METHOD AND DEVICE FOR MEASURING UNROUNDNESS OF AN OBJECT

摘要

A method and device for measuring unroundness of a rotating object having a substantial circular circumference with a radius R in a plane perpendicular to the axis of rotation of the object. Three probes are located in said plane at predetermined angular positions with respect to each other along said circumference. Each probe measures its distance to the surface of the object by detecting an area of said surface, said area having a dimension d in tangential direction. The unroundness is calculated based on the measurements of the three probes. The angle phi2 between the first probe and the second probe is n2 times 2pi/n radians, and the angle phi3 between the first probe and the third probe is n3 times 2pi/n radians. Both angles phi 2 and phi3 are measured in the same direction from the first probe. n is a power of 2, where n2 < N3 < N, AND WHERE N2 and n3 are integers and chosen such that the exponent of the largest square 2 common integer divisor of n2 and n3 is 1 or 0.