Patent ID: 6079489
Filing Date: 2000-06-27
Classification: F16D

Abstract:
A backspin retarder assembly for a well head drive assembly, comprising:means defining a backspin chamber in a pump drive housing rotatably mounting a drive shaft;brake members disposed within said backspin chamber in equally, angularly spaced relation, said members being movable between inner and outer positions and being biased toward said inner positions, each said brake member having brake surfaces on opposite sides thereof;means defining stationary brake surfaces in said drive housing and engageable with said brake member brake surfaces in said outer positions of said brake members; andmeans for biasing said brake members in said inner positions and preventing outward movement of said brake members below a predetermined speed of said shaft, said biasing means including a guide flange having a hub portion connected to said shaft for rotation therewith and a keeper plate defining a portion of said chamber;a guide pin associated with each brake member and extending radially outwardly from said hub into a passage in said associated brake member;a compression spring in said passage and receiving said pin and means connected to said pin and engageable with one end of said spring for pre-compressing said spring and urging said associated brake member in said inner position.