In the hydraulic transmission, hydraulic cylinder is one of the most simple and relatively complete hydraulic transmission system, analysis of its working process, you can clearly understand the basic principles of hydraulic transmission. Hydraulic system mainly consists of: power components (oil pump), the implementation of components (cylinder or hydraulic motor), control components (valves), auxiliary components and working medium five parts. 1, the advantages of hydraulic transmission (1) small size, light weight, so less inertia, when a sudden overload or parking, will not have a big impact; (2) in a given range of smooth automatic adjustment of traction speed , And can realize stepless speed regulation; (3) commutation is easy, without changing the direction of rotation of the motor, you can more easily achieve the rotation of the working mechanism and the linear reciprocating motion; (4) between the hydraulic pump and the hydraulic motor (5) Due to the use of oil as the working medium, the relative movement between the components can be self-lubricating, wear small, long service life; (6) the manipulation of control is simple, the degree of automation High; (7) easy to achieve overload protection. 2, the shortcomings of hydraulic transmission (1) the use of hydraulic transmission on the maintenance of high demand, the working oil should always be clean; (2) the hydraulic components of high precision, complex technology, high cost; (3) Complex and require a higher level of technology; (4) oil as a working medium, there is a fire hazard in the face; (5) transmission efficiency is low.