The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 16, 1986
Filed:
Jun. 10, 1985
Volker Kruger, Celle, DE;
Heinrich Daenicke, Wienhausen, DE;
Norton Christensen, Inc., Salt Lake City, UT (US);
Abstract
A drive device for driving a drill bit for drilling bore holes in underground formations comprises a tubular housing for attachment to a drill string with a rotary drive means in the housing arranged to be driven by fluid forced through the housing. The rotary drive means drives an output shaft for connecting to a drill bit, the output shaft being supported by at least one axial bearing which comprises a continuous bearing ring and a retaining ring carrying a plurality of bearing segments which are swivellingly mounted to provide for a spacing of reducing cross-section between the bearing surfaces so that relative rotation of the bearing ring and bearing segments causes fluid to flow into the space and build up a hydrodynamic lubricating film.