A method for learning a touch point of an engine clutch for a hybrid electric vehicle includes controlling a speed of an engine to have an idle speed. A fluid pipe of a clutch actuator is refilled with a working fluid by driving a driving motor in an idle control state of the engine, a speed of the driving motor is synchronized with the speed of the engine, and then the engine clutch is engaged. The engine clutch is released after the refill is performed, and the speed of the driving motor is decreased. A working fluid is applied so that the engine clutch is operated in an engagement direction by operating the clutch actuator, and a state change of the driving motor is detected. The touch point of the engine clutch is determined based on the state change of the driving motor.

Methods and systems for a clutch assembly in an electric drive axle of a vehicle are provided. In one example, a clutch assembly in a gear train is provided that includes a locking clutch. The locking clutch includes a gear including a plurality of teeth having at least one tooth with a tapered end, an indexing shaft rotationally connected to an output shaft, a shift collar mounted on the indexing shaft, configured to translate on the indexing shaft into an engaged and disengaged configuration, and including a plurality of teeth on a face, where at least one tooth in the plurality of teeth in the shift collar includes a tapered end, and an indexing mechanism coupled to the shift collar and the indexing shaft and configured to accommodate for indexing between the indexing shaft and the shift collar during shift collar engagement.

A hybrid drive system for a motor vehicle has an input shaft which is rotatably mounted around an axis of rotation, via which torques provided by an internal combustion machine can be introduced into the hybrid drive system, an output drive shaft arranged coaxially with the input shaft, an electric machine which has a stator and a rotor, and a torque converter which has an impeller, a converter cover connected to the impeller, an interior for receiving oil, and a converter hub which is connected to the converter cover. The converter hub is connected to the rotor in a manner fixed against rotation. The system further has a separable clutch having a disc pack, a clutch chamber in which the disc pack is received, an operating piston, and an associated operating chamber. Via the separable clutch the converter hub can be connected to the input shaft fixed against rotation.

A failure determination device of a hybrid vehicle, includes an engine, a motor arranged in series with the engine, a clutch arranged between the motor and a driving wheel, a pressure adjusting mechanism that adjusts hydraulic pressure supplied to the clutch, and that performs wet start clutch control for adjusting the hydraulic pressure, supplied to the clutch at least upon starting, to the hydraulic pressure causing the clutch to slip, and a controller configured to calculate required driving force on the basis of accelerator opening, and calculate torque capacity of the clutch, required for transmitting the required driving force by the clutch, as target torque capacity, calculate actual torque of the engine and actual torque of the motor, and calculate a torque deviation as a deviation between the target torque capacity and a sum of the actual torque of the engine and the actual torque of the motor.

A power transmission unit that can prevent an entrance of excessive torque to the powertrain is provided. The power transmission unit includes a transmission that transmits torque between an engine and drive wheels; a locking device that selectively halts a rotation of an output shaft of the engine; a transmission case holding a first motor, a second motor, the transmission, and the locking device; a first torque limiter disposed between the engine and the locking device to restrict torque transmitted between the drive wheels and the engine; and a second torque limiter held in the transmission case to restrict torque transmitted between the drive wheels and the locking device.

A drive device includes a first drive unit and a second drive unit. A transmission unit includes a primary shaft for connection to the first drive unit, a secondary shaft, and at least one gear pair via which the primary and secondary shafts are operatively connectable to one another. Mounted in coaxial relationship to the secondary shaft is a driving gear which is operatively connected to the second drive unit, and mounted in coaxial relationship to the primary shaft is an output gear which meshes with the driving gear. A secondary-shaft coupling device can couple the driving gear directly with the secondary shaft, and a primary-shaft coupling device can couple the output gear directly with the primary shaft.

A method for learning a contact point of an engine clutch configured to control connection of power between an engine and a motor of a hybrid vehicle is provided. The method includes performing a first learning of the contact point of the engine clutch by increasing a contact speed of the engine clutch and storing information of a first contact point learned by the first learning. A second learning of the contact point of the engine clutch is then performed by decreasing the contact speed of the engine clutch.

Provided are a hydraulic control valve, a hydraulic control system, and a transmission. The hydraulic control valve includes a valve body, a slidable valve cartridge, and a pressing mechanism. A valve hole, a first oil supply port, a second oil supply port, and an oil discharge port are formed at the valve body, and each of the first oil supply port, the second oil supply port, and the oil discharge port is in communication with the valve hole. Both the slidable valve cartridge and the pressing mechanism are accommodated within the valve hole. The slidable valve cartridge has a small end close to an end of the valve hole and a large end abutting against the pressing mechanism. The pressing mechanism is disposed at another end of the valve hole.

The method for controlling the starting of an internal combustion engine (MT) is implemented in an electric hybrid vehicle having a powertrain (eGMP) comprising the internal combustion engine and a hybrid transmission system (eTR), the transmission system having a rotating electric machine (ME) that is coupled to the engine via a clutch device (K0). According to the invention, the method comprises, during a phase for starting the engine with the electric machine while the vehicle is rolling, controlling (M_EB) the clutch by means of a maximum clutch torque setpoint determined according to a predetermined maximum speed gradient (LGR) and a moment of inertia (Jmth) of the engine, and controlling (M_MT) the engine by means of a maximum engine torque setpoint (CM) determined according to a difference (EC) between the maximum clutch torque setpoint and a torque (C0e) transmitted by the clutch.