Cage for rolling bearings and related rolling bearing unit

A rolling bearing unit comprising:

• a rolling bearing having an outer ring, an inner ring and a plurality of rolling bodies interposed between the inner and outer rings to make the inner and outer rings relatively rotatable with each other, and an annular cage retaining the rolling bodies and mounted interposed between the inner and outer rings;
• the annular cage comprising:
• a plurality of pockets each bounded by a respective spherical surface having a center lying in a radial median plane of the cage coincident with a corresponding radial median plane of the rolling bearing;
• two half-cages substantially symmetrical with respect to the median plane, and connected to each other, each half-cage presenting an annular body and a plurality of at least partially hemispherical cavities facing axially to the hemispherical cavities of the opposite half-cage to define the pockets;
• and
• connection elements associated with the half-cages to constrain the two half-cages together to form said annular cage;
• characterized by the fact that said connection elements include, in combination:
• first pairs of conjugate connection elements consisting, for each first pair, of a pin at least partially elastically deformable and of a respective hole configured to receive the pin snappingly, each half-cage being provided with a plurality of said pins projecting axially from the annular body on the side of a first frontal face of the annular body and of a corresponding plurality of holes formed axially in the annular body on the side of a second frontal face thereof, opposite to the first frontal face, the annular body of each half-cage being provided with said holes and said pins that are arranged in such a way that each pin of said half-cage mates with the hole facing the pin of the opposite half-cage through an opening of the hole facing the first face;
• and
• second pairs of conjugate connection elements consisting, for each second pair, of a male element configured as a substantially rigid and solid block projecting axially from the first frontal face of the annular body of each half-cage, and of a corresponding recess configured to mate in integral manner with the solid block constituting the male element, the recess being obtained through the first frontal face of the annular body of each half-cage;
• each half-cage being provided with a plurality of said male elements and with a corresponding plurality of said recesses arranged so that each male element of said half-cage mates with said recess facing said male element of the opposite half-cage;
• each pin projecting axially from a corresponding male element consisting of one said solid block, so as to be arranged axially in series with the one said solid block, downstream of the one said solid block with respect to said first frontal face of the annular body of each half-cage;
• and each recess being arranged axially in series with a respective said hole, upstream of said hole with respect to said first frontal face of the annular body of each half-cage;
• each half-cage being provided radially on the outside with a first radial annular ridge formed in the vicinity of said second frontal face of the annular body of each half-cage, so as to be axially distal from the seats or pockets for the rolling bodies;
• said first radial annular ridge of each half-cage mating within an annular groove obtained radially on the inside of the outer ring of the rolling bearing to exert a labyrinth seal function with the outer ring;
• a second radial annular ridge being optionally obtained radially on the inside of each half-cage, substantially flush with the first radial annular ridge, and coupling within a second annular groove optionally obtained radially on the outside of the inner ring of the rolling bearing to exert with the inner ring a labyrinth sealing function.