A bench test calibration method for generating wet clutch torque transfer functions includes obtaining in-vehicle clutch torques at a set of shift conditions; performing a series of bench tests at various clutch pack clearances and lubrication oil flow rates at the set of shift conditions; adjusting clutch pack clearances and lubrication oil flow rates during the series of bench tests in response to a difference between a bench test measured clutch torques and the corresponding in-vehicle clutch torques exceeding a threshold; and recording relationships between first bench test measured torques and force profiles of a clutch actuator relative to the adjusted clutch pack clearances and lubrication oil flow rates for each of the set of shift conditions as a first transfer function.

Proposed is a hydraulic supply system in an automatic transmission of a vehicle, said hydraulic supply system having a primary hydraulic circuit (I) for supplying the transmission components, having a secondary hydraulic circuit (II) for lubricating and cooling the transmission components and having at least one pump (P) for generating a supply flow rate in the hydraulic circuits (I, II), wherein a detecting device (E) for detecting the current hydraulic fluid volumetric flow rate in the secondary hydraulic circuit (II) for adjusting a minimum supply flow rate of the pump (P) is provided. Furthermore, a method for controlling a pump of a hydraulic supply system in an automatic transmission of a vehicle is proposed, wherein the respectively current hydraulic fluid volumetric flow rate in a secondary hydraulic circuit (II) for lubricating and cooling the transmission components is detected, wherein a volumetric flow rate requirement is determined from a characteristic map relating to the current operating range of the automatic transmission, and wherein the supply flow rate of the pump (P) is controlled as a function of the determined volumetric flow rate requirement.

A method for the control of a hydraulic system of a motor vehicle is provided. A high-pressure branch is fed by a main oil pump which is driven by an internal combustion engine. The high-pressure branch or a low-pressure branch is fed by an additional oil pump depending on a switch position of a switching valve. The additional oil pump is used for feeding the high-pressure branch or the low-pressure branch depending on a total volume flow demand and on the volume flow available from the main oil pump. A nominal rotation speed of an electric motor which drives the additional oil pump is determined based on a volume flow balance, a valve status of the switching valve, a low-pressure pump map or a high-pressure pump map. Depending on the valve status, either the low-pressure pump map or the high-pressure pump map is used to determine the nominal rotation speed.

A pressurized fluid supply system for a vehicle transmission is provided. The fluid supply system has a pump with at least high and low pressure outputs that supplies high and low pressure components via a directional valve. The pressurized fluid supply system minimizes the parasitic loss upon a vehicle engine.

A hydraulic system (10) for a vehicle is provided. The hydraulic system comprises a shifting mechanism (20) and a pump assembly (30) configured to provide pressurized fluid to said shifting mechanism (20), and an electrical motor (40). The movement of the shifting mechanism (20) controls a valve function which serves to open a connection from the pump assembly (30) to the electrical motor (40).

A hydraulic arrangement for a vehicle transmission includes a hydraulic system path leading to a hydraulic system circuit with a system pressure, a hydraulic lubrication path leading to a hydraulic lubrication circuit with a lubrication pressure, and a branching point connected to an output side of the system and lubrication paths. A variable displacement pump or a pump combination includes at least two fixed displacement pumps hydraulically connected to an input side of the branching point, and a variable displacement pump or at least one fixed displacement pump are hydraulically connected to the output side of the branching point and integrated into the hydraulic system path.

An electric oil pump control method for operating a transmission of a hybrid vehicle which is driven by a first motor, a second motor, and an engine is provided. The method includes determining a number of revolutions of a low-pressure pump of an electric oil pump based on lubrication flow amount of the first motor, lubrication flow amount of the second motor, cooling flow amount of the first motor, and cooling flow amount of the second motor and determining a number of revolutions of a high-pressure pump of the electric oil pump based on control flow amount of a clutch of the transmission and lubrication flow amount of a rotation driver included in the transmission. A maximum value is determined of the determined number of revolutions of the low-pressure pump and the determined number of revolutions of the high-pressure pump as a number of revolutions of the electric oil pump.

An oil supply device comprises a main pump driven by an engine and capable of supplying oil to an automatic transmission and to a hydraulic control valve, an electric motor, a subsidiary pump driven by the electric motor that raises the pressure of a portion of the oil discharged from the main pump and supplies the oil to the hydraulic control valve, and a motor controller which controls driving of the electric motor on the basis of the pressure of the oil supplied to the automatic transmission. The motor controller implements control to drive the subsidiary pump by the electric motor to raise the pressure of a portion of the oil discharged from the main pump to a prescribed pressure or above and supply the oil to the hydraulic control valve when the pressure of the oil supplied to the automatic transmission is less than the prescribed pressure.

A power transmission device for a hybrid vehicle has a first clutch device (1a) disposed in a drivetrain between an engine (E) and a driving wheel (D). A second clutch device (1b) disposed in a drivetrain extends from a motor (M) to the driving wheel (D). The oil pump (P), connected to the motor (M), supplies oil to a predetermined moving component disposed in the vehicle by using driving power of the motor (M). A transmission (A) is disposed in a drivetrain between the engine (E) and the motor (M) and the driving wheel (D). The transmission adjusts rotation speed of the motor (M). The power transmission device supplying oil by causing the motor (M) to rotate the oil pump (P) at an appropriate rotation speed.

A pump unit provides a hydraulic pressure for actuating an actuator in the drive train of a motor vehicle, in particular a clutch actuator or gearbox actuator. The pump unit includes a pump, a storage container for hydraulic fluid, and at least one solenoid valve. The solenoid valve is arranged within the storage container such that it is surrounded by hydraulic fluid.