Low friction sealing device for a wheel hub assembly connected to a constant velocity joint

Patent metadata

Field	Value
Publication number	US-9701159-B2
Application number	US-201514951493-A
Country	US
Kind code	B2
Filing date	Nov 25, 2015
Priority date	Nov 28, 2014
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A sealing device for a wheel hub assembly having an outer ring and an inner ring. The sealing device includes a first (stationary) annular shield and a second (rotating) annular shield, each having a journalling portion and a flange portion radially extending in cantilever fashion from the journalling portion and towards the other shield; and an annular sealing element carried by the first shield and provided with a plurality of annular sealing lips. The first shield is coupled radially on the outside of the outer ring. The second shield flange portion includes a radially outer annular stretch opposite the journalling portion, extending axially towards the first shield and is incurved radially from the exterior towards the interior, on the side opposite the first shield, forming a U-arranged parallel to a common symmetry axis of the first and second shields, having a concavity thereof facing the side opposite the first shield.

First claim

What is claimed is:

1. A sealing device for a wheel hub assembly connected to a constant velocity joint and intended to be interposed on at least one of an inner ring and an outer ring of the wheel hub assembly and to extend straddling between the wheel hub assembly and the constant velocity joint; the sealing device comprising:
a first annular shield, stationary in use, the first annular shield comprising a first shield journalling portion and a first shield flange portion, the first shield journalling portion extending axially and being fixed in a fluid-tight manner to an outer cylindrical surface of the outer ring, the first shield flange portion extending from a first shield journalling portion axial end in a radial direction towards the inner ring, and
a second annular shield, rotating in use, the second annular shield comprising a second shield journalling portion and a second shield flange portion, the second shield journalling portion being fixed to the inner ring, the second shield flange portion extending from the second shield journalling portion in the radial direction towards the outer ring,
an annular sealing element carried by the first annular shield and which is provided with a plurality of annular sealing lips; the second shield flange portion carrying, on the side opposite to the first annular shield and in use toward the constant velocity joint, an annular signal generating element made of a synthetic plastic or magnetizable elastomeric material; wherein:
the second shield flange portion comprises a radially inner annular stretch extending from the second shield journalling portion in a radial direction perpendicular to an axis of rotation and ending at a radially outer end, the radially inner annular stretch extends entirely in the radial direction perpendicular to an axis of rotation, the second shield flange portion further comprising a U-shaped radially outer annular stretch which extends axially toward the first annular shield from the radially outer end of the radially inner annular stretch extending portion and forms a U-shape in cross section, the U-shaped radially outer annular stretch further comprising first and second walls that are generally parallel to each other and parallel to the axis of rotation, the first wall extends axially from the radially outer end of the radially inner annular stretch, the U-shaped radially outer annular stretch further comprising a curved bottom wall being convex with respect to the first annular shield and connecting the first and second walls that are generally parallel, the curved bottom wall cooperating with the first shield flange portion to form a labyrinth seal therebetween, the second wall of the U-shaped radially outer annular stretch having a free end that is axially aligned with the first shield journalling portion,
a maximum radial distance of the sealing device with respect to the axis of rotation is equal to the radial distances of the first shield journalling portion and the free end of the second wall of the U-shaped radially outer annular stretch such that no portion of the sealing device extends radially past the first shield journalling portion or the free end of the second wall of the U-shaped radially outer annular stretch,
a first radially outer annular lip of the annular sealing element radially and axially extending in cantilever fashion from the first shield flange portion and toward the second annular shield so as to move obliquely away from the axis of rotation, and being arranged radially inwardly from the first wall of the U-shaped radially outer annular stretch of the second shield flange portion, the first radially outer annular lip forming a V-shaped annular channel facing radially outwardly and arranged in radial section immediately below the curved bottom wall of the U-shaped radially outer annular stretch of the second shield flange portion,
a first annular lip free end forming, with a radially inner surface of the first wall of the U-shaped radially outer annular stretch, and within an annular chamber delimited between the first and the second annular shields, a second labyrinth seal, which is directed axially, and wherein
no portion of the sealing device is located within a bearing chamber, the bearing chamber being an area defined radially between an outer surface of the inner ring and an inner surface of the outer ring and defined axially between first and second axial ends of the outer ring.

2. The device according to claim 1 , the second shield journalling portion further comprising:
a first stretch defined by a first L-shaped fold which axially extends in cantilever fashion from the second shield flange portion and toward the first annular shield; and
a second stretch defined by a U-shaped fold, which radially overlaps in contact with the first stretch defined by the first L-shaped fold on the side of the inner ring and which extends axially backward with respect to the first L-shaped fold, toward the constant velocity joint and beyond the second shield flange portion.

3. The device according to claim 2 , wherein:
a third L-shaped fold extends from the U-shaped fold, on the side opposite to the first stretch, the third L-shaped fold being obtained in one piece with the second stretch and extending radially toward the interior of the second shield journalling portion;
the third L-shaped fold being intended to axially extend, in use, in cantilever fashion from the inner ring and, with respect to the second shield flange portion, toward the constant velocity joint to form a tubular element adapted to be arranged, in use, straddling the wheel hub assembly and the constant velocity joint, coaxial with the inner ring;
the third L-shaped fold defining a first thrust shoulder for mounting the second annular shield onto a radially outer surface of the inner ring.

4. The device according to claim 2 , further comprising a third annular shield intended, in use, to couple radially toward the interior of the second shield journalling portion;
a third L-shaped fold facing radially toward the exterior and toward the second shield journalling portion; and
a tubular element which extends in cantilever fashion from the third L-shaped fold and is adapted to be arranged, in use, straddling the wheel hub assembly and the constant velocity joint, coaxial with the inner ring and intended to be journalled onto the inner ring, in axial sequence immediately after the second annular shield in a direction which moves away from the first annular shield, to axially extend, in use, in cantilever fashion from the inner ring, toward the constant velocity joint; the third L-shaped fold defining a first thrust shoulder for mounting the third annular shield within an annular step of one end of the inner ring.

5. The device according to claim 3 , wherein a tubular element free end is provided, radially on the interior thereof, with an L-shaped edge on the side opposite to a direction of cantilevered radial extension of the second shield flange portion; the L-shaped edge of the free end of the tubular element being entirely embedded in an annular gasket.

6. The device according to claim 1 , wherein the first shield journalling portion is adapted to be coupled radially on the outer cylindrical surface of the outer ring with the interposition of an o-ring which is arranged radially on the inside of the first shield journalling portion.

7. The device according to claim 1 , wherein the first annular lip free end is delimited by an annular flat surface,
wherein the annular flat surface is parallel to the axis of rotation and faces the radially inner surface of the first wall of the U-shaped radially outer annular stretch, with which the annular flat surface cooperates to form the second labyrinth seal.

Assignees

• Duch Daniele
• Morello Fausto
• Skf Ab

Inventors

• Duch Daniele
• Morello Fausto

Classifications

• F16J15/3232

  having two or more lips · CPC title

• F16C2326/02

  Wheel hubs or castors · CPC title

• F16C33/7876

  with sealing lips · CPC title

• F16C33/7823

  of sealing lips · CPC title

• F16C19/186

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