Apparatus and methods are for coupling a drive unit to a tool adapter. A drive unit includes a drive stem; a plurality of sliding coupling members; a retainer; a torque profile; a plurality of drive stem ports; a coupling collar; coupling recesses; a plurality of transmission units; and/or first portions of a hydraulic coupling unit. A tool adapter includes a tool stem; a tool stem sleeve; coupling recesses; a torque profile; a plurality of sliding coupling members; and/or second portions of the hydraulic coupling unit. A method of coupling a drive unit to a tool adapter includes positioning the tool adapter below the drive unit; stabbing a drive stem into an interior of a tool stem sleeve; coupling torque between the drive unit and the tool adapter; and coupling load between the drive unit and the tool adapter by engaging a plurality of sliding coupling members.

A rotation brake for stopping rotation of a spindle assembly on a horizontal directional drill. The rotation brake comprises a brake lock that is actuated by a cylinder and spring to interact with a non-rotating brake cap and a rotating pinion, thereby stopping rotation of the pinion. The brake lock is removed from the pinion by applying pressurized fluid to a cylinder such that a cylinder rod moves the brake lock out of a cavity between the brake cap and the pinion. Upon removing fluid pressure from the cylinder, a compressed spring moves the brake lock back to into the cavity, preventing rotation.

A rotation brake for stopping rotation of a spindle assembly on a horizontal directional drill. The rotation brake comprises a brake lock that is actuated by a cylinder and spring to interact with a non-rotating brake cap and a rotating pinion, thereby stopping rotation of the pinion. The brake lock is removed from the pinion by applying pressurized fluid to a cylinder such that a cylinder rod moves the brake lock out of a cavity between the brake cap and the pinion. Upon removing fluid pressure from the cylinder, a compressed spring moves the brake lock back to into the cavity, preventing rotation.

A tool coupler includes a first component having a tubular body and a locking member and a second component. The second component includes a housing having an opening for receiving the tubular body; a locking ring having a latch; and an axial channel; a recess for receiving the locking member, wherein the latch is positioned in the channel to retain the locking member in the recess.

A tool coupler includes a first component having a tubular body and a locking member and a second component. The second component includes a housing having an opening for receiving the tubular body; a locking ring having a latch; and an axial channel; a recess for receiving the locking member, wherein the latch is positioned in the channel to retain the locking member in the recess.

A downhole motor having an improved thread fastening structure is proposed. In the downhole motor, a thread structure disposed therein and having ridges formed at both end portions at a predetermined distance from ends is improved and the internal structures of a first coupler and a second coupler in which the end portions of the thread are respectively inserted and fastened are improved to correspond to the end portions of the thread, thereby being able to improve sealing ability.

A downhole motor having an improved thread fastening structure is proposed. In the downhole motor, a thread structure disposed therein and having ridges formed at both end portions at a predetermined distance from ends is improved and the internal structures of a first coupler and a second coupler in which the end portions of the thread are respectively inserted and fastened are improved to correspond to the end portions of the thread, thereby being able to improve sealing ability.

Couplers for connecting a power source to a drilling string are disclosed. The coupler may include an elongate assembly including a first portion and a second portion. The first portion and the second portion are configured to move relative to each other such that the coupler may be arranged in a retracted position, an extended position, and one or more intermediate positions. In the retracted position, the coupler may transmit a compressive force and/or a torque to the drilling string. In the extended position, the coupler may transmit a tensile force and/or a torque to the drilling string. In the intermediate positions, the first portion and the second portion are able to translate and rotate independently relative to each other.

Couplers for connecting a power source to a drilling string are disclosed. The coupler may include an elongate assembly including a first portion and a second portion. The first portion and the second portion are configured to move relative to each other such that the coupler may be arranged in a retracted position, an extended position, and one or more intermediate positions. In the retracted position, the coupler may transmit a compressive force and/or a torque to the drilling string. In the extended position, the coupler may transmit a tensile force and/or a torque to the drilling string. In the intermediate positions, the first portion and the second portion are able to translate and rotate independently relative to each other.

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.