Abstract: A difference between a maximum value and a minimum value of arithmetic mean roughness Ra of an annular surface region in contact with a larger flange surface, in a larger end face of the tapered roller, is not greater than 0.02 ?m. A value of a ratio R/RBASE is not smaller than 0.75 and not greater than 0.87 where R represents a set radius of curvature of the larger end face of the tapered roller and RBASE represents a distance from a point which is an apex of a cone angle of the tapered roller to the larger flange surface of the inner ring. A ratio Rprocess/R is not lower than 0.5 where Rprocess represents an actual radius of curvature after grinding of the larger end face of the tapered roller and R represents a set radius of curvature.

Abstract: The present invention provides a bearing device for vehicle wheel reducing the occurrence of abnormal heat generation caused by metal contact and enhancing anti-seizing properties. Each of the tapered rollers 4 has a large diameter-side end surface 41, the inner raceway surface 31, and the large flange part 32. The large flange part 32 includes a chamfered part 32c and a rounded part 32d. The large flange part 32 has a large flange part-side cutout part 34, the large diameter-side end surface 41 of each of the tapered rollers 32 has a tapered roller-side cutout part 43 having a circular shape formed coaxially with the large diameter-side end surface 41, and a clearance of the large diameter-side end surface 41 as viewed from a contact point between the large diameter-side end surface 41 and the guide surface 32a is greater than or equal to 15 ?m.

Abstract: A difference between a maximum value and a minimum value of arithmetic mean roughness Ra of an annular surface region in contact with a larger flange surface, in a larger end face of the tapered roller, is not greater than 0.02 ?m. A value of a ratio R/RBASE is not smaller than 0.75 and not greater than 0.87 where R represents a set radius of curvature of the larger end face of the tapered roller and RBASE represents a distance from a point which is an apex of a cone angle of the tapered roller to the larger flange surface of the inner ring. A ratio Rprocess/R is not lower than 0.5 where Rprocess represents an actual radius of curvature after grinding of the larger end face of the tapered roller and R represents a set radius of curvature.

Abstract: A tapered roller bearing for an automobile includes an inner ring including a raceway surface having a tapered shape on an outer periphery, an outer ring including a raceway surface having a tapered shape on an inner periphery, a plurality of tapered rollers incorporated into a space defined between the raceway surfaces, and a retainer configured to receive the tapered rollers. The inner and outer rings are each made of carburized steel, and the raceway surfaces of the inner and outer rings each have a straight generating line shape. The tapered rollers each are made of high carbon chromium bearing steel, and each have a rolling surface including a straight portion, which is formed at a center portion in an axial direction, and crowning portions, which extend from the straight portion to both end portions. The crowning portions are each formed of logarithmic crowning.

Abstract: A difference between a maximum value and a minimum value of arithmetic mean roughness Ra of an annular surface region in contact with a larger flange surface, in a larger end face of the tapered roller, is not greater than 0.02 ?m. A value of a ratio R/RBASE is not smaller than 0.75 and not greater than 0.87 where R represents a set radius of curvature of the larger end face of the tapered roller and RBASE represents a distance from a point which is an apex of a cone angle of the tapered roller to the larger flange surface of the inner ring. A ratio Rprocess/R is not lower than 0.5 where Rprocess represents an actual radius of curvature after grinding of the larger end face of the tapered roller and R represents a set radius of curvature.

Abstract: Two projecting portions (45a and 45b) configured to guide a tapered roller (3) on distal end surfaces thereof are formed on a side surface (43a) of a pillar portion (43) of a retainer (4) so as to be separated apart from each other in a roller axis direction. The projecting portions (45a and 45b) are separated apart from each other in the roller axis direction with respect to both a small-diameter-side annular portion (41) and a large-diameter-side annular portion (42). The projecting portions (45a and 45b) each have a force-fit margin (F).

Abstract: A tapered roller bearing for an automobile includes an inner ring including a raceway surface having a tapered shape on an outer periphery, an outer ring including a raceway surface having a tapered shape on an inner periphery, a plurality of tapered rollers incorporated into a space defined between the raceway surfaces, and a retainer configured to receive the tapered rollers. The inner and outer rings are each made of carburized steel, and the raceway surfaces of the inner and outer rings each have a straight generating line shape. The tapered rollers each are made of high carbon chromium bearing steel, and each have a rolling surface including a straight portion, which is formed at a center portion in an axial direction, and crowning portions, which extend from the straight portion to both end portions. The crowning portions are each formed of logarithmic crowning.

Abstract: Provided is a tapered roller bearing (1, 1?, 21) which is to be used for a pilot portion and an idler portion of a synchronous mesh-type transmission in which a component corresponding to a bearing outer ring (3, 23) is formed of a gear (34, 43), wherein a ratio L/Dw of a roller length (L) of a tapered roller (4) serving as a rolling element to a roller diameter (Dw) is set to 1.7 or more, wherein a rolling surface (6) of the tapered roller (4) includes a straight portion (6a) in a center portion of the rolling surface (6) in an axial direction and crowning portions (6b, 6c) extending from the straight portion (6a) to both end portions, and wherein the crowning portions (6b, 6c) are each formed of logarithmic crowning.

Abstract: A value of R/RBASE is not smaller than 0.75 and not greater than 0.87 where R represents a reference radius of curvature of a larger end face of a roller and RBASE represents a distance from an apex of a cone angle of the roller to a larger flange surface of an inner ring 13. A distance from an outermost surface of at least any one of an outer ring, the inner ring, and a plurality of rollers to a bottom of a nitrogen enriched layer is not shorter than 0.2 mm. A crowning profile is formed on a rolling surface of the roller.

Abstract: In a tapered roller bearing, a cage includes a plurality of trapezoidal pockets and the pockets accommodate and hold a plurality of rollers. A notch having a width is provided in a post on a smaller width side of the pocket of the cage from a boundary between a smaller annular portion and a post toward a larger annular portion. Lubricating oil which flows from an inner diameter side of the cage toward an inner ring is quickly discharged through the notch toward an outer ring on an outer diameter side. A distance from an outermost surface of at least any one of the outer ring and the inner ring of the roller and a plurality of rollers to a bottom of a nitrogen enriched layer is equal to or longer than 0.2 mm. A rolling surface of the roller is provided with a logarithmic crowning profile.

Abstract: 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 (RBASE) from a vertex of a cone angle of each of the tapered rollers to the large-collar surface has a ratio R/RBASE in a range of 0.75 to 0.87, and when RACTUAL represents an actual curvature radius of the large end surface, a ratio RACTUAL/R is equal to or larger than 0.5.

Abstract: Provided is a tapered roller bearing (1, 1?, 21) which is to be used for a pilot portion and an idler portion of a synchronous mesh-type transmission in which a component corresponding to a bearing outer ring (3, 23) is formed of a gear (34, 43), wherein a ratio L/Dw of a roller length (L) of a tapered roller (4) serving as a rolling element to a roller diameter (Dw) is set to 1.7 or more, wherein a rolling surface (6) of the tapered roller (4) includes a straight portion (6a) in a center portion of the rolling surface (6) in an axial direction and crowning portions (6b, 6c) extending from the straight portion (6a) to both end portions, and wherein the crowning portions (6b, 6c) are each formed of logarithmic crowning.

Abstract: A difference between a maximum value and a minimum value of arithmetic mean roughness Ra of an annular surface region in contact with a larger flange surface, in a larger end face of the tapered roller, is not greater than 0.02 ?m. A value of a ratio R/RBASE is not smaller than 0.75 and not greater than 0.87 where R represents a set radius of curvature of the larger end face of the tapered roller and RBASE represents a distance from a point which is an apex of a cone angle of the tapered roller to the larger flange surface of the inner ring. A ratio Rprocess/R is not lower than 0.5 where Rprocess represents an actual radius of curvature after grinding of the larger end face of the tapered roller and R represents a set radius of curvature.

Abstract: A tapered roller bearing includes inner and outer rings including raceway surfaces having tapered shapes on their outer and inner peripheries, respectively, tapered rollers between the raceway surfaces, and a retainer configured to receive the tapered rollers. At least the raceway surface of the inner ring includes cut crowning of a complex curve including a center curve and end portion curves formed on both sides of the center curve each have a curvature radius smaller than a curvature radius of the center curve. The tapered rollers each have a rolling surface including a straight portion and logarithmic crowning portions formed on both sides of the straight portion. When the raceway surface of the inner ring has an effective raceway surface width represented by LG, and the straight portion of the rolling surface of the tapered roller has a width represented by LW1, 0.7?LW1/LG<0.95 is satisfied.

Abstract: 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 (RBASE) from a vertex of a cone angle of each of the tapered rollers to the large-collar surface has a ratio R/RBASE in a range of 0.75 to 0.87, and when RACTUAL represents an actual curvature radius of the large end surface, a ratio RACTUAL/R is equal to or larger than 0.5.

Abstract: A value of R/RBASE is not smaller than 0.75 and not greater than 0.87 where R represents a reference radius of curvature of a larger end face of a roller and RBASE represents a distance from an apex of a cone angle of the roller to a larger flange surface of an inner ring 13. A distance from an outermost surface of at least any one of an outer ring, the inner ring, and a plurality of rollers to a bottom of a nitrogen enriched layer is not shorter than 0.2 mm. A crowning profile is formed on a rolling surface of the roller.

Abstract: In a tapered roller bearing, a cage includes a plurality of trapezoidal pockets and the pockets accommodate and hold a plurality of rollers. A notch having a width is provided in a post on a smaller width side of the pocket of the cage from a boundary between a smaller annular portion and a post toward a larger annular portion. Lubricating oil which flows from an inner diameter side of the cage toward an inner ring is quickly discharged through the notch toward an outer ring on an outer diameter side. A distance from an outermost surface of at least any one of the outer ring and the inner ring of the roller and a plurality of rollers to a bottom of a nitrogen enriched layer is equal to or longer than 0.2 mm. A rolling surface of the roller is provided with a logarithmic crowning profile.

Abstract: A tapered roller bearing includes inner and outer rings including raceway surfaces having tapered shapes on their outer and inner peripheries, respectively, tapered rollers between the raceway surfaces, and a retainer configured to receive the tapered rollers. At least the raceway surface of the inner ring includes cut crowning of a complex curve including a center curve and end portion curves formed on both sides of the center curve each have a curvature radius smaller than a curvature radius of the center curve. The tapered rollers each have a rolling surface including a straight portion and logarithmic crowning portions formed on both sides of the straight portion. When the raceway surface of the inner ring has an effective raceway surface width represented by LG, and the straight portion of the rolling surface of the tapered roller has a width represented by LW1, 0.7?LW1/LG<0.95 is satisfied.

Abstract: A washer (5) to be mounted to an end surface (14) of an inner ring includes an extension portion (52) extending along an outer peripheral surface (15) of the inner ring. The extension portion (52) includes an engaging projection portion (53) to be engaged with an engaging recessed portion (16) formed in the outer peripheral surface (15) of the inner ring. The engaging projection portion (53) includes a rounded curved surface portion (55), and a flat surface portion (54) formed continuously with a forward side in a pressing direction of the rounded curved surface portion (55) and inclined radially outward.

Abstract: A washer (5) to be mounted to an end surface (14) of an inner ring includes an extension portion (52) extending along an outer peripheral surface (15) of the inner ring. The extension portion (52) includes an engaging projection portion (53) to be engaged with an engaging recessed portion (16) formed in the outer peripheral surface (15) of the inner ring. The engaging projection portion (53) includes a rounded curved surface portion (55), and a flat surface portion (54) formed continuously with a forward side in a pressing direction of the rounded curved surface portion (55) and inclined radially outward.