HIRADMAT MULTI-MATERIAL TESTING PROJECT
Evaluation of master cylinder’s motion system:
analysis and improvement of Geneva mechanism.
Alessio D’Andrea, Oussama Id Bahmane, Pascal Secouet and Emilien Rigutto
Geneva mechanism
Main features:
•translates a continuous rotation into
an intermittent rotary motion;
•easy developing and dimensioning;
•repeatability in placement;
•precision in placement;
•accidental shock resistant;
•no backlash motion;
•compact size;
•cheap motion and control systems;
•BUT…needs a gap to work correctly
A solution to improve the precision in stop phases
The strategy consists in the continuous translation of the drive wheel.
• In the stop phases the springs
pushes the drive wheel onto the
driven wheel ensuring zero gap
so the precision increases
(decrease of random error);
calibrated
cylinder
• The cam in stop phases doesn’t
work and the springs have a
adjustable limiting system.
The plate and
drive wheel
translate up
and down
together.
position of
new cam
springs
A solution to improve the precision in stop phases
• During the transient phases a cam, solidal to drive wheel, imposes the
right gap of operation;
Example of radial gap’s trend
transient phase
stop phase
Finally this solution allows, through the variable gap,
to reach kinematic and precision goals.