Synthesis, design and analysis of a novel variable liftcam follower system

摘要

This work proposes a novel variable lift cam follower system. Here follower lift varies according to input or camshaft speed. The system comprises a trapezoidal shape cam with ping finite spline curve as displacement profile. The height of the cam varies along the axis of the shaft and it slides in the axial direction so that the lift of the cam varies. Sliding motion of cam was executed by actuating mechanism and it works on principle of centrifugal actuation. When input speed varies, due to centrifugal force, actuator initiates linear axial movement of bush and cam on the shaft. This axial movement of cam varies the follower lift with respect to speed. Various components of proposed mechanism are designed and fabricated by proper processes and assembled together with suitable provisions. The system is tested experimentally and follower lift was measured using the computerised measuring system. Results show that the mechanism works properly and is useful to get variable lift. The proposed mechanism can be used in automotive engines as a valve train for variable valve actuation with necessary modifications.