Cage for rolling bearings and associated rolling bearing unit

Abstract

Rolling bearing unit (6) with a rolling bearing (3) and an annular cage (1) formed from two half-cages (10) connected to each other by pins (16) and holes (18) arranged alternately in a row on each half-cage (10), the pins (16) of one half-cage snappingly connected to the holes (18) of the opposite half-cage, and rigid blocks (21) alternating with recesses (22), the rigid blocks (21) of one half-cage (10) coupling to the recesses (22) of the opposite half-cage (10), the projecting rigid blocks (21) supporting the projecting pins (16), the holes (18) being formed on the rear side of the recesses (22), such that the half-cages (10) are connected by a first coupling and a second coupling in a row (14, 15) are connected, which are designed to absorb tangential and axial stresses separately;wherein the half-cages (10) are provided with a radial annular rib (34) which serves as a shield.;

Description

Technical FieldThe present invention relates to a cage for rolling bearings and an associated rolling bearing unit comprising the cage.Prior ArtFrom DE1914884U a rolling bearing is known, comprising an outer ring, an inner ring and a plurality of rolling elements (balls) interposed between the rings to make them relatively rotatable with low friction. The rolling elements are held in the correct position by a cage comprising:a plurality of pockets or seats each defined by a spherical surface having a central point lying in a radial central plane which, in operation, coincides with a corresponding radial central plane of the bearing,two half-cages substantially symmetrical to the median plane and connected to each other, each half-cage having an annular body and a plurality of at least partially hemispherical cavities axially facing the hemispherical cavities of the opposite half-cage, so as to define the pockets,connecting means connected to the half-cages for connecting the two half-cages to each other,for each half-cage, two substantially concentric and circumferentially continuous radial reliefs extending radially in opposite directions from each annular body, the first relief extending radially outwards to sealingly engage a groove formed in the outer ring of the bearing, and the second relief extending radially inwards to sealingly engage a groove formed in the inner ring of the bearing, the inner ring being divided into two half-rings connected to each other.A cage for rolling bearings made up of two half-cages joined together to form seats for the balls of the rolling bearing is known from JP2007040383A. The seats are formed by simple circular holes and the associated connecting means are mating snap-in coupling elements in the form of dovetail joints or snap-in coupling pins in the respective cylindrical seats.Both solutions described have the drawback that the cage formed by assembling the two half-cages may not be rigid enough to prevent elastic deformations of the cage during operation caused by variations in the speeds normally occurring in rolling bearings during operation.In DE1914884U, this results in the radial reliefs moving towards or away from the respective grooves due to accelerations or decelerations of the bearing. If the reliefs are configured to form a labyrinth seal, they may contact the grooves, leading to undesirable friction and associated energy consumption and heating, or they move too far away from the grooves, thereby failing the seal.Likewise, when the reliefs are designed to form a contact seal in the grooves, an increased interference or loss of interference may have the same negative consequences.However, in JP2007040383A, which does not provide reliefs for sealing, the undesirable elastic changes in size of the cage may make the retaining and guiding action the cage exerts on the balls (or other rolling elements) of the bearing less effective or ineffective.Finally, in the known rolling bearings described above, a considerable part of the grease remains "caught" on the shields and thus does not contribute to the lubrication of the bearing.SUMMARY OF THE INVENTIONThe object of the present invention is to overcome the disadvantages of the prior art and in particular to provide a cage which makes it possible to keep the rolling elements in a correct position at all times and thus to eliminate possible noises during operation, and which at the same time is capable of providing a seal both against external contaminants for protecting the rolling elements and for the lubricant contained in the rolling bearing between the inner and outer rings, as a result of which the risk of friction or at least excessive friction between the cage and the rolling bearing is to be reduced or eliminated.A further object of the invention is to optimize the quantity and position of the grease in the bearing not only to prevent grease leakage (i.e. leakage of a part, although a small part, of the lubricant from the bearing), but also to reduce grease losses by "splashing" and in particular to use all the grease for lubricating the raceways, whereby the required quantity of grease can be reduced with constant service life lubrication of the bearing.A final object of the invention is to provide a rolling bearing unit comprising such a cage designed to provide a good low friction seal between the cage and the rings of the rolling bearing.The invention is therefore provided with a cage for holding rolling elements in a rolling bearing and a corresponding rolling bearing unit according to the appended claims.In particular, the invention is based on the increase in the stiffness of the cage obtained by the connection of the two half-cages without increasing its size and weight, which would negatively affect the number of rolling elements that can be inserted in the cage and / or the amount of grease available for the rolling elements.Brief Description of the DrawingsFurther features and advantages of the present invention will be more clearly set forth in the following description of non-limiting embodiments provided with reference to the figures in the accompanying drawings, in which:FIG. 1 is a schematic three-quarter side view, partially cut away, of a rolling bearing unit according to the invention, comprising, in the non-limiting example shown, a rolling bearing with a single row of rolling elements, shown as balls in the non-limiting example, and a cage for holding the rolling elements according to a first embodiment of the invention,FIG. 2 is an enlarged schematic circumferential cross-sectional view of a detail in FIG. 1 ,FIG. 3 is a slightly enlarged schematic radial cross-sectional view of a bearing unit and the associated cage for the rolling elements according to the first embodiment of the invention in FIG. 1 and according to a possible variant thereof, which is shown only shaded for simplicity and better clarity,FIG. 4 is a schematically enlarged perspective view of a circumferential section of an axially inner annular end face of an annular half cage belonging to the cage for holding the rolling elements in FIGS. 1 and 2, the circumferential section being rotated through 90° for the sake of clarity to show the axially inner annular end face of the half cage at the top in the figure, the annular end face being opposite the rolling elements of the rolling element bearing in FIG. 1 in use,FIGS. 5 and 6 are corresponding schematic perspective views of two components of the cage for holding the rolling elements of the bearing in FIG. 1, comprising two identical half-cages joined together at the ends in the axial direction to form the cage in FIGS. 1 and 2, the half-cage being shown in FIG. 5 with an end face opposite to the same end face of the half-cage in FIG. 6, andFIG. 7 is an axial exploded perspective view of the rolling bearing unit in FIGS. 1 to 3.DETAILED DESCRIPTIONIn Figs. 1 to 7, reference numeral 1 as a whole denotes a cage for accommodating rolling elements 2 in a rolling bearing 3.The rolling bearing 3 includes an outer ring 4, an inner ring 5, and a plurality of rolling elements 2 interposed between the outer ring 4 and the inner ring 5 to make them relatively rotatable with low friction, and forms a rolling bearing unit 6 with the cage 1 interposed between the outer ring 4 and the inner ring 5.The cage 1 is therefore intended to be interposed, in operation, between the respective inner ring 5 and outer ring 4 of the rolling bearing 3 in order to maintain, in a known manner, the rolling elements 2 in the correct position between the rings 4 and 5 with the desired pitch between the rolling elements 2, which are balls in the non-limiting example illustrated.The annular cage 1 has an axis of symmetry A which during operation coincides with the axis of symmetry of the rolling bearing 3 and is also the axis of symmetry of the rolling bearing unit 6. Axis A is also the axis of relative rotation between rings 4 and 5.The cage 1 comprises a plurality of radial through seats or pockets 7 arranged in a row, each of which is intended to receive a rolling body 2.Each of the radial through seats or pockets 7 is defined, in the preferred embodiment illustrated, in which the rolling elements 2 are balls, by a respective spherical surface 8 (Figures 1 and 2), the centre of which lies in a radial median plane P of the cage 1, which coincides, in operation, with a corresponding radial median plane of the rolling bearing 3. The geometric contour of the central plane P is schematically shown in FIGS. 2 and 3.According to one aspect of the invention, the annular cage 1 comprises two axially opposed annular half-cages 10 arranged substantially symmetrically about the median plane P and rigidly connected to each other, as explained in more detail below, so as to form, after assembly, a cage 1 acting as if it were substantially formed of a single piece.The two identical half-cages 10, therefore identified by the same reference number, are formed by molding a suitable synthetic plastic, for example a polyamide, and have an identical axis of symmetry A along which they are connected together at the end to form the cage 1.Each half-cage 10 has an annular body 11 with the axis A as the axis of symmetry and a plurality of cavities 12 which in the preferred embodiment shown are at least partially hemispherical. The cavities 12 are at least partially or completely bounded by a corresponding portion of the spherical surface 8 of each pocket or seat 7.Once the half-cages 10 are coupled in the axial direction, the at least partially hemispherical cavities 12 of each half-cage 10 are axially opposite the hemispherical cavities 12 of the opposite half-cages 10, thus defining the seats or pockets 7 defined by the spherical surface 8.The annular cage 1 further comprises connecting elements between the two half-cages 10, generally designated by reference numeral 13, for rigidly connecting the two opposite half-cages 10 to each other to form the annular cage 1 as if it were a one-piece part.According to a first aspect of the invention, the connecting elements 13 are intended to connect the half-cages 10 to a first mechanical coupling 14 and a second mechanical coupling 15 (FIG. 2 ), which are arranged axially in series with each other and are intended to separately receive axial stresses and tangential stresses, respectively, to which the cage 1 is subjected in use.In particular, the first mechanical connection 14 is formed by a plurality of first pairs of mating connection elements 16, 18 (FIGS. 5-7 ) comprising, for each first pair of connection elements 13 forming the mechanical connection 14, an at least partially elastically deformable pin 16 and a corresponding hole 18 intended to receive the pin 16 by snap-connection.Each half-cage 10 is then provided with a plurality of pins 16 axially protruding from the annular body 11 on the side of a first end face 19 (FIGS. 2 and 6 ) of the annular body 11, and a corresponding plurality of holes 18 axially formed in the annular body 11 on the side of a second end face 20 (FIGS. 2 and 5 ) of the annular body 11 opposite the first face 19.The annular body 11 of each half-cage 10 is thus provided with holes 18 and pins 16. The pins 16 and the holes 18 are provided in the same number and are preferably arranged alternately in a row, in any case such that, when two half-cages 10 are coupled at the end face in the axial direction, each pin 16 of one half-cage 10 is coupled to an opposite hole 18 in the opposite half-cage 10, in particular by an opening of the hole 18 which faces the first surface 19. The holes 18 are preferably through-holes which open into the end face 20.According to an important aspect of the invention, the second mechanical connection 15 is formed by a plurality of second pairs of mating connecting elements 21, 22 (Figures 4, 6 and 7) for each second pair forming the mechanical connection 15 comprise a male element 21 in the form of a substantially rigid solid block integral with the annular body 11 and projecting axially from the first end face 19 of the annular body 11 of each half-cage 10, and a corresponding recess 22 intended to be rigidly connected to the solid block 21 forming the male element, the recess 22 being formed in the annular body 11 by the first end face 19 of the annular body 11 of each half-cage 10.Also in this case, each half-cage 10 is provided with a plurality of male elements formed as rigid solid blocks 21 and a corresponding plurality of recesses 22, which are preferably arranged alternately in a row, so that each male element 21 of a half-cage 10 is coupled to an opposite recess 22 in the opposite half-cage 10.According to a further essential aspect of the invention, in order to form the couplings 14, 15 arranged one behind the other in the axial direction, each pin 16 protrudes axially from a respective male element 21 formed by a solid block, so as to be arranged axially in series therewith and downstream thereof with respect to the position of the first end face 19 of the annular body 11 of each half-cage 10.Similarly, each recess 22 is axially arranged in series with such a hole 18, upstream thereof with respect to the position of the first end face 19 of the annular body 11 of each half-cage 10.By selecting a particular type of connecting elements 16, 18 and 21, 22 and a particular relative position thereof, the mating connecting elements 21, 22 of the second pair of connecting elements 13 forming the mechanical connection 15 are adapted to receive tangential components of mechanical loads exerted on the annular cage 1 in use, while the mating connecting elements 16, 18 of the first pair of connecting elements 13 forming the mechanical connection 14 are adapted to receive axial components of said mechanical loads and keep the half cages 10 in contact with each other, the respective end faces 19 being arranged in axial abutment against each other.According to a preferred aspect of the invention, each solid block of shaped polymeric material forming the male element 21 of the second pairs of mating connecting elements 13 is wedge-shaped and preferably a truncated pyramid with rectangular or square base, as is each corresponding recess 22, so that each solid block 21 is coupled to the corresponding recess 22 via surfaces 23 (Fig. 6) arranged obliquely to the common axis of symmetry A of the opposite half-cages 10. The inclined surfaces 23 face each other in pairs, either (wedge-shaped) in the circumferential direction or in the radial direction, or (truncated pyramid-shaped) in both directions.According to a preferred embodiment of the invention (Fig. 6), each solid block 21 forming a male element of the second pairs of mating connecting elements 23 is provided laterally in the circumferential direction with respective radial teeth or reliefs 24 intended to engage with respective radial grooves 25 formed in each recess 22.Naturally, according to a possible variant not shown for the sake of simplicity, the alternative arrangement may also be used in which the radial grooves 25 are formed laterally in the solid blocks forming the male elements 21 and the radial teeth or reliefs 24 protrude circumferentially in the recesses 22.It is also understood that the possible inclined surfaces arranged to face each other in the circumferential direction of the solid blocks 21 and the recesses 22 may or may not be provided with teeth 24 and grooves 25, or vice versa.According to a further aspect of the invention, each at least partially hemispherical cavity 12 of each half-cage 10 is delimited, on the respective opposite peripheral sides, by a first axial nose and a second axial nose, respectively denoted by reference numerals 26 and 27 (Figures 4 and 6), which are arranged side by side and which project axially from the annular body 11 of each half-cage 10 from the side of the end face 19.Each axial tab 26 in turn carries a male element made up of a solid block 21 and a pin 16 on top of the male element or block 21 arranged to project axially in series away from the end faces 19.Each axial lug 27 is, on the other hand, hollow on the inside and defines a respective internal recess 22, a respective hole 18 passing axially from the inside of each recess 22 away from the surface 19, through the respective annular body 11 and then through the second end face 20.In the embodiment in which the connecting elements 13 comprise the grooves 25 and the associated teeth or reliefs 24 (Figs. 3 and 6), the mutually opposite peripheral sides of respective adjacent pairs of cavities 12 of the annular body 11 of each half-cage 10 flank respective opposite side walls 23 of each recess 22 provided with the radial grooves 25.The latter are designed to engage circumferentially with the radial teeth or reliefs 24 of the male elements 21. As mentioned above, according to a possible variant, the radial teeth or reliefs 24 are formed on the opposite side walls 23 of each recess 22, and are designed to engage circumferentially with the radial grooves 25, which in this case are formed on the opposite sides of the circumferentially arranged male elements 21.According to another important aspect of the invention, each cavity 12 of the annular body 11 of each half-cage 10 is delimited axially towards the second face 20 of the annular body 11 by a rear wall, which in the example shown is spherical and is defined by a portion of the spherical surface 8.This rear wall 8 is provided towards the first end face 19 of the annular body 11 with a recess 29 (Figures 3, 4 and 6) having an axial depth towards the second end face 20 and a circumferential extension to form a grease receiving chamber, so that, in use and with axial coupling of the half-cages 10, the respective opposite sides of each seat or pocket 7 for the rolling elements 2 are delimited by opposite grease receiving chambers defined by the recesses 29 which are therefore in direct contact with the rolling elements 2 and also at a primitive or mean diameter of the rolling element 3.As a result, the distribution of the grease on the rolling bodies 2 during operation is optimized, in particular if the rolling bodies are balls, as in the illustrated preferred exemplary embodiments.According to another aspect of the invention, the spherical rear wall 8 of each at least partially hemispherical cavity 12 is provided with a pair of radial grooves 30 (FIG. 4 ) that are parallel to each other and are disposed proximate the opposing axial sides of the cavity 12 that are bounded by the axial tabs 26, 27. The grooves 30 pass through the recess 29 in the same cavity 12 in which the grooves are located and are therefore interrupted by the recess 29 so that they are in hydraulic communication therewith.The grooves 30 are therefore designed to allow the lubricant to circulate in each seat or pocket 7 for the rolling elements 2 during operation.In connection with this feature, the mutually opposite circumferential sides of each at least partially hemispherical cavity 12 are bounded, on the side of the first end face 19 of the annular body 11, by mutually opposite chamfers 31 (FIG. 4 ) which, when the half-cages 10 are axially coupled, form mutually opposite curved radial channels 32 (FIG. 2 ) for the circulation of the grease, which are arranged around the circumference of each seat or pocket 7 for the rolling elements 2.According to a very preferred aspect of the invention, each half-cage 10 is radially provided on the outside with a substantially flange-shaped first annular rib 34 formed in the vicinity of the second end face 20 of the annular body of each half-cage, so as to be axially remote from the seats or pockets 7 for the rolling elements 2.The radial annular rib 34 of each half-cage 10 is configured to be coupled, in use (FIGS. 1-3 ), to an annular slot 35 formed radially inside the outer ring 4 of the rolling bearing 3 to form therewith a labyrinth seal, which is known as a whole.In a possible embodiment, schematically shaded in Figure 3 for simplicity, a second annular rib 36 is optionally formed radially on the inside of each half-cage 10, substantially aligned with the first radial annular rib 34 and adapted to be coupled, in use, to a second annular slot 37 formed radially on the outside of the inner ring 5 of the rolling bearing 3, so as to also form a labyrinth seal, known as a whole.However, in order to both improve the effect of the labyrinth seal and simplify and compress the structure of the half-cages 10, the radial annular rib 34 (FIGS. 2 and 3 ) is radially provided on the outside of an axial relief 38. The axial relief 38 is formed radially on the inside of a radially outer peripheral edge 39 of the annular rib 34 so as to be remote from the edge 39. The rim 39 preferably has a radial profile that mates with a corresponding curved profile of the annular slot 35.From the above, the scope of the invention clearly comprises a rolling bearing unit 6 comprising a rolling bearing 3 which in turn comprises an outer ring 4, an inner ring 5 and a plurality of rolling elements 2 interposed between the inner ring 5 and the outer ring 4 so as to make them relatively rotatable with low friction, and an annular cage 1 for housing the rolling elements 2 interposed between the inner ring 5 and the outer ring 4.The annular cage 1 comprises a plurality of pockets 7, each defined by a spherical surface 8, the centre of which lies in a radial median plane P of the cage 1 coincident with a corresponding radial median plane of the rolling bearing 3.The cage 1 is also formed by assembling two half-cages 10 substantially symmetrical to the median plane P and axially connected to each other.Each half-cage 10 has an annular body 11 and a plurality of at least partially hemispherical cavities 12 axially facing the hemispherical cavities 12 of the opposite half-cage 10 to form the pockets 7. The cage 1 further comprises connecting elements 13 associated with the half-cages 10 for connecting the two half-cages 10 together and forming the annular cage 1.These connecting elements 13 comprise, in combination (i), first pairs of mating connecting elements consisting, for each first pair, of an at least partially elastically deformable pin 16 and a corresponding hole 18 intended to receive the pin 16 by snap-connection, each half-cage 10 being provided with a plurality of such pins 16 projecting axially from the annular body 11 on the side of a first end face 19 of the annular body 11, and a corresponding plurality of holes 18 formed axially in the annular body 11 on the side of a second end face 20 thereof opposite the first face 19, the annular body 11 of each half-cage 10 being provided with both the holes 18 and the pins 16 arranged alternately in a row with each other, such that each pin 16 of a half cage 10 is coupled to an opposing hole 18 in the opposing half cage 10 through an opening of the hole 18 opposing the first surface 19.In combination with the foregoing, the connecting elements 13 also comprise second pairs of mating connecting elements, which for each second pair comprise a male element 21 formed as a substantially rigid solid block axially protruding from the first end face 19 of the annular body 11 of each half-cage 10, and a corresponding recess 22 formed to be rigidly connected to the solid block 21 forming the male element, said recess 22 being formed by the first end face 19 of the annular body 11 of each half-cage 10.Each half-cage 10 is provided with a plurality of male elements 21 and a corresponding number of recesses 22 arranged alternately in a row, so that each male element 21 of a half-cage 10 is coupled to an opposite recess 22 in the opposite half-cage 10.Each pin 16 protrudes axially from a respective male element formed by a solid block 21 so as to be arranged axially in series therewith and downstream thereof with respect to the first end face 19 of the annular body 11 of each half-cage 10.Each recess 22 is also axially arranged in series with a corresponding bore 18, upstream thereof with respect to the first end face 19 of each half-cage 10.Finally, each half-cage 10, which is part of the rolling bearing unit 6, is radially provided on the outside with a substantially flange-shaped first radial annular rib 34 formed in the vicinity of the second end face 20 of the annular body 11 of each half-cage 10 so as to be axially remote from the seats or pockets 7 for the rolling elements 2.The radial annular rib 34 of each half-cage 10 is coupled into an annular groove 35 formed radially inside the outer ring 4 of the rolling bearing 3 so as to form therewith a labyrinth seal. A second radial annular rib 36 is optionally radially formed on the inside of each half cage 10, substantially flush with the first radial annular rib 34, and is coupled in a second annular groove 37 optionally radially formed on the outside of the inner ring 5 of the rolling bearing 3, to thereby form a labyrinth seal.Based on the above, it is clear that while known rolling bearings comprise one or two shields to prevent the ingress of foreign dust particles into the bearing and to avoid grease losses, the solution described replaces the conventional shields with a symmetrical cage 1 having an additional shielding function. Due to the special design of the pockets 7, which have a constant volume for lubricant that is easily adjustable during the design phase of the cage, a smaller amount of grease can also be held in the bearing due to the presence and the position of the depressions 29, in particular in direct contact with the rolling bodies.Since the male member 21 connected to the female recess 22 is formed on pairs of respectively adjacent axial noses 26 and 27, it resists the tangential force when the cage is accelerated or decelerated due to the acceleration or deceleration of the bearing, thereby avoiding undesirable and / or excessive deformations of the cage 1, thereby maintaining the sealing effect of the annular ribs 34 and 36 (if present) in an optimum state without friction (or with reduced friction). The pins 16 which are snapped into the bores 18 in a known manner block the half-cages 10 axially.In this way, all the objects of the invention are achieved.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 1914884U [0002, 0005]JP 2007040383A [0003, 0007]

Claims

An annular cage (1) for holding rolling elements (2) in a rolling bearing (3) configured to be mounted, in use, between an inner ring (5) and an outer ring (4) of the rolling bearing, and comprising a plurality of radially continuous seats or pockets (7) arranged in a row with respect to each other and each configured to receive a respective rolling element (2), said plurality of radially continuous seats or pockets each being delimited by a respective spherical surface (8) whose centre lies in a radial median plane (P) of the cage which, in operation, coincides with a respective radial median plane of the rolling bearing; wherein the annular cage comprises: (a) two axially opposed and substantially symmetrical half-cages (10) with respect to the median plane, joined together, each half-cage (10) constituting an annular body (11) and a plurality of at least partially hemispherical cavities (12) axially opposed to the hemispherical cavities of the opposed half-cage to define with the latter the seats or pockets (7); and (b) connecting elements (13) for holding the two opposed half-cages (10) together to form together the annular cage (1); characterized in that the connecting elements (13) comprise in combination (c) - first pairs of conjugated connecting elements consisting, for each first pair, of an at least partially elastically deformable pin (16) and a corresponding hole (18) configured to snap receive the pin (16), wherein each half-cage (10) is provided with a plurality of said pins (16) projecting axially from said annular body (11) on the side of a first face surface (19) of said annular body, and with a corresponding plurality of holes (18) obtained axially in said annular body (11) on the side of a second face surface (20) thereof opposite said first surface, said annular body of each half-cage (10) being provided with both said holes (18) and said pins (16) arranged such that each pin (16) of a half-cage mates with a hole (18) opposite it of said opposite half-cage through an opening of said hole opposite said first surface (19); (d)-second pairs of conjugate connecting elements consisting, for each second pair, of a male element (21) formed as a substantially rigid solid block projecting axially from the first face (19) of the annular body of each half-cage and of a corresponding recess (22) formed so as to integrally mate with the solid block (21) forming the male element, said recess (22) being obtained by the first face (19) of the annular body of each half-cage; each half-cage (10) being provided with a plurality of said male elements (21) and a corresponding plurality of said recesses (22) arranged so that each male element (21) of a half-cage mates with a recess (22) of the opposite half-cage facing it; (e) - wherein each pin (16) protrudes axially from a respective solid block male element (21) so as to be arranged axially in series therewith, downstream thereof with respect to the first frontal face (21) of the annular body (11) of each half-cage (10); and each recess (22) is arranged axially in series with a respective hole (18) upstream thereof with respect to the first frontal face (19) of the annular body of each half-cage.An annular cage according to claim 1, characterized in that the conjugate connection elements of the second pair of connection elements (21, 22) are configured to receive tangential components of mechanical loads acting on the annular cage in use, while the conjugate connection elements of the first pair of connection elements (16, 18) are configured to receive axial components of the mechanical loads.Annular cage according to claim 2, characterised in that each of the solid blocks (21) forming one of the male elements of the second pairs of conjugated connecting elements, as well as each corresponding recess (22), presents a truncated pyramid shape, so that the coupling between each solid block and the corresponding recess is achieved by means of surfaces (23) arranged obliquely to a common axis of symmetry (A) of the opposite half cages.Annular cage according to any one of the preceding claims, characterized in that each solid block forming one of the male elements (21) of the second pairs of conjugated connecting elements is provided laterally in a circumferential direction with corresponding radial reliefs or teeth (24) designed to engage in corresponding radial grooves (25) obtained within each recess (22); or vice versa, the radial grooves (25) being machined laterally on the solid blocks (21) forming the male elements of the second pairs of conjugated connecting elements, and the radial reliefs or teeth (24) projecting circumferentially within the recesses (22).Annular cage according to claim 4, characterised in that each at least partially hemispherical cavity (12) of each half cage is delimited on its respective opposite axial sides by first and second axial lugs (26, 27) arranged side by side and projecting axially from the annular body (11) of each half cage, said first axial lug (26) in turn supporting axially in series a male element (21) consisting of a solid block and a pin (16), said second axial lug (27) being internally hollow and delimiting a recess (22) from the interior of which there extends axially a corresponding bore (18) passing through the corresponding annular body (11) until it passes through the second end face (20); wherein the opposite circumferential sides of respective adjacent pairs of said at least partially hemispherical recesses (12) of the annular body of each half cage flank respective opposite side walls of each recess (22) provided with said radial grooves (25) adapted to snap fit circumferentially with said radial teeth or reliefs (24) of said male elements, or conversely provided with said radial teeth or reliefs (24) adapted to snap fit circumferentially with said radial grooves (25) of said male elements.An annular cage according to any one of the preceding claims, characterized in that each at least partially hemispherical cavity (12) of the annular body (11) of each half cage is axially delimited towards the second end face (20) of the annular body by a spherical rear wall (8) provided towards the first end face of the annular body with a recess (29) developing axially towards the second end face (20) in depth and having a circumferential extension, configured to form a grease accommodation chamber, so that in use, when the half cages (10) are axially coupled, the respective opposite sides of each of the seats or pockets (7) for accommodating the rolling elements (2) are delimited by opposite grease accommodation chambers which are directly in contact with the rolling elements (2) at a mean or primitive diameter of the rolling bearing.An annular cage according to claim 6, characterized in that the spherical rear wall (8) of each of the at least partially hemispherical cavities (12) is provided with a pair of radial grooves (30) parallel to each other and formed in the vicinity of opposite circumferential sides of each at least partially hemispherical cavity (12) to allow, in operation, the circulation of grease within each rolling element seat or pocket (7); and in combination the opposite circumferential sides of each at least partially hemispherical cavity (12) are bounded on the side of the first end face (19) of the annular body by opposite slopes (31) formed to form with the axially coupled half cages opposite curved radial channels (32) for the circulation of grease, which are circumferentially arranged around each seat or pocket (7) for the rolling elements.Annular cage according to any one of the preceding claims, characterized in that each half-cage (10) is radially provided on its outer side with a first annular rib (34) shaped substantially in the form of a flange and formed in the vicinity of the second end face (20) of the annular body of each half-cage (10) so as to be axially remote from the seats or pockets (7) for the rolling elements; the first radial annular rib (34) of each half-cage being configured, in use, to fit into an annular groove (35) formed radially on the inner side of the outer ring (4) of the rolling bearing so as to perform a labyrinth-sealing function therewith; wherein a second radial annular rib (36), optionally obtained radially on the inside of each half cage (10), substantially flush with the first radial annular rib (34), and configured to fit, in use, a second annular groove (37) obtained radially on the outside of the inner ring (5) of the rolling bearing, to perform a labyrinth seal function therewith.Annular cage according to Claim 8, characterized in that the first radial annular rib (34) is provided radially on the outside with an axial relief (38) which is spaced radially on the inside from a radially outer peripheral edge (39) of the first rib and has a curved profile in radial section.Rolling bearing assembly (6) comprising a rolling bearing (3) comprising in turn an outer ring (4), an inner ring (5) and a plurality of rolling elements (2) arranged between the inner and outer rings so as to make them relatively rotatable with low friction, and an annular cage (1) holding the rolling elements and arranged between the inner and outer rings; the annular cage (1) comprising: - a plurality of pockets (7) each delimited by a spherical surface (8) whose centre lies in a radial median plane (P) of the cage which coincides with a corresponding radial median plane of the rolling bearing; - two half-cages (10) substantially symmetrical and interconnected with respect to the median plane, each half-cage having an annular body (11) and a plurality of at least partially hemispherical cavities (12) axially facing the hemispherical cavities of the opposite half-cage to form with them the pockets (7); and - connecting elements (13) associated with the half-cages to hold the two half-cages together to form the annular cage; characterized in that the connecting elements (13) comprise in combination: (i) - first pairs of conjugated connecting elements consisting, for each first pair, of an at least partially elastically deformable pin (16) and a corresponding hole (18) configured to snap receive the pin, each half-cage (10) being associated with a plurality of the pins (16), projecting axially from the annular body on the side of a first face (19) of the annular body and provided with a corresponding plurality of holes (18) formed axially in the annular body (11) on the side of a second face (20) opposite the first face, the annular body of each half-cage being provided with both the holes (18) and the pins (16) arranged so that each pin (16) of one half-cage mates with a hole (18) of the opposite half-cage (10) opposite it through an opening of the hole opposite the first face (19); (ii) second pairs of conjugate connecting elements consisting, for each second pair, of a male element (21) formed as a substantially rigid and solid block projecting axially from the first face (19) of the annular body of each half-cage, and of a corresponding recess (22) formed so as to integrally mate with the solid block (21) forming the male element, said recess (22) being obtained through the first face (19) of the annular body of each half-cage; each half-cage (10) being provided with a plurality of said male elements (21) and with a corresponding plurality of said recesses (22) arranged so that each male element (21) of a half-cage (10) mates with a recess (22) of the opposite half-cage (10) facing it; (iii) - each pin (16) protrudes axially from a respective male element (21) made up of such a solid block as to be arranged axially in series with the latter downstream thereof with respect to the first face (19) of the annular body of each half-cage, and each recess (22) being arranged axially in series with a respective hole (18) upstream thereof with respect to the first face (19) of the annular body of each half-cage; (iv) - each half-cage (10) being provided radially on the outside with a first radial annular rib (34) shaped substantially in the form of a flange and formed in the vicinity of the second face (20) of the annular body (11) of each half-cage (10) so as to be axially remote from the seats or pockets (7) for the rolling bodies; wherein the first radial annular rib (34) of each half cage engages an annular groove (35) formed radially on the inside of the outer ring (4) of the rolling bearing (3) to perform a labyrinth function therewith; wherein a second radial annular rib (36) is optionally obtained radially on the inside of each half cage (10) substantially flush with the first radial annular rib (34) and engages a second annular groove (37) optionally obtained radially on the outside of the inner ring (5) of the rolling bearing to perform a labyrinth function therewith.

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