Nsk Corporation

Masahiro Nobutomo

Yutaka Nagai

Daisuke Maruyama

Junji Minakuchi

Kazunari Miyazaki

Kazuhito Yamamoto

Keisuke Muto

Satoru Arai

Provided is a screw shaft in a ball screw device. At least a part of the screw shaft includes a cylindrical body which is manufactured by a filament winding method or a sheet winding method, and a spiral member or a partitioned spiral member which is fixed to an outer circumferential surface of the cylindrical body and forms a thread groove.

Screw shaft, manufacturing method thereof, and ball screw device

A ball screw apparatus is provided which is less likely to increase dynamic friction torque even when a nut is contracted by cooling, and in which cooling effect is made as high as possible and which does not invite excessive machining efficiency droop and increase in pressure loss. The ball screw apparatus includes a screw shaft, a nut screwed with the screw shaft via a plurality of balls, and a cooling section cooling the nut. The plurality of balls to which preload is applied in a two-point contact state, with a preload direction as a tensile direction, are disposed between a screw groove of the screw shaft and a screw groove of the nut. Or, a ratio of the axial length L of the through hole axially formed in the nut and the diameter D of the through hole axially formed in the nut is given by an equation '10&#x2266;L/D&#x2266;60'.

Ball screw device

Growing community of inventors

Fujisawa, Japan

Masahiro Nobutomo