Provided is a bearing lubrication structure for a rotation unit having a bearing that is of a grease lubrication type in which the bearing is provided at both sides thereof with a seal structure, wherein the grease lubrication performance is improved. The bearing is provided on both sides thereof with fixed-side seal portions, and rotating side seal portions that are opposed thereto, respectively. The fixed-side seal portion is provided with a shield. The distance from the inner periphery of the shield to the axis of the rotary shaft varies depending on the location of a point on the inner periphery. The shield, which is one of the two shields, and the shield, which is the other one, are arranged so as not to have plane symmetry.

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 rolling bearing includes an outer ring and an inner ring, a rolling element disposed in a rollable manner between the outer ring and the inner ring, a cage holding the rolling element, and a shield. The outer ring includes a raceway surface supporting the rolling element in a rollable manner, recess parts formed at both direction sides in an axial direction with respect to the raceway surface, and a ridge part formed between the recess part and the raceway surface. The recess part includes a placement surface for placing a grease, and a first inclined part formed between the placement surface and the ridge part and approaching an outer peripheral surface of the outer ring toward an outer side in the axial direction.

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.

A method for lubricating a rolling element bearing, the method comprising a step of providing a bearing cage for retaining rolling elements when the bearing cage is in use, the bearing cage having at least one first ring structure to which at least one first cage bar is connected. The at least one first cage bar is constructed so that a diameter of the bearing cage is largest at one of a point or a region along the length of the at least one first cage bar so as to improve lubricant flow towards the rotational center of rolling elements when the bearing cage is in use.

The present invention relates to a retainer for a bearing. The retainer is entirely formed into an annular shape and has a crown shape. The retainer includes pockets (15c) which are formed at a plurality of locations in a circumferential direction of the retainer and are each opened on a radially outer side and a radially inner side. The pockets (15c) retain balls (14) being rolling elements so that the balls (14) are rollable. A grease flow-in passage (22) is provided between an inner surface (18) of each of the plurality of pockets and each of the balls.

A bearing retainer for use in a bearing is provided. The bearing includes an inner ring, rolling elements and an outer ring. The bearing retainer includes a body. The body defines an inner periphery and an outer periphery of the body. The body further defines a plurality of inner walls. Each inner wall defines an opening extending from the inner periphery to the outer periphery of the body. The plurality of openings are adapted to receive one of the rolling elements. The inner walls are adapted to keep the rolling elements in a spaced apart relationship. At least one of the inner walls defines a aperture through the body. The aperture is adapted for storing lubrication therein.

An axial rolling bearing unit includes a first annular axial bearing washer, a second annular axial bearing washer, a bearing cage formed from a sheet metal material, and rolling elements arranged between the first annular axial bearing washer and the second annular axial bearing washer. The bearing cage includes an inner radial edge rim extending in an axial direction, and an outer radial edge rim extending in the axial direction. The rolling elements are radially guided by the inner radial edge rim and the outer radial edge rim. A one of the inner radial edge rim or the outer radial edge rim has a double-rim design with an end-side bend extending in a direction opposite to the axial direction, and the end-side bend has a first distal end section that holds the first annular axial bearing washer in a form-fitting manner.

The invention relates to a rolling element bearing having at least one inner bearing inner and at least one outer bearing ring. Rolling elements are arranged between the inner ring and the outer ring, and the rolling elements are guided by a cage. To improve the lubrication of the bearing the invention proposes that the cage includes at least one opening, preferably a bore. The opening penetrates the cage from a radial inner surface to a radial outer surface.

A tapered roller bearing includes inner ring, outer ring, plurality of tapered rollers placed between inner and outer rings, and retainer having pockets receiving tapered rollers. Small diameter annular portion of retainer closes a small diameter side opening portion so that lubricating oil more than needed for lubrication can be limited from flowing into a bearing internal space. The small diameter side opening portion is constituted by a small collar portion provided on one axial end side of inner ring and one axial end portion of outer ring. A sliding contact face and recess portion are provided in radially outer side surface of each columnar portion. The sliding contact face is in sliding contact with outer ring raceway surface so that the retainer can be positioned radially by an outer ring raceway surface. Recess portion is recessed radially so that adjacent ones of the pockets can communicate with each other.