Formulation of camshaft Dynamic Load Factor under Uniform Acceleration Excitation

Abstract

Due to their importance in many mechanical application, Cams was the subject of many researches regarding the improvement strength to withstand dynamic contact stresses and wear based on cam geometry modifications and follower variables. This work assesses the effect of harmonic cam variables on the induced dynamic forces and camshaft dynamic load factor. The equation of motion is formulated based on Newton's second law taking into account the geometry of cam lobe and follower motion to evaluate the dynamic contact force during the course of action in terms of camshaft angular speed and time. Theoretical analysis contains two parts these are; the evaluation of static and dynamic contact stresses based on Hertz and dynamic load factor formulation for single element camshaft as a continuous simply supported beam based on Euler- Bernoulli beam theory. FEM has been adopted to simulate the static and dynamic contact stresses and dynamic deflection for multi elements camshaft and to verify the result of theoretical solution. Results show that the increasing of damping ration and spring stiffness has appositive effect on dynamic load factor reduction while the increasing of follower mass has negative effect on dynamic load factor reduction