Rotating flow control devices having stabilized bearings

Abstract

Rotating flow control diverters and rotating blow our preventers having stabilized bearings. The bearing elements are stabilized in a neutral operational position using coil springs disposed in passages in a shoulder defined on the outer surface of the rotating tubular shaft of the rotating flow control device.

1 . A rotating flow control device apparatus having stabilized bearing elements, the apparatus comprising;
 (a) a stationary housing having a central bore;   (b) a tubular shaft rotatably mounted in the central bore of the stationary housing, the tubular shaft having an inner surface and an outer surface, the outer surface of the tubular shaft defining a shoulder having an upper face and a lower face, the shoulder defining a plurality of passages extending from the upper face to the lower face;   (c) a coil spring disposed in each passage;   (d) a bearing assembly axially and radially supporting the tubular shaft, the bearing assembly comprising;
 (i) an outer housing releasably mounted to the stationary housing, the outer housing and the outer surface of the tubular shaft defining an annular space between them; 
 (ii) bearing elements disposed in the annular space, the bearing elements being mounted on the outer surface of the tubular shaft in a position adjacent to the upper and the lower faces of the shoulder whereby the coil springs in the passage are compressed by the bearing elements and exert a resistive push force on the bearing elements. 
   
     
     
         2 . The apparatus of  claim 1  wherein the passages and the tubular shaft are aligned longitudinally. 
     
     
         3 . The apparatus of  claim 1  further comprising shims mounted on the outer surface of the tubular shaft adjacent to the bearing elements such that the bearing elements are sandwiched between the shoulder and a shim. 
     
     
         4 . The apparatus of  claim 1  further comprising a top cap that releasably attaches to the outer housing of the bearing assembly, the top cap retaining the bearing elements within the annular space and compressing the bearing elements against the springs. 
     
     
         5 . The apparatus of  claim 1  wherein the rotating flow control device is a rotating flow control diverter. 
     
     
         6 . The apparatus of  claim 1  wherein the rotating flow control device is a rotating blow out preventer. 
     
     
         7 . A rotating flow control device apparatus having a stabilized bearing elements, the apparatus comprising;
 (a) a stationary housing having a central bore;   (b) a tubular shaft rotatably mounted in the central bore of the stationary housing, the tubular shaft having an inner surface and an outer surface, the outer surface of the tubular shaft defining a shoulder having an upper face and a lower face, the shoulder defining a plurality of pockets recessed into the upper face and the lower face;   (c) a coil spring disposed in each pocket;   (d) a bearing assembly axially and radially supporting the tubular shaft, the bearing assembly comprising;
 (i) an outer housing releasably mounted to the stationary housing, the outer housing and the outer surface of the tubular shaft defining an annular space between them; 
 (ii) bearing elements disposed in the annular space, the bearing elements being mounted on the outer surface of the tubular shaft in a position adjacent to the upper and the lower faces of the shoulder whereby the coil springs in the pockets are compressed by the bearing elements and exert a resistive push force on the bearing elements. 
   
     
     
         8 . The apparatus of  claim 7  wherein the pockets and the tubular shaft are aligned longitudinally. 
     
     
         9 . The apparatus of  claim 7  further comprising shims mounted on the outer surface of the tubular shaft adjacent to the bearing elements such that the bearing elements are sandwiched between the shoulder and the shims. 
     
     
         10 . The apparatus of  claim 7  further comprising a top cap that releasably attaches to the outer housing of the bearing assembly, the top cap retaining the bearing elements within the annular space and compressing the bearing elements against the springs. 
     
     
         11 . The apparatus of  claim 7  wherein the rotating flow control device is a rotating flow control diverter. 
     
     
         12 . The apparatus of  claim 7  wherein the rotating flow control device is a rotating blow out preventer. 
     
     
         13 . The apparatus of  claim 7  wherein the pockets are only defined in one of the faces of the shoulder and a single bearing element is mounted on the outer surface of the tubular shaft adjacent to such face. 
     
     
         14 . A method of stabilizing bearing elements in a bearing assembly of a rotating flow control device, the bearing assembly comprising an outer housing, the bearing elements and a rotatable tubular shaft having an outer surface, the tubular shaft being disposed within the outer housing and being supported axially and radially by the bearing elements, the method comprising;
 (a) defining a shoulder having an upper face and a lower face on the outer surface of the tubular shaft;   (b) defining a plurality of passages through the shoulder extending from the upper face to the lower face;   (c) inserting a coil spring into each passage; and   (d) mounting the bearing elements on the outer surface of the tubular shaft in a position adjacent to the upper and lower faces of the shoulder such that the coil springs in the passages are compressed and exert a resistive push force on the bearing elements.   
     
     
         15 . The method of  claim 14  wherein the passages and the tubular shaft are aligned longitudinally. 
     
     
         16 . The method of  claim 14  further comprising the step of securing a top cap to the outer housing to retain the bearing elements and to compress the bearing elements against the coil springs. 
     
     
         17 . The method of  claim 14  wherein the rotating flow control device is a rotating flow control diverter. 
     
     
         18 . The method of  claim 14  wherein the rotating flow control device is a rotating blow out preventer. 
     
     
         19 . The method of  claim 14  wherein instead of defining passages in the shoulder, pockets are defined in the upper face and the lower face of the shoulder and coil springs are inserted into each such pocket. 
     
     
         20 . The method of  claim 19  wherein pockets are only defined in one of the faces of the shoulder.