A hydraulic system of a transmission having a controller and a variable displacement pump. The pump includes an inlet and outlet and is adapted to be driven by a torque-generating mechanism. The system also includes a lube circuit fluidly coupled to the pump. A lube regulator valve is disposed in the lube circuit, such that the lube regulator valve is configured to move between at least a regulated position and an unregulated position. The regulated position corresponds to a regulated pressure in the lube circuit. A pressure switch is fluidly coupled to the lube regulator valve and configured to move between a first position and a second position, where the switch is disposed in electrical communication with the controller. A solenoid is disposed in electrical communication with the controller and is controllably coupled to the pump to alter the displacement of the pump.

A control device for an automatic transmission is provided, which includes a friction engagement element, and a processor configured to execute gear change control logic configured to control a gear change operation by supplying and discharging hydraulic fluid for forming a gear stage to/from the friction engagement element, and lubricant supply control logic configured to control to switching operation of a supply amount of lubricant to the friction engagement element according to an operating state of a vehicle. The processor controls the gear change operation and the switching operation to not overlap with one another.

A hydraulic arrangement for a vehicle transmission includes a hydraulic pump for providing a system pressure for a first hydraulic system circuit and a lubrication pressure for a second hydraulic lubrication circuit. The arrangement also includes a control valve connected between a pump outlet of the pump and the two hydraulic circuits and has two different switching positions. The control valve, depending on its switching position, acts as a hydraulic connection between the pump and the system circuit or between the pump and the lubrication circuit.

A transmission, includes a transmission mechanism including a torque converter having a lock-up clutch; an oil pump configured to discharge an oil to be supplied to the transmission mechanism; a lock-up oil pressure control valve configured to adjust a pressure of the oil discharged from the oil pump and supply the oil to the lock-up clutch; a lubricating oil pressure control valve configured to adjust the pressure of the oil discharged from the oil pump and supply the oil to a portion to be lubricated of the transmission mechanism; and a controller configured to control the lock-up oil pressure control valve. The controller controls the lock-up oil pressure control valve so that a precharge time when a lubricating oil pressure which is an oil pressure supplied from the lubricating oil pressure control valve is a first lubricating oil pressure becomes shorter than another precharge time when the lubricating oil pressure is a second lubricating oil pressure which is lower than the first lubricating oil pressure when performing a precharge of supplying the oil to the lock-up clutch.

A working-fluid supply system includes: a first pump and a second pump driven by an engine; a first switching valve capable of switching a supply target of the second pump to either one of the discharge side and the suction side of the first pump; a first switching control unit configured to perform a switching control of the first switching valve; and a first pressure control unit configured to perform a control such that pressure on the suction side of the first pump becomes a predetermined first pressure when the first switching valve is switched such that the supply target of the second pump becomes the suction side of the first pump.

A hydraulic control device for an auto transmission may include: an oil pump unit configured to supply oil; a line pressure control unit configured to form line pressure using the oil supplied from the oil pump unit; a lubricating pressure control unit configured to form lubricating pressure using the oil passing through the line pressure control unit; a reducing pressure control unit configured to form reducing pressure using the oil passing through the lubricating pressure control unit; a damper control pressure control unit configured to form damper control pressure using the oil supplied from the oil pump unit; a switch unit configured to supply the lubricating pressure or the reducing pressure to a torque converter; a collection unit configured to collect the lubricating pressure; and a retention unit connected to the switch unit, and configured to retain the lubricating pressure of the torque converter.

A method for controlling an electric oil pump (EOP) of a hybrid vehicle may include determining whether or not the hybrid vehicle is in a decelerating situation in an EV mode, driving the EOP at an RPM at a point L, corresponding to a minimum RPM of the EOP to form a target line pressure of a transmission, upon determining that the hybrid vehicle is decelerating in the EV mode, determining whether or not an RPM of a turbine is equal to or greater than a predetermined reference RPM, and driving the EOP at an RPM acquired by adding a predetermined additional RPM to secure an additional flow rate of automatic transmission fluid supplied to a balance chamber of an engine clutch to the RPM at the point L, upon determining that the RPM of the turbine is equal to or greater than the predetermined reference RPM.

A transmission, includes a transmission mechanism configured to shift a rotary power input from a power source; an oil pump configured to discharge an oil to be supplied to the transmission mechanism; a lubricating oil pressure control valve configured to adjust a pressure of the oil discharged from the oil pump and supply the oil to a lubrication target portion of the transmission mechanism; and a cooler configured to cool the oil to be supplied to the lubrication target portion of the transmission mechanism by outside air. The lubricating oil pressure control valve adjusts the pressure of the oil supplied to the lubrication target portion in a manner that the pressure of the oil supplied to the lubrication target portion increases as an outside air temperature decreases.

A vehicular power transmitting system including a power transmitting member, an oil pump, and an oil piping assembly, and the oil piping assembly includes an oil piping body having an oil inlet and fixed, and a branch pipe. The branch pipe has a width direction parallel to a longitudinal direction of the oil piping body, and includes proximal and distal end portions. The proximal end portion is connected to the oil piping body, and the distal end portion has a delivery nozzle from which the oil is delivered toward the lubricated portion. The branch pipe has an opening formed in the proximal end portion, for communication of the branch pipe with the oil piping body, the opening having a dimension in a width direction of the branch pipe, which dimension is larger than a dimension of the distal end portion in the width direction of the branch pipe.

A transmission lubrication system for a vehicle providing a continuous return flow of a lubricant. The transmission lubrication system includes a differential housing, a transmission housing, a lubricant tank, a suction line, a lubricant pump, and an air suction pump. The transmission housing is connected to the differential housing in an air-tight manner and a lubricant through-passage is provided between the transmission housing and the differential housing. The lubricant tank is provided in the differential housing and has a lubricant suction opening in a lower region. The lubricant pump conveys lubricant from the lubricant tank through the suction line and conducts the lubricant to the lubrication points in the differential housing and transmission housing. The air suction pump pumps air from the lubricant tank into the transmission housing so that an excess air pressure is maintained in the transmission housing.