Rotary sun gear 1 rotates about fixed axis A-A and meshes with planet gear 2 which is rigidly attached to planet gear 3. Gear 3 meshes with planet gear 4 which is rigidly attached to planet gear 5. Planet gears 2 and 3, and 4 and 5 are connected by turning pairs to carrier 6 which rotates about axis A-A. Gear 5 meshes with internal gear 7 which rotates about axis A-A. The speeds n₁, n₆ and n₇ of gear 1, carrier 6 and gear 7 (in rpm) are related by the equation n₆=(z₂z₄z₇n₁+z₁z₃z₅n₇)/(z₂z₄z₇+z₁z₃z₅) where z₁, z₂, z₃, z₄, z₅ and z₇ are the numbers of teeth of gears 1, 2, 3, 4, 5 and 7.
$2900$CxG,DR$