A retainer is rotationally driven about a axis of a ball bearing, and convex areas having pockets provided therein along a ball pitch circle of the retainer and concave areas between adjacent pockets is detected by a sensor. Grease is discharged according to phases of the convex areas and concave areas in the rotationally driven retainer from a dispenser having grease discharge ports arranged to face an annular space.

A rolling bearing includes a stationary radially outer ring, a groove, at least a rotatable radially inner ring, at least a plurality of rolling bodies, interposed between the radially outer ring and the radially inner ring and a grease dispenser device configured to be accommodated within the groove of the radially outer ring. The dispenser device is further provided with a radially outer crown on which at least a radially inner protrusion is rigidly fixed, the protrusion having a barrier function against a flow of grease.

An inner ring includes: a pair of shoulder outer peripheral surfaces on first and second axial sides of a raceway surface of the inner ring in contact with balls; seal grooves disposed in first and second axial ends of the inner ring and defining labyrinth clearances with lips; and edges disposed on the first and second axial sides. Each of the edges is configured to cause grease flowing along an associated one of the shoulder outer peripheral surfaces to leave the shoulder outer peripheral surface in the direction of an extension thereof. Each of the lips includes a lip oblique surface functioning as a guide surface to guide the grease that has left the edge not to a radially inner region of the bearing but to a radially outer region of the bearing.

A lubricatable ball screw device includes a ball screw shaft, a ball nut slidably sleeved on the ball screw shaft and having oil guide holes, a linear bearing unit mounted between the ball screw shaft and the ball nut, a bearing ring rotatably sleeved on the ball nut and having an oil supplying hole, a positioning portion disposed between the bearing ring and the ball nut, and an oil passage corresponding to the oil supplying hole. The oil supplying hole, the oil passage, an oil storage space of the positioning portion and any one of the oil guide holes cooperatively form a continuous oil path.

A tapered roller bearing includes an inner ring, an outer ring, a plurality of tapered rollers provided in an annular space formed between the inner and outer rings and rolling on an inner raceway surface and an outer raceway surface, and an annular cage that holds the tapered rollers. The cage has a small annular portion positioned toward an axially first side with respect to the tapered rollers, a large annular portion positioned toward an axially second side with respect to the tapered rollers, and a plurality of cage bars that couples the small annular portion and the large annular portion together. A minute clearance is formed between the inner ring and the large annular portion and between the outer ring and the large annular portion, respectively.

An object is to provide a motor-incorporation-spindle ball bearing capable of allowing cooling air which enters inside the bearing of the motor-incorporation-spindle to be discharged smoothly out of the bearing without causing turbulent flow inside the bearing, does not cause a retainer easily to be vibrated, and provides a high level of silent operation. A seal plate has a length to allow air to pass through the bearing from an entrance side toward an exit side substantially straightly without resistance. Therefore, the seal plate is less likely to be exposed to unnecessary force when the air passes through the bearing; the seal plate is prevented from wobble and deformation; stable sealing is ensured; the air is discharged smoothly without causing turbulent flow inside the bearing; a retainer is not easily vibrated, and silent operation is maintained.

A turbocharger including a housing and a rotary assembly disposed within the housing and including a turbine wheel and a compressor wheel attached to one another by a shaft. The rotary assembly being subject to aero-load in a lateral direction. A bearing is disposed in the housing and rotatably supports the shaft, the bearing including an inner bearing surface that engages the shaft and an outer bearing surface that engages the housing, the outer bearing surface having a pair of axially extending recessed grooves extending at least partially along the bearing. The pair of axially extending grooves being located perpendicular to the aero-load direction.

A turbocharger including a housing and a rotary assembly disposed within the housing and including a turbine wheel and a compressor wheel attached to one another by a shaft. The rotary assembly being subject to aero-load in a lateral direction. A bearing is disposed in the housing and rotatably supports the shaft, the bearing including an inner bearing surface that engages the shaft and an outer bearing surface that engages the housing, the outer bearing surface having a pair of axially extending recessed grooves extending at least partially along the bearing. The pair of axially extending grooves being located perpendicular to the aero-load direction

A bearing unit provided with a rolling bearing having a radially outer race, two radially inner races, a ring of conical rollers arranged between the radially outer race and the two radially inner races, and a device for retaining grease and metering oil housed inside a groove of the radially outer race and having an annular wall arranged transversely with respect to the rolling bearing and acting as barrier for the flow of grease and provided with a plurality of through-openings for retaining the grease and allowing the oil to pass between the two rings of conical rollers in any operating condition, and also with a plurality of radial vanes engaged with the annular wall for retaining the grease.

An inner ring includes: a pair of shoulder outer peripheral surfaces on first and second axial sides of a raceway surface of the inner ring in contact with balls; seal grooves disposed in first and second axial ends of the inner ring and defining labyrinth clearances with lips; and edges disposed on the first and second axial sides. Each of the edges is configured to cause grease flowing along an associated one of the shoulder outer peripheral surfaces to leave the shoulder outer peripheral surface in the direction of an extension thereof. Each of the lips includes a lip oblique surface functioning as a guide surface to guide the grease that has left the edge not to a radially inner region of the bearing but to a radially outer region of the bearing.