Experimental Study For Finite Line Contact EHL Under Non-steady State

As the line contacts can understand greater load than the point contacts, it has been widely used in engineering. The line contacts, usually working under lubrication, whose pressure distribution, film thickness and shape are very important for performance and life of the machine parts. The current account of various effects of the modern theory of EHL has been formed, and further improved on the basis of conditions to a more realistic direction. However, the experimental study of EHL finite line contact, especially under non-steady state has not been reported. In order to faithfully study the lubrication of mechanical parts under the engineering situation, whose condition is limited to the oscillation of the line contact EHL lubrication, characteristics are studied.1. According to the optical interference principle, taken into account and analysis of the influence line contact factors EHL experiments, it has been founded test rig newly design method based on optical interference, basically from the classic way of rotation to linear mode, eliminating the transparent material, overcoming the shortcoming of testing machine unbearable overload. It is showed that the total load capacity 2450N, the maximum contact pressure 0.92GPa in experiment.A newly set of experimental setup has been designed and manufactured for non-steady state (oscillation) of pure rolling line contact based on optical interference. Experimental rig to accompany two floating rollers bearing test method, moving parts are crank, the entrainment speed of test roller was similar to the sine law of change, reciprocating frequency variable speed by motor control. Experimental device with adjustable intensity light source with xenon gas-cooled light source, plus a narrow-band front-end filter, a quasi-monochromatic light, the center wavelength of 600 nm, between two bodies of pure rolling contact the interference fringes were taken by CCD through the microscope, and then collected by tape recording system.2. The newly developed EHL experiments carried out on a logarithmic profile rollers device on several crown roller. It is included that:â‘ same lubricant viscosity, same load, different oscillation frequencies;â‘¡same lubricant viscosity, same oscillating frequency, different loads;â‘¢oscillating in the same frequency, the same load, different lubricant viscosity. It is showed that have been the necking in roller's export zone and lubricant viscosity, load, oscillating frequency and other factors to EHL of finite line contact has some effect, the largest of the oscillating frequency, mainly entrainment velocity.3. Overload experiment was studied. K9 used as a transparent glass, when it is 1.0GPa crushing phenomenon exists, this study the maximum contact pressure is less 1.0 GPa, It is indicated that a roller end condition of "edge effects" and " closure effect" under overload, the more obvious roller film thickness than the end of the exit zone in central film thickness much smaller. and closure effect is more apparent under heavy load.4. Numerical analysis applied by multi-grid technique, theory discussion group has research and experimental results were compared, the result is basically the same. Application research group have numerical analysis of multigrid technique theory, theory of computation results indicate that the value is greater than the experimental measurements, theoretical calculations do not reflect the roller in the middle of the zone of the neck; but in the film thickness varies, depending on the speed of change, as well as the closure of film thickness of lag are consistent.5. It has been researched and developed of a visual software of logarithmic profile rollers crown designed based on static elasticity theory, numerical calculation methods, and it has showed that this software works on a certain value by the fatigue life of roller results.The research is useful for help line contact EHL experiments to further develop and perfect understanding of the finite line contact mechanism of lubrication and its characteristics of a variety of factors, deputy for engineering optimization line contact design and performance analysis to provide good foundation.