A fluid pump unit includes: an electric pump unit configured to circulate a fluid in a gear mechanism; a cooling unit configured to cool the circulating fluid; and a flow path distribution member disposed on the gear mechanism and including therein a first flow path connected to the electric pump unit and a second flow path connected to the cooling unit, the electric pump unit and the cooling unit being installed on the flow path distribution member.

A method and apparatus for controlling transmission oil temperature are provided. The transmission oil is heated using a motor coil of an electric oil pump (EOP) as a heater before a startup of a vehicle. The method includes applying a current to the motor coil of the EOP configured to operate a transmission of the vehicle to thus heat the transmission oil by heat generated from the motor coil.

An automatic transmission system includes a housing containing automatic transmission fluid (ATF), a plurality of clutches configured to be engaged to generate gear ratios corresponding to forward speeds of the automatic transmission, wherein one clutch of the plurality of clutches is a friction clutch movable between a disengaged state, an engaged state utilized to create one or more gear ratios of the automatic transmission, and a slippingly engaged state between the disengaged state and the engaged state where the friction clutch is not engaged to create a gear ratio of the automatic transmission, and a controller configured to selectively move the friction clutch to the slippingly engaged state when the friction clutch is not being utilized to generate the one or more gear ratios, such that the friction clutch generates heat from friction to thereby rapidly heat the ATF in the housing and improve operating efficiency of the transmission.

In one example embodiment, a valve can include a piston configured to open the valve when a first force is greater than a second force, a biasing member that pushes against the piston and exerts a substantial portion of the first force against the piston, and a material that exerts a substantial portion of the second force against the piston, wherein the material changes from a solid to a liquid at an approximate, predetermined temperature, the change of the material from solid to liquid decreases the second force and allows the piston to move and open the valve.

A hydraulic system of vehicle transmission device is provided. A heat exchanger configured downstream is used to cool working oil discharged from a torque converter, and the working oil is supplied, as lubricating oil, to a lubricating system hydraulic circuit. On the other hand, excess oil flowing out of a regulator valve for regulating line pressure returns to an input side of an oil pump through a recycle oil path. A bypass oil path is disposed in a manner of branching from the recycle oil path and connecting to an input side of the heat exchanger. A control mechanism is disposed, and when hydraulic pressure at the side of the recycle oil path is higher than that at the side of the heat exchanger, the bypass oil path is opened to guide oil at the side of the recycle oil path to the input side of the heat exchanger.

A hydraulic system of vehicle transmission device is provided. A heat exchanger configured downstream is used to cool working oil discharged from a torque converter, and the working oil is supplied, as lubricating oil, to a lubricating system hydraulic circuit. On the other hand, excess oil flowing out of a regulator valve for regulating line pressure returns to an input side of an oil pump through a recycle oil path. A bypass oil path is disposed in a manner of branching from the recycle oil path and connecting to an input side of the heat exchanger. A control mechanism is disposed, and when hydraulic pressure at the side of the recycle oil path is higher than that at the side of the heat exchanger, the bypass oil path is opened to guide oil at the side of the recycle oil path to the input side of the heat exchanger.

A drag torque reduction device for an automatic transmission includes a hydraulic controller with a parallel connection of a pressure relief valve, a constant aperture and a temperature-dependent, switchable aperture that is positioned upstream of a radiator relative to a flow of fluid to the radiator. The parallel connection is disposed between a first control edge of a converter switching valve and a first line. The first line leads to both to the radiator and through a check valve to the converter ring. The first control edge of the converter switching valve is open and lubricating oil flows through the parallel connection when the converter switching valve is in a first switching position. The first control edge of the converter switching valve is closed and lubricating oil does not flow through the parallel connection when the converter switching valve is in a second switching position.

A cooling system for a vehicle that includes a temperature detection device for detecting a temperature related to a power transmission apparatus. The cooling system includes a cooling fan and an electronic control apparatus including a load limiting portion configured, when the detected exceeds a limit temperature value, to limit a load applied to the power transmission apparatus. The electronic control apparatus is configured to determine whether the detected temperature is equal to or higher than a fan-cooling temperature value that is lower than the limit temperature value, and to control rotation of the cooling fan, such that the cooling fan is rotated when the detected temperature is not lower than the fan-cooling temperature value, and such that a rotational speed of the cooling fan is higher when a temperature of the power transmission apparatus is high, than when the temperature of the power transmission apparatus is low.

The present disclosure relates to gearboxes for aircraft gas turbine engines, in particular to arrangements for journal bearings such gearboxes, and to related methods of operating such gearboxes and gas turbine engines. Example embodiments include a gearbox for an aircraft gas turbine engine, the gearbox comprising: a sun gear; a plurality of planet gears surrounding and engaged with the sun gear; and a ring gear surrounding and engaged with the plurality of planet gears, each of the plurality of planet gears being rotatably mounted around a pin of a planet gear carrier with a journal bearing having an internal sliding surface on the planet gear and an external sliding surface on the pin.

A transmission cooler thermal bypass device that includes a body having a front side, a back side, a top side, and a bottom side. A first opening, a second opening, a third opening, and a fourth opening, whereby a first passageway connects the first opening and the second opening, and a second passageway connects the third opening and the fourth opening. At least one fin. The first passageway and the second passageway do not include a flow control valve.