The invention relates to oil production equipment and can be used for actuating submersible downhole plunger pumps in the operation of marginal wells. A drive of a downhole pump comprises a housing, a submersible electric motor with a protector, the drive shaft of which is coupled to the screw of a ball screw actuator that is movably coupled to the housing and is coupled to a rod which is sealed inside the housing. The interior cavities of the housing are filled with oil and are in communication with an annular space of the borehole through an elastic shell. The drive shaft of the electric motor is connected to the ball screw actuator via a reverse reduction gear having a switching mechanism. The reverse reduction gear is switched only when the nut of the ball screw actuator (or of an additional ball screw actuator) arrives at its terminal positions, thus improving the operational reliability of the drive. The electric motor operates in a continuous mode, which increases the reliability and energy efficiency of the drive owing to the absence of repeated starting and stopping of the electric motor; consequently, a spike in current intensity upon start-up is avoided. Therefore, the solutions used in the invention make it possible to improve the reliability and energy efficiency of the drive of a downhole pump.

A system includes a rotating drive and a linear drive. An input driven gear may be coupled to the rotating drive while a sun gear is coupled to the shaft of the input driven gear. A first counterweight may support an idler gear and an output gear. The first counterweight is coupled to the driven gear and which rotates with the driven gear. The idler gear is coupled to the sun gear and an output gear. The idler gear may rotate the output gear when the idler gear is translated around the sun gear. A second counterweight is coupled to the output gear and which rotates with the output gear when the output gear is rotated by the idler gear. An end portion of the second counterweight coupled to the linear drive moves in substantially straight line as the second counterweight rotates while also being translated around the sun gear.

A fluid-powered linear motor with rotary pistons is disclosed. An application is for a downhole motor but it could be used in other applications. Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long (generally up to a maximum length of 30 ft.), a high-torque motor can be produced using this method. A pressurized fluid is used to drive the piston assemblies to produce bit shaft power. This concept employs rotary pistons and a mechanical rectifier to convert the rotational reciprocation produced by a reciprocating rotational piston into continuous rotary motion.

A harmonic drive assembly and fluid-powered linear motors with both axial pistons are rotary piston arrangements incorporating the harmonic drive assembly are disclosed. The motors may be used in downhole drilling applications, but the drive assembly and/or motors may be used in other applications. The assembly, motors and methods use advanced harmonic drives, advanced helical drives, and combinations thereof with 1) motors with axial pistons and reciprocating linear rings to convert reciprocative axial motion to continuous rotary motion, and 2) motors with rotary pistons and reciprocating linear rings to rectify reciprocative rotary motion to continual rotary motion to improve performance over prior configurations. Axial pistons provide a robust simple solution for generating rotation; Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long, a high-torque motor can be produced using this method.

A telescopic structure is provided in the disclosure, which comprises: a lower cover, an upper cover, a linkage shaft, a ring provided to an outer side of the lower cover, a motor provided to an inner side of the lower cover. The linkage shaft is provided to an end of the motor, a telescopic ring is provided to an end of the linkage shaft, a guiding post is provided above the telescopic ring, a fixing block is provided above the guiding post, the upper cover is provided above the fixing block, and the ring is further provided to an outer side of the upper cover. The telescopic structure has the beneficial effects that it is telescopic, simple in structure, o convenient to operate and efficient in use.

A harmonic drive assembly and fluid-powered linear motors with both axial pistons are rotary piston arrangements incorporating the harmonic drive assembly are disclosed. The motors may be used in downhole drilling applications, but the drive assembly and/or motors may be used in other applications. The assembly, motors and methods use advanced harmonic drives, advanced helical drives, and combinations thereof with 1) motors with axial pistons and reciprocating linear rings to convert reciprocative axial motion to continuous rotary motion, and 2) motors with rotary pistons and reciprocating linear rings to rectify reciprocative rotary motion to continual rotary motion to improve performance over prior configurations. Axial pistons provide a robust simple solution for generating rotation; Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long, a high-torque motor can be produced using this method.

A harmonic drive assembly and fluid-powered linear motors with both axial pistons are rotary piston arrangements incorporating the harmonic drive assembly are disclosed. The motors may be used in downhole drilling applications, but the drive assembly and/or motors may be used in other applications. The assembly, motors and methods use advanced harmonic drives, advanced helical drives, and combinations thereof with 1) motors with axial pistons and reciprocating linear rings to convert reciprocative axial motion to continuous rotary motion, and 2) motors with rotary pistons and reciprocating linear rings to rectify reciprocative rotary motion to continual rotary motion to improve performance over prior configurations. Axial pistons provide a robust simple solution for generating rotation; Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long (generally up to a maximum length of 30 ft.), a high-torque motor can be produced using this method. A pressurized fluid is used to drive the piston assemblies to produce bit shaft power. The axial piston motor converts the axial reciprocation produced by reciprocating pistons into continuous rotary motion. The rotary piston motor uses a mechanical rectifier to convert the rotational reciprocation produced by a reciprocating rotational piston into continuous rotary motion.

A fluid-powered linear motor with rotary pistons is disclosed. An application is for a downhole motor but it could be used in other applications. Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long (generally up to a maximum length of 30 ft.), a high-torque motor can be produced using this method. A pressurized fluid is used to drive the piston assemblies to produce bit shaft power. This concept employs rotary pistons and a mechanical rectifier to convert the rotational reciprocation produced by a reciprocating rotational piston into continuous rotary motion.

A system includes a rotating drive and a linear drive. An input driven gear may be coupled to the rotating drive while a sun gear is coupled to the shaft of the input driven gear. A first counterweight may support an idler gear and an output gear. The first counterweight is coupled to the driven gear and which rotates with the driven gear. The idler gear is coupled to the sun gear and an output gear. The idler gear may rotate the output gear when the idler gear is translated around the sun gear. A second counterweight is coupled to the output gear and which rotates with the output gear when the output gear is rotated by the idler gear. An end portion of the second counterweight coupled to the linear drive moves in substantially straight line as the second counterweight rotates while also being translated around the sun gear.

A linear actuator member applies a vertical force to a vessel or to a holding apparatus in which a vessel is contained. A linear to angular motion constraining member such as a cage structure having a helical track translates linearly directed force and motion applied by the linear actuator member into a combined linear and rotational motion of the vessel. The combined vertical and rotational motion of the vessel in response to the vertical force is repeatable according to a predefined agitation pattern for mixing components in the vessel.