REDUCING NOISE, VIBRATION, AND HARSHNESS IN P/M COMPONENTS

A Water Pump Hub recently tooled by GM includes unbalance as a specification. Because unbalance is a nontraditional P/M product specification, in reality a resultant variable, a study was conducted to investigate the effects of dimensional and physical variation on unbalance. The results indicate that density distribution throughout the part is the most significant contributor to unbalance in P/M parts and far outweighs the effects of circular runout, face runout, symmetry, and other traditional considerations.