Synthesis and analysis of coupler curves with combined planar cam follower mechanisms

Abstract

Cam and follower mechanisms are widely used to convert a rotary input motion into a controlled reciprocating or oscillating motion as output in machines or robots. As this mechanism has an ability to provide unlimited variety of output motions. Many works are done on the synthesis of coupler curves or path generation using four bar mechanism. The present work investigates the alternative way of dealing with the path generation problems of industrial application by using cam mechanisms. Proposed a new mechanism which comprises four bar and cam follower mechanism, these mechanisms are combined together to obtain a single-input combined cam mechanism (CCM). Dimensional synthesis has been carried out by guiding the coupler point along predefined path (ellipse or straight line) of profile cutting machine. One of the objectives was to compare the path of coupler in four bar and CCM. Further, kinematic simulation of both mechanisms was performed to estimate the error and validate the proposed methodology. Results show that coupler point follows same path as ellipse or straight line profile in both mechanisms. Proposed CCM successfully applied to the complex path generation problems of profile cutting machine like square, circle and figure eight profiles. A method of kinematic analysis of proposed mechanism was also discussed. Finally, dynamic stability and separation of cam follower contact was simulated by using Matlab Simulink tool. Results show that proposed CCM was found stable from kinematic and dynamic point of view.

International Journal of Engineering, Science and Technology, Vol. 2, No. 6, 2010, pp. 231-243