flange for the assembly of a vehicle wheel.

8. A rolling bearing according to claim 7 , wherein a closed chamber is delimited between the sensor bearing element in the shape of a cover, the outer ring and the inner ring, in which an element to be detected is housed,
wherein the element to be detected is integrally carried by the inner ring in position facing a bottom wall of the sensor bearing element,
wherein the bottom wall of the sensor bearing element supports a sensor in protected manner, facing the inside of the closed chamber,
wherein the sensor is adapted to detect t

Assignees

• Gemello Marco
• Magli Giampaolo
• Wu Zhengjiang
• Skf Ab

Inventors

• Gemello Marco
• Magli Giampaolo
• Wu Zhengjiang

Classifications

• B60B27/0005

  with ball bearings · CPC title

• B60B27/0073 Primary

  characterised by sealing means · CPC title

• F16C2326/02

  Wheel hubs or castors · CPC title

• F16C41/007

  Encoders, e.g. parts with a plurality of alternating magnetic poles · CPC title

• F16C19/186

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