Planar Mechanisms with Friction
We consider a planar, R-RPR, mechanism with three moving links with frictionless revolute joints and a prismatic joint with friction. The driver link is 1, the connecting rod is 2 and the slider is the link 3. The driver and the slider are connected to the ground with revolute joints. Between the link 2 and the slider is a prismatic joint with friction. The equations of motion for the direct dynamics are developed using the Kane’s dynamical equations with friction. There is a friction force that acts on the links connected by the prismatic joint. In order to take in consideration the normal reaction force N between the links 2 and 3, a generalized speed is introduced. The friction forces are introduced in the generalized active forces. The equations of motion are obtained and solved. The results are plotted for different coefficients of friction and different geometries of the slider.