Abstract: A preload inspection method for a bearing device for a vehicle wheel comprises: a first bearing preload value calculation step for calculating a first bearing preload value; a first rotating torque measurement step for measuring a first rotating torque; a caulking step for swaging the small-diameter stepped part to the inner ring; a second bearing preload value calculation step for calculating a second bearing preload value; a second rotational torque measurement step for measuring a second rotational torque; a third bearing preload value calculation step for calculating a third bearing preload value by adding, to the first bearing preload value, a preload change amount based on a differential torque between the first rotating torque and the second rotating torque; and a determination step for determining the suitability of the preload from the second bearing preload value and the third bearing preload value.

Abstract: A preload inspection method with which a preload value can be calculated more accurately. The preload inspection method for a wheel bearing device provided with an outer member having an outside raceway surface, an inner member having an inside raceway surface, and rolling bodies, is provided with: a power calculation step in which the outer member or the inner member is rotated in a relative manner and the power is calculated; a preload value calculation step in which a preload value is calculated on the basis of the power calculated in the power calculation step; and a pass/fail determination step is made on the basis of whether the preload value calculated in the preload value calculation step is within a permissible range.

Abstract: A preload inspection method with which a preload value can be calculated more accurately. The preload inspection method for a wheel bearing device provided with an outer member having an outside raceway surface, an inner member having an inside raceway surface, and rolling bodies, is provided with: a power calculation step in which the outer member or the inner member is rotated in a relative manner and the power is calculated; a preload value calculation step in which a preload value is calculated on the basis of the power calculated in the power calculation step; and a pass/fail I determination step is made on the basis of whether the preload value calculated in the preload value calculation step is within a permissible range.

Abstract: A preload inspection method for a bearing device for a vehicle wheel comprises: a first bearing preload value calculation step for calculating a first bearing preload value; a first rotating torque measurement step for measuring a first rotating torque; a caulking step for swaging the small-diameter stepped part to the inner ring; a second bearing preload value calculation step for calculating a second bearing preload value; a second rotational torque measurement step for measuring a second rotational torque; a third bearing preload value calculation step for calculating a third bearing preload value by adding, to the first bearing preload value, a preload change amount based on a differential torque between the first rotating torque and the second rotating torque; and a determination step for determining the suitability of the preload from the second bearing preload value and the third bearing preload value.

Abstract: A method is directed to a production of a bearing device for a wheel including an inner member and an outer member rotatable relative to each other through a plurality of rolling elements, in which a component part forming one of the inner member and the outer member is a hot forged product. In the practice of this method, during or at the end of a hot forging step for hot forging the component part, a portion of the component part is cooled by spraying a coolant or by controlling an atmospheric temperature, to thereby render a matrix of the component part to represent a standard structure and render a surface portion of the component part to represent a non-standard structure.

Abstract: A wheel support bearing assembly, which enables an increase in the strength and the fatigue strength of its wheel mounting flange or vehicle body fitting flange against high stress and repeated stress and the suppression of the increase of the number of processes, includes an inner member and an outer member rotatable relative to each other through rolling elements. The flange is formed on the inner member or the outer member. A component part having the flange is a hot-forged product of steel in which a matrix portion is formed as a standard structure and the non-standard structural portion is formed on the surface of the flange. The non-standard structure is formed of either of a fine ferrite/pearlite structure, an upper bainite structure, a lower bainite structure, and a tempered martensite structure, or mixture of two or more of these structures.

Abstract: A vehicle wheel bearing apparatus has an outer member with a body mounting flange, an inner member and double row rolling elements freely rollably contained between the inner and outer raceway surfaces of the inner and outer members. The body mounting flange is formed with a plurality of screw apertures. An inner side flange surface of the body mounting flange is formed by machining to have a flat vertical surface relative to a longitudinal axis of a wheel hub. An outer side flange surface of the body mounting flange is formed by forging to have a tapered surface of a predetermined inclined angle. Thus, the thickness of the body mounting flange is gradually reduced radially outward.

Abstract: A vehicle wheel bearing apparatus has an outer member, an inner member, and double row rolling elements freely rollably contained between the inner and outer raceway surfaces of the inner and outer members. A brake pilot portion extends from a base of a wheel hub mounting flange toward the outer side to guide an inner circumferential surface of a brake rotor. A wheel pilot portion extends from the brake pilot portion further toward the outer side to guide an inner circumferential surface of the wheel. The wheel pilot portion including a plurality of separated pilots separated along a circumferential direction. A chamfered portion is formed, by forging, on a forward end of each separated pilot in view of its lathe cutting direction. The chamfered portion has a predetermined inclined angle relative to an axial end surface of each separated pilot after lathe cutting.

Abstract: A wheel hub of a wheel bearing apparatus has an outer member and an inner member. The inner member includes a wheel hub and an inner ring. The wheel hub has a wheel mounting flange, a shaft portion, an inner raceway surface, a cylindrical portion, a shoulder portion, and a through bore. The inner ring is press-fit onto the cylindrical portion abutting against the shoulder portion. Double row rolling elements are contained between the inner and outer raceway surfaces of the inner member and the outer member. Fiber flow near the inner circumference of the material forming the wheel hub from the shoulder to the open end surface of the wheel hub is in a condition substantially parallel to the axis of the wheel hub.

Abstract: A wheel support bearing assembly includes an inner member having a hub axle and an inner race mounted on the hub axle. This bearing assembly includes one of an engagement recess formed in a portion of an inner peripheral surface of the inner race corresponding to an inboard edge portion of the hub axle and an engagement projection is formed in the hub axle for engagement with the engagement recess, and an annular recess formed in the outer peripheral surface of the hub axle and is opposed to an inboard side face of the inner race by the radially outward deformation of an inboard edge portion of the hub axle.

Abstract: A bearing device for a wheel enabling the easy control of quality since there is no possibility of cracking even if caulking is applied thereto. The bearing device comprises an outer ring having double rows of raceway surfaces on the inner periphery thereof, an inner member having raceway surfaces opposed to the raceway surfaces, and balls interposed between the double rows of raceway surfaces opposed to each other. The inner member further comprises a HUB ring and an inner ring. Caulking is applied to the HUB ring to join it to the inner ring. The grain size number of the austenite grains of a caulked section is at least 6.

Abstract: A hub ring and/or an outer ring constituting a bearing device for a wheel, which is formed of a steel which contains 0.45 to 0.70 mass % of C and at least one of V, Nb and Ti in a total amount of 0.3 mass % or less, wherein a micro structure of a part being not surface-hardening-treated contains a ferrite in 15 to 30 area % and contains a particulate ferrite.

Abstract: A vehicle wheel bearing apparatus has an outer member with a body mounting flange, an inner member and double row rolling elements freely rollably contained between the inner and outer raceway surfaces of the inner and outer members. The body mounting flange is formed with a plurality of screw apertures. An inner side flange surface of the body mounting flange is formed by machining to have a flat vertical surface relative to a longitudinal axis of a wheel hub. An outer side flange surface of the body mounting flange is formed by forging to have a tapered surface of a predetermined inclined angle. Thus, the thickness of the body mounting flange is gradually reduced radially outward.

Abstract: A vehicle wheel bearing apparatus has an outer member, an inner member, and double row rolling elements freely rollably contained between the inner and outer raceway surfaces of the inner and outer members. A brake pilot portion extends from a base of a wheel hub mounting flange toward the outer side to guide an inner circumferential surface of a brake rotor. A wheel pilot portion extends from the brake pilot portion further toward the outer side to guide an inner circumferential surface of the wheel. The wheel pilot portion including a plurality of separated pilots separated along a circumferential direction. A chamfered portion is formed, by forging, on a forward end of each separated pilot in view of its lathe cutting direction. The chamfered portion has a predetermined inclined angle relative to an axial end surface of each separated pilot after lathe cutting.

Abstract: A wheel hub of a wheel bearing apparatus has an outer member and an inner member. The inner member includes a wheel hub and an inner ring. The wheel hub has a wheel mounting flange, a shaft portion, an inner raceway surface, a cylindrical portion, a shoulder portion, and a through bore. The inner ring is press-fit onto the cylindrical portion abutting against the shoulder portion. Double row rolling elements are contained between the inner and outer raceway surfaces of the inner member and the outer member. Fiber flow near the inner circumference of the material forming the wheel hub from the shoulder to the open end surface of the wheel hub is in a condition substantially parallel to the axis of the wheel hub.

Abstract: A wheel support bearing assembly, which enables an increase in the strength and the fatigue strength of its wheel mounting flange or vehicle body fitting flange against high stress and repeated stress and the suppression of the increase of the number of processes, includes an inner member and an outer member rotatable relative to each other through rolling elements. The flange is formed on the inner member or the outer member, for example, a hub. A component part having the flange is a hot-forged product of steel in which a matrix portion is formed as a standard structure and the non-standard structural portion is formed on the surface of the flange. The non-standard structure is formed of either of a fine ferrite/pearlite structure, an upper bainite structure, a lower bainite structure, and a tempered martensite structure, or mixture of two or more of these structures.

Abstract: A method is directed to a production of a bearing device for a wheel including an inner member (1) and an outer member (2) rotatable relative to each other through a plurality of rolling elements (3), in which a component part forming one of the inner member (1) and the outer member (2) is a hot forged product. In the practice of this method, during or at the end of a hot forging step for hot forging the component part, a portion of the component part is cooled by spraying a coolant or by controlling an atmospheric temperature, to thereby render a matrix of the component part to represent a standard structure and render a surface portion of the component part to represent a non-standard structure (30).

Abstract: A vehicle wheel bearing apparatus which can increase the strength and durability of the hub wheel under rotary bending conditions as well as lighten the apparatus without changing the configuration and dimension of the wheel mounting flange and without causing surface run-out has an outer member formed with double row outer raceway surfaces on its inner peripheral surface. An inner member is formed with double row inner raceway surfaces arranged opposite to the double row outer raceway surfaces. Double row rolling elements are freely rollably contained between the outer and inner raceway surfaces, respectively, of the outer and inner members. A wheel mounting flange is integrally formed with either one of the outer or inner members. At least one of the outer and inner members, on which the wheel mounting flange is formed, is heat treated and their raceway surfaces are hardened by quenching to a predetermined surface hardness.

Abstract: A wheel support bearing assembly includes an inner member (2) having a hub axle (2A) and an inner race (2B) mounted on the hub axle (2A). This bearing assembly includes one of an element (A), in which an engagement recess (26) is formed in a portion of an inner peripheral surface of the inner race (2B) corresponding to an inboard edge portion of the hub axle (2A) and an engagement projection (27) is formed in the hub axle (2A) for engagement with the engagement recess (26), and an element (B), in which an annular recess (11) is formed in the outer peripheral surface of the hub axle (2A) and is opposed to an inboard side face of the inner race (2) by the radially outward deformation of an inboard edge portion of the hub axle (2A).

Abstract: A bearing device for a wheel enabling the easy control of quality since there is no possibility of cracking even if caulking is applied thereto. The bearing device comprises an outer ring having double rows of raceway surfaces on the inner periphery thereof, an inner member having raceway surfaces opposed to the raceway surfaces, and balls interposed between the double rows of raceway surfaces opposed to each other. The inner member further comprises a HUB ring and an inner ring. Caulking is applied to the HUB ring to join it to the inner ring. The grain size number of the austenite grains of a caulked section is at least 6.