Influence of Gears and Oil Levels Upon Efficiency of Ravigneaux Gearset

Abstract

Nowadays planetary gearsets have found their use primarily due to meeting of reasonable requirements for reduction of mass and overall dimensions of gearsets, as well as due to ability to set upgear ratio within very wide limits which fact gives freedom to mechanical design engineers when solving various problems of power transmission and movement. This paper presents results of experimental research of power losses and determination of efficiency of multi-stage planetary gearset for which calculation, design and construction were done for that purpose. The research was conducted in the Center for testing mechanical power gearsets at the Faculty of Engineering University of Kragujevac. The device was made for switching gears and blocking of certain elements of gearsets: planetary carrier, small sun gear and big sun gear. On the grounds of defined experiment plan we determined in our research efficiencies in certain gears with defined number of rotations, different oil levels and appropriate values of brake force. On the grounds of results we got we could conclude that decrease of power losses along with increase of efficiencies are achieved by switching of gears, i.e. by gearing down. The important conclusion we made was that power losses increased and efficiencies decreased with increase of oil level while keeping the same number of rotations.