Conceptual Dynamics - Independent Learning

Relative Sliding in Mechanisms


This section will focus on mechanisms that have relative sliding between components as shown in the figure. Notice that point B is not pinned to link CD, but slides within a slot. This type of sliding adds complexity to the analysis of the system.



Again, consider the system shown above. Point B is fixed to link AB and point B' is fixed to link CD. Notice that at state 1, points B and B' coincide. However, at state 2 their positions differ. This means that they must have different velocities. Therefore, finding the velocity of point B is not as easy as using the relative velocity equation between point C and B. The equations must contain the relative velocity between points B and B' as shown in the following equations.


vB = vC + ωCD x rB/C + vB/B'