Failure analysis and redesign of a helix upper dispenser

Failure analysis was conducted on a fractured helix upper dispenser for a side-by-side refrigerator with ice dispenser system. To reproduce the failure modes and mechanisms causing the fracture, a tailored set of accelerated life testing were applied to sample dispensers. Using bond graphs and state equations, key noise parameters in the assembly, including a variety of mechanical loads, were analyzed. The failure modes and mechanisms found experimentally were identical with those of the failed sample. To correct the problem, the key controllable design parameters of the helix upper dispenser were modified by eliminating gaps and enforcing ribs. The B1 life of the new design is now guaranteed to be over 14 years with a yearly failure rate of 0.021%.