Abstract: A holder of a tapered roller bearing is made of a resin, has a first gap between an axially inner end surface of a small-diameter-side annular part and small-diameter-side end surfaces of tapered rollers, has a second gap between an axially inner end surface of a large-diameter-side annular part and large-diameter-side end surfaces of the tapered rollers, and is provided to be capable of moving within a prescribed range along the axial direction. The surface of the axially inner end surface of the large-diameter-side annular part is rough, the large-diameter-side annular part is provided with one or more grooves which are oil-holding parts that hold the lubricating oil, and ends of the grooves are positioned to be capable of coming into contact with the tapered rollers.

Abstract: A holder of a tapered roller bearing is made of a resin, has a first gap between an axially inner end surface of a small-diameter-side annular part and small-diameter-side end surfaces of tapered rollers, has a second gap between an axially inner end surface of a large-diameter-side annular part and large-diameter-side end surfaces of the tapered rollers, and is provided to be capable of moving within a prescribed range along the axial direction. The surface of the axially inner end surface of the large-diameter-side annular part is rough, the large-diameter-side annular part is provided with one or more grooves which are oil-holding parts that hold the lubricating oil, and ends of the grooves are positioned to be capable of coming into contact with the tapered rollers.

Abstract: A friction roller type speed increaser (100) includes a high speed side shaft (11), a ring roller (21), a low speed side shaft (13), at least one fixed roller (15), at least one movable roller, and a housing (23) that surrounds the rollers. A bearing unit (45) that includes a cylindrical bearing housing (51) into which the high speed side shaft (11) is inserted, bearings (53 and 55) on an inner circumferential portion of the bearing housing (51) which rotatably support the high speed side shaft (11), an oil seal (59) which is provided at one end portion of the bearing housing (51) and closes an inner space including the bearings is floating-supported such that the bearing unit can move in a radial direction of the high speed side shaft (11) in a unit accommodating section (47) formed in the housing (23).

Abstract: There is provided a resin cage of a tapered roller bearing. The cage includes a small diameter annular portion, a large diameter annular portion, and a plurality of bar portions arranged at intervals in a circumferential direction to connect the annular portions. The bar portion has a pair of circumferentially-directed side surfaces, each having a roller guide surface, and an inner-side inner peripheral surface, a circumferential width of which is smaller on a side of the large diameter annular portion than on a side of the small diameter annular portion, and has a roller retaining region in which a radially outer side pocket width and a radially inner side pocket width between the opposed circumferentially-directed side surfaces of the adjacent bar portions are smaller than a diameter of the roller.

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.

Abstract: A tandem angular ball bearing is provide that prevent damage from occurring to the rolling surfaces of the balls during assembly and transport to an extent that would cause an excessive decrease in life of the balls, and that can maintain excelled durability without the occurrence of excessive vibration and noise during operation. In order to accomplish this, the entire portion of the inner peripheral surface of an outer ring (5b) from a small-diameter side outer ring raceway (11) to the continuous section (25a) that is continuous with the end surface (23) on the large inner diameter side of the outer ring (5b), and the entire portion of the outer peripheral surface of an inner ring (6b) from a large-diameter side inner ring raceway (12) to the continuous section (25g) that is continuous with the end surface (14) on the small outer-diameter side of the inner ring (6b) are polished smooth surfaces having no indifferentiable corner sections in the cross-section shape.

Abstract: There is provided a resin cage of a tapered roller bearing. The cage includes a small diameter annular portion, a large diameter annular portion, and a plurality of bar portions arranged at intervals in a circumferential direction to connect the annular portions. The bar portion has a pair of circumferentially-directed side surfaces, each having a roller guide surface, and an inner-side inner peripheral surface, a circumferential width of which is smaller on a side of the large diameter annular portion than on a side of the small diameter annular portion, and has a roller retaining region in which a radially outer side pocket width and a radially inner side pocket width between the opposed circumferentially-directed side surfaces of the adjacent bar portions are smaller than a diameter of the roller.