Improving the reliability of a water dispenser lever in a refrigerator subjected to repetitive stresses

Based on field data and a tailored set of accelerated life testing, the dispenser lever of the water dispensing system in a bottom-mounted freezer (BMF) was redesigned. Using force and moment balances, the simple mechanical loads of the dispensing process were analyzed. The failure modes and mechanisms found experimentally were similar to those of the failed samples returned from the field. Failure analysis, accelerated life testing (ALT) and corrective action plans were used to identify the key control parameters and level of the mechanical dispenser lever. The missing controllable design parameters of the dispenser lever in the design phase included corner rounding, rib thickness, and front lever thickness. The B1 life of the new design is now guaranteed to be over 10 years with a yearly failure rate of 0.1%.