In recent years, the widespread adoption of the multi speed hoisting mechanism of planetary gear transmission, the control of multi pump combined hydraulic motor and series parallel or the use of variable hydraulic motor speed to achieve a variety of hoisting mechanism, so as to realize the high speed light load and heavy load speed, improve work efficiency, to meet the various requirements.

Hydraulic lifting mechanism can be divided into the following forms:

Due to the different forms of the hydraulic motor, the hydraulic lifting mechanism can be divided into two types: high speed hydraulic motor drive and low speed high torque motor drive.

High speed hydraulic motor drive needs to drive the drum through the reducer. Reducer can be used in the production of the standard reducer, usually cylindrical gear, worm gear and planetary gear reducer. This kind of transmission is characterized by its light weight, small volume, high volumetric efficiency and low production cost. But the whole hydraulic lifting mechanism is heavy and large in volume.

Low speed high torque motor drive can be driven directly or through a first open cylindrical gear driven drum. Although the low speed motor itself is larger in volume and weight, it does not need to reduce the speed, so that the weight of the hydraulic lifting mechanism is reduced and the volume is reduced. The utility model has the advantages of simple transmission, few parts, good starting performance and good braking performance, and is less sensitive to hydraulic oil pollution. Incurvature line radial plunger type rotary casing of low speed and high torque motor, can be installed in the drum, a motor driven rotating drum shell, simple and compact structure, convenient arrangement.