Diagnosis method and diagnosis apparatus for hydraulic machine

摘要

A diagnosis method is for a hydraulic machine 10 including a rotational shaft 12, a plurality of cylinders 14, a plurality of pistons 16, and a casing 18 for accommodating the cylinders 14 and pistons 16. The pistons 16 are each guided by corresponding one of the cylinders 14 to reciprocate in relation to rotation of the rotational shaft 12. The diagnosis method includes a vibration detection step of detecting vibration of the casing 18 by a vibration sensor 2 disposed on the casing 18 while rotating the rotational shaft 12 in an unloaded state of the hydraulic machine 10 and a determination step of determining, on the basis of a detection result detected by the vibration sensor 2, whether a piston jump phenomenon which is accompanied by collision and separation of at least one of the pistons 16 with respect to a rotational shaft 12 side has occurred.