The Japan Atomic Power Company

Nippon Gear Co., Ltd.

Osamu Okada

Susumu Watanabe

Haruo Ito

A valve drive device which can prevent a locknut fixing a stem nut to a drive sleeve from getting loosened. The valve drive device comprises: the stem nut for screwing a valve stem thereinto; the drive sleeve engaging with a male spline formed on a peripheral outer surface of said stem nut, said drive sleeve including a worm gear on a peripheral outer surface thereof; a worm in meshing engagement with said worm gear; and a housing that supports said drive sleeve by bearings. The valve drive device further comprises: a stem nut fastening member having a first male screw that engages with a female screw provided on a peripheral inner surface of said drive sleeve; and a locknut that engages with a second male screw provided on a reduced diameter portion of said stem nut fastening member, said second male screw having a reverse screw thread relative to said first male screw, so that no slack may arise between said stem nut fastening member and said drive sleeve.

Growing community of inventors

Kanagawa, Japan

Osamu Okada