Mechanical Engineering ETDs

Publication Date



In this thesis the phenomenon of waviness distortion in mechanical face seal washers is investigated. Waviness in face seals leads to leakage in some applications. When leakage becomes significant, the seal must be replaced. If the distortion causing mechanism can be described, improvement in seal performance and behavior may be possible.

The components and function of the mechanical face seal are first discussed. It is seen that only one component of the seal unit shows significant deterioration over a period of time. It is also seen that this component, the face washer, wears in a characteristic manner. The characteristics of washer waviness are investigated.

The source of waviness in the washers is discussed. It is seen that under the influence of mechanical or thermal loading in conjunction with its elastic behavior, the washer distorts in a circumferentially varying manner. This leads to a wavy wear pattern. Distortion due to thermal effects for the class of washers studied can be eliminated by results form pervious investigations, leaving loading at the drive notches as a possible distortion causing mechanism.

By use of equilibrium equations and deflection equations, an overall governing differential equation is derived. This equation includes distortion due to distributed moments, distributed loads, and concentrated loads. Each of these possible distortion causing mechanisms is then analyzed.

Distortion due to mechanical loading is investigated. It is seen that significant distortion due to moments applied at the drive notches of the washer may be a source of waviness distortion. This is seen by considering two idealized cases. A model which more closely approximates the real system behavior is developed so that the distortion due to loads applied at drive notches can be investigated more closely.

The results of the computer model are then compared to experimental results. It is seen that on the basis of several comparisons, the model predicts distortion having many of the same characteristics as the distortion measured from experiment.

From the above, it is concluded that the basic distortion causing mechanism is the drive force system and its associated moment system occurring at the drive notches of the washer.

Degree Name

Mechanical Engineering

Level of Degree


Department Name

Mechanical Engineering

First Committee Member (Chair)

Alan Otto Lebeck

Second Committee Member

Youn-Chang Hsu

Third Committee Member

William Ernest Baker


Research Initiation Grant

Document Type