A bearing of a wind turbine, wherein the bearing is lubricated with a lubricant for reducing wear and fatigue of the bearing, the bearing is sealed such that the amount of lubricant which is leaking out of the bearing is minimized, is provided. The bearing includes a ventilation device with at least one pressure compensation hole for enabling a pressure compensation between the sealed bearing and the ambient. The ventilation device further includes a compressor unit, which is connected with the pressure compensation hole. Thus, a compressed medium can be selectively blown through the pressure compensation hole to ensure that the pressure compensation hole remains substantially unobstructed such that overpressure within the bearing compared to the ambient is minimized and leakage of lubricant out of the bearing is reduced. A wind turbine including such bearing and an associated method is also provided.

A ball bearing is provided which includes a cage circular annular portion and a seal member. The cage circular annular portion has a cage-side sliding contact surface axially opposed to the seal member and configured to come into sliding contact with the seal member. The seal member has a seal-side sliding contact surface configured to come into sliding contact with the cage-side sliding contact surface. A plurality of axial protrusions each having an axially convex circular arc shape in cross sections along a circumferential direction are formed on one of the cage-side sliding contact surface and the seal-side sliding contact surface at constant pitches in the circumferential direction.

Disclosed is a sealed bearing arrangement that provides at least a bearing with an outer ring and an inner ring, which are rotatable to each other and form a rolling chamber between each other, in which a set of rolling elements. A lubricant is encompassed in the rolling chamber and the rolling chamber is sealed off from an environment by at least one sealing element. The inner ring, the outer ring and/or the sealing element includes at least one opening for providing a fluid passage through the sealing element. The bearing is arranged in a housing that is adapted to seal off the bearing from an outside environment. A lubricant is encompassed inside the housing. The housing including the at least one opening for providing a fluid passage from the inside of the housing to the outside. The opening is fluid tightly connected to an oxygen removing element and/or to a gas tank, which provides an oxygen poor to free fluid flow to the rolling chamber.

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 rolling bearing device includes a rolling bearing; and a spacer provided adjacent to one side of the rolling bearing in an axial direction and having a grease reservoir and a flow path, the grease reservoir being in a form of a groove, extending along a circumferential direction, and having grease reserved in the grease reservoir, and the flow path providing communication between the grease reservoir and an inner part of the rolling bearing. The spacer includes an annular wall surface that defines an inner periphery of the grease reservoir. An end of the annular wall surface on a side of the rolling bearing in the axial direction of the grease reservoir is continuous with an opposed end face of the spacer that is opposed to the rolling bearing. An entire area of the annular wall surface is constituted by a flat surface.

A rolling-element bearing subassembly includes a first bearing ring having an axial face lying in a plane and a plurality of rolling elements on a running surface of the first bearing ring. The first bearing ring is connectable to a second bearing ring to form a rolling-element bearing. An annular retaining body having a first leg connected to a second leg by a bridge, the first leg being shorter than the second leg, is mounted on an axial face of the first bearing ring with the first leg contacting the axial face so that the bridge is located on a first side of the plane and the second leg extends through the plane to define an annular gap between a portion of the first bearing ring and the bridge and a portion of the second leg for retaining a lubricant.

The application provides a rolling bearing including a grease composition, the grease composition containing a base oil and a thickener, the base oil containing an aromatic ester-based base oil, and the thickener containing a urea-based thickener, where the grease composition has a storage elastic modulus at 25 C. of from 1200 to 3000 Pa as measured under conditions of a film thickness of 1 mm and a shear strain of 1% and has an oil separation amount at 80 C. of from 200 to 270 mm.sup.2/mg; a pivot assembly bearing apparatus including the rolling bearing; and a disk drive apparatus including the pivot assembly bearing apparatus.

A ball bearing includes a cage circular annular portion and a seal member. The cage circular annular portion has a cage-side sliding contact surface axially opposed to the seal member and configured to come into sliding contact with the seal member. The seal member has a seal-side sliding contact surface configured to come into sliding contact with the cage-side sliding contact surface. A plurality of axial protrusions each having an axially convex circular arc shape in cross sections along a circumferential direction are formed on one of the cage-side sliding contact surface and the seal-side sliding contact surface at constant pitches in the circumferential direction.

A grease composition includes a base oil, a thickener and at least one kind of an antioxidant selected from an amine-based antioxidant and a phenol-based antioxidant expressed by the following respective general formulas (1) and 2: ##STR00001##
The base oil contains a poly--olefin and a mineral oil. A mass ratio of poly--olefin/mineral oil is 1.25 to 9.

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.