Gear reducer device

A gear reducer device belongs to the technical field of transmission devices and comprises a machine box, a working cavity with an upward opening is formed in the machine box, an oil injection hole is formed in the machine box and communicated with the working cavity, and a valve is arranged in the oil injection hole in a sealed mode. A floating ball used for providing traction force is arranged in the working cavity, the floating ball is connected with a traction assembly used for converting the traction force into opening and closing power of the valve body, the traction assembly is in power connection with the valve body, the valve body is in pipeline connection with a reserve oil tank, and the gravity center of the reserve oil tank is higher than that of the case; the liquid level change of lubricating oil in the case is automatically converted into automatic opening and closing of the valve through the floating ball and the traction assembly, the aim of injecting oil into the case is achieved in combinat