Design, Analysis And Experimental Study Of Hydraulic Tensioner For Engine Timing System

Hydraulic tensioner is one of the key parts in timing system ofengine, the dynamical characteristics of which has a great practicalengineering value to enhance the transmission characteristics of timingchain, improve fuel economy and reduce the vibration and noise. Eventhough the hydraulic tensioners are widely used on vehicle, the valuablepatents and key research are mastered by few developed countries and theintegral design method has not been figured out in our country. Combinedwith the key technology project in Jilin province, this papersystematically has provided a method for the design, dynamical analysisand test of hydraulic tensioner on the basis of the serious research aboutthe structure, the characteristics and the working principles of many kindsof hydraulic tensioner, establishing the mathematical model abouthydraulic tensioner according to the components movement and the oilflow performance in hydraulic tensioner.According to the specification parameters about the engine, theinstall position of hydraulic tensioner and the layout formation, thepermissive load and noise level for the timing chain system, as well as theFEM and Multi-body dynamical software, this paper has elaborated thedesign method in details about tensioner on the basis of the research thatthe parameters’ effect on the dynamical response performance, explainingthe design boundary conditions and principles for every part in hydraulictensioner, verifying the PV value of plunger by the Hertz theory.Aiming to the designed hydraulic tensioner, this paper haveestablished the dynamical model by the multi-body dynamical systemsoftware, analyzing the dynamical response performance and thedamping behavior with the boundary conditions of different excitation amplitudes and frequencies, different oil temperature and pressure anddifferent air content in hydraulic oil.By studying the excitation characteristic produced by the timingchain, this paper has designed a test equipment for all kinds of structureof hydraulic tensioner, which are available for various layouts of timingsystem. Using the test equipment, this paper has tested the maximumreaction force about this tensioner for different excitation frequencies andamplitudes. The test results are not beyond the permissive value and in areasonable scope, meeting the design requirements. The simulationresults calculated from the established dynamical model have a goodcorrelation with the experiment datas under the certain boundaryconditions. As the simulation results can reflect real change about thedynamical behavior of hydraulic tensioner, the simulation method can beas an effective tool to predict the dynamical response and designhydraulic tensioner, which can contribute to reduce the design period andcosts.Consequently, the designed tensioner is in accord with the designprinciple and meet the practical necessary. At the same time, the designtheory and dynamical simulation method are effective and the researchabout hydraulic tensioner from this paper have a great meaning to designhigh quality and reliability product in our country.