A New Type of Elevator Speed Governor

Elevator speed governor is an equipment to limit the moving speed of the elevator lift car.When the lift car exceeds the speed limit,the speed governor stops rotating quickly and brakes the lift car through steel wire ropes and safety pincers so as to fully guarantee the safety of passengers and cargoes.In view of the deficiencies of mechanical speed governor,a new type of elevator speed governor is designed in the paper,which measures the rotating speed of the speed governor wheel with the aid of photoelectric encoder,and calculates the moving speed of the lift car combined with the pitch circle diameter of the speed governor wheel.The AT89S52 single-chip microcomputer is used to receive the encoder pulses and calculate the moving speed of the elevator lift car,and control an electro-magnetic expansion link to trigger the mechanism of the speed governor according to the measured speed.In the paper,the working principle of the new type speed governor is analyzed,the mechanical schematic diagram is given and the detailed circuits of the measuring and controlling system are designed,and the prototype of the new type speed governor is manufactured finally.The trial results in the laboratory indicate that this new type speed governor is simple in mechanical structure,acts quickly when limiting speed,has high speed measuring precision and good precision maintainability.So it has wide prospects of being widely popularized.