METHOD FOR INSPECTING INSIDE OF FLUID BEARING

摘要

PROBLEM TO BE SOLVED: To inspect the inside of a fluid bearing without disasembling it by transmitting ultrasonic waves to a component inside the fluid bearing device and inspecting whether a lubricant exists or not in a bearing according to the state of the reflection echoes. SOLUTION: A lubricant 10 is included between a sleeve 4A and a shaft 2. For inspection, first an ultrasonic sensor 12 is inserted from a hole being provided in a base so that it touches the sleeve 4A. An ultrasonic device transmits ultrasonic waves to a component in the device. An ultrasonic wave 13 being propagated inside a bearing causes a difference in a reflection echo 14 according to the presence or absence of the lubricant 10. The sensor 12 is moved in a direction marked by an arrow A and at the same time, the reflection echo 14 is continuously captured. Then, the distribution of the presence or absence of the lubricant 10 in a bearing gap is obtained from a voltage difference indicated by the waveform.