Abstract: A hydraulic pressure control method for a vehicle transmission includes accumulating factors representing vehicle usage, accumulating factors representing driver's driving tendency, calculating a first line pressure compensation value according to the usage depending on the accumulated values of the factors representing the vehicle usage, calculating a second line pressure compensation value according to the driver's driving tendency depending on the accumulated values of the factors representing the driver's driving tendency, determining a final line pressure by adding the first and second line pressure compensation values according to the usage and the driver's driving tendency to a basic line pressure, and operating a transmission hydraulic system according to the final line pressure.

Abstract: A method of controlling an EOP of a powertrain may include determining, by a controller electrically connected to the EOP, whether an oil sloshing phenomenon in which it is difficult for oil to return to a space where an oil intake port of the EOP is positioned may occur while a vehicle is running; and reducing, by the controller, the revolutions per minute (RPM) of the EOP by a predetermined reduced RPM when it is determined that the oil sloshing phenomenon may occur.

Abstract: An oil pump is connected to an electric motor and receives driving power, and the oil pump operates normally in a forward direction at normal times regardless of whether the electric motor operates in the forward or reverse direction thereof. Therefore, according to A system for operating an oil pump for a vehicle, the oil pump, which operates in conjunction with the electric motor, is applied, which reduces costs in comparison with an electric oil pump. Furthermore, regardless of whether the electric motor operates in the forward or reverse direction, the oil pump operates normally, which normally circulates oil and stabilizes components of an oil system.

Abstract: A powertrain-cooling system of a hybrid vehicle may include an electric oil pump, a pressure control valve, which includes an input port receiving fluid discharged from the electric oil pump, an output port outputting the fluid to a transmission while adjusting the pressure of the fluid, and a drain port discharging a portion of the fluid in accordance with adjustment of the pressure of the fluid, a first motor cooling path connecting the drain port of the pressure control valve to a first motor forming a hybrid powertrain, and a controller electrically connected to the electric oil pump and configured for controlling the electric oil pump to cool the transmission and the first motor.

Abstract: A method of controlling an electric oil pump (EOP) for a vehicle includes, if a current temperature of oil is lower than a reference temperature, determining whether an EOP RPM is lower than a minimum driving RPM, if the EOP RPM is lower than the minimum driving RPM, applying a first reduction rate for a first setting time and reducing a target line pressure and an instruction RPM of the EOP, if the EOP RPM is equal to or higher than the minimum driving RPM, determining whether vibration of the EOP RPM is generated above a reference vibration, and if the vibration is generated above the reference vibration, applying a second reduction rate for a second setting time and reducing the target line pressure or the instruction RPM of the EOP.

Abstract: A method of controlling an electric oil pump (EOP) of a vehicle includes: confirming a gear shift type when a gear shift of a vehicle is started; compensating for the number of revolutions of the EOP according to the confirmed gear shift type; confirming whether a measured line pressure converges on a command line pressure while the compensating for the number of revolutions of the EOP according to the gear shift type is performed; and, when it is determined that the measured line pressure does not converge on the command line pressure, additionally compensating for the number of revolutions of the EOP.

Abstract: A method of controlling an EOP of a hybrid vehicle may include controlling the EOP in a predetermined high-speed mode when the vehicle is started; controlling the EOP in a predetermined middle-speed mode in which the EOP is driven at revolutions per minute (RPM) lower than RPM of the high-speed mode when the high-speed mode is terminated; and controlling the EOP in a predetermined low-speed mode in which the EOP is driven at RPM lower than the RPM of the middle-speed mode when the vehicle is stopped.

Abstract: A hydraulic pressure control method for a vehicle transmission includes accumulating factors representing vehicle usage, accumulating factors representing driver's driving tendency, calculating a first line pressure compensation value according to the usage depending on the accumulated values of the factors representing the vehicle usage, calculating a second line pressure compensation value according to the driver's driving tendency depending on the accumulated values of the factors representing the driver's driving tendency, determining a final line pressure by adding the first and second line pressure compensation values according to the usage and the driver's driving tendency to a basic line pressure, and operating a transmission hydraulic system according to the final line pressure.

Abstract: A method of controlling an electric oil pump (EOP) for a vehicle includes, if a current temperature of oil is lower than a reference temperature, determining whether an EOP RPM is lower than a minimum driving RPM, if the EOP RPM is lower than the minimum driving RPM, applying a first reduction rate for a first setting time and reducing a target line pressure and an instruction RPM of the EOP, if the EOP RPM is equal to or higher than the minimum driving RPM, determining whether vibration of the EOP RPM is generated above a reference vibration, and if the vibration is generated above the reference vibration, applying a second reduction rate for a second setting time and reducing the target line pressure or the instruction RPM of the EOP.

Abstract: 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.

Abstract: A method of controlling an electric oil pump (EOP) of a vehicle includes: confirming a gear shift type when a gear shift of a vehicle is started; compensating for the number of revolutions of the EOP according to the confirmed gear shift type; confirming whether a measured line pressure converges on a command line pressure while the compensating for the number of revolutions of the EOP according to the gear shift type is performed; and, when it is determined that the measured line pressure does not converge on the command line pressure, additionally compensating for the number of revolutions of the EOP.

Abstract: 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.

Abstract: A hybrid vehicle control method includes: monitoring an electric oil pump (EOP) driving current in which an EOP is being driven at a predetermined target RPM, and determining whether the EOP driving current is in a predetermined reference range in which it possible to estimate a situation in which the EOP suctions air; determining whether a measured hydraulic pressure at a place receiving oil supplied by the EOP is less than reference hydraulic pressure when the EOP driving current is in the predetermined reference range; and temporarily decreasing line pressure and increasing an RPM of the EOP.

Abstract: A method of controlling an EOP of a hybrid vehicle may include controlling the EOP in a predetermined high-speed mode when the vehicle is started; controlling the EOP in a predetermined middle-speed mode in which the EOP is driven at revolutions per minute (RPM) lower than RPM of the high-speed mode when the high-speed mode is terminated; and controlling the EOP in a predetermined low-speed mode in which the EOP is driven at RPM lower than the RPM of the middle-speed mode when the vehicle is stopped.

Abstract: A method of controlling an EOP of a powertrain may include determining, by a controller electrically connected to the EOP, whether an oil sloshing phenomenon in which it is difficult for oil to return to a space where an oil intake port of the EOP is positioned may occur while a vehicle is running; and reducing, by the controller, the revolutions per minute (RPM) of the EOP by a predetermined reduced RPM when it is determined that the oil sloshing phenomenon may occur.

Abstract: A powertrain-cooling system of a hybrid vehicle may include an electric oil pump, a pressure control valve, which includes an input port receiving fluid discharged from the electric oil pump, an output port outputting the fluid to a transmission while adjusting the pressure of the fluid, and a drain port discharging a portion of the fluid in accordance with adjustment of the pressure of the fluid, a first motor cooling path connecting the drain port of the pressure control valve to a first motor forming a hybrid powertrain, and a controller electrically connected to the electric oil pump and configured for controlling the electric oil pump to cool the transmission and the first motor.

Abstract: A shift control method of a transmission including an electric oil pump (EOP) directly connected to a friction clutch for a vehicle may include: when a shift is initiated, setting, by a controller, a predetermined first target RPM for controlling the EOP; determining, by the controller, a target current based on the first target RPM; maintaining, by the controller, the first target RPM until an EOP driving current reaches the target current; when the EOP driving current is greater than or equal to the target current, linearly reducing, by the controller, an RPM of the EOP from a predetermined second target RPM to a third target RPM; and increasing, by the controller, an EOP driving power to increase a friction force of the friction clutch such that a slip of the friction clutch is smaller than a predetermined reference slip.

Abstract: A shift control method of a transmission including an electric oil pump (EOP) directly connected to a friction clutch for a vehicle may include: when a shift is initiated, setting, by a controller, a predetermined first target RPM for controlling the EOP; determining, by the controller, a target current based on the first target RPM; maintaining, by the controller, the first target RPM until an EOP driving current reaches the target current; when the EOP driving current is greater than or equal to the target current, linearly reducing, by the controller, an RPM of the EOP from a predetermined second target RPM to a third target RPM; and increasing, by the controller, an EOP driving power to increase a friction force of the friction clutch such that a slip of the friction clutch is smaller than a predetermined reference slip.

Abstract: A hydraulic pressure control method for a transmission includes determining whether a current shift range is among a plurality of shift ranges, setting a dither frequency of a pressure control solenoid valve of a hydraulic circuit for the transmission to a predetermined first frequency when the current shift range is a predetermined first range, and setting the dither frequency of the pressure control solenoid valve to a predetermined second frequency when the current shift range is a shift range other than the first range.

Abstract: A torque converter may include: an impeller and a turbine hub to form a chamber together, a damper piston connected to a damper clutch and divide the chamber into a damper chamber and a balance chamber, a discharge path to connect and block the balance chamber and control an internal flow rate of the torque converter, and an O-ring to open or close the discharge path.