Reliability allocation for CNC turrets based on fuzzy comprehensive evaluation

When it comes to the reliability allocation of Computerized Numerical Control (CNC) turrets, there are two problems. One problem is that the corresponding reliability index is only allocated into each subsystem; another problem is that neglecting the coordination between each subsystem will affect the results of reliability allocation. To solve these two problems a new research method for CNC turret reliability allocation is proposed. It classifies the components of the CNC turret system according to the extent to which these components affect the system's reliability. It takes assembly relationships and CNC turret system sealing as two factors. Along with the components screened out, a reliability block diagram (RBD) is built. The reliability allocation method previously proposed is based on fuzzy comprehensive evaluation. It takes the mean time between failures (MTBF) as the index of allocation and assigns reliability to the components screened out, assembly relationships and sealing. Reliability allocation directly for the components of CNC turrets and research into comprehensive consideration of various factors which affect reliability makes the results of reliability allocation more reasonable, and also provides a specific basis for the design of CNC turrets.