Patent ID: 9476417
Filing Date: 2016-10-25
CPC Classification: F04B,G01H,G01M,G06F,G16Z

Claim Text:
1. A method for detecting and localizing a valve leak in a piston machine having a shaft, comprising: attaching one or more vibration sensors to a valve block of the piston machine; measuring vibrations from at least one of the vibration sensors; attaching a sensor to the piston machine where the sensor is configured to produce, directly or indirectly, an angular shaft position signal for the shaft; determining, directly or indirectly, an angular shaft position signal for the shaft; transforming vibration signals from the one or more vibration sensors into one envelope signal representing an instant vibration level; using the angular position signal for constructing window functions that pick the envelope signal in selected angular shaft sectors; using the window functions to find sector based averages of the vibration level, and comparing said averages with a critical ambient vibration level to detect and localize leaks in one or two valves.