An automatic transmission includes a transmission housing having a sump portion, a main transmission fluid pump arranged at the sump portion, and a recess having a fluid return passage. A torque converter mounted in the recess and a scavenging pump arranged in the sump portion and fluidically connected to the fluid return passage.

A cooling prioritization valve (5) for a hydraulic system (4) of a motor vehicle transmission (3) includes a valve housing (6), a valve slide (7), an inlet (18), an outlet (15), and a further outlet (21). A secondary system pressure circuit (39) of the hydraulic system (4) can be connected to the inlet (18), a cooler (54) can be connected to the outlet (15) or to the further outlet (21), and a suction loading (44) can be connected to the outlet (15) or to the further outlet (21). In a starting position, the inlet (18) is not connected either to the outlet (15) or to the further outlet (21). In a first control position, the inlet (18) is connected to the outlet (15). In a second control position, the inlet (18) is connected to the outlet (15) and the further outlet (21).

In a hydraulic control device switchable between a first state in which a first oil is supplied from a first pump to a hydraulic operation part via a bypass valve and a second state in which the first oil supplied from the first pump is pressurized by using the second pump and the pressurized first oil is supplied, as a second oil, to the hydraulic operation part, control that adds a correction hydraulic pressure of a predetermined amount to the hydraulic pressure of the oil discharged from a valve for adjusting the pressure of the oil supplied to the hydraulic operation part is performed when the second state is switched to the first state due to a stop or a low rotation state of the second pump.

The disclosure provides a hydraulic control device capable of suppressing an excessive increase in the rotation speed of a second pump and stabilizing the discharge pressure of the second pump. The target rotation speed of the second pump for making a pressure value of a first oil close to an estimated value of a pressure value of a third oil is calculated, and a feedback amount with respect to the target rotation speed is calculated by subtracting the estimated value of the pressure value of the third oil from the pressure value of the first oil detected by a hydraulic sensor. Time regions for performing calculation of the feedback amount include an update region in which the feedback amount with respect to the target rotation speed is updated, and a hold region in which update of the feedback amount with respect to the target rotation speed is temporarily stopped.

Provided is a hydraulic control device in which in the rotation control of the second pump, the required discharge pressure of the second pump can be more reliably maintained below a predetermined pressure in the control that keeps the target rotation speed constant after the feedback control ends. In the rotation control of the second pump, in the control which keeps the target rotation speed constant after the feedback control ends, the rotation of the second pump is controlled by adding a predetermined addition rotation speed to the target rotation speed corresponding to the required discharge pressure. Since the required discharge pressure of the second pump can be maintained below a predetermined pressure in the fixed mode by the addition rotation speed, it can reliably obtain the effect of reducing the work load of the first pump and contribute to the improvement of the fuel efficiency of the vehicle.

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 hydraulic control system includes a primary sump and an auxiliary sump. When the transmission fluid is warm, fluid remains in the auxiliary sump reducing the volume of oil in circulation throughout the transmission to reduce parasitic losses. An oil control valve is designed to block flow of oil from the auxiliary sump to the primary sump when the fluid is warm and to allow flow when the fluid is cold. The oil control valve also responds to transmission line pressure. At moderate temperatures, fluid is held in the auxiliary sump when the engine is running but drains back to the primary sump when the engine is off.

An automatic transmission that includes a lubricating oil supply source that supplies lubricating oil; a plurality of friction engagement elements that can attain a plurality of shift speeds according to combinations of the friction engagement elements to be engaged simultaneously; a plurality of hydraulic servos that engage and disengage the plurality of friction engagement elements according to whether an oil pressure is supplied thereto or not; and a rotary shaft that can transmit power.

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 control device for an automatic transmission is provided, which includes a vehicle-propelling friction engagement element configured to be engaged when a vehicle starts traveling, an other friction engagement element, a vehicle-propelling friction engagement element temperature detector configured to detect a temperature of the vehicle-propelling friction engagement element, an input torque detector configured to detect an input torque inputted into the automatic transmission, and a control unit comprising a lubricant supply control logic configured to control supply of lubricant to the vehicle-propelling friction engagement element and the other friction engagement element. The lubricant supply control logic switches the supply amount of lubricant to the vehicle-propelling friction engagement element according to the temperature of the vehicle-propelling friction engagement element, and switches the supply amount of lubricant to the another friction engagement element according to the input torque.