External rotor electric pumping unit is a new type of mechatronics tower pumping unit developed by Sanjack Petro. The whole system is mainly composed of eight parts, namely, external rotor motor, frequency conversion control panel, unit frame, moving pulley group, counterweight, brake and loss of load protection device, wire rope, base and so on. Compared with the traditional beam pumping unit, the gear reducer, crank and pitman mechanism are omitted so that transmission efficiency is improved.

The unit frame works as the carrier of all the structure, the AC external rotor permanent magnet synchronous motor is the power source of the pumping unit. The product uses frequency conversion control technology to control the forward and backward rotation and speed of the motor.

rare-earth permanent magnet motor

1) .Constant torque
2).Torque value up to 4500Nm
3).Can realize “ABS” positive and negative conversion
4). Intelligent temperature control switch
The traction system consists of external rotor, movable pulley, wire rope and counterweight. The sucker rod is moved up and down by a flexible wire rope. The brake device installed outside the outer rotor can brake the unit in time when the motor stops to ensure safety. Because of saving gear reducer, there is no high-speed rotating parts in the unit, the overall design is more reasonable.

To decrease the load of the power source and increase the driving force, the sucker rod end and the counterweight end of the product are equipped with movable pulleys respectively, so that the equipment is more energy efficient. The whole unit has the advantages of simple structure, small volume, long stroke, low frequency and convenient maintenance.

The inverter control program and the auxiliary stroke switching device effectively control the reverse motion of the motor, and the stepless speed regulation of the motor is also realized. It owns the advantage of convenient parameter adjustment, compared with the traditional beam pumping unit.
The electrical control program has the following functions: overload protection, phase loss protection, motor overheating protection, etc. Short circuit power protection makes sure equipment more intelligent and safer. When a load loss occurs, braking and load loss protection devices will maximize their effectiveness in protecting personnel and equipment safety.
In short, external rotor motor pumping unit is a new type of mechatronics pumping unit, with the advantages of energy saving, emission reduction, safety and intelligence.

It makes a good sale in ShengLi oilfield, ZhongYuan oilfield, LiaoHe oilfield, DaGang oilfield and Huabei oilfield, etc.
Working Principle
During the sucker rod rising, the counterweight is less than the sucker rod load, and the motor rotates counterclockwise to output torque to help the counterweight lift the sucker rod. When the rod is lowered and the rod load is less than the counterweight, the motor rotates clockwise to output torque to help the rod lift the counterweight. The periodic advance and retreat of the motor realize the reciprocating movement of the sucker rod.
Due to that the counterweight is the average of the maximum and minimum load, the positive and negative work of the motor are basically equal.

Applications
⦁ Conventional oil
⦁ Deep wells
⦁ Thermal wells
⦁ Light, medium, and some of heave crude
⦁ Vertical, slant, deviated, and some of horizontal well application
⦁ Dewatering natural gas and coalbed methane
⦁ Operations requiring energy savings
⦁ Operations requiring lower noise (only 48 decibels,
ultra low-noise design is suitable for quiet environment.)
⦁ Wells that experience frequent downhole equipment failures because of friction.
Product advantage
1. Energy saving: Average energy saving rate can reach 30%, compared with the conventional beam pumping unit.
2. Improved efficiency: Compared with the traditional beam pumping unit, the production efficiency is increased by 30% on average.
3. Noise reduction: No intermediate deceleration mechanism, low noise, so the measured noise is less than 40dB.
4. Deep well production: Especially suitable for long stroke, low stroke and small pump deep pumping environment.
5. Save space:Especially suitable for high-density small space.
6. Easy to operate: stroke adjustment can achieve 0-3 stepless adjustment, 0-12 meters can be customized according to user requirements.
7. Convenient maintenance: conventional beam pumping unit fault points is up to 35 meanwhile the equipment has only 6 maintenance points