Research on Fault Diagnosis of Piston Pump based on Inaction Principle

As a key component in agricultural machinery and equipment, the health status of axial piston pumps directly affects the reliability of system operation. At present, the fault diagnosis method for piston pumps mainly uses the vibration signal of the casing to analyze the operating status of the components and diagnose the cause of the fault. The multi-field and multi-scale strong coupling of hydraulic system makes fault diagnosis difficult.In order to monitor and diagnose the swash plate axial piston pump under various running state, normal state or fault state, the instantaneous speed signal is proposed to reflect the fault information. The instantaneous angular speed signal of the valve pair under normal and wear condition was measured on the piston pump of the electromechanical hydraulic system. The instantaneous angular speed fluctuation signal was filtered by using the principle of inaction, and the fault identification was realized by order analysis. The research shows that the instantaneous speed signal can be used as an effective means to reflect the valve plate wear fault, and provides a new way for the hydraulic component fault diagnosis and detection.