A tapered roller bearing includes an inner ring and an outer ring, and a plurality of rollers that are rollably disposed between raceway surfaces of the inner ring and the outer ring. A flange part is provided at one end portion or both end portions of the inner ring. Crownings are respectively formed on a rolling contact surface of each roller and the raceway surface of the inner ring. At least at one end portion of an effective contact length Le in a generatrix direction of the rolling contact surface of each roller and the raceway surface of the inner ring, a crowning drop amount in the raceway surface of the inner ring is smaller than a crowning drop amount in the rolling contact surface of each roller.

A double-row self-aligning roller bearing, which is suitable for receiving an axial load and a radial load, and loads having different magnitudes acting on rollers in two rows, and achieves sufficient load capacity for the rollers that receive axial load within the constraint of dimensional standards, is provided. The double-row self-aligning roller bearing includes inner and outer rings; and rollers in two rows arranged in a bearing width direction interposed between the inner and outer rings and having lengths different from each other. The roller has an outer peripheral surface of a cross-sectional shape along a raceway surface of the outer ring having a spherical shape. Length of the longer rollers is equal to or greater than 39% of the bearing width. A ratio of contact angle of the shorter rollers and contact angle of the longer rollers is within a range of 1:4 to 1:2.

A raceway surface (3a) of an outer ring (3) of a tapered roller bearing (1) includes a composite crowning surface. The composite crowning surface includes a center curve (3a1), which is formed at a center portion in a generating-line direction, and end portion curves (3a2 and 3a3), which are formed on both sides of the center curve (3a1) in the generating-line direction. The raceway surface (3a) of the outer ring (3) is entirely subjected to superfinishing. Each of a ratio (R.sub.2/R.sub.1) of a curvature radius (R.sub.2) of the end portion curve (3a2) to a curvature radius (R.sub.1) of the center curve (3a1) and a ratio (R.sub.3/R.sub.1) of a curvature radius (R.sub.3) of the end portion curve (3a3) to the curvature radius (R.sub.1) is set to 0.02 or more. Each of drop amounts of the end portion curves (3a2 and 3a3) is set to 0.07 mm or less.

A tapered roller bearing includes inner and outer rings having tapered raceway surfaces. The inner ring also includes large-collar and small-collar surfaces respectively on large-diameter and small-diameter sides of its raceway surface. A plurality of tapered rollers are arrayed between the raceway surfaces. Each of the tapered rollers has a large end surface that contacts and is guided by the large-collar surface. A set curvature radius (R) of the large end surface of each of the tapered rollers and a base curvature radius (R.sub.BASE) from a vertex of a cone angle of each of the tapered rollers to the large-collar surface has a ratio R/R.sub.BASE in a range of 0.75 to 0.87, and when R.sub.ACTUAL represents an actual curvature radius of the large end surface, a ratio R.sub.ACTUAL/R is equal to or larger than 0.5.

A bearing system for a compressor including an unloader at least partially received within a recess of a driveshaft. The unloader includes an outer surface that is engaged with a bearing. An inner surface of the unloader is curved such that the unloader is pivotable relative to the driveshaft unload forces on bearing caused by deflection of the driveshaft.

A bearing system for a compressor including an unloader at least partially received within a recess of a driveshaft. The unloader includes an outer surface that is engaged with a bearing. An inner surface of the unloader is curved such that the unloader is pivotable relative to the driveshaft unload forces on bearing caused by deflection of the driveshaft.

A double-row self-aligning roller bearing has rollers interposed, in two rows aligned in a bearing width direction, between an inner ring and an outer ring. The outer ring has a spherical raceway surface. Each of the rollers has an outer circumferential surface having a cross-sectional shape that matches the raceway surface of the outer ring. Either or both of shapes and contact angles of the rollers are different from each other. An attachment hole to which a protrusion prevention jig is attachable is provided in an end surface of at least either one of the inner ring and the outer ring. The protrusion prevention jig prevents protrusion of the end surface of the inner ring in the bearing width direction with respect to the end surface of the outer ring.

A self-aligning roller bearing having inner and outer bearing ring elements and at least one row of roller elements disposed in between. The inner bearing ring element having a retaining flange provided on a first axial side of the roller bearing being configured for preventing the roller elements from falling out from the roller bearing. The roller bearing having a first sealing ring element located at the first axial side for sealing the first axial opening, the first sealing ring being rotatable in relation to the inner bearing ring and seals against a sealing mating surface of the inner bearing ring. The retaining flange has at least one filling slot configured for allowing the roller elements to be inserted in-between the inner and the outer bearing ring elements during assembly of the roller bearing, and the sealing mating surface being axially outside the at least one filling slot.

A bearing device for supporting a shaft to rotate relative to an outer hub includes: an annular outer race mountable within an interior bore of the hub, the outer race including an inwardly facing radial groove sized to receive a rounded bearing element; and an annular inner race mountable to an outwardly curved exterior surface of the shaft. The inner race includes an outwardly facing radial groove sized to receive the bearing element, the respective radial grooves of the inner and outer races together forming an annular raceway to retain the bearing element when the bearing device is assembled. The inner race further includes an axially convex surface along an innermost diameter of the inner race, the convex surface shaped to directly engage the exterior surface of the shaft when mounted thereto, such that the inner race remains in contact with the shaft while accommodating radial deflection of the shaft.

A raceway surface (3a) of an outer ring (3) of a tapered roller bearing (1) includes a composite crowning surface. The composite crowning surface includes a center curve (3a1), which is formed at a center portion in a generating-line direction, and end portion curves (3a2 and 3a3), which are formed on both sides of the center curve (3a1) in the generating-line direction. The raceway surface (3a) of the outer ring (3) is entirely subjected to superfinishing. Each of a ratio (R.sub.2/R.sub.1) of a curvature radius (R.sub.2) of the end portion curve (3a2) to a curvature radius (R.sub.1) of the center curve (3a1) and a ratio (R.sub.3/R.sub.1) of a curvature radius (R.sub.3) of the end portion curve (3a3) to the curvature radius (R.sub.1) is set to 0.02 or more. Each of drop amounts of the end portion curves (3a2 and 3a3) is set to 0.07 mm or less.