Patent ID: 8444530
Filing Date: 2013-05-21
Classification: F16H,Y10T

Abstract:
1. An automatic transmission system, comprising: a transmission having a plurality of transmission elements with lubrication-requiring portions and hydraulic actuators therefor; a hydraulic circuit having a switching valve that switches a supply of hydraulic fluid to the hydraulic actuators; a valve actuator that actuates the switching valve; an oil cooler disposed on a lubricating oil supply line to the lubrication-requiring portions; a shift range detection unit that detects a shift range of the transmission selected by a driver; and a control unit that controls the valve actuator to actuate the switching valve in accordance with the selected transmission shift range, the switching valve having a bypass position to supply the hydraulic fluid from the switching valve to the lubrication-requiring portions by bypassing the oil cooler; and the control unit having a judgment section to judge whether the transmission is in a low lubrication state in which an amount of the lubricating oil supplied to the lubrication-requiring portions is smaller than a given amount based on a given operating parameter of the transmission and being configured to control the valve actuator to switch the switching valve to the bypass position at the time the judgment section judges that the transmission is in the low lubrication state.