Apparatus and method for evaluating rotational accuracy of rolling bearing and rolling bearing evaluated by the rotational accuracy evaluation method, and apparatus and method for radial vibration of rotating body and rotation unit with rotating body evaluated by the radial vibration evaluation method

Abstract

The x- and y-direction vibration components of radial vibration of a rotational shaft obtained by measurement from x and y directions are transformed into frequency sample values {X Y , k=0, 1, . . . N−1} by discrete Fourier transform. RMS amplitude values {2 (2 &pgr;/M)|, j=0, 1, . . . M/2−1} are calculated at azimuths {&thgr; =2 &pgr;/M, j=0, 1, . . . M/2−1} corresponding to 0 to &pgr; on the basis of frequency sample values at frequency points {k , i=1, . . . P} corresponding to specific frequencies {fi, i=1, . . . P} of NRRO vibration components selected from the x- and y-direction frequency sample values obtained by the discrete Fourier-transform. RMS evaluation values A are selected from these RMS amplitude values.