Door closer

A door closer includes a door closer which is provided with a hydraulic cavity. The hydraulic cavity is divided into two reservoir compartments by a plunger. The hydraulic cavity is provided with a plunger return spring inside. A one-way valve and a fluid passage are arranged between the two reservoir compartments. The door closer is provided with a draw rod. A transmission mechanism is arranged between the draw rod and the plunger. The door closer is characterized in that the transmission mechanism includes a dragline whose one end is connected with the plunger and the other end is connected with a revolution axis which is connected with the draw rod. As the utility model adopts the dragline and the revolution axis to transmit between the plunger and the draw rod, the structure of the transmission mechanism is simple and the production cost is low. The exterior of the hydraulic cavity is provided with a door closer casing. The door closer casing is provided with the revolution axis inside. The revolution axis is arranged outside the hydraulic cavity. Thus the both ends of the revolution axis of the utility model do not need to be sealed and the oil leakage phenomenon of the door closer is dramatically reduced.