Research On Reliability And Data Analysis Of ME Type Travel Switch

The travel switch is a kind of safety protection device which is widely used in all types of equipment,such as automatic production line,open and close of the subway doors,lift crane limit and so on,playing an important role in the whole industry.The principle of travel switch is to convert the mechanical movement into electrical signal of the external equipment,matching with the contactor so as to protect and control of the main body of the equipment.It can be said that the reliability level of the travel switch directly affects the safe operation of the main body of the equipment;therefore,it plays a significant role to study the reliability of the travel switch.In the actual production process,the ME type travel switch possesses some advantages,such as flexible operation,easy installation,high breaking capacity and wide use range,so the representative ME type travel switch is selected is this paper to carry out the reliability evaluation test,which aims to discuss the influence of electrical characteristics on travel switch life in actual usage,and to provide the effective evaluation method for the travel switch reliability of ME type on the basis of the existing model distribution.Through the reliability research,it is acquired that the maintenance and replacement cycle of the ME travel switch under different functions,so as to ensure the reliability of the main mechanical equipment,and to guarantee the safety and smooth running of the production order in this industry.The fault tree analysis is applied in this paper to do the failure analysis of ME type travel switch to conclude the main factors affecting the reliability of the travel switch in actual work process,they are: contact resistance and switch operating time.According to the two main factors,a set of test device on travel switch reliability is designed and developed,and the reliability test is designed in accordance with the actual using conditions of the travel switch.In the test,6 travel switches are selected to do the experiment,and it is recorded that the change regulations of the contact resistance and switch operating time of travel switch in the actual work.At last,theswitch failure condition is judged based on the correlative requirements in national standard Travel Switch.Finally,according to the data obtained in the test,the Weibull distribution is used as a basic travel switch model for reliability analysis in this paper,the goodness of fit method is used to verify the match degree of the selected model,and the unknown parameter of the model are estimated by utilizing the maximum likelihood estimate theory and Minitab statistical software,as a result of which a mathematical model of travel switch reliability evaluation is got in actual production process.By making examples and drawing the life curve of control,start and stop,limiting function of the travel switch,the maintenance strategy is put forward under different functions for ME type travel switch,and provide reference for the installation,selection and inspection and maintenance of the travel switch.