MEASUREMENT WHILE DRILLING FLUID PRESSURE PULSE GENERATOR

摘要

A coupling key for fixedly coupling a driveshaft to a rotating component of a measurement while drilling telemetry apparatus comprises a key body and at least one zero backlash ring. The key body has dimensions selected to fit within a keyhole of a driveshaft and a receptacle of a rotating component, with a gap that is large enough that the key body can be freely inserted into the keyhole and receptacle and small enough that the coupling body can couple the driveshaft to the rotating component in a rotational direction. The least one zero backlash ring extends around the key body and protrudes from surfaces of the key body and into the gap such that an interference fit is established between the coupling key, the keyhole, and the receptacle when the coupling key is coupling the driveshaft and rotating component together.