Abstract: The present invention provides a manufacturing method of a bearing ring member such as an outer ring comprising an installation portion on the outer peripheral surface and a double row of outer-ring raceways on the inner peripheral surface, in which a raw material is processed to obtain a final stage intermediate member through a first upsetting process, a forward-backward extrusion process, a second upsetting process, a burr removing process, and a punching process, wherein a movable die which leaves a stationary die in the final step is used in the second upsetting process, and the excess metal material is moved toward outside in the radial direction to a portion which become the installation section and a burr formation section, exposing a high pure metal material at least in a portion where the load of rolling bodies acts so as to ensure the rolling fatigue life of the both of outer-ring raceways.

Abstract: A raceway member 6 of a wheel support hub unit, having wheel or vehicle body fixing portions 7 extending radially outward from a solid or hollow shaft portion, and a wheel or vehicle body positioning cylindrical portion 9 extending concentrically with the shaft portion, the fixing portion 7 being formed by the cold side extrusion so that the fixing portion is integral with the shaft portion 5.

Abstract: The present invention provides a manufacturing method of a bearing ring member such as an outer ring comprising an installation portion on the outer peripheral surface and a double row of outer-ring raceways on the inner peripheral surface, in which a raw material is processed to obtain a final stage intermediate member through a first upsetting process, a forward-backward extrusion process, a second upsetting process, a burr removing process, and a punching process, wherein a movable die which leaves a stationary die in the final step is used in the second upsetting process, and the excess metal material is moved toward outside in the radial direction to a portion which become the installation section and a burr formation section, exposing a high pure metal material at least in a portion where the load of rolling bodies acts so as to ensure the rolling fatigue life of the both of outer-ring raceways.

Abstract: This invention provided a manufacturing method to process a small-diameter step section 18 on an inside end section of a hub body 13a that comprises an outward facing flange 15 and a positioning cylinder 16 stably and with high precision. In this invention, an intermediate material 40 is pressed between a lower punch 36 and an upper punch 46 with an outer peripheral surface of the intermediate material 40 being held by a lower die 37 and an upper die 43, and then a part of the intermediate material 40 is pressed into the lower punch 36 such that the small-diameter step section 18 is formed by cold plastic working.

Abstract: There is provided a bearing unit including one raceway ring 2 which is mounted on a vehicle body, the other raceway ring 4 which is disposed to face the one raceway ring 2 and is mounted on a wheel, and a plurality of rolling elements 6, 8 which are built in rollably between an outer ring raceway 2s and an inner ring raceway 4s which are formed continuously on facing surfaces of both the raceway rings 2, 4, respectively, along a circumferential direction, at least either of the raceway rings 2, 4 having a connecting flange 12a or a mounting flange 12a at which the raceway ring is mounted on the vehicle body or the wheel, wherein both the raceway rings 2, 4 are formed entirely through cold forging with no machining given to a surface of the flange 2a, 12a, while a quenching and tempering treatment by electromagnetic induction and grinding are given to at least the outer ring raceway 2s and the outer ring raceway 4s.

Abstract: A raceway member 6 of a wheel support hub unit, having wheel or vehicle body fixing portions 7 extending radially outward from a solid or hollow shaft portion, and a wheel or vehicle body positioning cylindrical portion 9 extending concentrically with the shaft portion, the fixing portion 7 being formed by the cold side extrusion so that the fixing portion is integral with the shaft portion 5.