Patent ID: 6878087

Claim:
A speed change mechanism of an automatic transmission, comprising: a single pinion type planetary gear unit concentrically disposed on a position of a given axis and includes a sun gear, pinions meshed with the sun gear, a ring gear meshed with the pinions and a carrier rotatably carrying the pinions; a double sun gear type planetary gear unit concentrically disposed on the other position of the given axis and includes two sun gears, pinions meshed with the two sun gears, a ring gear meshed with the pinions and a carrier rotatably carrying the pinions; first and second brakes concentrically arranged on different positions of the given axis, the first brake being arranged to selectively fix the carrier of the double sun gear type planetary gear unit and the second brake being arranged to selectively fix one of the two sun gears of the double sun gear type planetary gear unit; and first and second clutches coaxially arranged on different positions of the given axis to transmit a speed changed rotation to rotational elements of the two planetary gear units to provide the automatic transmission with a desired speed or position, wherein the first clutch is arranged to transmit the speed changed rotation to the ring gear of the single pinion type planetary gear unit, and the second clutch is arranged to transmit the speed changed rotation to the sun gear of the single pinion type planetary gear unit; and wherein the first clutch is concentrically arranged around the single pinion type planetary gear unit, and the second clutch is coaxially arranged beside the first clutch at a position that is a first distance apart from the double sun gear type planetary gear unit and a second distance apart from the single pinion type planetary gear unit, the first distance being greater than the second distance.