Abstract: An automatic transmission where the first engagement element is positioned between the continuously variable speed change mechanism and a portion of the second power transmission path on the wheel side, at which the second power transmission path is coupled to the first power transmission path, and is allowed to be switched to the disengaged state for inertial traveling.

Abstract: An automatic transmission where the first engagement element is positioned between the continuously variable speed change mechanism and a portion of the second power transmission path on the wheel side, at which the second power transmission path is coupled to the first power transmission path, and is allowed to be switched to the disengaged state for inertial traveling.

Abstract: In a gear pump, an outer inner wall surface of a suction port which is located on a downstream side in a rotor rotation direction, that is, a first inner wall surface, is located inward of a bottom land between internal teeth of an outer rotor, and the suction port has a shallow portion extended inward from the first inner wall surface on the downstream side in the rotor rotation direction, and a deep portion that is formed so as to be continuous with the shallow portion and that is deeper than the shallow portion. Communication between an inter-tooth chamber and the suction port is cut off with the inter-tooth chamber facing only the shallow portion.

Abstract: In a gear pump, an outer inner wall surface of a suction port which is located on a downstream side in a rotor rotation direction, that is, a first inner wall surface, is located inward of a bottom land between internal teeth of an outer rotor, and the suction port has a shallow portion extended inward from the first inner wall surface on the downstream side in the rotor rotation direction, and a deep portion that is formed so as to be continuous with the shallow portion and that is deeper than the shallow portion. Communication between an inter-tooth chamber and the suction port is cut off with the inter-tooth chamber facing only the shallow portion.

Abstract: An oil pump includes a first spill passage formed on a side surface (60) of a pump chamber (58) to communicate a hydraulic pressure chamber (54) with a first high pressure discharge passage (68) when the entire hydraulic pressure chamber (54) is positioned between the first high pressure discharge passage (68) and a first low pressure discharge passage (70). Therefore, when the hydraulic pressure chamber (54) passes between the first high pressure discharge passage (68) and the first low pressure discharge passage (70), the hydraulic pressure inside the predetermined hydraulic pressure chamber (54) escapes to the first high pressure discharge passage (68) through a first spill passage (76), so a hydraulic pressure value inside the hydraulic pressure chamber (54) is maintained at the pressure value inside the first high pressure discharge passage (68).

Abstract: A vehicular power transmitting system including an oil pump constructed to sufficiently reduce a required drive torque. A high-pressure-port discharge amount of first and second high-pressure passages of the oil pump is determined such that an amount of consumption of working oil of relatively high pressure can be afforded only by the high-pressure-port discharge amount, during steady-state running of a vehicle in which engine speed is not lower than a predetermined threshold value corresponding to a predetermined lowest target input shaft speed of a continuously variable transmission for its shifting control. The pressure of the working oil discharged from first and second low-pressure discharge passages is kept at a predetermined low level, and the required drive torque of the oil pump is sufficiently reduced.

Abstract: A vehicular power transmitting system including an oil pump constructed to sufficiently reduce a required drive torque. A high-pressure-port discharge amount of first and second high-pressure passages of the oil pump is determined such that an amount of consumption of working oil of relatively high pressure can be afforded only by the high-pressure-port discharge amount, during steady-state running of a vehicle in which engine speed is not lower than a predetermined threshold value corresponding to a predetermined lowest target input shaft speed of a continuously variable transmission for its shifting control. The pressure of the working oil discharged from first and second low-pressure discharge passages is kept at a predetermined low level, and the required drive torque of the oil pump is sufficiently reduced.

Abstract: An oil pump includes a first spill passage formed on a side surface (60) of a pump chamber (58) to communicate a hydraulic pressure chamber (54) with a first high pressure discharge passage (68) when the entire hydraulic pressure chamber (54) is positioned between the first high pressure discharge passage (68) and a first low pressure discharge passage (70). Therefore, when the hydraulic pressure chamber (54) passes between the first high pressure discharge passage (68) and the first low pressure discharge passage (70), the hydraulic pressure inside the predetermined hydraulic pressure chamber (54) escapes to the first high pressure discharge passage (68) through a first spill passage (76), so a hydraulic pressure value inside the hydraulic pressure chamber (54) is maintained at the pressure value inside the first high pressure discharge passage (68).