Double Plus Chain Principle

・Chain speed : ν

・Pallet speed : V

・Small roller radius : r

・Large roller radius : R

Frictional force between the large roller (O) and the small roller (●) causes the rollers to rotate simultaneously. The difference in diameters of the rollers causes the speed of the conveyed object to be 2.5 times that of the chain.

When the chain runs at speed v, the circumferential speed on the periphery of the small roller (rolling speed on the rail running face) becomes v.
Since the large and small rollers now rotate at the same angular speed, the circumferential speed on the periphery of the large roller is calculated as below, based on the ratio of the radii (R/r) x v.

Consequently, the conveying speed V is the sum of the circumferential speed (R/r)×ν and chain speed v.

V=(R/r)×ν+ν

V=(R/r+1)×ν

From the ratio of radii (R/r)≒1.5

V≒(1.5+1)

ν≒2.5ν

When a braking force is applied to the large roller,
a slip occurs between the large (O) and small (●) rollers
so as to allow free-flow conveyance.