Abstract: In order to diagnose the fault of axial piston pump and avoid the false alarm caused by the change of load condition,the adaptive fault diagnosis method based on multi characteristic parameters is proposed.Study the method of feature parameters selection,threshold interval determined,load under the condition of adaptive threshold computation,qualitative analysis the type piston pump vibration characteristics and fault mechanism,reveals the plunger pump main fault modes of vibration signal characteristics,experimental results show,threshold adaptive fault diagnosis method can accurately detect the variable load conditions of piston pump port plate wear fault,provide an important theoretical basis for the development of axial piston pump reliability evaluation and fault diagnosis research.

Key words: axial piston pump, threshold adaptive, fault diagnosis, variable load condition