What is the usage of sucker rod?

The sucker rod is an important part of the rod oil pumping equipment. The sucker rod is connected to a sucker rod string by the coupling, the upper part is connected to the pumping unit or PCP motor through a polished rod, and the lower part is connected to the plunger of the sucker pump or PCP. Its function is transmitting the reciprocating motion of the horse head suspension point of the ground pumping unit to the down hole pump or transmitting the rotating torque of the PCP motor to the down hole PCP.