文档介绍：Available online at hanism
and
Machine Theory
Mechanism and Machine Theory 43 (2008) 996–1008
ate/mechmt
Numerical and experimental analysis of non-circular gears
and cam-follower systems as function generators
Erika Ottaviano a, Domenico Mundo b, Guido A. Danieli b, Marco arelli a,*
a LARM: Laboratory of Robotics and Mechatronics, University of Cassino, Cassino (Fr), Italy
b Department of Mechanics, University of Calabria, Arcavacata di Rende (Cs), Italy
Received 24 November 2006; received in revised form 2 July 2007; accepted 3 July 2007
Available online 20 August 2007
Abstract
The paper shows an analysis of two mechanisms that are typically used as function generators. The former consists of a
pair of non-circular gears, which drives a slider-crank mechanism, the latter is a cam-follower system. Both mechanisms
are designed to obtain a specific motion law. In this paper the proposed application is to generate a pulsating blood flow
during cardiopulmonary by-pass for cardiac surgery. The prescribed motion law can be obtained by a volumetric pump,
which can be used to modulate the blood flow in external circulation machines. The reciprocating motion consists of a
quick forward stroke, corresponding to the Systolic phase, and a slow return stroke, corresponding to the Diastolic phase.
The study has been focused on specific transmission characteristics that are related to a mechanical blood pumping design.
In particular, experimental tests have been analyzed to understand benefits and drawbacks for using non-circular gears and
polynomial cams in pure mechanical transmissions with limited motion regulation but with specific prescribed motion law.
The contribution of the paper can be recognized paring numerically and experimentally a traditional cam transmis-
sion with a non-circular gear solution to show proper operation feasibility for both solutions without plex con-
trol equipment, even for a robust/reliable demanding application like