Gear 1 is keyed to shaft a, rotates about fixed axis A-A and meshes with planet gear 2 which is connected by a turning pair to carrier 4. Drive pulley 5 is keyed to carrier 4 and rotates about axis A-A. Planet gear 2 meshes with fixed internal gear 3. When gear 1 rotates, gear 2 rolls around inside gear 3 and rotates pulley 5 about axis A-A. The numbers of teeth of gears 1, 2 and 3 satisfy the conditions: z₁=z₂ and z₃=3z₁. Then the speeds n₁ and n₅ of gear 1 and pulley 5 (in rpm) satisfy the condition n₅=n₁/4 i.e. drive pulley 5 rotates in the same direction as gear 1 but at an angular velocity only one-fourth that of the gear.
$2883$CxG,PR$