A rotary percussive hydraulic drill comprises a body; a shank having female coupling splines and male coupling splines; a striking piston configured to strike the shank; a rotation drive device configured to drive the shank in rotation; a front abutment surface against which the shank is configured to come into abutment. The shank has an annular bearing flange which is provided on an outer surface of the shank and which has an annular bearing surface configured to come into abutment against the front abutment surface. Each of the female and male coupling splines provided on the shank extends from the annular bearing flange in the direction of the striking piston, wherein a connecting surface of each female coupling spline provided on the shank being at least in part formed by a curved concave surface extending substantially in an extension direction of the respective female coupling spline and having a radius of curvature which is less than a radial height of each of the male coupling splines provided on the shank.

In the preferred mode of the present invention, the bottom end of a connector sleeve couples the non-rotating sleeve to the top drive swivel. The top end of the connector sleeve rotatably impinges on a non-rotating member of the top drive directly, the top drive longitudinal carriage, or a combination of the two. Rotation of the top drive out put shaft will transmit a force to the non-rotating sleeve through seal friction until the top end of the connector sleeve contacts a non-rotating body of the top drive's longitudinal carriage or the top drive directly or both. Upon contact, the non-rotating sleeve will resist the torque aided by the connector sleeve and overcome the seal friction transmitted to the non-rotating sleeve. The top drive and connector move axially in tandem and even have some capability of relative axial movement while resisting further relative rotation while facilitating assembly of the components.

A drill steel includes a metal rod with an end to fit within a chuck of a drilling machine, and an integrally formed collar provided along the length of the metal rod. A ferrule is fastened on the metal rod adjacent the integrally formed collar on the side of the end of the metal rod. The ferrule forms a stop that prevents the drill steel from moving too far into the chuck.

A catch assembly is provided for a downhole motor assembly of a drilling system. The catch assembly may include a catch basket that may be coupled to a saver sub. The saver sub may be coupled to a stator tube housing a rotor of a downhole motor. The rotor knob may be coupled to the rotor and include a flange that may be positioned in the catch basket. The flange may be positioned uphole of an internal shoulder of the catch basket. Subsequent to a connection failure in or near the stator tube, the flange may engage the internal shoulder of the catch basket to prevent the rotor from falling downhole.

A catch assembly is provided for a downhole motor assembly of a drilling system. The catch assembly may include a catch basket that may be coupled to a saver sub. The saver sub may be coupled to a stator tube housing a rotor of a downhole motor. The rotor knob may be coupled to the rotor and include a flange that may be positioned in the catch basket. The flange may be positioned uphole of an internal shoulder of the catch basket. Subsequent to a connection failure in or near the stator tube, the flange may engage the internal shoulder of the catch basket to prevent the rotor from falling downhole.

A driveshaft transmission assembly may include a coupling mechanism for coupling a radial bearing assembly to a driveshaft. The coupling mechanism may include a bearing cap for creating an interference fit with a downhole portion of the radial bearing assembly. The coupling mechanism may include locking pins and a retention sleeve to retain the locking pins in grooves of the driveshaft and openings in the radial bearing sleeve. The radial bearing assembly may include a catch mechanism for preventing the loss of certain driveshaft transmission assembly components downhole in the event of a failure of the driveshaft transmission. The coupling mechanism may prevent the loss of the driveshaft downhole subsequent to separation of certain driveshaft transmission assembly components.

A driveshaft transmission assembly may include a coupling mechanism for coupling a radial bearing assembly to a driveshaft. The coupling mechanism may include a bearing cap for creating an interference fit with a downhole portion of the radial bearing assembly. The coupling mechanism may include locking pins and a retention sleeve to retain the locking pins in grooves of the driveshaft and openings in the radial bearing sleeve. The radial bearing assembly may include a catch mechanism for preventing the loss of certain driveshaft transmission assembly components downhole in the event of a failure of the driveshaft transmission. The coupling mechanism may prevent the loss of the driveshaft downhole subsequent to separation of certain driveshaft transmission assembly components.

A progressive cavity device including an articulated coupling for converting the complex motion of a rotor into simple rotation. The coupling may include two shafts coupled to one another by joint assemblies connected to opposite ends of an intermediate shaft. The joint assemblies may include interleaved male and female spline portions and an elastomer filling the spaces between the male and female splines. The elastomer may deflect under load to allow the male and female splines to move relative to each other to allow the assembly to react to shaft misalignments. To limit elastomer bulging from the ends of the joint in response to shaft movement, the bulge area may be capped so that the elastomer cannot bulge outward and become extremely stiff.

A progressive cavity device including an articulated coupling for converting the complex motion of a rotor into simple rotation. The coupling may include two shafts coupled to one another by joint assemblies connected to opposite ends of an intermediate shaft. The joint assemblies may include interleaved male and female spline portions and an elastomer filling the spaces between the male and female splines. The elastomer may deflect under load to allow the male and female splines to move relative to each other to allow the assembly to react to shaft misalignments. To limit elastomer bulging from the ends of the joint in response to shaft movement, the bulge area may be capped so that the elastomer cannot bulge outward and become extremely stiff.

A well tool device may include a first subsection and a second subsection connected to each other. The first subsection comprises a first connector having an outwardly facing first connection interface and the second subsection comprises a second connector having an inwardly facing second connection interface, where the second connector is provided radially outside of the first connector. The first connection interface is facing towards the second connection interface. The first connection interface comprises a first recess provided in the first connector. The second connection interface comprises a second recess provided in the second connector. The first and second recesses together are forming a bolt compartment. The well tool device further comprises a locking bolt provided in the bolt compartment formed by the first and second recesses in order to connect the first and second subsections to each other. The bolt compartment formed by the first and second recesses has an opening in the outer surface of the second connector.