Safety Analysis On Counterweight Reversed Sheave Of Elevator

With growing demand for elevators all over the Country, elevator accidents are increasing. Elevator, as a complex transportation facility, every minor problem may lead to serious accident. The counterweight reversed sheave is an important part of the elevator traction system, if there is any problem, it will lead to serious consequences.The movable pulley, wheel, bearing, axle clamp, fixed bolts and other parts on the counterweight rack compose counterweight reversed sheave. The individual characteristics of each component, as well as their combinations contribute to the safety features of the counterweight reversed sheave. This paper presented the study of counterweight reversed sheave falling accident which occurred in Foshan. The author analyzed influence factors on the safety of counterweight reversed sheave and carried out the detailed analysis for these factors to seek the preventive measures.In this paper, the guiding ideology is from the operation characteristics of the counterweight reversed sheave, based on the investigation of accidents. Analysis of safety features of counterweight reversed sheave using the methods for intuitive experience and system safety analysis, and the effect of the failure of the bearing and the structural design of the components on the safety of the heavy anti- rope wheel are also verified. Analysis of failure bearings by macroscopic inspection, physical and chemical property and the theory of bearing life are conducted. Structure mechanical calculations of counterweight reversed sheave are also implemented.Comprehensive analysis results showed that the bearing failure, structural design of wheel axle and axle clamp and bolt performance are the key factors for the safety of the counterweight reversed sheave. According to the results of the analysis, feasible measures to prevent and reduce such counterweight sheave reversed failure are also put forwarded.