Abstract: A hub unit bearing H1 includes a rotational speed detector 9 which is made up of an encoder 6 and a sensor 8. A seal 5b on a side facing a center side of a vehicle includes a primary seal 5bp and a secondary seal 5bq which are disposed in that order in an axial direction from rolling elements 32 on a side facing the center side of the vehicle towards the center side of the vehicle so as to define a primary sealed space portion I between the vehicle's center side facing rolling elements 32 and the primary seal 5bp and a secondary sealed space portion II between the primary seal 5bp and the secondary seal 5bq, with the rotational speed detector 9 disposed within the secondary sealed space portion II.

Abstract: In a wheel supporting rolling bearing unit in which pitch circle diameters of balls 6a, 6b in an outside row and an inside row are made different, contact angles ?OUT, ?IN of the balls 6a, 6b in the two rows in a completed state are equal to each other. Initial contact angles ?OUT, ?IN of the two rows are smaller than predetermined contact angles ?OUT, ?IN. The extent [?IN??IN] to which the initial contact angle ?IN of the balls 6b, 6b in the inside row is made smaller than the predetermined contact angle ?IN of the balls 6b, 6b is made larger than the extent [?OUT??OUT] to which the initial contact angle ?OUT of the balls 6a, 6a in the outside row is made smaller than the predetermined contact angle ?OUT of the balls 6a, 6a {[?IN??IN]>[?OUT??OUT]}. By this configuration, imparting the predetermined contact angles ?OUT, ?IN to the balls 6a, 6b in the two rows in the completed state, and the preloads and contact angles of the balls 6a, 6b in the two rows are made proper.

Abstract: A hub unit bearing H1 includes a rotational speed detector 9 which is made up of an encoder 6 and a sensor 8. A seal 5b on a side facing a center side of a vehicle includes a primary seal 5bp and a secondary seal 5bq which are disposed in that order in an axial direction from rolling elements 32 on a side facing the center side of the vehicle towards the center side of the vehicle so as to define a primary sealed space portion I between the vehicle's center side facing rolling elements 32 and the primary seal 5bp and a secondary sealed space portion II between the primary seal 5bp and the secondary seal 5bq, with the rotational speed detector 9 disposed within the secondary sealed space portion II.

Abstract: In a wheel supporting rolling bearing unit in which pitch circle diameters of balls 6a, 6b in an outside row and an inside row are made different, contact angles ?OUT, ?IN of the balls 6a, 6b in the two rows in a completed state are equal to each other. Initial contact angles ?OUT, ?IN of the two rows are smaller than predetermined contact angles ?OUT, ?IN. The extent [?IN??IN] to which the initial contact angle ?IN of the balls 6b, 6b in the inside row is made smaller than the predetermined contact angle ?IN of the balls 6b, 6b is made larger than the extent [?OUT??OUT] to which the initial contact angle ?OUT of the balls 6a, 6a in the outside row is made smaller than the predetermined contact angle ?OUT of the balls 6a, 6a {[?IN??IN]>[?OUT??OUT]}. By this configuration, imparting the predetermined contact angles ?OUT, ?IN to the balls 6a, 6b in the two rows in the completed state, and the preloads and contact angles of the balls 6a, 6b in the two rows are made proper.

Abstract: The distance L15 in the axial direction between the surface on the axially outside end of the spline shaft 28a and the opening edge on the axially inside end of the center hole 15 of the hub 5 when the unit is installed, and more preferable the distance L16 in the axial direction between this surface on the axially outside end of the spline shaft 28a and the edge on the axially inside end of the spline hole 16, is greater than the distance L18 that the tripod 21 of the constant-velocity joint 18 on the differential side can move inward in the axial direction when installed in the automobile. Therefore, it is possible to prevent the spline shaft 28 from falling out of the center hole 15 even when the connection member 3 is damaged, and to maintain the spline connection between the spline shaft 28 and the spline hole 16.

Abstract: A rolling-bearing unit for wheel support comprising an outer-race with a double row of tapered and concave-shaped outer-ring raceways, a hub comprising a hub body with an outside inner-ring raceway and a separate inner-race with an inside inner-ring raceway, and a tapered rollers between the inner-ring raceways and the outer-ring raceways respectively, the hub body formed with a cylindrical section, and a support-step section which the separate inner-race is fitted onto, the cylindrical section plastically deformed radially outward to form a crimped section, the support-step section formed with a step surface, one end surface of the separate inner-race abutted to the step surface while the other end surface retained by the crimped section, the inner-ring raceway of the separate inner-race connected to the side surface of the large-diameter-side collar section through a connecting portion which is provided with a grinding-relief groove, and wherein the contact area between the other end surface of the separate

Abstract: The distance L15 in the axial direction between the surface on the axially outside end of the spline shaft 28a and the opening edge on the axially inside end of the center hole 15 of the hub 5 when the unit is installed, and more preferable the distance L16 in the axial direction between this surface on the axially outside end of the spline shaft 28a and the edge on the axially inside end of the spline hole 16, is greater than the distance L18 that the tripod 21 of the constant-velocity joint 18 on the differential side can move inward in the axial direction when installed in the automobile. Therefore, it is possible to prevent the spline shaft 28 from falling out of the center hole 15 even when the connection member 3 is damaged, and to maintain the spline connection between the spline shaft 28 and the spline hole 16.

Abstract: The present invention provides a double row taper-roller bearing and a method of assembling a double row taper-roller bearing, which are, when in an assembly, capable of assembling and being assembled by controlling a negative axial gap after the assembly. The present invention-provides also a wheel support structure and a method of the assembling the same structure.

Abstract: A rolling-bearing unit for wheel support comprising an outer-race with a double row of tapered and concave-shaped outer-ring raceways, a hub comprising a hub body with an outside inner-ring raceway and a separate inner-race with an inside inner-ring raceway, and a tapered rollers between the inner-ring raceways and the outer-ring raceways respectively, the hub body formed with a cylindrical section, and a support-step section which the separate inner-race is fitted onto, the cylindrical section plastically deformed radially outward to form a crimped section, the support-step section formed with a step surface, one end surface of the separate inner-race abutted to the step surface while the other end surface retained by the crimped section, the inner-ring raceway of the separate inner-race connected to the side surface of the large-diameter-side collar section through a connecting portion which is provided with a grinding-relief groove, and wherein the contact area between the other end surface of the separate

Abstract: A double row taper-roller bearing and a method of assembling a double row taper-roller bearing, which are, when in an assembly, capable of assembling and being assembled by controlling a negative axial gap after the assembly.

Abstract: The present invention provides a double row taper-roller bearing and a method of assembling a double row taper-roller bearing, which are, when in an assembly, capable of assembling and being assembled by controlling a negative axial gap after the assembly. The present invention provides also a wheel support structure and a method of the assembling the same structure.