The Application of a Two-Input Cam-Actuated Mechanism to Variable Valve Timing

890676

02/01/1989

Event
SAE International Congress and Exposition
Authors Abstract
Content
Little of the long-recognized potential of variable valve timing (VVT) has yet been realized, mainly because of the many limitations that characterize virtually all the mechanisms that have been proposed for VVT application. These limitations include high cost and complexity, mechanism energy losses, limited range of variability, and high valve impact velocities.
We have developed a two-degree-of-freedom mechanism, actuated by two cams operating in series, that appears well-suited for VVT applications. This new mechanism avoids the serious limitations that characterize virtually all other VVT mechanisms. It is relatively simple and it can be implemented using only standard-type major components. It can provide a wide range of valve open duration without excessive mechanical losses or high impact velocities. We examine this mechanism in depth. Experimental verification of the operation of this mechanism confirms the mechanical adequacy of the concept at practical engine speeds.
Meta TagsDetails
DOI
https://doi.org/10.4271/890676
Pages
24
Citation
Dresner, T., and Barkan, P., "The Application of a Two-Input Cam-Actuated Mechanism to Variable Valve Timing," SAE Technical Paper 890676, 1989, https://doi.org/10.4271/890676.
Additional Details
Publisher
Published
Feb 1, 1989
Product Code
890676
Content Type
Technical Paper
Language
English