Motor reducer protector

The invention discloses a motor reducer protector, solving the problem that devices in the prior art are incapable of protecting motor reducers effectively. The motor reducer protector is characterized in that a motor reducer is mounted on an upper end face of a supporting base; an output end of the motor reducer is connected with a toothed-chain coupler; an upper coupling sleeves a load input shaft, the upper end of the upper coupling is connected with the toothed-chain coupler through a bush roller chain, and the lower end of the upper coupling is integrally fixed to a lower coupling through a safety pin, a nut and a spring washer; and the lower coupling is connected with the load input shaft through keys. The motor reducer protector adopts the toothed-chain coupler and is added with one safety unit; the safety pin is cut off when load exceeds a preset limit, the motor reducer is separated from the load; thus, the motor reducer is protected, damage to the motor reducer is avoided, and the motor reducer can continue to be used only after small parts thereof are changed. The motor reducer protector is safe, convenient, laborsaving and timesaving and further is easy and convenient to maintain when in failure; by the motor reducer protector, maintenance and operating efficiency is improved greatly while production cost is lowered.