Patent ID: 7819773
Filing Date: 2010-10-26
Classification: F16H

Abstract:
1. An automatic transmission for a vehicle, comprising: a case including a sidewall; an input shaft; a speed reduction planetary gear set that comprises a stationary element which is held against rotation, an input rotary element that receives input rotation from the input shaft; a reduced speed rotary element that outputs a reduced speed rotation at a speed less than that of the input rotation; a planetary gear unit that includes first, second, third, and fourth rotary elements that are arranged in a rotational speed relationship according to their gear relationships; a first input transfer clutch, having output side and input side transfer members, for selective transfer of the input rotation to the first rotary element; a second input transfer clutch, having output side and input side transfer members, for selective transfer of the input rotation to the third rotary element; a first speed reduction transfer clutch, having output side and input side transfer members, for selective transfer of reduced speed rotation through the speed reduction planetary gear set to the first rotary element; a second speed reduction transfer clutch, having output side and input side transfer members, for selective transfer of reduced speed rotation through the speed reduction planetary gear set to the second rotary element; a first brake for selectively locking the first rotary element against rotation; and a second brake for selectively locking the third rotary element against rotation; and wherein the automatic transmission outputs rotation from the fourth rotary element; wherein the output side transfer member of the second input transfer clutch extends coaxially with and radially outward of the output side transfer members of the first and second speed reduction transfer clutches to link with the third rotary element; wherein the output side transfer member of the first input transfer clutch and the output side transfer member of the first speed reduction transfer clutch are linked to the first rotary element, thereby rotate integrally, and are coaxial with and radially inward of the output side transfer member of the second speed reduction transfer clutch; and wherein: a first forward speed is established by engaging the second speed reduction transfer clutch and locking the second brake; a second forward speed is established by engaging the second speed reduction transfer clutch and locking the first brake; a third forward speed is established by engaging the second speed reduction transfer clutch and the first speed reduction transfer clutch; a fourth forward speed is established by engaging the second speed reduction transfer clutch and the first input transfer clutch; a fifth forward speed is established by engaging the second speed reduction transfer clutch and the second input transfer clutch; a sixth forward speed is established by engaging the second input transfer clutch and the first input transfer clutch; a seventh forward speed is established by engaging the second input transfer clutch and the first speed reduction transfer clutch; an eighth forward speed is established by engaging the second input transfer clutch and locking the first brake; and a reverse speed is established by engaging the first speed reduction transfer clutch or the first input transfer clutch, and locking the second brake.