ZYJ series hydraulic automatic take-up device possess the following feathers:  (1) According to different working conditions, the tension can be set to ensure the optimum of equipment;  (2)The device can keep the system in a state of constant tension after the tension force is set;  (3)The device is of quick response and good dynamic, which can make up for plastic deformation of belts or steel wires;  (4) Oil pump motor can start in an unloaded state, and will be off when the hydro-cylinder reaches the rated tension;the oil pump motor will start automatically to replenish oil when oil pressure is below the specified value. The function of keeping constant oil pressure and replenishing oil can be realized by accumulators when lack of electricity, which ensures the device to energy-saving operate.  (5)The device is of compact structure and installed conveniently;  (6)The device can be connected with integrated control system, which realizes all kinds of automatic controls and hand-operated controls.