| 主权项 |
1. An automatic transmission for a vehicle, comprising:
an input shaft; an output shaft; a first planetary gear set including three rotational elements of a sun gear, a ring gear and a pinion carrier; a second planetary gear set including three rotational elements of a sun gear, a ring gear and a pinion carrier; a third planetary gear set including three rotational elements of a sun gear, a ring gear and a pinion carrier; a fourth planetary gear set including three rotational elements of a sun gear, a ring gear and a pinion carrier; and six friction engagement elements of a first brake, a second brake, a first clutch, a second clutch, a third clutch and a fourth clutch, wherein, when the three rotational elements of the first planetary gear set are arranged on a common velocity diagram in dependence upon distances corresponding to a teeth-number ratio of the first planetary gear set, the three rotational elements of the first planetary gear set are defined as a first element, a second element and a third element in order of arrangement on the common velocity diagram, wherein, when the three rotational elements of the second planetary gear set are arranged on the common velocity diagram in dependence upon distances corresponding to a teeth-number ratio of the second planetary gear set, the three rotational elements of the second planetary gear set are defined as a fourth element, a fifth element and a sixth element in order of arrangement on the common velocity diagram, wherein, when the three rotational elements of the third planetary gear set are arranged on the common velocity diagram in dependence upon distances corresponding to a teeth-number ratio of the third planetary gear set, the three rotational elements of the third planetary gear set are defined as a seventh element, an eighth element and a ninth element in order of arrangement on the common velocity diagram, wherein, when the three rotational elements of the fourth planetary gear set are arranged on the common velocity diagram in dependence upon distances corresponding to a teeth-number ratio of the fourth planetary gear set, the three rotational elements of the fourth planetary gear set are defined as a tenth element, an eleventh element and a twelfth element in order of arrangement on the common velocity diagram, wherein, the first planetary gear set is configured to integrally rotate by an engagement of the first clutch, the first element is coupled with the fifth element, the second element is configured to be locked through the first brake to a stationary section and configured to be coupled through the second clutch with the ninth element, the third element is coupled with the input shaft, the fourth element is configured to be coupled through the third clutch with the ninth element, the sixth element is locked to the stationary section, the seventh element is configured to be locked through the second brake to the stationary section, the eighth element is coupled with the output shaft, the ninth element is coupled with the twelfth element, the tenth element is configured to be coupled through the fourth clutch with the output shaft, and the eleventh element is coupled with the input shaft. |
