Periodic Shock Pulses Occurring in a Rooler Chain Driving System with a Reduction Gear.

This paper describes research on periodic shock pulses occurring in a roller chain driving system, which is used as the bed-sliding mechanism of X-ray diagnostic tables. The shock pulses, which had the periodicity of a mesh frequency between the chain and the sprocket, were observed only when the bed was moved downward with a loaded mass in a certain weight range. This roller chain system consists basically of a driving motor, a reduction gear, and two-stage chains and sprockets. Using an experimental device modeling the roller chain driving system, the shock-pulse phenomenon was investigated by changing the weight of the mass, the tension of the chain and the number of sprocket teeth. It was found that the phenomenon occurred due to periodic hits between the gear teeth at the reduction gear, which were caused by torque oscillation between the roller chain and the sprockets of the second stage. Theoretical analysis on torque oscillation was performed, which led to the elimination of the periodic shock pulses from the roller chain driving system.