VIBRATIONLESS LUFFING HYDRAULIC SYSTEM FOR DOOR-BASE CRANE

The utility model is mainly composed of a reversing buffering loop composed of a reversing buffering valve and a slide valve combined hydraulic lock, wherein, the reversing buffering valve controls the time of the reversing course of the slide valve combined hydraulic lock, changes the time of the value increasing course of the flow quantity of a main system, and has obvious damping and buffering effect in the whole course of reversing and amplitude change. The system has the advantages of few hydraulic elements, reasonable structural arrangement, convenient maintenance, low no-load pressure, convenient installation and dismounting of an assembly, etc. The utility model mainly solves the great technological problems of amplitude change and vibration of a portal crane, and is also applied to vibrationless amplitude changing mechanisms of single-stage cylinders of other large-sized hoisting machines and loading and unloading devices.