The device according to the finding is also used in mechanical applications in which it is required to fix the bearing on a shaft or in a housing taking it into abutment against a shoulder, without the need to use other axial locking devices.

In the current state of the art commercial bearings (members upon which a shaft abuts and in which it rotates, or else the shaft remains still and the outer ring of said members rotates) have the surfaces of the hole and of the outer surface, respectively, perfectly smooth and with a coupling (on the shaft or on the housing) with clearance or with interference.

Specifically, with a coupling with clearance, in the absence of suitable locking systems such as ring nuts, nuts, shoulders, elastic rings or other, suitable for the purpose, the shaft can slide axially on the bearing, braked only by friction.

Again specifically, with a coupling through interference the axial sliding of the shaft is prevented.

Substantially, in both of the aforementioned embodiments, if it is not foreseen to use further devices, the shaft is susceptible to sliding and positioning itself axially in an uncontrollable manner.

In the current state of the art there are devices, commercially known with the term"ball sleeves", which allow the movements, axial and rotary, of the shaft, but they are only susceptible to bearing purely radial loads.

The first purpose of the present finding is that of realising a bearing that allows the axial positioning of the shaft in the aforementioned bearing to be controlled and adjusted, even in the presence of axial loads.

A further purpose of the finding is that of realising a bearing, which can be locked directly against a shoulder of the shaft and/or of the housing or of any other device that can block the axial sliding of said bearing, without the need to use attachment means such as ring nuts, screw nuts, bushes, elastic rings, covers and others with the consequence of a reduction in axial bulk of the support group of the shaft.

Such purposes are achieved with a bearing characterised in that it has the surface of the hole and/or its threaded outer circumferential surface such as to allow the assembly of the aforementioned bearing on shafts and/or threaded housings.

Specifically, in a bearing that has the threaded hole a relative rotation of the shaft-inner ring of the bearing is induced, which engages the shaft into a controlled axial translation in the bearing.

In the same way, in a bearing that has the outer circumferential surface threaded, it is possible to adjust the axial position of the bearing inside its housing, by simply inducing a relative rotation of housing-threaded outer ring of the bearing.

In the operative step, by screwing the bearing in until it is taken into abutment against a shoulder of the shaft or of the housing or of any other device that blocks the axial moment and thus locking it against the aforementioned shoulder, said bearing remains locked without the need to use further attachment means.

The bearing with the characteristics according to the finding is of the per se known type-sliding, rolling (with balls, with rollers, conical rollers, barrel rollers, small rollers), axial and/or radial of whatever type, size and material; moreover, the inner ring and/or the outer ring can be threaded with any type of threading.

The finding is intended to also extend to constructive solutions consisting of bearings with smooth surfaces, on which threaded bushes are fixed, which give the aforementioned bearings the typical operative characteristics of the aforementioned bearings.

The finding is also intended to extend to bearings in which the outer ring and/or the inner ring or the possible bushes fixed to them are projecting and/or equipped with holes, slots, levellings, hexagons, collars and other impressions, which allow gripping with keys to generate the screwing rotation and determine the position on the shaft and/or in the housing of the bearing.

Moreover, the collars can also consist of end-of-screwing abutments.

Finally, it is possible to foresee devices such as threaded holes, pressure screws, slots, keys, tongues and the like, suitable for preventing the mutual rotation of inner ring- shaft and/or of outer ring-housing, after the position of use of the bearing has been adjusted and defined.

The finding shall be better understood with the description of some possible embodiments thereof, given only as a non- limiting illustrative example, with the help of the attached tables of drawings, where: - figs. 1 and 2 (Table I) respectively represent a front elevated view and a plan view, sectioned according to the line II-II of fig. 1, of a first embodiment of the bearing according to the finding; -figs. 3 and 4 (Table II) respectively represent a front elevated view and a plan view, sectioned according to the line IV-IV of fig. 3, of a second embodiment of the bearing according to the finding; -figs. 5 and 6 (Table III) respectively represent a front elevated view and a plan view, sectioned according to the line VI-VI of fig. 5, of a third embodiment of the bearing according to the finding; -figs. 7 and 8 (Table IV) respectively represent a front elevated view and a plan view, sectioned according to the line VIII-VIII of fig. 7, of a fourth embodiment of the bearing according to the finding; -figs. 9 to 12 (Tables V-VII) represent schematic perspective views of the various types of bearings according to the finding.

As can be seen in figures 1 to 6, the bearing according to the finding, wholly indicated with reference numeral 1, foresees that the inner ring 2 is threaded (figs. 1 and 2), or else that the outer ring 3 is threaded (figs. 3 and 4); furthermore, it is possible to foresee that both of the rings are threaded (figs. 5 and 6).

As can be seen in figs. 7 and 8, the finding foresees that the threaded inner ring 20 is projecting with respect to the outer ring 3 and that it is equipped with a threaded hole 21, for the attachment of a pressure screw, not represented, and slots 22, for the insertion of a pin wrench.

Finally, as can be seen in fig. 9, it is foreseen for it to be possible for a threaded bush 30 to be applied on at least one of the rings 2 or 3.

Of course, embodiments different to those described are also possible, according to the type and shape of the rotating bodies used, without for this reason departing from the scope of the claims, defined hereafter.