Carrier 1 rotates about fixed axis A and is connected by turning pair B to internal friction wheel 2 which contacts and rolls around fixed friction wheel 3. The speeds n₁ and n₂ (in rpm) without slippage of carrier 1 and wheel 2 are related by the condition: n₂=n₁*((R-r)/R) where R and r are the radii of wheels 2 and 3.
$3366$SmF,3L$