Nikitin S. Prediction of characteristics of bearings with steel and ceramic balls in structure of gas-turbine engines shaft bearings

The Object is the radial-thrust bearings with balls from nitride of silicon and bearing steel; The aim is - obtainment of techniques for definition of characteristics of ball bearings with ceramic balls on the basis of physical modeling and the analysis of hydrodynamic, thermodynamic and power processes which allow to predict behavior of characteristics of bearings in a wide range of operating modes; methods - experimental methods of research of the moment of resistance to rotation of the bearing and its temperatures, methods of analytical research of oscillatory processes for definition of influence of imbalance of a rotor on loading which affects the bearing, methods of the solution of a contact problem of interaction of balls and the races of bearings, methods of statistical processing and the regression analysis of results of experiment; novelty - improvement of the criterion expressions developed for traditional bearings with steel balls which allowed to predict power loss in ball bearings with ceramic balls and their influence on a thermal condition of support of gas-turbine engines rotors at oil-jet and oil-mist lubrication for the first time was carried out, for the first time is shown that because of considerable a contribution to the general power loss of a hydraulic component in comparison with bearings with steel balls of advantage of bearings with ceramic balls caused by reduction of influence of centrifugal forces on contact stresses and reduction of losses on a friction in a zone of contact, become appreciable only at speeds of more than 3 million DN, the new experiment-calculated method of determination of value of the centrifugal force operating on support caused by an unbalance of a rotor is offered, a radial gap in bearings and deformation of a ball and a bearing race under loading, the method allows to define the forces operating on support of a rotor using results of measurement of amplitude of fluctuation of a rotor; results - were received criterion expressions for definition of power loss at oil-jet and oil-mist lubrication, conditions of an effective use of hybrid bearings and influence of properties of ceramics are outlined; industry - aircraft industry and rocket production.