Speed protection controller of leather belt oil pumping machine

The invention provides a speed protection controller used in a belt pumping unit. The controller consists of a sensor, a programmable controller, an electric motor and an electric brake, and is characterized in that the electric motor is connected with the pumping unit, the pumping unit is connected with the sensor, the sensor is integrated with the programmable controller as a whole, the programmable controller is further connected with the electric brake and the electric motor, and the electric brake is further connected with the pumping unit; the sensor senses the speed signals of the pumping unit and is a proximity switch or a speed encoder which judges whether a pumping rod is broken or whether a pump is blocked according to the speed change; the speed range of the pumping unit can be set, the controller controls the electric motor to be switched off and controls the electric brake to protect the pumping unit when the speed of the pumping unit is out of the set speed range, thus causing the pumping unit