Abstract: A notch communicating a pair of pockets adjacent to each other in the circumferential direction of pockets of a retainer is provided in a range from an end section on the axially one side to the axially intermediate section of each of pillar portions of the retainer for an angular contact ball bearing, the notch having a substantially rectangular opening shape as seen from the circumferential direction, and an inner surface of the notch having an outer diameter side flat surface portion arranged on the radially outer side from the center of a pocket and extending substantially linearly in the axial direction, an inner diameter side flat surface portion arranged on the radially inner side from the center and extending substantially linearly in the axial direction, and a back side flat surface portion arranged on the axially other side from the center and extending linearly in the radial direction.

Abstract: Rotary forging for forming a hub-side face spline is started in a state in which a caulking section is made to come in contact with a flat surface section that is an inner end surface of an inner ring in an axial direction and a chamfer. In addition, a contact portion between an inner end surface of the caulking section in the axial direction and a processing surface of a roll at the beginning of the rotary forging overlaps a contact portion between the caulking section and the flat surface section and the chamfer of the inner ring in the axial direction.

Abstract: A tapered roller bearing improves durability during a state of insufficient lubrication by sufficiently lengthening the time until rotation becomes impossible due to seizure. Oil retaining concave sections, recessed outward in the radial direction, are formed in portions on the inner circumferential surface of a large-diameter rim section of the retainer whose phase in the circumferential direction coincides with the pockets. A portion of the bottom surface of each of the oil retaining concave sections, open to the inside surface of the pocket, face a concave section formed in an end surface on the large-diameter side of tapered roller that is held inside the pocket. When lubrication becomes insufficient, oil remaining in the concave sections is effectively used for lubricating areas of sliding contact between the end surfaces on the large-diameter side and the inside surface in the axial direction of a large-diameter side flange section.

Abstract: A tapered roller bearing improves durability during a state of insufficient lubrication by sufficiently lengthening the time until rotation becomes impossible due to seizure. Oil retaining concave sections, recessed outward in the radial direction, are formed in portions on the inner circumferential surface of a large-diameter rim section of the retainer whose phase in the circumferential direction coincides with the pockets. A portion of the bottom surface of each of the oil retaining concave sections, open to the inside surface of the pocket, face a concave section formed in an end surface on the large-diameter side of tapered roller that is held inside the pocket. When lubrication becomes insufficient, oil remaining in the concave sections is effectively used for lubricating areas of sliding contact between the end surfaces on the large-diameter side and the inside surface in the axial direction of a large-diameter side flange section.