Rotating drilling head gripper

摘要

A rotating drilling head seals around drill pipe while drilling. The drilling head has an outer housing that mounts to the rig floor. An inner housing is rotatably mounted in the outer housing. An annular bladder is mounted in the inner housing. An annular elastomeric gripping member is mounted in the bladder. The inner housing having a passage for delivering hydraulic fluid pressure to the outer surface of the bladder to cause the bladder to deform inwardly, thereby forcing the gripping member to deform inwardly to grip and rotate with a drill pipe. The gripping member has a first end secured to the inner housing for rotating the inner housing as the drill pipe rotates and a second end that is free to move axially to allow the bladder to elongate in response to the deformation by the bladder.