YJ21 motor is squirrel cage variable frequency speed regulating saynchronous motor developed for AC-DC-AC electric drive oil drilling machine. The motor takes international advanced insulation processes and special measures protecting bars from breaking. Its centerline height and installation dimension are the same as that of imported DC oil drilling machine. The motor's main features are: large torque, wide range constant power speed regulating, free maintenance, high universality, efficiency and reliability. YJ21 motor can be used as slurry pump motor, rotary table motor or winch motor of AC drive drilling machine.

The oil drilling motors Yonge manufactured can meet various installing requirements on oil

drilling rig. The motors can be divided into two series. One is the YZ DC motor with separate

excitation and series excitation, the other is the YJ asynchronous motor with frequency control

of motor speed. Its rated power can be from 200kw to 1600kw (different grades of rated power

can be supplied according to the needs of users). At present, these motors are installed on the

drilling rigs with drilling depth from 1000m to 7000m.