A drive unit of a top drive system includes a drive stem having a plurality of ports from an exterior thereof to an interior thereof. A plurality of sliding coupling members is disposed in the ports. A coupling collar encircles the drive stem and has actuation surfaces and recessed surfaces on an interior thereof, wherein the recessed surfaces align with the ports when the coupling collar is in a first position, and the actuation surfaces align with the ports when the coupling collar is in a second position.

A drilling motor assembly can include a housing, a shaft, and a pawl which selectively engages a recess, the pawl having an axis of rotation and a generally planar engagement face which engages a generally planar engagement face of the recess when relative rotation between the housing and the shaft is prevented. The engaged engagement faces can be oblique relative to a radius extending from the axis of rotation to the engaged engagement faces. A method of drilling a wellbore can include flowing a fluid through a drilling motor assembly, thereby rotating a shaft relative to a housing, and rotating the housing, thereby engaging a pawl with a recess and preventing relative rotation between the housing and the shaft, the pawl and recess each having a generally planar engagement face, whereby the engaged engagement faces prevent relative rotation between the shaft and the housing.

A drill string section includes at least one plug-and-rotate seat (bayonet seat) for interacting with a (bayonet) catch, wherein the seat allows an additional plug-in step for fixing the catch in a connection secure against rotation in both directions of rotation about the longitudinal axis of the drill string section.

A drill string section includes at least one plug-and-rotate seat (bayonet seat) for interacting with a (bayonet) catch, wherein the seat allows an additional plug-in step for fixing the catch in a connection secure against rotation in both directions of rotation about the longitudinal axis of the drill string section.

A universal joint (U-joint) assembly transmits torque from a drive component to a driven component across an articulating joint. The U-joint assembly includes male and female U-joint members, a central ball joint, and a retaining device configured to secure the assembly in an assembled configuration. The female U-joint member includes a cavity extending into a receptacle end thereof. The cavity terminates in a circular receptacle and includes a plurality of rectangular channels extending radially outward from the cavity at equal intervals, each channel defined by three planar drive surfaces. The male U-joint member has a drive end with a plurality of corresponding rectangular extensions protruding from an outer periphery of the drive end, each extension including a plurality of axial angular surfaces. When assembled, each of the angular surfaces of the drive end opposes a corresponding one of the drive surfaces of the cavity. Other embodiments are also disclosed.

A universal joint (U-joint) assembly transmits torque from a drive component to a driven component across an articulating joint. The U-joint assembly includes male and female U-joint members, a central ball joint, and a retaining device configured to secure the assembly in an assembled configuration. The female U-joint member includes a cavity extending into a receptacle end thereof. The cavity terminates in a circular receptacle and includes a plurality of rectangular channels extending radially outward from the cavity at equal intervals, each channel defined by three planar drive surfaces. The male U-joint member has a drive end with a plurality of corresponding rectangular extensions protruding from an outer periphery of the drive end, each extension including a plurality of axial angular surfaces. When assembled, each of the angular surfaces of the drive end opposes a corresponding one of the drive surfaces of the cavity. Other embodiments are also disclosed.

A drive shaft assembly for use with downhole mud motors is capable of handling greater torque and thrust forces. The drive shaft assembly has an elongated central drive shaft, and at least one end housing optionally disposed at one or both ends of the central drive shaft. At least one end of the central drive shaft defines a rounded or partially-spherical outer end surface and a plurality of elongate protrusions or “keys” that extend radially outward from the exterior surface of the shaft. Each end housing has a concave interior surface defining a seat for receiving a rounded end surface of the central drive shaft, as well as a plurality of circumferentially spaced axial keyways adapted to receive and engage with the keys in mating relationship. The shaft and end assemblies cooperate to facilitate omnidirectional pivotal movement and the transfer of torque forces between the shaft and each of said end housings.

A ground drilling device for cable-guided drilling comprising a drive for connecting and/or moving rod sections of a drill string along a drill string axis, wherein a cable reserve for receiving a cable with a length of at least two rod sections is provided and a contact device for electrical contacting of one end of the cable of the cable reserve is provided.

A method of joining a steel first member to a stainless steel second member includes buttering a first joint surface on the first member, the buttering including: preheating the first joint surface; welding a border layer of weld material to the first joint surface; and heat treating the border layer and the first joint surface after welding the border layer. A weld is formed between the first and second members after heat treating the border layer and the first joint surface. The border layer and a second joint surface on the second member are preheated; and a body of weld material is added between the border layer and the second joint surface.

An apparatus in the form of an adapter for forming a connection comprising a first part adapted for coupling with a second part by a quick-release coupling formed by a first projection of the first part having an at least partial dovetail shape and a recess of the second part having an at least partial dovetail shape. An opening in the recess is adapted for receiving the projection in an axial direction. In other embodiments, the adapter is: (1) frictionally enhanced for engaging an internal portion of the drilling element; (2) includes a radial projection elongated in an axial direction for engaging the internal portion of the one drilling element; and/or (3) has a cutter for scoring an internal portion of the one drilling element upon being inserted therein and rotated. An adapter is also disclosed for use with a drill check, including for creating a “twist lock” connection.