Take B as the moving point (B as the small slider pressed by the black spring in theory) and OA as the moving system. The absolute motion of B is a circular motion around the edge of the big wheel; The relative motion is a linear motion along the chute on the OA rod; Implication motion is the motion of the coincidence point between OA rod and B slider.

Velocity vector equation: vB=vr+ve,? The size can be obtained by geometric method;

The equation of acceleration velocity vector: aBt+aBn=ar+aen+ak, and the size can be obtained by projection method.