Cardioid motion
Cardioid motion can be defined by rolling the circle on the outside of the fixed circle which is inside the rolling circle.
Radius of the moving circle is double radius of the fixed circle that is the cardioid motion is special case of pericycloidal motion.
The paths of points which are obtained by this motion are limaçon of Pascal or circle, in special case limaçon of Pascal is cardioid.