Patent ID: 7637363
Filing Date: 2009-12-29
Classification: F16D

Abstract:
1. A clutch device for an automatic transmission comprising: a clutch drum, a first frictional coupling elements and a second frictional coupling elements, both of which are supported by the clutch drum, a first piston axially movably disposed radially outwardly of the clutch drum and operating to couple the first frictional coupling elements, a second piston axially movably disposed radially inwardly of the clutch drum and operating to couple the second frictional coupling elements: wherein the clutch drum includes an inner drum portion welded on a rotary shaft, and an outer drum portion welded on the inner drum portion and supporting the first frictional coupling elements and the second frictional coupling elements; wherein the first piston is axially slidable on the inner drum portion; wherein the second piston is axially slidable on the rotary shaft; and wherein a welded portion of the rotary shaft and the inner drum portion, and a welded portion of the inner drum portion and the outer drum portion are radially spaced a predetermined distance from each other and concentric with each other.