Optimum Phasor Tolerances for Machines With Designed Unbalance

This paper describes the development of a procedure to determine optimum tolerances for the balancing of machines with inherent unbalance, such as, 90 degree V-6 engines. The conventional circular tolerances were found not to be the optimum ones. The optimum tolerances result in increased feasible area for the random unbalance vector, without exceeding the vibration levels encountered with conventional tolerances. The development is based on the fact that the absolute unbalance vectors are the controlling factors of the vibration levels. Experimental results have been presented to show the feasibility of the optimum tolerances concept. The application of optimum tolerances in the manufacturing facility, where thousands of nearly identical machines need to be balanced, will result in increased productivity, and a reduction in procurement, repair and operation costs of balancing machines.