Preload measuring apparatus of rolling bearing

Abstract

A preload measuring apparatus to measure the preload of a rolling bearing that includes a bearing support, a pressurization device, an excitation device, a vibration sensor, and a control section. The bearing support supports a rolling bearing by supporting both ends of a shaft inserted into an inner ring of the rolling bearing. The pressurization device loads a predetermined weight in the axial direction onto the rolling bearing. The excitation device applies vibration onto the rolling bearing by the drive of the piezoelectric elements. The vibration sensor detects the vibration generated on the rolling bearing by the vibration application of the excitation device. The control section operates the excitation device in the situation that the pressurization device presses the rolling bearing, and obtains the resonance frequency by the output signal from the vibration sensor and calculates the preload of the rolling bearing according to the obtained resonance frequency before the predetermined weight as loaded.