US-12617230-B2 - Integrated hub bearing unit

US12617230B2US 12617230 B2US12617230 B2US 12617230B2US-12617230-B2

Abstract

A hub bearing unit includes a radially outwardly extending flange, a first portion on a first side of the flange and a tubular portion on a second side of the flange. A bearing outer ring surrounds the first portion, and rolling elements are mounted between the first portion and the outer ring. A splined shaft of a constant velocity joint extends into the hub and has a threaded end portion inside the tubular portion. A threaded connector is mounted on the threaded end portion and has a deformable portion configured to be deformed to prevent the threaded connector from being unscrewed. A portion of the tubular portion near the flange includes a radial through hole configured to allow a torque arm of a deformation tool to access and deform the deformable portion.

Inventors

Fausto Morello
Pruthviraj Mandya Shekar
Laura Baracco

Assignees

AKTIEBOLAGET SKF

Dates

Publication Date: 20260505
Application Date: 20231016
Priority Date: 20221111

Claims (10)

1 . A hub bearing unit for a wheel of a motor vehicle, the hub bearing unit comprising: a hub having a first axial end, a second axial end spaced from the first end in an axial direction, a radially outwardly extending flange at a location between the first axial end and the second axial end, an axial opening extending from the first axial end to the second axial end and a tubular portion extending from the radial flange toward the second axial end, the tubular portion including a proximal cylindrical centering portion at the flange; a bearing outer ring surrounding a portion of the hub between the flange and the first axial end of the hub, the bearing outer ring including a first raceway and a second raceway, a bearing inner ring mounted on the portion of the hub, a first row of rolling elements mounted between the first raceway of the outer ring and a raceway formed on an outer surface of the portion of the hub and a second row of rolling elements mounted between the second raceway of the outer ring and a raceway of the bearing inner ring, a splined shaft of a constant velocity joint extending into the axial opening from the first axial end of the hub to a location inside the tubular portion of the hub, the splined shaft having a threaded end portion inside the tubular portion of the hub, and a threaded connector threadedly engaged with the threaded end portion of the splined shaft and having a deformable portion configured to be deformed relative to the splined shaft to prevent the threaded connector from being unscrewed from the splined shaft, wherein the proximal portion of the tubular portion includes at least one radial through hole radially aligned with the deformable portion of the threaded connector and configured to allow a torque arm of a deformation tool to access the deformable portion, and wherein a surface of the through hole closest to the second axial end of the hub is configured to absorb forces applied to the surface of the through hole by the torque arm during a deformation of the deformable portion.
2 . The hub bearing unit according to claim 1 , wherein the surface of the through hole is a flat surface parallel to an axially outer surface of the flange.
3 . The hub bearing unit according to claim 2 , wherein the at least one through hole comprises two diametrically opposed through holes.
4 . The hub bearing unit according to any of the claim 2 , wherein a length of the at least one through hole in the axial direction is less than or equal to half of an axial length of the proximal cylindrical centering portion of the tubular portion.
5 . The hub bearing unit according to claim 4 , an axial distance from the at least one through hole to a surface of the radial flange facing the second axial end of the hub is greater than 2 mm.
6 . The hub bearing unit according to claim 5 , wherein a circumferential width of the at least one through hole is less than or equal to twice the length of the at least one through hole in the axial direction.
7 . The hub bearing unit according to claim 1 , wherein the at least one through hole has a straight section in a shape of a circular segment, the base of which generates the surface.
8 . The hub bearing unit according to claim 7 , wherein a portion of the through hole that does not form the surface is cylindrical.
9 . The hub bearing unit according to claim 1 , wherein the at least one through hole has a straight section in a shape of a circle, a slot or a square.
10 . The hub bearing unit according to claim 1 , wherein the threaded connector is a nut.

Description

CROSS-REFERENCE This application claims priority to Italian patent application no. 102022000023265 filed on Nov. 11, 2022, the contents of which are fully incorporated herein by reference. TECHNOLOGICAL FIELD The present disclosure is directed to an integrated hub bearing unit for the wheel of a motor vehicle and more specifically to an integrated bearing unit for the wheel hub of a motor vehicle configured to accommodate a deformation tool used during the assembly of the hub bearing unit. BACKGROUND Such assemblies comprise a hub with a flange directed radially outward from one axial end thereof for mounting a vehicle wheel, an outer ring with axially spaced raceways, and a plurality of rolling elements in the annular space between the outer ring and the hub. The rolling elements are arranged in two rows: an axially outer row in an annular space between the outer ring and the hub and an axially inner row in an annular space between the outer ring and an inner ring keyed on the hub. The radial flange of the hub has a number of holes to allow mounting of the vehicle wheel by means of bolts. The flange also has a flat radial surface on its axially external side that defines a precise reference surface against which the brake disc and the wheel are supported. The hub further includes a tubular portion which projects in an axially outward direction beyond the radial flange. This tubular portion serves to allow the support and preliminary centering of the wheel, before it is fixed, in a perfectly centered position, by means of the fixing bolts that are inserted through the holes in the flange. Inside the protruding tubular portion there is a thread in which a single central threaded fixing element can be screwed to lock the wheel on the hub. In the case of application to a drive wheel, the hub is angularly coupled to a constant velocity joint, the shaft of which is axially locked to the hub by means of a threaded nut which is screwed onto a protruding threaded end of the joint shaft and abuts against a radial surface of the hub. The threaded nut is secured against accidental unscrewing by means of a crunch, that is, a plastic deformation of one of its axial ends on the shaft of the constant velocity joint. The crunching process is performed using special equipment. In the case of sports applications, the tubular portion of the hub that protrudes in an axially external direction has a remarkable axial dimension and is very close to the shaft of the constant velocity joint. This makes the crunch machining of the threaded nut very difficult as the same nut will be in a corresponding recess with respect to the axial end of the tubular portion of the hub. For the same reason, moreover, it is almost impossible to carry out a visual inspection that checks the correctness of the crunching process. SUMMARY An aspect of the present disclosure is to provide an integrated hub bearing unit for the wheel of a motor vehicle which is free from the drawbacks described above. According to the present disclosure, a hub bearing unit for a wheel of a motor vehicle comprises a hub having a first axial end, a second axial end spaced from the first end in an axial direction, a radially outwardly extending flange at a location between the first axial end and the second axial end, an axial opening extending from the first axial end to the second axial end and a tubular portion extending from the radial flange toward the second axial end, the tubular portion including a proximal cylindrical centering portion at the flange. A bearing outer ring surrounds a portion of the hub between the flange and the first axial end of the hub and includes an outer ring including a first raceway and a second raceway, the hub bearing unit also includes a bearing inner ring mounted on the portion of the hub. A first row of rolling elements is mounted between the first raceway of the outer ring and a raceway formed on an outer surface of the portion of the hub and a second row of rolling elements is mounted between the second raceway of the outer ring and a raceway of the bearing inner ring. A splined shaft of a constant velocity joint extends into the axial opening from the first axial end of the hub to a location inside the tubular portion of the hub, and the splined shaft has a threaded end portion inside the tubular portion of the hub. A threaded connector is threadedly engaged with the threaded end portion of the splined shaft and has a deformable portion configured to be deformed relative to the splined shaft to prevent the threaded connector from being unscrewed from the splined shaft. The proximal cylindrical centering portion of the tubular portion includes at least one radial through hole radially aligned with the deformable portion of the threaded connector and configured to allow a torque arm of a deformation tool to access the deformable portion, and a surface of the through hole closest to the second axial end of the hub is configured to absorb