Bearing wheel hub unit

Bearing wheel hub unit (1) is provided with a mounting flange (3) which is integral with an inner race (21) of the bearing (2) in order to mount a wheel, and with a centering collar (4) which extends from a frontal surface (31) of the flange (3) to permit the centering of the wheel in relation to the unit (1). The centering collar (4) produced, preferably of alloy, in such a way as to be independent of the mounting flange (3), and is assembled with the flange (3) by fixing onto the frontal surface (31).

BACKGROUND OF THE INVENTION

The present invention relates to a bearing wheel hub unit.

In general, bearing wheel hub units of a well known kind comprise a mounting flange which is integral with an inner race of the bearing in order to mount a wheel, and a centering collar, which is defined by an annular body which is produced in a single piece with the flange by means of removing shavings, and which extends frontally and transverse to the flange itself in order to permit the centering of the wheel in relation to the unit itself.

Bearing wheel hub units of the kind which have just been described above present some disadvantages due to the fact that, once the centering collar has been produced by means of turning, it is then necessary to subject the same centering collar to anti-corrosion treatment, which can only be carried out after the centering collar has been carefully cleaned and, in the case in which such treatment is carried out at a certain temperature, it must also be carried out in such a way as to ensure that no damage is suffered by the other components of the unit.

SUMMARY OF THE INVENTION

The aim of the present invention is to produce a bearing wheel hub unit, which will permit the resolution of the above-mentioned disadvantages in a simple and cost-effective manner.

According to the present invention, a bearing wheel hub unit will be produced, presenting a rotation axis and comprising a mounting flange which is integral with an inner race of the bearing for the mounting of a wheel, and a centering collar which extends from a frontal surface of the flange itself in order to permit the centering of the wheel in relation to the axis; the unit being characterised by the fact that the centering collar is produced, preferably made of alloy, in such a way as to be independent of the mounting flange, and is assembled to the flange by means of being fixed onto the frontal surface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

With reference toFIG. 1, the number1refers to a bearing wheel hub unit in its entirety.

The unit1presents a rotation axis A, and comprises a bearing2which is provided with an inner race21which can rotate around the axis A, and a mounting flange3, which is integral with the race21, and which is arranged transverse to the axis A, and which presents a number of passing attaching holes34which are uniformly distributed around the axis A in order to fix a wheel (which is noted but not illustrated).

The unit1also comprises a centering collar4, which is fixed to the flange3at the end of the production cycle of the unit1, and which extends from a frontal surface31of the flange3itself in order to permit the centering of the above-mentioned wheel in relation to the unit1, or rather in relation to the axis A.

The inner race21presents a central body22which is co-axial to the axis A, and the flange3is integral with an axial end23of the body22, and extends radially towards the outside of the end23and transverse to the axis A. Both the body22and the flange3are laterally delimited by the surface31, which is arranged transverse to the axis A, and which presents, substantially in correspondence to the body22itself, a notch32with a flat base33which is centred on the axis A.

The collar4is produced in such a way as to be totally independent of the unit1and preferably, but not necessarily, of alloy, and is defined by a cup-shaped body41which comprises a base wall42, and a lateral wall43which is externally cylindrical and which is integral with the base wall42itself.

The base wall42is arranged inside the notch32in such a way as to be in direct contact with the base33, and is fixed to the base33itself by means, for example, of welding, or gluing, while the lateral wall43comprises two external cylindrical sections44and45, which present respective external diameters D1and D2which have tapering dimensions starting from the frontal surface31, and of which the section44is directly joined to the base wall42.

The form of embodiment which is shown inFIG. 2relates to a unit1′ which is similar to the unit1, from which the unit1′ differs due to the fact that the lateral wall43also comprises, in addition to the two external cylindrical sections44and45, an intermediate connecting section46between the two sections44and45and the base wall42.

In particular, the section46presents a tapering shape which narrows towards the surface31, and directly connects the position45to the wall42in such a way as to permit, in the first place, the section44to be arranged in direct contact with and transverse to the surface31, and, in the second place, the sections44and45, to form with the section46a doughnut/ring-shaped chamber47which is delimited by the sections44and45and46themselves, and which is axially delimited by the surface31and the section46.

Furthermore, in the form of embodiment which is shown inFIG. 2, the central body22comprises an annular projection24, which extends from the frontal surface31transverse to the frontal surface31itself, and it is both included inside the notch32, and enclosed inside the chamber47rendering obvious the possibility of being able to use the collar4of the unit1′ on bearing wheel hub units which are also provided with the already noted collar which is made in a single piece with the flange3.

The form of embodiment which is shown inFIG. 3relates to a unit1″ which is similar to the unit1′, from which the unit1″ differs due to the fact that the lateral wall43comprises a single external section44which has a substantially cylindrical shape, which is connected to the base wall42by means of the intermediate connecting section46, and is arranged in direct contact with the projection24.

In practice, any form of embodiment whatsoever of the above-described bearing wheel hub unit may be produced without any particular kind of working in the area of the surface31apart from the production of the notch32, and may be coupled to a centering collar4as has been described above in its various different forms of embodiment at the end of its production cycle which not only makes it possible to reduce the production cycle time, but also to produce a general kind of bearing wheel hub unit which does not depend on the kind of wheel to be mounted.

The collar4, which at this point, its production being totally independent of that of the unit1or the unit1′, may be made of materials which are alternative to the above-mentioned alloy, and may also be pre-treated with an anti-corrosion treatment before being arranged inside the notch32centred both in relation to the axis A and in relation to the holes34.

The advantages of being able to fix the collar4to the bearing wheel hub unit at the end of the production cycle reside above all in the simplification of the so-called forging, or rather the basic element from which the production of the bearing wheel hub unit itself starts, in eliminating costly working operations and anti-corrosion treatment, which, as has already been noted, are carried out on the finished bearing wheel hub unit and which, as has already been discussed, require a high level of cleaning as well as protection against polluting agents arising from other areas with the risk of damaging the bearing2in the case that certain temperatures are reached.

Furthermore, in the case of the bearings2which differ only due to the diameters D1and D2, the adoption of the collar4permits the standardization of the race21with considerable advantages in terms of reducing production and planning costs.

It is intended that the present invention should not be limited to the forms of embodiment which are herein described and illustrated, which are to be considered as examples of forms of embodiment of the bearing wheel hub unit, and which may be instead subject to further modifications in terms of the shape and disposition of its parts, as well as to details pertaining to construction and assembly.