Research On Reliability Of Axial Piston Pump Valve Plate Degradation Feature Under Variable Rotating Speed

The axial-flow piston pump,as the main power component of many hydraulic systems,often works in the environment of varying working conditions,and its running state is closely related to the state of the whole hydraulic system.Therefore,the reliability requirements of hydraulic pump are becoming more and more stringent.The vibration signal of axial piston pump under variable working conditions will produce amplitude modulation phenomenon,which makes the signal appear obvious nonlinear and non-stationary characteristics.Therefore,how to extract the degradation characteristic information effectively and estimate its reliability,has become the focus a focus in the study of this article.Firstly,in order to find an effective processing method to solve the hydraulic pump vibration signal about non-linear and non-stationary at variable speed,the time-frequency analysis and order tracking method is applied to signal analysis,which can make full use of the rich degradation characteristic information of the hydraulic pump in the process of variable speed,using software to realize order analysis method and ensure the accuracy.Secondly,the reconstruction errors of CEEMDAN and EMD-EEMD algorithm was compared by simulation signals,and verified the superiority of CEEMDAN.Based on the spectral kurtosis and CEEMDAN theory,a method of fast spectral kurtosis and energy spectrum is proposed,which can effectively extract the containing sensitive degenerate IMF components.Based on instantaneous frequency extraction,the superiority of wavelet ridge is verified.In addition,aiming at the VMD method is not suitable to deal with the signal of large-speed fluctuations,a feature extraction method of angle domain signal VMD degradation is proposed,a degenerate feature extraction method for angle domain signal VMD decomposition is proposed.The simulation signal analysis shows that this method can effectively avoid the influence of variable speed on the vibration signal.Thirdly,considering the influence of the above methods on signal extraction comprehensively,the experimental platform is built,the experimental data is collected,and data processing is carried out.Through experiments,it is verified that the feature indicators that containing sensitive information of degradation characteristics can be effectively extracted.Finally,a proportional failure rate model of active pump monitoring based on Weibull distribution is put forward,which provides a new idea for reliability analysis of hydraulic pumps without degradation data.and through the real-time data of different health degree valve plate of axial piston pump confirmed the validity of the model reliability evaluation.Based on the experimental platform of variable frequency hydraulic system,the degenerative study of valve plate is carried out,the reliability of axial piston pump with variable frequency hydraulic system is verified,and good results have been achieved.It is largely enriched the theoretical system of the vibration signal processing of the hydraulic pump under variable speed,and lays a foundation for the reliability study of the hydraulic pump,which provides a basis for further research in the future.