A mechanical roller bearing comprising two bearing races each having a rolling track, rolling elements arranged between the races, the rolling elements being able to roll against a portion of the rolling tracks, the rolling elements being made of a defined material, wherein it includes a plurality of intermediate blocks arranged between the races, the intermediate blocks being made of a material having a greater stiffness than the stiffness of the material of the rolling elements in directions normal to the rolling tracks, and, when the bearing is subjected to loading below a threshold load, the intermediate blocks have a smaller dimension than the rolling elements in directions normal to the rolling tracks, the races having a greater stiffness than the rolling elements.

An axial air movement fan having a plurality of variable pitch fan blades (2), extending radially from a hub (4) rotatable about a main axis (3), each blade (2) further being pivotable about its radial axis to vary the blade pitch. The blades (2) each are mounted on an associated bearing (5) mounted on said hub, the bearing comprising a ball bearing having a first radially inner race (25) fast the blade (2) and a second radially outer race (26) rotationally fast to the hub (4). The balls (14) in the bearing are separated by separators (15), each separator being generally cylindrical and having its cylindrical axis coaxial with the orbital axis (22) of the orbit of the balls (14) and being adapted to rotate about the said orbital axis (22), the side faces of the separator each having a part spherical recess (16) adapted to receive a ball (14). Rotation of the separator (15) about the orbital axis (22) is such as to entrain lubricant in the bearing and to bias the lubricant from adjacent the outer race (26) over the balls (14) towards the inner race (25).

An axial air movement fan having a plurality of variable pitch fan blades (2), extending radially from a hub (4) rotatable about a main axis (3), each blade (2) further being pivotable about its radial axis to vary the blade pitch. The blades (2) each are mounted on an associated bearing (5) mounted on said hub, the bearing comprising a ball bearing having a first radially inner race (25) fast the blade (2) and a second radially outer race (26) rotationally fast to the hub (4). The balls (14) in the bearing are separated by separators (15), each separator being generally cylindrical and having its cylindrical axis coaxial with the orbital axis (22) of the orbit of the balls (14) and being adapted to rotate about the said orbital axis (22), the side faces of the separator each having a part spherical recess (16) adapted to receive a ball (14). Rotation of the separator (15) about the orbital axis (22) is such as to entrain lubricant in the bearing and to bias the lubricant from adjacent the outer race (26) over the balls (14) towards the inner race (25).

A separator is provided for a ball bearing including inner and outer rings and a plurality of balls disposed between the inner and outer rings. The separator includes an annular body having a centerline, opposing first and second axial ends spaced apart along the centerline, an inner circumferential surface defining a central pocket sized to receive one of the plurality of balls and an outer circumferential surface defining an outer perimeter. A plurality of inner axial channels extend radially outwardly from the inner circumferential surface and a plurality of outer axial channels extend radially inwardly from the outer circumferential surface, each inner axial channel and each outer axial channel being configured to contain lubricant. Preferably, both the inner and outer axial channels are spaced circumferentially about the centerline and each channel extends entirely axially between the first and second axial ends of the annular body.