The friction engagement device connects the input shaft and the output shaft to transmit a driving force from a driving source from the input shaft to the output shaft. The friction engagement device includes a housing, a friction engagement portion, a piston, an oil pump, and a motor. The housing is disposed between the input shaft and the output shaft. The friction engagement portion is disposed in the housing and composed of a plurality of friction components. The piston is disposed at one side of the friction engagement portion for pressing the friction engagement portion. The oil pump is used to operate the piston. The motor is used to drive the oil pump. In the friction engagement device, abnormal wear of the friction components of the friction engagement portion is detected by monitoring a value of an operation parameter of the friction engagement device.

A vehicle includes an engine, a transmission, and a controller. The transmission has clutches, a circuit configured to transport fluid to the clutches, a pump configured to circulate the fluid through the circuit, and an accumulator disposed along the circuit. The controller is programmed to, responsive to an engine start and a fluid temperature being less than a temperature threshold, discharge the accumulator to prime the pump.

The friction engagement device connects the input shaft and the output shaft to transmit a driving force from a driving source from the input shaft to the output shaft. The friction engagement device includes a housing, a friction engagement portion, a piston, an oil pump, and a motor. The housing is disposed between the input shaft and the output shaft. The friction engagement portion is disposed in the housing and composed of a plurality of friction components. The piston is disposed at one side of the friction engagement portion for pressing the friction engagement portion. The oil pump is used to operate the piston. The motor is used to drive the oil pump. In the friction engagement device, abnormal wear of the friction components of the friction engagement portion is detected by monitoring a value of an operation parameter of the friction engagement device.

A system and method for controlling engine clutch slip for a hybrid vehicle, in which it is determined whether an engine clutch has entered a slip mode and lubrication of the engine clutch is easily achieved through an additional lubrication hydraulic pressure circuit whenever the engine clutch enters the slip mode, thereby achieving the engine clutch slip control in all shift ranges including low-speed and medium-speed ranges and maintaining the heat energy that is generated from the engine clutch at a predetermined level or lower.

A vehicle includes an engine, a transmission, and a controller. The transmission has clutches, a circuit configured to transport fluid to the clutches, a pump configured to circulate the fluid through the circuit, and an accumulator disposed along the circuit. The controller is programmed to, responsive to an engine start and a fluid temperature being less than a temperature threshold, discharge the accumulator to prime the pump.

An apparatus for determining a failure of an engine clutch is provided. The apparatus includes an engine clutch that is disposed between an engine generating power and a motor and a driving information detector that senses driving information including a shift speed stage, an engine speed, a motor speed, a SOC of a battery, and a vehicle speed. A controller then determines a driving mode of the engine from the detected driving information and determines whether oil leakage of the engine clutch is generated from the driving information and the driving mode.

A system and method for controlling engine clutch slip for a hybrid vehicle, in which it is determined whether an engine clutch has entered a slip mode and lubrication of the engine clutch is easily achieved through an additional lubrication hydraulic pressure circuit whenever the engine clutch enters the slip mode, thereby achieving the engine clutch slip control in all shift ranges including low-speed and medium-speed ranges and maintaining the heat energy that is generated from the engine clutch at a predetermined level or lower.

An apparatus for determining a failure of an engine clutch is provided. The apparatus includes an engine clutch that is disposed between an engine generating power and a motor and a driving information detector that senses driving information including a shift speed stage, an engine speed, a motor speed, a SOC of a battery, and a vehicle speed. A controller then determines a driving mode of the engine from the detected driving information and determines whether oil leakage of the engine clutch is generated from the driving information and the driving mode.

A vehicle transmission includes a first transmission mechanism arranged to transmit mechanical driving power from an output shaft of the prime mover to a first input shaft and to put any one of a first set of gears in an engaged state to drivingly connect the first input shaft to the driving wheels; and a second transmission mechanism arranged to transmit mechanical driving power from the output shaft of the prime mover to a second input shaft and to put any one of a second set of gears in an engaged state to drivingly connect the second input shaft to the driving wheels. Controllable first and second clutch units are arranged to bring the output shaft of the prime mover and the first and the input shaft, respectively, into engagement with each other. A lubrication pump is drivingly connected to the first input shaft to lubricate the transmission and an electronic control unit is arranged to determine a lubricated state of the transmission and the operational state of the lubrication pump. When the first clutch unit is engaged to connect the output shaft of the prime mover to the first input shaft, the lubrication pump is driven by the first input shaft. When the second clutch unit is engaged to connect the output shaft of the prime mover to the second input shaft, the lubrication pump is arranged to be driven by the first input shaft by at least partly engaging the first clutch unit.