Patent attributes
The present invention relates to a two-speed transmission and includes a first sun gear; a second sun gear; a plurality of first planetary gears which are engaged with the first sun gear to rotate or revolve along a circumferential direction of the first sun gear; a ring gear which includes an inner circumferential gear and an outer circumferential gear, the outer gear rotating by being engaged with an input gear which rotates by a driving device; a plurality of second planetary gears which are engaged with the inner circumferential gear and the second sun gear to rotate or revolve along a circumferential direction of the second sun gear; a carrier to which the first planetary gears and the second planetary gears are rotatably connected; and a brake part which selectively fixes the first sun gear and the second sun gear.