A rolling bearing includes an inner ring, an outer ring, a plurality of balls, a cage, and sealing devices. An action that forces grease from one axial side to the other axial side occurs in an annular space. The cage includes an annular body provided on one axial side, and a plurality of cage prongs provided so as to extend from the annular body to the other axial side. Cage pockets that house the balls are each formed on the other axial side of the annular body and between the cage prongs adjacent to each other in a circumferential direction. The cage pockets are open to the other axial side.

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 ball bearing includes an inner ring, an outer ring, and a cage that supports balls. At least one portion of each prong of the cage overlaps with an inner ring raceway surface in an axial direction and the entirety of the prongs do not overlap with a shoulder of the inner ring in the axial direction. A pocket of the cage overlaps with virtual conical planes that are parallel to a reference virtual conical plane including an inner ring nominal contact point and an outer ring nominal contact point, and that are part, on the other axial side, of both a virtual conical plane including an edge between the inner ring raceway surface and the shoulder of the inner ring and a virtual conical plane including an edge between the outer ring raceway surface and the outer ring counter-bored portion.

A bearing housing structure (101) comprises a support section (102) for supporting a bearing (117), a reception interface (103) for receiving lubrication grease, and grease channels (104-106) for conducting the lubrication grease to both sides of the bearing which are mutually opposite in the axial direction of the bearing. The bearing housing structure comprises exit conduits (107, 108) for allowing the lubrication grease to exit the bearing from the both sides of the bearing and a grease reservoir (109) for storing the lubrication grease exiting the bearing via one or more of the exit conduits. The bearing housing structure is capable of operating in different positions so that the axial direction of the bearing can be horizontal, vertical, or slanting.

A rolling bearing includes an inner ring, an outer ring, a plurality of rolling elements, and a cage. A first seal is provided on one side of the annular space between the inner ring and the outer ring in the axial direction and has a first lip portion that forms a first labyrinth clearance with the inner ring to prevent spill of the grease. A second seal is provided on the other side of the annular space in the axial direction and has a second lip portion that forms a second labyrinth clearance with the inner ring to prevent spill of the grease. The second lip portion is larger than the first lip portion such that the path length of the second labyrinth clearance is longer than the path length of the first labyrinth clearance.

A rolling bearing with an inner ring and an outer ring which is rotatable about a rotation axis relative to the inner ring, or with an outer ring and an inner ring which is rotatable about a rotation axis relative to the outer ring, and with at least one sealing element arranged between the inner ring and the outer ring for sealing an interior of the rolling bearing which can be filled with a lubricant. The rolling bearing includes a conveying element for conveying the lubricant which is arranged on the one of the inner ring and outer ring so as to be rotatable about the rotation axis of the rolling bearing and in such a way that a play exists between the conveying element and the other of the inner ring and outer ring.

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.

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 grease for a rolling bearing of an information recording and reproducing apparatus contains a base oil, a thickener, and at least one kind of an antioxidant selected from an amine-based antioxidant expressed by the General Formula (1), and a phenol-based antioxidant expressed by the General Formula (2). The base oil contains a refined mineral oil classified as Group III in a base oil category defined by the American Petroleum Institute, and the flash point of the refined mineral oil is 240 C. or higher.