| 摘要 |
PURPOSE:To automatically diagnose abnormality, by picking up blade stress, generated by rotating a windmill blade, as an electric signal from a means, containing a strain gage, while detecting a deviation between each blade from this signal and generating an alarm when the deviation increases its maximum value to a predetermined value or more. CONSTITUTION:When the invention is applied to a three blade propeller type windmill, a strain gage is mounted in the vicinity of a point generating the maximum stress of each blade, and bridge circuits 1a-1c, which are built so as to pick up stress, are connected to signal conditioners 2a-2c. In this way, an electric signal is generated in proportion to a stress level, and a changing component in this electric signal is extracted in DC component removal circuits 3a-3c and converted into a DC voltage signal in proportion to the changing component. And the windmill, detecting a deviation of the changing component between each blade by subtraction circuits 6a-6c and the maximum of the deviation absolute value by a maximum value detecting circuit 8 to be compared with a preset level, actuates an alarm means by closing a switch 11a when the maximum value is in the preset level or more. |
