Patent ID: 6745621
Filing Date: 2004-06-08
Classification: G01L

Abstract:
A method of measuring twist in a rotating shaft of an engine which shaft is subjected to torque, between a datum point on the shaft and a measure point on the shaft longitudinally spaced from the datum point, the method includingestablishing a datum time period between a datum time moment the datum point passes a stationary datum station and a time moment the measure point passes a stationary measure station under a no load condition and recording rotational speed of the shaft as the datum speed; measuring a measure time period between a time moment the datum point passes the stationary datum station and a time moment the measure point passes the stationary measure station when the shaft is subjected to torque, recording the rotational speed of the shaft as the measure speed and establishing a length of the shaft over which torque is applied; calculating the twist in the shaft on the basis of the difference between the measure time period and the datum time period, the measure speed and the length over which torque is applied, including ameliorating the effects of vibrations and resonances in rotating or reciprocating components of the engine to isolate at least to a degree data relating to said difference between the measure time period and the datum time period, said measure speed and said length over which torque is applied, by means of a preprogrammed processor.