Experimental Study Of Behaviors Of Traction Characteristics For High-speed Lubricating Grease

The study for traction properties of lubricants is a vital field inelastohydrodynamic lubrication (EHD) research. It has great influence on dynamicproperties of rolling bearings and behaves as one of the essential factors in dynamicdesign of rolling bearing. In the modern design about bearing, the bearing lubricanthas become one of the basic components, so the traction properties of lubricant underdifferent conditions is an indispensable basic basis for the design of bearing. As greaseis widely used in the rolling bearing, the traction force of grease film obtained bysimulating the actual conditions from the two surfaces of contact is the most reliabledata. Therefore, it is of great practical significance to study the traction properties ofgrease under the condition of providing sufficient grease to optimize the design of thebearing.In order to simulate actual conditions of rolling bearing grease in the laboratory andcontrol the working conditions, a test rig of was specially designed to test the tractionproperties of high-speed rolling bearing grease. The test rig includes the followingseveral parts: testing ball speciman, the system for providing grease, cooling system,auxiliary lubrication system, power system and the system for controling speed, thehydraulic system for load and hydrostatic spindle, data measurement and acquisitionsystem. Based on existing test equipment, a lot of improvements to the test systemshad been done. Two major parts of the system for controling speed and the system forproviding grease have been improved greatly to improve the accuracy of the test andcontrol. With improved experimental conditions, a series of experiments of high-speed lubricant greases NO.7018and LGLT2under the conditions of different speeds,different loads and different slide-roll ratio were done.The traction properties curvesfor the traction coefficient with the slide-roll ratio changing of two greases wereobtained. By examining the existing traction theoretical model and analysing of experimental data obtained, the results showing that the experimental results have acertain gap between most models and the measured values, only T-J elastoplasticmodel can be used to accurately predict the test results. Therefore, the T-J elastoplasticmodel was used to analyze the traction properties of LGLT2grease. It was provedthat the traction force model can more accurately predict the data for tractionproperties within the experimental range and we got satisfactory results.The project of testing the traction properties of SKF high-speed lubricant greaseLGLT2was successfully completed; at the same time, it lays a solid foundation forthe future development of the SKF Company in its research about special bearinggrease or other tests of greases for traction properties.