| 摘要 |
PROBLEM TO BE SOLVED: To improve degree of freedom in switching of a mechanical engagement mechanism.SOLUTION: An automatic transmission includes a plurality of engagement mechanisms, and the engagement mechanisms have a mechanical engagement mechanism functioning as a brake. The mechanical engagement mechanism can switch a rotational element between a first state of regulating only one-direction rotation and a second state of regulating bidirectional rotation; in a case of a reverse gear, makes the rotational element into the second state; and in a case of a forward lowest gear, enables the rotational element to be made into any of the first state and the second state. In order to switch the rotational element from the second state to the first state at the forward lowest gear, the automatic transmission engages a predetermined engagement mechanism, and thereby reduces a load acting on the mechanical engagement mechanism in switching.SELECTED DRAWING: Figure 11 |
