Sun gear 1 is keyed to the input shaft, rotates about fixed axis A-A and meshes with planet gears 2. Gears 2 mesh with internal gear 3 which is rigidly attached to brake drum a. Planet gears 4 are rigidly attached to gears 2 and mesh with internal gear 5 which rotates about axis A-A. Carrier 6 is connected by turning pairs to planet gears 2 and 4, and is rigidly attached to brake drum b which rotates about axis A-A. Forward or reverse rotation of internal gear 5 is obtained by braking either drum a or b. In forward rotation, when drum a is braked, the speeds n₁ and n₅ of gears 1 and 5 (in rpm) are related by the equation n₅=n₁(z₄+z₅)/(z₁+z₃). In reverse rotation, when drum b is braked, the speeds are related by the equation n₅=-n₁(z₁z₄)/(z₂z₅) where z₁, z₂, z₃, z₄ and z₅ are the numbers of teeth of gears 1, 2, 3, 4 and 5.
$2896$CxG,PR$