System and method for determining bearing preload by vibration measurement

A method of determining bearing preload by vibration measurement includes: mounting a bearing on a vibration tester; clamping an outer ring to prevent rotation; mounting a sensor in the vicinity of the outer ring to measure vibration; rotating a bearing inner ring to excavate eigen-frequencies; transmitting the measured vibration data from the sensor to a computer workstation; by the computer workstation, performing a numerical FFT transforming data to frequency domain; analyzing the spectral data from the FFT by the computer workstation; by a peak detection algorithm, determining the peaks that are the various modes of the outer ring; classifying the modes and identifying main modes; obtaining numerical relationship for each mode between the resonance and preload; comparing the mode relationships with one or more references, wherein a match between the numerical relationships for each mode and the ideally referenced graph modes indicates a correct preload is determined. Also, a system is disclosed for carryi