Abstract: A power transmission shaft includes a metal shaft member, and a resin shaft member connected to the metal shaft member in an axial direction of the power transmission shaft. The resin shaft member is made of fiber reinforced plastic. The metal shaft member and the resin shaft member are joined to each other through a close-contact fitting portion between a male spline, which is formed in an outer surface of the metal shaft member, and a female spline formed by press-fitting the male spline into the resin shaft member. An edge is formed at a radially outer edge portion of a press-fitting-start end surface of the male spline of the metal shaft member.

Abstract: A tripod type constant velocity universal joint includes an outer joint member having three track grooves each including roller guide surfaces opposing each other in a circumferential direction of each of the track grooves, a tripod member including three leg shafts, and roller units each including a roller and an inner ring to support the roller. An outer peripheral surface of the roller has a partially spherical surface having a curvature center on an axis of each of the leg shafts. The roller guide surfaces are each formed of a partially cylindrical surface having a curvature center on a horizontal line passing an intersection of a pitch circle of the track grooves and a center line of each of the track grooves, and when no torque is applied to the joint, an end portion of the outer peripheral surface of the roller abuts against the roller guide surfaces.

Abstract: The present invention provides a grease composition for constant velocity joints, which includes a lubricating base oil, a thickener including a nitrogen-containing compound, a triglyceride, a diester, and a boron nitride, wherein a total content of the triglyceride and the diester is 1 to 5 mass % based on a total amount of the grease composition, and a mass ratio of a content of the triglyceride to a content of the diester (triglyceride/diester) is 0.3 to 1.5.

Abstract: Provided is a power transmission shaft, including: a metal shaft member; and a resin shaft member connected to the metal shaft member in an axial direction of the power transmission shaft. The resin shaft member is made of fiber reinforced plastic. The metal shaft member and the resin shaft member are joined to each other through a close-contact fitting portion between a male spline, which is formed in an outer surface of the metal shaft member, and a female spline formed by press-fitting the male spline into the resin shaft member. An edge is formed at a radially outer edge portion of a press-fitting-start end surface of the male spline of the metal shaft member.

Abstract: A boot band includes a band body, which is obtained by forming a band-plate-like member into a ring shape, and a lever, which is obtained by forming a strip-like member into an arc shape, and is provided on a joined portion of the band body. The boot band fastens a boot for a constant velocity universal joint, which is arranged on an inner side of the band body, by reducing the band body in diameter such that the lever is turned over using an end portion of the lever as a fulcrum and then superposed on the band body, thereby reducing the band body in diameter. The lever includes two chamfered portions formed in a fulcrum-side region of the end portion of the lever along a thickness direction of the lever.

Abstract: A corrugated portion is formed in one end edge portion of the metallic shaft main body (2), and a triangular corrugated portion (11) is formed in an end edge portion of the shaft auxiliary body (3) on the metallic shaft main body side. The metallic shaft main body (2) and the shaft auxiliary body (3) are integrated by being linearly arranged by way of meshing that brings a side of the triangular corrugated portion (9) on the main body side and a side of the triangular corrugated portion (11) on the auxiliary body side into contact with each other. A fiber orientation angle (?) of the fiber reinforced plastic of the shaft auxiliary body (3) is set so as to be in the same direction as a direction of stress generated in a hypotenuse of each triangular portion under a torque load state.

Abstract: The present invention provides a grease composition for constant velocity joints, which includes a lubricating base oil, a thickener including a nitrogen-containing compound, a triglyceride, a diester, and a boron nitride, wherein a total content of the triglyceride and the diester is 1 to 5 mass % based on a total amount of the grease composition, and a mass ratio of a content of the triglyceride to a content of the diester (triglyceride/diester) is 0.3 to 1.5.

Abstract: A boot band includes a band body, which is obtained by forming a band-plate-like member into a ring shape, and a lever, which is obtained by forming a strip-like member into an arc shape, and is provided on a joined portion of the band body. The boot band fastens a boot for a constant velocity universal joint, which is arranged on an inner side of the band body, by reducing the band body in diameter such that the lever is turned over using an end portion of the lever as a fulcrum and then superposed on the band body, thereby reducing the band body in diameter. The lever includes two chamfered portions formed in a fulcrum-side region of the end portion of the lever along a thickness direction of the lever.

Abstract: A corrugated portion is formed in one end edge portion of the metallic shaft main body (2), and a triangular corrugated portion (11) is formed in an end edge portion of the shaft auxiliary body (3) on the metallic shaft main body side. The metallic shaft main body (2) and the shaft auxiliary body (3) are integrated by being linearly arranged by way of meshing that brings a side of the triangular corrugated portion (9) on the main body side and a side of the triangular corrugated portion (11) on the auxiliary body side into contact with each other. A fiber orientation angle (?) of the fiber reinforced plastic of the shaft auxiliary body (3) is set so as to be in the same direction as a direction of stress generated in a hypotenuse of each triangular portion under a torque load state.

Abstract: A fixed type constant velocity universal joint includes an outer joint member, an inner joint member, a plurality of balls for transmitting torque provided between track grooves of the outer joint member and track grooves of the inner joint member, and a cage for retaining the balls. Grease is enclosed in the fixed type constant velocity universal joint which includes a thickener and a lubricant component which is constituted by base oil. The grease contains 90% by mass or more of paraffinic mineral oil with respect to the total mass of the lubricant component of the grease, and 3 to 8% by mass of the thickener with respect to the total mass of the components of the grease.

Abstract: A driving-wheel bearing device includes an outer race having double-row outer raceway surfaces formed on an inner periphery thereof, a hub wheel and an inner race having a wheel attachment flange at one end thereof and double-row inner raceway surfaces on an outer periphery thereof, and double-row rolling elements interposed between the outer raceway surfaces of the outer race and the inner raceway surfaces of the hub wheel and the inner race, the hub wheel having a shaft hole into which a stem section extending from an outer joint member of a constant velocity universal joint is spline-fitted by being press-fitted, in which a plate having a molybdenum coating layer or a fluorine-resin coating layer formed thereon and having a plate thickness ranging from 0.5 mm to 2 mm is interposed between opposite surfaces of a shoulder portion of the outer joint member and an crimped portion of the hub wheel.

Abstract: A constant velocity universal joint has track shapes which facilitate quality control on a forging die set, securing higher durability through securement of a stable contact state of forging-molded tracks and finishing-processed tracks with respect to balls. At least one of each of track grooves of an outer joint member and each of track grooves of an inner joint member is formed by cold-forging finishing. A track groove bottom side of the at least one of each of the track grooves is formed into a Gothic arch shape in horizontal cross-section, and a track groove opening side of the at least one of each of the track grooves is are each formed into an elliptical shape in horizontal cross-section.

Abstract: A driving-wheel bearing device includes an outer race having double-row outer raceway surfaces formed on an inner periphery thereof, a hub wheel and an inner race having a wheel attachment flange at one end thereof and double-row inner raceway surfaces on an outer periphery thereof, and double-row rolling elements interposed between the outer raceway surfaces of the outer race and the inner raceway surfaces of the hub wheel and the inner race, the hub wheel having a shaft hole into which a stem section extending from an outer joint member of a constant velocity universal joint is spline-fitted by being press-fitted, in which a plate having a molybdenum coating layer or a fluorine-resin coating layer formed thereon and having a plate thickness ranging from 0.5 mm to 2 mm is interposed between opposite surfaces of a shoulder portion of the outer joint member and an crimped portion of the hub wheel.

Abstract: A driving-wheel bearing device includes an outer race having double-row outer raceway surfaces formed on an inner periphery thereof, a hub wheel and an inner race having a wheel attachment flange at one end thereof and double-row inner raceway surfaces on an outer periphery thereof, and double-row rolling elements interposed between the outer raceway surfaces of the outer race and the inner raceway surfaces of the hub wheel and the inner race, the hub wheel having a shaft hole into which a stem section extending from an outer joint member of a constant velocity universal joint is spline-fitted by being press-fitted, in which a plate having a molybdenum coating layer or a fluorine-resin coating layer formed thereon and having a plate thickness ranging from 0.5 mm to 2 mm is interposed between opposite surfaces of a shoulder portion of the outer joint member and an crimped portion of the hub wheel.

Abstract: An outer joint member for a fixed type constant velocity universal joint contributes to the reduction of the number of man-hours through the reduction of the number of processes after a forging process, to an increase in yield, and to the reduction of manufacturing cost. The outer joint member is made of machine-structural carbon steel. The portions of the outer joint member that are finished by cold forging are track grooves, radially inner spherical-surface portions, a cup-inlet chamfer, track chamfers, track-inlet chamfers, a part except for a boot fixing portion on a radially outer surface of the cup section, and a center hole at an end surface of the shaft section.

Abstract: A fixed type constant velocity universal joint includes an outer joint member, an inner joint member, a plurality of balls interposed between the outer and inner joint members, and a cage to hold the plurality of balls. At least one of the plurality of track grooves of the outer joint member and the plurality of track grooves of the inner joint member is formed by cold-forging finishing. The outer joint member, the inner joint member, the balls, and the cage are assembled to each other based on matching in which the plurality of balls and the cage each having a rank corresponding to a measured value of a pitch circle diameter of the outer joint member and to a measured value of a pitch circle diameter of the inner joint member, which have been arbitrarily selected, are selected with respect to the arbitrarily selected outer and inner joint members.

Abstract: Provided is a constant velocity universal joint having track shapes which facilitate quality control on a forging die set and products as in a conventional case while securing higher durability through securement of a stable contact state of forging-molded tracks and finishing-processed tracks with respect to balls. At least one of each of track grooves (22) of an outer joint member (23) and each of track grooves (25) of an inner joint member (26) is formed by cold-forging finishing. A track groove bottom side of the at least one of each of the track grooves (22) and the track grooves (25) is formed into a Gothic arch shape in horizontal cross-section, and track groove opening sides of the at least one of each of the track grooves (22) and the track grooves (25) are each formed into an elliptical shape in horizontal cross-section.

Abstract: An outer joint member (10) and an inner joint member (40) each have a shaft portion (18 and 46) having a male spline formed thereon, and shaft clamps (60) are press-fitted onto the respective shaft portions (18 and 46). Each of the shaft clamps (60) includes: a connection hole (66) that has a female spline formed therein, extends from a first axial end partway toward a second axial end, and has no quench-hardened layer; and a cylindrical portion (64) that has no female spline formed therein and extends from the second axial end partway toward the first axial end. The shaft portions (18 and 46) each have a quench-hardened layer on the outer circumference thereof. The inner diameter of the connection hole (64) at a portion having no female spline formed therein is less than the outer diameters of the shaft portions (18 and 46).

Abstract: Provided is a fixed type constant velocity universal joint which can prevent stick slip from occurring due to lack of lubricity, and prevent abnormal noises from occurring at low temperatures, even during use in an extremely cold region.

Abstract: An object of the present invention is to ensure the miniaturization, strength, durability, load-carrying capacity, and an operating angle of a constant velocity universal joint. Six balls 3 are disposed in the constant velocity universal joint. The ratio r1 (=PCDBALL/DBALL) between the pitch circle diameter PCDBALL (PCDBALL=2×PCR) of the ball 3 and the diameter DBALL thereof is set in a range of 1.5?r1?4.0. The ratio r2 (=DOUTER/PCDSERR) between the outside diameter DOUTER of an outer member 1 and the pitch circle diameter PCDSERR of serrations (or splines) 2d of an inner joint member 2 is set in a range of 3.0?r2?5.0.