Mechanical Seal Deformation Studies

Mechanica1 sea1 is a kind of important shaft seal widely used inindustries. To obtain satisfying performance, the sea1 end faces ofrotating ring and static ring of the mechanica1 seal must keep para11e1or approximately paral1e1 each other. However, the rings underexterna1 1oads wi ll have a significant deformation. Therefore, it isf very important to accurate1y ca1cu1at ing the mechanica1 deformat ion ofthe ring for carrying out des igning and manufacturing good mechanica1- sea1 ing products.In the past, there are three main methods used to calculating thedeformation of the ring of mechanica1 sea1. 0ne is the method based onGermma's ring theory, the other one is based on Becheno's ring theory;the third is the finite e1ement method.In this paper, the method of the ana1ysis so1ution of mechanica1deformation of the ring was fouflded on the basis of the moment theoryof shell for the first time.According to the moment theory of she11, the mechanism mode1 andca1culating mode1 of the sea1 ring was estab1ished. The sea1 ring withcomplex section shape cafl be treated as a combined body made of severalindividual cy1 inders with di fferent dimensions. By app1ying the methodused in the' edge prob1 em' of the fnoment theory of she11, the deformat ion- --radia1 disp1acement and rotation at the two edges of each individual.cy1 inder-- caused by externa1 force and/or pressure can be easilyca1cu1ated out.At the interface between adjacent two cylinders, the radia1disp1acement and rotat ion must be equal. For meet ing the conditi on, theremust be a shear and a moment cal1ed' edge 1oads' at the interface betweenadjacent two cyl inders. Then, the edge 1oads can be so1ved according tothe coordination condi tions of deformation, and the radia1 disp1acementsand rotat ions of each individua1 cy1 inder under corresponding edge 1oadscan be obtained. Finally, the total mechanical deformation of seal rings can be obtained by superposition of the results due to the external loads and the edge loads respectively.A special program of this analysis method has been compiled for easily calculating and engineering application by using Visual basic language.This method of calculating the mechanical deformation of mechanical seal ring based on the moment theory of shell is of reliability and validity through a great deal of analysis, calculating and test verification for industrial instances.