Calculating the kinematics of moving parts
Instantaneous speed fluctuations of thermal engines. Excitations applied to the crankshaft

This study focuses on the kinematic characteristics of the connecting rod center of gravity and the connecting rod base. These two points are acted upon respectively by the loads associated with the acceleration of the connecting rod mass, its rotational inertia and the acceleration of the piston mass. As this type of analysis is customary for engine manufacturers, and in order not to make the text unnecessarily long, the intermediate calculation steps are only briefly detailed.

To deal with this problem in a simple way, let's consider that the connecting rod operates in line with the cylinder axis, i.e. :

• without an offset between the axis of rotation of the line bearings and the axis of the cylinder barrel (an offset sometimes presented as being able to reduce friction losses in the mobile coupling);

• without any offset between the axis of rotation...