| 摘要 |
PURPOSE: A piston device for an automatic transmission is provided to simplify the entire structure of a transmission by releasing the pressure which is actuated as frictional force and is applied to the body of the piston. CONSTITUTION: A piston device for the auto transmission comprises a first support element(10) of the ring shape, a first piezoelectric element(30), and a second supporting member(50), and a body of the piston(70). The first piezoelectric element is settled on the first support element. A first and a second supporting member support the first support at the both sides of first piezoelectric element. A second supporting member forms oil chamber receiving the oil corresponding to the first piezoelectric element. The body of the piston comprises a plurality of rolling projections(71) and a plurality of operation projections(72). |
