Simulation of a dynamic seal by finite element method and experimental validation

Nowadays, dynamic sealing elements are one of the machine elements that make life easier at every point of life. Rotary (radial) shaft seals, also known as lip seals, are the most common of dynamic sealing elements. Rotary shaft seals are generally made of materials such as elastomers or low-friction coefficient polytetrafluoroethylene (PTFE) and are used as sealing elements in a wide range of products such as aerospace, automotive and industrial equipment. This function is achieved by ensuring continuous contact between the surface of the rotating shaft seal called the lip and the shaft during operation. The amount of contact pressure on the shaft of the seal is a critical factor for the performance and wear behavior of the seal. However, it is very difficult to determine the contact pressure below the high oil pressure that will come upon it during operation. During the design phase, it is of great importance that the determination of deformation during assembly and operation by a realistic simulation with the contact pressure level. In this thesis, finite element analysis simulations have been carried out in order to examine various aspects of the above mentioned rotary shaft seals before the experimental processes are started. Considering the elastomer material behavior used in rotary shaft seals that used in this study, Mooney-Rivlin was the most suitable hyperelastic material model. This inference was made by taking into account the behaviors seen as a result of material tests. Accordingly, mechanical tests and material characterization tests were performed. In addition, thermal analyzes were made by considering the working conditions of the rotary shaft seal. In this way, the design verification of the seal has been realized and a seal development study that requires minimum trial –and- error process has been demonstrated without the need for manufacturing and performance testing processes. Study results showed simulation of seal which was produced and tested in SKT A.Ş. R & D laboratories, was 95% compatible with experimental result.