Document Type

Thesis - University Access Only

Award Date

1997

Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

Abstract

This research work was conducted to study parametric excitation and dynamic stability associated with a flexible cam-follower system. A typical single-degree-of freedom dynamic system for an automotive valve train is obtained. The developed method is applied to study the parametric excitation and stability of this system for different angular speeds of the camshaft, and system damping. The transverse and rotational flexibilities of the camshaft along with the flexibility of the follower are taken into consideration. This gives rise to a system governed by a linear, second-order, ordinary differential equation with time-dependent coefficients. In general this class of equations is known as second order Hill's equation. The present research work provides development of an equivalent model of the system, derivation of its equation of motion, and a method to evaluate its parametric stability. The stability analysis is based on Floquet theory in conjunction with Hill's infinite determinant. In this approach the roots of the characteristic equation are determined and the stability of the system for a particular value of the angular speed of the cam is examined. The time response of the cam-follower system is estimated by using a 4th order Runge Kutta' s method to solve the resulting linear differential equation with time variant coefficients. For the special case of cam-follower system that has been considered, it has been found that the system is stable for lower values of the angular speed of the cam. As the speed is increased gradually, a few unstable regions occur. In general damping has a significant effect for stabilizing the present cam-follower system.

Library of Congress Subject Headings

Cams - Stability
Cams - Vibration

Format

application/pdf

Number of Pages

232

Publisher

South Dakota State University

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