Abstract: Both an end surface of a first rib, over which a first cylindrical rollers slide, and an end surface of a second rib, over which the first cylindrical rollers slide, slope to approach the perpendicular bisector plane of a first cylindrical raceway surface of an outer ring or slope to be spaced away from the perpendicular bisector plane as it goes outward in a radial direction in a cross section of the outer ring taken in an axial direction. A first sliding contact portion of each first cylindrical roller, which is in sliding contact with the end surface of the first rib, and a second sliding contact portion of each first cylindrical roller, which is in sliding contact with the end surface of the second rib, both are located inward in the radial direction with respect to an orbital cylindrical plane of the first cylindrical rollers.

Abstract: An inner ring is formed with an oil hole extending through a part between an inner ring raceway surface and an inner peripheral face thereof, and configured to force out grease, which has been supplied to an area between the inner ring raceway surface and an outer ring raceway surface, to the inner peripheral face in accordance with rolling of cylindrical rollers. The inner peripheral face of the inner ring is formed with a plurality of V-shaped inclined grooves configured to guide the grease, which has been forced out to the inner peripheral face of the inner ring through the oil hole, to opposite end portions of the inner peripheral face in an axial direction of the inner ring.

Abstract: A tapered roller thrust bearing is disposed in each of both sides in an axial direction of a cylindrical roller bearing with aligning housing ring which is provided with an inner ring, an outer ring, cylindrical rollers and an aligning housing ring. The tapered roller thrust bearing is constituted by disposing tapered rollers between a first raceway surface which is an outer side face in the axial direction of the outer ring and a second raceway surface of a side raceway ring disposed in an outer side in the axial direction of the outer ring. An intersection of lines extended from generatrices of each of the tapered rollers which are in contact with the first raceway surface and the second raceway surface, and an intersection of lines extended from the first raceway surface and the second raceway surface are disposed on a curvature center of the aligning sliding surface.

Abstract: A gap between a bearing box and a roll portion and so on which are not used for absorbing an expansion of a roll are reduced, and by increasing axial widths of the bearing box and cylindrical roller bearing for that, a loading capacity of the cylindrical roller bearing is enhanced. A first side face 13A of the bearing box 13 located at one side in the axial direction is disposed outwardly with respect to a central line Y2 between two roll portions 22A, 22B than a second side face 13B located at an other side in the axial direction, and a gap a1 between this first side face 13A and the roll portion 22A opposed thereto is made smaller than a gap a2 between the second side face 13B and the roll portion 22B opposed thereto.

Abstract: A tapered roller thrust bearing is disposed in each of both sides in an axial direction of a cylindrical roller bearing with aligning housing ring which is provided with an inner ring, an outer ring, cylindrical rollers and an aligning housing ring. The tapered roller thrust bearing is constituted by disposing tapered rollers between a first raceway surface which is an outer side face in the axial direction of the outer ring and a second raceway surface of a side raceway ring disposed in an outer side in the axial direction of the outer ring. An intersection of lines extended from generatrices of each of the tapered rollers which are in contact with the first raceway surface and the second raceway surface, and an intersection of lines extended from the first raceway surface and the second raceway surface are disposed on a curvature center of the aligning sliding surface.

Abstract: A roller bearing includes: an outer ring that has outer ring raceway; an inner ring that has inner ring raceway surfaces that face the outer ring raceway surfaces; a plurality of cylindrical rollers that are arranged between the outer ring raceway surfaces and the inner ring raceway surfaces. The outer ring has an outer ring rib that is in point-contact with one axial end surface of each of the cylindrical rollers and that is arranged adjacent to the outer ring raceway surfaces. Contact positions at which the cylindrical rollers contact the outer ring rib are set to be on an axis of the cylindrical roller and an axis of the cylindrical roller.

Abstract: Both an end surface of a first rib, over which a first cylindrical rollers slide, and an end surface of a second rib, over which the first cylindrical rollers slide, slope to approach the perpendicular bisector plane of a first cylindrical raceway surface of an outer ring or slope to be spaced away from the perpendicular bisector plane as it goes outward in a radial direction in a cross section of the outer ring taken in an axial direction. A first sliding contact portion of each first cylindrical roller, which is in sliding contact with the end surface of the first rib, and a second sliding contact portion of each first cylindrical roller, which is in sliding contact with the end surface of the second rib, both are located inward in the radial direction with respect to an orbital cylindrical plane of the first cylindrical rollers.

Abstract: An inner ring is formed with an oil hole extending through a part between an inner ring raceway surface and an inner peripheral face thereof, and configured to force out grease, which has been supplied to an area between the inner ring raceway surface and an outer ring raceway surface, to the inner peripheral face in accordance with rolling of cylindrical rollers. The inner peripheral face of the inner ring is formed with a plurality of V-shaped inclined grooves configured to guide the grease, which has been forced out to the inner peripheral face of the inner ring through the oil hole, to opposite end portions of the inner peripheral face in an axial direction of the inner ring.

Abstract: A gap between a bearing box and a roll portion and so on which are not used for absorbing an expansion of a roll are reduced, and by increasing axial widths of the bearing box and cylindrical roller bearing for that, a loading capacity of the cylindrical roller bearing is enhanced. A first side face 13A of the bearing box 13 located at one side in the axial direction is disposed outwardly with respect to a central line Y2 between two roll portions 22A, 22B than a second side face 13B located at an other side in the axial direction, and a gap a1 between this first side face 13A and the roll portion 22A opposed thereto is made smaller than a gap a2 between the second side face 13B and the roll portion 22B opposed thereto.