GEAR (4) ROTATES AND IT IS FIXED IN THE MOTION PART AND AROUND IT THE GEARS (5)(6)(7) . THE ARE FOUND ON THE PART THAT WE WANT TO MOVE THE MOTION TO GEAR (4) . THE GEARS (5)(6)(7 (ARE FREE MOTION.THE ANGLE AMONG THEM 120ْ . AROUND THE GEARS (5)(6)(7) IS FOUND RING GEAR (20) . WHEN WE ROTATETHE GEAR (4) . THE GEARS AND RING GEAR WILL ROTATE. THIS IS THE OPERATION OF SEPARATION .WHEN WE STOP THE RING GEAR THAT CAUSES DISPLACEMENT TO CENTER OF GEARS (5)(6)(7) BY THIS THE OTHER PART WILL ROTATE THIS IS THE OPERATION OF CONNECTION . THE CHANGE OF SPEEDS HAPPEN BY PUTTINGAS THIS PART TO CONTROL IN GEARS (1)(2)(3)AND (4) . BY BRAKING THE RING GEAR THAT CONNECTS WITH THE GEARS . WE GET THE WANTED SPEEDS