US 7,320,374 B2
Wellbore top drive systems
Robert Alden Folk, Calgary (Canada); and Steven Lorne Folk, Sherwood Park (Canada)
Assigned to Varco I/P, Inc., Houston, Tex. (US)
Filed on May 28, 2005, as Appl. No. 11/140,462.
Application 10/872337 is a division of application No. 10/862787, filed on Jun. 07, 2004, granted, now 7,188,686.
Application 11/140462 is a continuation in part of application No. 10/870700, filed on Jun. 16, 2004, granted, now 7,222,683.
Application 10/870700 is a continuation in part of application No. 10/877949, filed on Jun. 24, 2004, granted, now 7,231,969.
Application 10/877949 is a continuation in part of application No. 10/872337, filed on Jun. 18, 2004, granted, now 7,228,913.
Prior Publication US 2005/0274508 A1, Dec. 15, 2005
Int. Cl. E21B 15/00 (2006.01); E21B 3/02 (2006.01); E21B 19/08 (2006.01)
U.S. Cl. 175—220  [175/162; 175/113; 173/213; 166/77.51; 277/377] 14 Claims
OG exemplary drawing
 
1. A seal system for a top drive system, the top drive system having a top drive motor and a gear system with a sun gear, the gear system located beneath the top drive motor, the seal system comprising
seal apparatus for selectively engaging the sun gear to seal off a pathway from the gear system to the top drive motor,
the seal apparatus including a seal, a body, a seal support supporting the seal and movably disposed within the body and movable so that the seal engages the sun gear to seal off the pathway, the seal support movable by fluid under pressure applied to the seal support during operation of the top drive motor, and
spring apparatus urging the seal support so that the seal contacts the sun gear to seal off the pathway when insufficient or no fluid under pressure is applied to the seal support.