| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the size and the weight of an automatic transmission for a vehicle having a friction engaging element, such as a clutch and a brake. SOLUTION: This automatic transmission is provided on the outside with a clutch hub 42 on which a clutch disc 47 is mounted, and a clutch drum 43 on which a plurality of clutch discs 48 making frictional engagement with the clutch disc 47 are mounted at the inside. A piston drum 52 having diameter larger than those of the clutch discs 47 and 48 is fixed between a hollow shaft part 51 having diameter smaller than that of the clutch hub 42 and the clutch drum 43. A piston 53 is axially movably situated in the piston drum 52, a piston oil chamber 54 is formed in the piston drum 52, and a cancel oil chamber 58 is formed axially externally of the piston oil chamber 54 by a retainer 57 situated between the outer peripheral surface of the piston and the piston drum 52.</p> |
