The pumping unit is the main ground equipment in the pumping unit deep well pumping system. The beam pumping unit mainly consists of four parts: beam connecting rod crank mechanism, gearbox, power equipment, and auxiliary equipment. During operation, the power machine transmits high-speed rotation to the crank shaft through a belt and a gearbox, driving the crank shaft to perform low-speed rotation motion. The crank drives the beam to swing up and down through a connecting rod and a crossbeam. The suspension device hanging on the donkey head then drives the pumping rod to reciprocating up and down.

Beam pumping units are mainly divided into two categories according to their structure: ordinary beam pumping units and front mounted beam pumping units.

With the continuous development and progress of pumping unit manufacturing technology, different forms of energy-saving pumping units have been developed since the 1990s, and energy-saving pumping units still belong to the ordinary beam pumping unit structure.

The main components of the ordinary beam pumping unit and the front mounted beam pumping unit are the same, except for the different connection positions between the beam and the connecting rod. Ordinary pumping units generally use mechanical balance, while front-end pumping units initially used pneumatic balance. However, due to technical imperfections, mechanical balance was later used. Currently, the front-end pumping units used in our factory are all mechanically balanced. The upper stroke crank angle of the front mounted pumping unit is 195 °, and the lower stroke crank angle is 165 °, making the upper stroke slower than the lower stroke.