Abstract: In the design of crank connecting rod mechanism, in order to timingly adjust
the distance from the crank to the center of the crankshaft, an innovative design of the
crankshaft structure is given. Through the CAM slot with relative rotation disc in synchronous
rotation, the planar linkage mechanism in the circumstance achieves the adjustment of the
crank shaft eccentricity, and can bring crank which was realized using the middle CAM phase
synchronous rotation. ADAMS simulation analysis shows that the structure can meet the
needs of the stepless speed regulation system, the crank displacement and the original
dynamic basic linear relation.

Key words: crank-link mechanism, speed control timing, crankshaft, adjustable eccentric
distance