Patent ID: 7621841
Filing Date: 2009-11-24
Classification: F16H

Abstract:
1. A gear train of an automatic transmission having first and second planetary gear sets comprising simple planetary gear sets and a third planetary gear set comprising a compound planetary gear set, and a plurality of friction members, wherein: the first planetary gear set reduces an engine speed received from an input shaft through a first input path and outputs the reduced speed through a first intermediate output path; the second planetary gear set receives the reduced speed through first and second intermediate input paths, and outputs the reduced speed or a reversed speed through a second intermediate output path, the second planetary gear set selectively acting as a fixed element; and the third planetary gear set selectively receives the engine speed from the input shaft through a second input path, selectively receives input speeds from the first and second planetary gear sets through third and fourth intermediate input paths, and outputs a plurality of changes speeds through a final output path; wherein the first and second planetary gear sets comprise single pinion planetary gear sets; and the third planetary gear set comprises a compound planetary gear set in a combination of single and double pinion planetary gear sets sharing a ring gear and a planet carrier.