Abstract:

Based on the structural characteristics of the new cycloid enveloping reducer， a fault tree model of the reducer was established. Considering such uncertain factors of the new cycloid reducer as fault phenomenon， fault probability and fault cause under actual conditions， the fuzzy sets theory was introduced into fault tree analysis. The triangular fuzzy numbers were utilized to qualify the probability of fault causes. Mean while， the fuzzy probability of failure and fuzzy importance measure of fault causes were calculated based on the λ cut-set theory and interval arithmetic. The results showed that the cycloid enveloping reducer has a high reliability and the wear of rollers， raceways and cycloid teeth profiles， and the failure of crankshaft bearings are the key influence factors for the reliability of the cycloid enveloping reducer.

Key words: cycloid enveloping reducer, precision transmission, reliability, fuzzy fault tree