Jawahir Zakaria Adam2023-01-102023-01-102004http://hdl.handle.net/123456789/18569This thesis is a study of Lubrication theory .Thc consept of Lubrication its to types and practice and some definitions are introduced in chapter one . In chapter Two the Reyn0ld's equation is derived. Chapter three deals with Further theory of Lubrication. In chapter four the variational ,approach to Lubrication problems is studied boundary conditions uses are also discussed .LubricationThesis