A controller for a transmission including a continuously variable transmission mechanism including a primary pulley to which power of an engine is input, a secondary pulley that transmits the power to a drive wheel, and a belt that is wound around the primary pulley and the secondary pulley, increases a rotation speed of the secondary pulley as a torque transmission capacity of a lock-up clutch of a torque converter provided between the engine and the primary pulley increases, and the lock-up clutch is engaged, performs a gear shift process to change a gear ratio of the continuously variable transmission mechanism to a high side or a low side so as to cancel return movement of a drive shaft which has been twisted by the engagement of the lock-up clutch.

A controller for a transmission including a continuously variable transmission mechanism including a primary pulley to which power of an engine is input, a secondary pulley that transmits the power to a drive wheel, and a belt that is wound around the primary pulley and the secondary pulley, increases a rotation speed of the secondary pulley as a torque transmission capacity of a lock-up clutch of a torque converter provided between the engine and the primary pulley increases, and the lock-up clutch is engaged, performs a gear shift process to change a gear ratio of the continuously variable transmission mechanism to a high side or a low side so as to cancel return movement of a drive shaft which has been twisted by the engagement of the lock-up clutch.

A power transmission device includes a housing that accommodates a power transmission mechanism, a partition section that is provided in the housing and that supports the power transmission mechanism, a first oil path that is provided inside the partition section, a second oil path that is provided inside the partition section, a recess that is provided in the partition section, and a filter member that is disposed inside the recess. The recess is provided with an opening facing a direction of an axis of rotation of the power transmission device. The first oil path and the second oil path communicate via the recess.