US-12623273-B2 - Equipment and method for forming a front toothing on an inner ring of a wheel hub

US12623273B2US 12623273 B2US12623273 B2US 12623273B2US-12623273-B2

Abstract

Equipment and method in which a creator tool is pressed against an annular upset collar of an inner ring of a wheel hub and is provided towards the collar with a toothing complementary to the toothing to be obtained, formed by a plurality of radial teeth separated by respective radial spaces, all arranged radially in a circular crown, symmetrically with respect to a first axis (B) defining the axis of symmetry of the tool; wherein the creator tool is provided with an annular radial containment element configured to delimit a continuous wall which closes off respective radially outer ends of the radial spaces.

Inventors

Laura Sguotti
Davide Antonio OLIVIERI

Assignees

AKTIEBOLAGET SKF

Dates

Publication Date: 20260512
Application Date: 20220129
Priority Date: 20210203

Claims (16)

1 . A device for forming a front toothing on an inner ring of a wheel hub, the device comprising: a unitary creator tool, having an axis of symmetry (B), the unitary creator tool comprising: a solid central portion; a first complimentary toothing positioned annularly about the solid central portion and configured to form the front toothing of the inner ring, the first complimentary toothing comprising: a plurality of radially extending teeth, wherein each tooth of the plurality of radially extending teeth comprises a ridge at a top end of the tooth defining a rounded radial profile; and a plurality of radially extending spaces separating the plurality of radially extending teeth respectively, wherein the plurality of radially extending teeth and the plurality of radially extending spaces are arranged annularly about the axis of symmetry (B); and an annular radial containment element radially disposed on an outside of the plurality of radially extending teeth and configured to define a continuous wall, wherein the continuous wall closes a radially outer end of each of the plurality of radially extending spaces; wherein, at an axially outermost end of the unitary creator tool, an axially outermost end surface of the annular radial containment element extends axially beyond an axially outermost end surface of the solid central portion.
2 . The device of claim 1 , wherein the annular radial containment element is arranged radially on an outside of a circular crown defined by the complementary toothing and configured such that the continuous wall encloses a radially outer end of each of the plurality of radially extending spaces over an axial height (H) of the plurality of radially extending spaces.
3 . The device of claim 1 , wherein the radial containment element is positioned axially higher than the ridge of each tooth so as to extend axially beyond the ridges of the teeth at a radially outer end of the plurality of radial spaces.
4 . The device of claim 3 , wherein an axial height of each ridge of each of the plurality of radially extending teeth progressively decreases in a radially inward direction and with a radius of curvature of the ridge, measured radially, progressively decreasing in a radially inward direction.
5 . The device of claim 2 , wherein the unitary creator tool further comprises a substantially flat front face configured to face towards a collar of the inner ring when in use.
6 . The device of claim 5 , wherein the complementary toothing is disposed within a shallow recess formed on the front face of the creator tool and on a bottom wall of the shallow recess.
7 . The device of claim 6 , wherein the annular radial containment element is defined by a radially outer and continuous edge of the shallow recess.
8 . The device of claim 5 , wherein the complementary toothing is formed on the front face of the unitary creator tool between a radially outer edge and a radially inner central shallow recess of the front face, the shallow recess disposed substantially flush with a base of each of the plurality of the radial spaces.
9 . The device of claim 8 , wherein the annular radial containment element comprises a ring disposed radially on the outside of the radially outer edge of the front face of the unitary creator tool and attached coaxially to a radially outer side wall of the creator tool delimiting the radially outer edge of the front face.
10 . The device of claim 9 , wherein the radially outer side wall of the unitary creator tool is provided with a cylindrical stop on a back face opposite the front face, the cylindrical stop having a diameter greater than a diameter of the front face, the cylindrical stop further defining an axial shoulder against which the ring of the annular radial containment element rests.
11 . The device of claim 1 , wherein the annular radial containment element and the plurality of radial spaces of the complementary toothing define a predetermined radial profile, the radial profile comprising: a first stretch, the first stretch being curved and immediately adjacent to a base of each of the plurality of radial spaces; and a second stretch, the second stretch being substantially straight and arranged immediately adjacent to the first stretch on a side opposing the base of each of the plurality of radial spaces and obliquely to the axis B.
12 . The device of claim 11 , wherein the first stretch has a radius of curvature (R) between 1 and 4 mm.
13 . The device of claim 12 , wherein the second stretch forms an angle with the bottom of each of the plurality of radial spaces of between 90° and 135°.
14 . The device of claim 1 , wherein the radial profile of each rounded ridge comprises a continuous curve.
15 . A device for forming a front toothing on an inner ring of a wheel hub, the device comprising: a unitary creator tool, having an axis of symmetry (B), the unitary creator tool comprising: a solid central portion, wherein the solid central portion comprises an axially external surface; a first complimentary toothing positioned annularly about the solid central portion and configured to form the front toothing of the inner ring, the first complimentary toothing comprising: a plurality of radially extending teeth, wherein each tooth of the plurality of radially extending teeth comprises a ridge at a top end of the tooth defining a rounded radial profile; and a plurality of radially extending spaces separating the plurality of radially extending teeth respectively, wherein the plurality of radially extending teeth and the plurality of radially extending spaces are arranged annularly about the axis of symmetry (B); and an annular radial containment element radially disposed on an outside of the plurality of radially extending teeth and configured to define a continuous wall, the continuous wall closing a radially outer end of each of the plurality of radially extending spaces, wherein the annular radial containment element comprises an axially external surface; wherein the axially external surface of the solid central portion is positioned in an axially inner position relative to the axially external surface of the radial containment element.
16 . A device for forming a front toothing on an inner ring of a wheel hub, the device comprising: a unitary creator tool, having an axis of symmetry (B), the unitary creator tool comprising: a solid central portion, wherein the solid central portion comprises an axially outermost surface; a first complimentary toothing positioned annularly about the solid central portion and configured to form the front toothing of the inner ring, the first complimentary toothing comprising: a plurality of radially extending teeth, wherein each tooth of the plurality of radially extending teeth comprises a ridge at a top end of the tooth defining a rounded radial profile; and a plurality of radially extending spaces separating the plurality of radially extending teeth respectively, wherein the plurality of radially extending teeth and the plurality of radially extending spaces are arranged annularly about the axis of symmetry (B); and an annular radial containment element radially disposed on an outside of the plurality of radially extending teeth and configured to define a continuous wall, the continuous wall closing a radially outer end of each of the plurality of radially extending spaces, wherein the annular radial containment element comprises an axial surface; wherein the axially outermost surface of the solid central portion is in an axially inner position relative to the axial surface of the radial containment element.

Description

CROSS-REFERENCE RELATED APPLICATION This application is based on and claims priority to Italian Patent Application No. 10202100002249 filed on Feb. 3, 2021, under 35 U.S.C. § 119, the disclosure of which is incorporated by reference herein. FIELD The present disclosure relates to forming a front toothing on an inner ring of a wheel hub. BACKGROUND In wheel hubs, face teeth are intended to form a head-to-head coupling between an inner ring of the wheel hub and the corresponding face teeth of an outer ring. BRIEF DESCRIPTION OF THE DRAWINGS Further features and advantages of the present disclosure will become clear from the following description of non-limiting exemplary embodiments thereof, provided with reference to the attached figures, in which: FIG. 1 schematically shows a perspective three-quarter view from below, flipped over by 180° for a clearer understanding, of a tool constituting a part of equipment according to the present disclosure for producing, by plastic deformation, a front toothing on an inner ring of a wheel hub; FIG. 2 schematically shows, on an enlarged scale and in radial section, a view in elevation of a detail of the tool embodiments illustrated in FIG. 1; FIG. 3 schematically shows, on a slightly smaller scale, a view in elevation and in radial cross section of embodiments of equipment in accordance with this disclosure during a process of producing by plastic deformation a front toothing on an inner ring of a wheel hub, which is also shown in radial section, in accordance with this disclosure; FIG. 4 schematically shows a view in radial cross section of various embodiments of the tool illustrated in FIG. 1; FIG. 5 schematically shows in radial section a view in elevation of the same detail as FIG. 2 but with reference to second various embodiments of embodiments of a tool as illustrated by FIG. 1; FIG. 6 schematically shows in radial cross section a view in elevation of the same detail as FIG. 2 but with reference to third various embodiments of a tool as illustrated by FIG. 1; and FIG. 7 schematically shows a view on an enlarged scale of a detail of various embodiments of a tool as illustrated by FIGS. 1 and 2. FIG. 8 illustrates aspects of various methods of forming a front toothing in accordance with this disclosure. DETAILED DESCRIPTION In various embodiments of wheel hubs in accordance with this disclosure, a front toothing serves the function of providing a head-to-head coupling of an inner ring of a wheel hub to a corresponding front toothing of an outer ring of a constant-velocity joint, so as to ensure the transmission of torque from the constant-velocity joint to the inner ring of the wheel hub, which carries a wheel of the vehicle via a flanged end. A coupling of this type is described in U.S. Pat. No. 4,893,960. According to that document, helical teeth may be obtained at the same time as the upset collar, by means of a relatively complex and bulky tool made up of three elements that are independent of and movable relative to one another. This tool is not only complex, bulky and expensive, but also does not make it possible to obtain such teeth with a highly constant tooth profile, which is an important feature in light of the increasingly high torques to be transmitted in modern applications. EP2551033B1 attempts to solve this problem by a technique involving an upset collar formed by orbital forming, with a predetermined first profile; and, subsequently, in a second step, a front toothing is produced by pressing on the upset collar a creator tool comprising a shank and a head, both symmetrical with respect to a first axis defining the axis of symmetry of the tool, about which the tool is rotated, the head consisting of a solid metal block having, towards the upset collar, a front annular projecting part bearing a toothing complementary to the toothing to be obtained. During the pressing step disclosed in EP2551033B1, the creator tool is rotated so as to describe an orbital movement, keeping the first axis inclined relative to an axis of symmetry of the wheel hub, and is simultaneously pushed against the upset collar in the direction of the first axis, i.e., along this axis, so as to imprint on the upset collar, in sequence, one or more teeth of the complementary toothing until the front toothing is completely formed on the upset collar. Because the ridges of the teeth of the complementary toothing borne by the creator tool are rounded and have a radius that is variable in the radial direction, specifically decreasing in the direction towards the first axis, or increasing in a direction radially away from the first axis, it is possible to obtain a front toothing with teeth having a constant profile at a given radial distance from the first axis and which are a negative “copy” of the teeth of the complementary toothing borne by the creator tool. However, the teeth of the front toothing thus obtained have teeth ridges or “heads” which, although they are all rounded, as p