Articulable joints having diamond bearing surfaces engaged with metal bearing surfaces are provided herein. The articulable joints provide multiple degrees of freedom to components, such as drivelines, and bear loads in multiple directions. The articulable joints include diamond bearing surfaces slidingly engaged with opposing metal bearing surfaces that include more than trace amounts of diamond solvent-catalyst.

Motor shaft adapters include a cylindrical shaft sleeve with a tubular body defined between inner and outer cylindrical surfaces, and frame adapters that include a section of structural tubing and flanges having sides aligned to the sides of the structural tubing section and fixed at respective ends of the section of structural tubing into assembly between a motor and gearhead. Key slot apertures are defined by opposing body end-walls of the tubular body and through the inner and outer cylindrical surfaces of the sleeve. A shaft key has outer sidewalls that include opposing outer sleeve aperture sidewall portions that enable the shaft key sidewall portions to fit within and to thereby engage the sleeve via the key slot aperture. The key sidewalls further include a base pair of opposing key seat engagement portions that fit within and engage opposing sidewalls of a key seat aperture defined within a workpiece shaft.

A drive shaft assembly for a downhole drilling motor includes a drive shaft having a first end portion engaging a first housing and a second end portion engaging a second housing. The first end portion and the first housing form the first constant velocity joint and the second end portion and the second housing form the second constant velocity joint of the drive shaft assembly. Each end portion including a base surface having a pair of prongs extending away from the base surface and a cylindrical side wall having a plurality of ball bearings held in a plurality of circumferentially spaced pockets. Each housing includes a cavity to retain respective end portions of the drive shaft. An inner side wall of each housing includes a plurality of cylindrical grooves to receive the plurality of ball bearings to transfer torque. An internal wall of the housing includes a first chamber and a second chamber to receive and retain the first prong and the second prong to transfer torque and thrust loads between the shaft and the housings.

A drive shaft assembly for a downhole drilling motor includes a drive shaft having a first end portion engaging a first housing and a second end portion engaging a second housing. The first end portion and the first housing form the first constant velocity joint and the second end portion and the second housing form the second constant velocity joint of the drive shaft assembly. Each end portion including a base surface having a pair of prongs extending away from the base surface and a cylindrical side wall having a plurality of ball bearings held in a plurality of circumferentially spaced pockets. Each housing includes a cavity to retain respective end portions of the drive shaft. An inner side wall of each housing includes a plurality of cylindrical grooves to receive the plurality of ball bearings to transfer torque. An internal wall of the housing includes a first chamber and a second chamber to receive and retain the first prong and the second prong to transfer torque and thrust loads between the shaft and the housings.

A ball-CV style transmission suitable for use in a Positive Displacement Motor (PDM). A shaft provides shaft wings received into housing receptacles on a housing. A ball and a Torque Transfer Element (TTE) is interposed between each shaft wing and housing within each housing receptacle, with the ball received into opposing recesses preferably on the shaft wing and the TTE. The TTEs float within their corresponding housing receptacles so as to maintain torque transfer contact between all thrust surfaces during articulated rotation of the shaft with respect to the housing. The TTEs preferably float generally radially towards the shaft centerline as angular deflection increases during articulated rotation.

A drive includes at least one motor with a drive shaft and at least one output shaft which is in particular mechanically connected to a gear. The drive shaft and the output shaft are aligned substantially axially. The drive shaft and the output shaft each have a coupling portion through which a torque can be transmitted from the drive shaft to the output shaft by mechanical coupling. Each coupling portion is connected to the shaft thereof for rotation therewith and the coupling portions can be mechanically coupled by being axially plugged together.

A drive shaft assembly for a down hole drilling motor is provided. The drive shaft assembly includes a drive shaft having a first end portion engaging a first housing and a second end portion, engaging a second housing. The first end portion and the first housing form the first constant velocity joint and the second end portion and the second housing form the second constant velocity joint of the drive shaft assembly. Each end portion including a base surface having a pair of prongs extending away from the base surface and a cylindrical side wall having a plurality of ball bearings held in a plurality of circumferentially spaced pockets. Each housing includes a cavity to retain respective end portions of the drive shaft. An inner side wall of each housing includes a plurality of cylindrical grooves to receive the plurality of ball bearings to transfer torque. An internal wall of the housing includes a first chamber and a second chamber to receive and retain the first prong and the second prong to transfer torque and thrust loads between the shaft and the housings.

A drive shaft assembly for a down hole drilling motor is provided. The drive shaft assembly includes a drive shaft having a first end portion engaging a first housing and a second end portion, engaging a second housing. The first end portion and the first housing form the first constant velocity joint and the second end portion and the second housing form the second constant velocity joint of the drive shaft assembly. Each end portion including a base surface having a pair of prongs extending away from the base surface and a cylindrical side wall having a plurality of ball bearings held in a plurality of circumferentially spaced pockets. Each housing includes a cavity to retain respective end portions of the drive shaft. An inner side wall of each housing includes a plurality of cylindrical grooves to receive the plurality of ball bearings to transfer torque. An internal wall of the housing includes a first chamber and a second chamber to receive and retain the first prong and the second prong to transfer torque and thrust loads between the shaft and the housings.

A universal joint assembled in a drill string transfers torque between two shafts where the shafts are not completely aligned. The universal joint includes a cable that passes through joint components. The cable limits separation or deflection of the joint components.

A universal joint assembled in a drill string transfers torque between two shafts where the shafts are not completely aligned. The universal joint includes a cable that passes through joint components. The cable limits separation or deflection of the joint components.