Down-Hole Drilling Motors

Product :Lisen Down-Hole Tools
Working Span:Motors Guarantee 300 Hours,Machinery Parts Guarantee 150 Hours.
Advantages:Uniform Thickness,Resistance High-temperature And Oil Based Mud,Corrosion-resistance,Air drilling

Down-hole motor is a kind of down-hole dynamic drilling tool upon the power of drilling mud.It is composed of five assemblies of by-pass valve, motor, cardan shaft, anti-drop and drive shaft.Mud stream from the outlet of mud pump flows through a by-pass valve into the motor. This stream produces pressure loss at both inlet and outlet of the pump, to push the rotor into rotating, and to transmit the torque and speed onto the bit. The down-hole motor property mainly depends upon power section assembly.

1.By-pass valve assembly mainly made up of body, spool and sleeve, spring, plate, seal the hole with a ring. It has two positions of by-pass and close .It is in by-pass position during trip operation, circulates mud fluid in the drill string into the annular space by-passing the idle motor, so that no mud may spray out onto the platform during the trip operation.When mud flow rate and pressure reach the setting value, the valve stem moves down and closes the valve. Meanwhile, mud stream flows through the motor, and converts the pressure energy into mechanical energy.As mud flow rate is too low, or mud pump stops, and as the created pressure is not enough to overcome spring force and static friction force, the spring presses the stem upward ,and by-pass is in open position


2. Composition of Anti-Drop including Assembly Anti-drop Connector Anti-drop Locknut  Anti-drop connecting rod.It acts as when the shell breaking or thread off caused by abnormal reason, prevent the entire assembly form dropping in the well bore , at the meanwhile, it makes pump pressure be increased, then let ground staff found the problem in time  to avoid any accidents.


3.Motors Assembly:

It consists of stator and rotor. Stator is made by squeezing rubber sleeve on the wall of steel tube. There forms spiral structure with a certain geometric parameter. Rotor is a crome-plated screw rod.


Motors Assembly working Principle:Stator and rotor matches with each other, to form spiral line and seal cavity through their guide rail difference. With rotor running in the stator, the seal cavity is moving along its axial direction, continuously forms and disappears to complete its energy conversion. This is the basic principle of down-hole motor.

 Spiral seal line on rotor is divided into single end and multi-end ( stator with one more end than rotor). The less ends the motor has, the higher speed and the lower torque is. The more ends it has, the lower speed and the higher torque is. According to the customer requirement, we can manufacture stator lobes to rotor lobes ratio are 1:2. 3:4, 5:6, 7:8, 9:10.  The below diagram shows the sectional profile of several typical motors.


4.Universal 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. Cardan shaft mostly use flat shaft ,but some are flexible shafts.

Lisen flat type shaft used on our down-hole motor is made by linear cutting technology. So the cut has high parallelism, roughness can reach 6.3. And it doesn’t damage metal chemical composition. Thus, it has longer running life and less mechanical loss

Ball drive universal shaft uses ball, rod, twisting connection way to transmit torque, and adopts high temperature grease to lubricate friction, rubber sleeve seal the movement part of steel ball, segregate drilling fluid with grinding, ball drive universal shaft working surface is specially treated, then make the surface hardness, high temperature resistance be relatively increasing, Therefore the abrasion resistance and stability get further improved and the running life extened.


(1)The composition of cardan shaft ball composed by Large steel ball Small steel,ball joint  rubber sleeves,Pressure ring,Live twist,connecting rod

(2)djustable Bend Shell composed by Upper Housing(offset housing),Positive Sleeve

(Adjusting ring),O-rings Bend Sub(bend sub)

(3)Adjustable bend housing:Our company is producing adjustable bend housing allows for angle adjustment from  0°-2°、0°-3° 、0°-4°.


5.Drive Shaft Assembly:Drive shaft is to transmit motor rotary dynamic force onto the bit ,meanwhile to withstand axial and radial load from drilling weight,We have two types of drive shafts. In order to meet the needs of drilling well, shaft housing assembly with different types of stabilizer are fixed and interchangeable sets of type, stabilizer righting of a variety of shapes, the customers can choose to use the drilling process needs . (See below):


(1)The motor can be classified according to temperature and medium

According to the underground actual recycling temperature:

The conventional stator, with 95℃ of rated temperature and 120℃ maximum temperature.

The hi-temperature stator, with 135℃ of rated temperature and 150℃ maximum temperature.

Super-temperature stator, with 150℃ of rated temperature and 180℃ maximum temperature.


(2)Different medium use different motors, it can make full play of down-hole motors' whole performance.

Oil based mud system: oil based mud motor

Salt water mud system: salt water mud motor

Air or foam under-balanced system: Air drilling down-hole motor


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