Analysis of two-dimensional gage repeatability and reproducibility

摘要

All rotating components exhibit some level of imbalance, which can lead to vibration problems. The measurement of imbalance is extremely important to practitioners. This provides a model of imbalance measurement process that matches the tolerance scheme as well as possible. Imbalance in a single plane can be considered as the vector in that plane between the measurements and the center of rotation. Imbalance consists of two attributes, magnitude and direction. The magnitude of imbalance is a mass or weight multiplied by the distance from the center of rotation. The direction of imbalance is defined relative to some known direction or feature of the component. These two attributes make imbalance a two-dimensional property. Rotating components usually have an allowable amount of imbalance or tolerance which has an upper specification limit that is a radius value. The focus of this article is to describe the use of appropriate statistical tools for evaluating repeatability and responsibility of the dimensional measurement data and to discuss what engineering tolerance should be measured or established for a resulting two-dimensional repeatability and responsibility.