Power swivel incorporating removable/replaceable bearing core

Abstract

A power swivel for rotation of tubulars, particularly in the drilling and servicing of oil and gas wells. The power swivel has a main body with a central cavity, and means for attaching the main body to the hoist mechanism (typically, the traveling block) of a drilling rig. A stem is rotatably disposed in the main body, with a threaded connection on its downward end, for connecting to the tubular string (drillstring). Vertical loads on the stem are transferred to a main thrust bearing which engages the stem. The vertical loads are then transferred to a removable bearing core contained within the main cavity of the main body. The removable bearing core permits relatively inexpensive and expeditious repair of the power swivel.

1 . A power swivel for rotation of tubulars, comprising:
 a) a main body comprising a means for lifting said main body by a hoist mechanism, and comprising a cavity therein;   b) a stem disposed within said cavity of said main body and rotatable therein, said stem having a longitudinal bore and a lower threaded end for connection to a threaded connection on a tubular, said stem engaging a main thrust bearing which supports vertical loads placed on said stem;   c) a drive motor engaged with said stem, to effect powered rotation of said stem; and   b) a bearing core removably disposed in said main cavity of said main body, between said main thrust bearing and said main body, whereby vertical loads on said main thrust bearing are transferred to said bearing core, and thence to said main body.   
   
   
       2 . The apparatus of  claim 1 , further comprising a torque arm connected to said power swivel. 
   
   
       3 . The apparatus of  claim 2 , wherein said means for lifting comprises lift ears attached to said main body and bails attached to said lift ears. 
   
   
       4 . The apparatus of  claim 3 , wherein said drive motor is attached to the bottom of said main body. 
   
   
       5 . The apparatus of  claim 3 , wherein said drive motor is attached to the top of said main body. 
   
   
       6 . The apparatus of  claim 1 , wherein said drive motor is attached to the top of said main body. 
   
   
       7 . The apparatus of  claim 1 , wherein said drive motor is attached to the top of said main body.