Nonlinear Finite Element Analysis of Radial Lip Seals

Abstract

Oil seals or radial lip seals are widely used in reciprocating, oscillating and rotating shaft applications. The sealability and durability of a lip seal greatly depends on the contact load and contact pressure distribution. It is challenging to find these contact parameters of the seal due to non-linear material behavior and small contact width, therefore numerical simulation can prove to be a viable method. In this paper, to address these challenges and to develop a robust numerical methodology, a Finite Element Model of a lip seal is created in ANSYS APDL. This model includes contact elements to model the lip seal’s contact-fit with certain interference, nonlinear material properties of elastomer and effect of the finger spring molded in the rubber body of the seal. The parameters for two term Mooney Rivlin Model for elastomer are obtained from simple uniaxial tension test. The numerical results demonstrate that the contact load exerted by the composite seal (with spring) is higher than the contact load exerted by elastomer portion of seal alone. It can be implied that the spring augments the radial load and increases the stiffness of the lip, which improves the lip’s sealability and durability. Experimental study is carried to validate the numerical results. The experimental results correspond well with the numerical results.