A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

The present disclosure relates to a shift control apparatus of a vehicle and its method. In particular, the shift control apparatus includes: a transmission including a first clutch and a second clutch; a torque source to generate power for driving a vehicle; a data detector to detect a vehicle state data; and a vehicle controller to connect a current stage synchronizer to a next stage driving gear if the vehicle state data satisfy a shift condition, release the first clutch to be connected to the driving gear of a current stage, perform a speed control of a torque source while maintaining the second clutch connected to the driving gear of the next stage in a slip state, and release the second clutch and connect the first clutch if the vehicle stage data satisfy a speed control completion condition to complete a shift to a target stage.

A method for operating a drive train of a motor vehicle may include, for a starting process of an internal combustion engine, transferring the separating clutch from a disengaged condition into an engaged condition or a slip state such that the electric machine accelerates the internal combustion engine to a starting speed. The method may further include actuating a torque-transmitting element between the electric machine and the output shaft to enter a slip state. The method may also include increasing the torque of the electric machine to reliably reach and hold the slip state of the torque-transmitting element. Additionally, the method may include operating the electric machine as a generator or as a motor depending on an expected load direction of the drive train during the starting process to reliably reach and hold the torque-transmitting element in the slip state.

The invention concerns a method for automatically controlling a motor vehicle (10) for switching from a “normal” mode to a “freewheel” mode, the vehicle (10) comprising an engine (12) capable of providing engine torque to drive wheels (14) via an automatically controlled clutch device (18) that comprises a drive shaft (15) and a driven shaft (16). A transition step (E1) is interposed chronologically between the “normal” mode and the “freewheel mode” during which the engine (12) is automatically controlled in such a way that the driven shaft (16) and the drive shaft (15) turn at the same speed without transmitting torque to the drive wheels (14).

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 hybrid electric vehicle capable of starting an engine in the event of failure of a DC-DC converter and a method of controlling the hybrid electric vehicle are provided. The hybrid electric vehicle includes a driving motor, an engine, and a first relay that starts a starter. A second relay is disposed between a first power line, connected the starter and a first battery, and second power line, connects a DC-DC converter that converts the power of a second battery and an electric load. A controller selectively adjusts the states of the first relay and the second relay. Upon determining starting of the engine and detecting failure of the DC-DC converter, the controller maintains the on state of the second relay and turns on the first relay to perform cranking of the engine.

A controller and a control strategy for a hybrid electric vehicle having a traction motor between an engine and an automatic transmission include maintaining a bypass clutch of a torque converter in an engaged position and applying a motor torque from a traction motor to the torque converter such that slip of the torque converter does not otherwise reach zero while the bypass clutch is maintained in the engaged position.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.

A first engagement member includes a first meshing portion and rotates integrally with a first shaft. A second engagement member includes a second meshing portion configured to mesh with the first meshing portion and rotates integrally with a second shaft. An electric clutch device drives the first engagement member via a pressing member that extends and contracts in response to drive of a clutch actuator. When the electric clutch device is to be engaged, the first shaft command computation unit sets the first shaft rotation speed command value to be smaller than the rotation speed of the second shaft. Further, after the rotation speed of the first shaft matches the first shaft rotation speed command value, the first shaft command computation unit sets the first shaft rotation speed command value to be gradually closer to the rotation speed of the second shaft.

In the case where the lockup clutch is in the complete engagement state when a changeover between shift stages is made with the second shift mode selected, an electronic control unit holds the lockup clutch in the complete engagement state. Meanwhile, in the case where the lockup clutch is in the slip engagement state, the electronic control unit holds the lockup clutch in the slip engagement state based on a slip amount of the torque converter, or switches the lockup clutch to the complete engagement state.