| 摘要 |
A controller comprises a valve body having a valve element and a valve seat defining therebetween a fluid channel openable and closable with reciprocating upward and downward movement of a valve stem, a casing fixed to an upper portion of the valve body, an operating rod provided in an upper inside portion of the casing and movable upward and downward, a drive device for moving the operating rod upward and downward, and a force transmission device provided in a lower inside portion of the casing for transmitting a force acting on the operating rod to the valve stem. The transmission device comprises a conical first roller contact member extending vertically downward from a lower end of the operating rod, a second roller contact member provided at an upper end of the valve stem, a pair of roller support members arranged between the two contact members symmetrically with respect to the axis of the first contact member, a pair of rollable rollers each rotatably supported by the support member at an upper portion thereof and bearing on a tapered face of the first contact member, and a pair of push rollers each rotatably supported by the support member at a lower portion thereof and bearing on a roller support upper surface of the second contact member. Each of the roller support members is supported by the casing so as to be pivotally movable about an axis on the side of the axis of the first contact member relative to the axis of the corresponding push roller.
|
