To provide a manufacturing method of an outer ring of a wheel support rolling bearing unit having desired depths of heat-treated hardened layers at both sides of a center part side and a both-end part side of a double-row outer ring raceway, and capable of preventing the protrusion of the heat-treated hardened layers to an external peripheral face, and also to provide the wheel support rolling bearing unit.SOLUTION: A manufacturing method of an outer ring of a wheel support rolling bearing unit comprises: a forging step for forming a cylindrical member 20A whose internal peripheral face becomes large in a diameter at an axial both-end part side rather than an axial center part side; a diameter expansion step for expanding a diameter of the internal peripheral face of the cylindrical member 20A so that an external peripheral face 28a of the cylindrical member 20A becomes large in a diameter at the axial both-end part side rather than the axial center part side; an induction heat treatment step for applying induction heat treatment to an outer ring raceway 22 and forming a heat-treated hardened layer 23 at the outer ring raceway 22; and a lathe turning step for lathe-turn finishing the external peripheral face 28a of the outer ring to form a prescribed shape after the induction heat treatment step.SELECTED DRAWING: Figure 1
【課題】複列の外輪軌道の中央部側及び両端部側の両側で所望の熱処理硬化層深さを有し、且つ、外周面への熱処理硬化層の突き抜けを防止することができる車輪支持用転がり軸受ユニットの外輪の製造方法及び車輪支持用転がり軸受ユニットを提供する。【解決手段】内周面が軸方向中央部側よりも軸方向両端部側において大径となる筒状部材20Aを成形する鍛造工程と、筒状部材20Aの外周面28aを軸方向中央部側よりも軸方向両端部側において大径となるように、筒状部材20Aの内周面を拡径する拡径工程と、外輪軌道22に高周波熱処理を施し、外輪軌道22に熱処理硬化層23を形成する高周波熱処理工程と、高周波熱処理工程後に外輪の外周面28aを所定の形状に旋削仕上げする旋削工程と、を備える。【選択図】図1
MANUFACTURING METHOD OF OUTER RING OF WHEEL SUPPORT ROLLING BEARING UNIT, AND WHEEL SUPPORT ROLLING BEARING UNIT
車輪支持用転がり軸受ユニットの外輪の製造方法及び車輪支持用転がり軸受ユニット
2023-04-18
Patent
Electronic Resource
Japanese