Abstract: An automatic transmission for an electric vehicle hub includes an external motor rotor fixedly connected with a motor shaft; a sun gear; at least three first planet gears; and at least three second planet gears coaxially fixed with the corresponding first planet gears and which are engaged with the sun gear. The first and the second planet gears are respectively engaged with first and second internal gears, and the second internal gear has a diameter greater than that of the first internal gear. The rotating disk is arranged between the first internal gear and the second internal gear, and a hub is fixed to exterior of the rotating disk. The automatic transmission further includes a clutch device, making the rotating disk and the first internal gear contact with each other for a transmission of slower rpm, and when the rpm reaches critical, at a high-speed rotation.

Abstract: An automatic transmission for an electric vehicle hub includes an external motor rotor fixedly connected with a motor shaft; a sun gear; at least three primary planet gears which are engaged with the sun gear; and at least three secondary planet gears coaxially fixed with the primary planet gears. The primary and the secondary planet gears are engaged with a primary and a secondary internal gears, and the secondary internal gear has a diameter greater than that of the primary internal gear. The rotating disk is arranged between the primary internal gear and the secondary internal gear, and a hub is fixed to exterior of the rotating disk. The automatic transmission further includes a clutch device, making the rotating disk and the primary internal gear contact with each other for a transmission of slower rpm, and when the rpm reaches critical, at a high-speed rotation.