Patent ID: 8303457
Filing Date: 2012-11-06
Classification: F16H

Abstract:
1. An automatic transmission comprising: a casing; an input shaft provided inside said casing and connected to a driving source; an output member arranged at a radially outward position on a same axis as an axis of said input shaft and at an intermediate position of said input shaft; first, second and third gear sets each formed as a single-pinion type planetary gear set including a sun gear, a pinion, a carrier and a ring gear, said sun gear of said first gear set being continuously interconnected with said sun gear of said second gear set, said ring gear of said first gear set being continuously interconnected with said carrier of said second gear set, said ring gear of said second gear set being continuously interconnected with said carrier of said third gear set, said sun gear of said third gear set being continuously interconnected with said input shaft, said carrier of said first gear set being continuously interconnected with said output member; a first clutch to selectively connect and disconnect said sun gear of said first gear set and said sun gear of said second gear set to and from said input shaft; a second clutch to selectively connect and disconnect said ring gear of said first gear set and said carrier of said second gear set to and from said input shaft; a first brake to selectively connect and disconnect said ring gear of said first gear set and said carrier of said second gear set to and from said casing; a second brake to selectively connect and disconnect said ring gear of said second gear set and said carrier of said third gear set to and from said casing; and a third brake to selectively connect and disconnect said ring gear of said third gear set to and from said casing, wherein: said first clutch and said first brake are respectively placed in engaged states to establish a first speed stage, said first clutch and said second brake are respectively placed in engaged states to establish a second speed stage, said first clutch and said third brake are respectively placed in engaged states to establish a third speed stage, said first clutch and said second clutch are respectively placed in engaged states to establish a fourth speed stage, said second clutch and said third brake are respectively placed in engaged states to establish a fifth speed stage, said second clutch and said second brake are respectively placed in engaged states to establish a sixth speed stage, said first, second, and third gear sets are disposed on said input shaft in a side by side relationship and said first and second clutches are disposed on said input shaft on a near side closer to said driving source, relative to said first, second and third gear sets, and a diameter of a portion of said input shaft where said first, second, and third gear sets are disposed is smaller than a diameter of another portion of said input shaft where said first and second clutches are disposed.