Patent ID: 7311634

Claim:
A seven-speed powertrain for an automatic transmission comprising: an input shaft; an output shaft disposed in parallel with the input shaft; a primary shift portion arranged on the input shaft so as to receive an input from the input shaft, and including a compound planetary gear set having a first, a second, a third, and a fourth operational element and a first simple planetary gear set having a fifth, a sixth, and a seventh operational element; a secondary shift portion arranged on the output shaft so as to transmit an output to the output shaft, and including a second simple planetary gear set having an eighth, a ninth, and a tenth operational element; and a transfer gear device connecting one of the operational elements of the primary shift portion and one of the operational elements of the secondary shift portion such that power from the primary shift portion can be transmitted to the secondary shift portion, wherein the first to the seventh operational elements of the primary shift portion are combined by three clutches, two brakes, and one one-way clutch, such that three operational elements of the first to the seventh operational elements act as variable input elements and two operational elements act as variable reaction elements; and the eighth to the tenth operational elements of the secondary shift portion are combined by one clutch, one brake, and one one-way clutch, such that one operational element of the eighth to the tenth operational elements acts as a variable reaction element and one operational element acts as an output element, and wherein the first simple planetary gear set of the primary shift portion is formed by a single pinion planetary gear set, and the compound planetary gear set of the primary shift portion is formed by a Ravingneaux type planetary gear set; the first simple planetary gear set comprises a first ring gear of the fifth operational element, a first planet carrier of the sixth operational element, and a first sun gear of the seventh operational element; and the compound planetary gear set comprises a second sun gear of the fourth operational element, a third sun gear of the first operational element, a second ring gear of the second operational element, and a second planet carrier of the third operational element.