Downhole motor is a kind of downhole dynamic tool driven by the power of drilling mud. Mud stream from the outlet of a mud pump flows through a by-pass valve into the motor. This stream produces pressure loss at both inet and outlet of the pump, to push the rotor into rotating, and to transmit the torque and speed onto the bit. The downhole motor property mainly depends on its property parameters.

Motor assembly
Downhole motor stator is manufactured from high quality alloy steel, while rotor is made of rubber. High force and tearing strength of the rubber stator allows the tool to run in the high temperatures (about 180℃) and high oil mud condition. All these benefits help to obtain good operation effect.

Cardan shaft assembly
The function of cardan shaft is to convert planetary motion into fixed constant rotation of drive shaft, to transmit torque and speed from motor on the drive shaft, and to the bit.

Drive shaft assembly
The drive shaft assembly converts the eccentric motion of the rotor into concentric rotation for the bearing assembly. It also accommodates any angle set on the adjustable bent housing (or fixed bend housing) and carries the thrust load from the rotor caused by the pressure drop across the power section.

The drive shaft assembly are forged using superior alloy steel, it gives the shaft assembly good strength and toughness and also greatly improve the antifatigue capacity during the rotating movement, thus giving the downhole motor a much longer services life.