Patent ID: 6569020
Filing Date: 2003-05-27
Classification: E21B,F16D

Abstract:
A drilling motor flexible coupling apparatus for connecting internal parts of a down hole drilling motor, the apparatus comprising:a) an assembly of two opposed half-couplers, each half-coupler having a rotational axis, the two resulting axes of rotation crossing at a center of development of spherical surfaces, said surfaces, one concave and one convex, situated one surface on each half, and engaging the other in rubbing contact, each half-coupler with jaws extending toward the other for an interdigitating relationship to rotationally couple the two half-couplers; b) a cylindrical sleeve sealingly and rigidly attached to one said half-coupler and extending to place a seal containing a peripheral groove opening radially inward to place the contained seal in rubbing contact with a surface on the other half-coupling, the seal positioned generally in a transverse plane that contains the center of development of the spherical surfaces; c) axial constraining means, to prevent separation of the two half couplings, comprising an inwardly extending flange on the sleeve and an outwardly extending flange on the half-coupling in said rubbing contact with the seal, the outwardly extending flange being of larger diameter than the inner diameter of said inwardly extending flange; d) said seal extending peripherally around the inwardly opening groove in the sleeve; and e) a lubricant reservoir in fluid communication with the surfaces defining the jaws and the inner surface of the sleeve, the reservoir being a variable volume enclosure arranged to function as a hydrostatic compensator having a fluid separator with a mud side and a lubricant side, the mud side arranged with channel means to fluidly communicate with the ambient region outside the sleeve.