Abstract
Escalators run by chain drive, and the chain, which is wound up as a polygon inscribed in the sprocket, causes speed pulsation due to its geometric motion on the sprocket. If the number of teeth on the sprocket is fewer, the speed pulsation will be large. It is obvious that the number of teeth decreases in the following two cases, one is the case when we make the diameter of the sprocket smaller to reduce the space, the others is the case when we make the chain link larger to reduce the cost. In these cases, the pulsation in the chain will be large and it will make a rider uncomfortable significantly. This paper explains a new drive mechanism to suppress the speed pulsation, which in the method adding fixed rail which can achieve optimal trajectory against the chain roller. The mechanical design of the new system is investigated by kinematics analysis, and experiment results with prototype shows its validity.
