| 摘要 |
PURPOSE:To improve the mechanical rigidity of a hob head as a hob head as well as to make improvement in power transmission efficiency of a gear hobbing machine, by constituting a gear blank and a hob cutter so as to make them relatively shiftable in a direction in parallel with the axial direction of the gear blank, a radial direction of the gear blank and a direction orthogonal with both these directions. CONSTITUTION:A gear blank 4 and a hob cutter 9 both are rotated, while a headstock 3 is slidden and thereby the gear blank 4 and the hob cutter 9 are made to come nearer to each other in the horizontal direction. Here, when a helix angle of a helical gear 11 is set down to beta and a lead angle of the hob cutter 9 to gamma, respectively, an axial end face of the helical gear 11 and the angle made by a shaft center of the cutter 9 come to (beta+gamma) in view of necessity to accord a tooth trace direction of the cutter 9 with that of the helical gear 11. From this state, a lifting block 7 is made to go down by a numerical control system, a movable frame 6 is horizontal slidden, and when the cutter 9 is parallel moved in the tooth trace direction (A direction), the gear 11 is generated. Therefore, a hob head 8 becomes simplified in structure and, what is more, its mechanical rigidity is improved, thus a differential gear mechanism is made unnecessary. |
