Patent ID: 6918574

Claim:
A gate valve which comprises: a valve body which includes a flow bore that extends completely therethrough and a gate cavity that extends partially therethrough and intersects the flow bore; a bonnet which is connected to the valve body over the gate cavity; a gate which is disposed in the gate cavity across the flow bore and which includes a transverse opening that extends completely therethrough; a valve stem which includes a first portion that is connected to the gate and a second portion that extends through the gate cavity; a handwheel; a roller screw assembly which is connected between the handwheel and the second portion of the valve stem and which converts rotation of the handwheel into translation of the valve stem; wherein translation of the valve stem raises or lowers the gate to bring the opening into or out of alignment with the flow bore to either open or close the gate valve, respectively; wherein the roller screw assembly includes a roller screw nut which is connected to the handwheel and a roller screw shaft which connected to the valve stem and is rotatably received within the roller screw nut; a roller thrust bearing which is secured to the roller screw nut; and a roller adapter shaft which includes a lower portion that is secured to the roller screw nut and an upper portion that is connected to the handwheel; wherein rotation of the handwheel rotates the roller adapter shaft, the roller screw nut and the roller thrust bearing in unison.