The present document relates to a method of disengaging a clutching device. The method comprises sweeping an output torque of an electric motor drivingly connected to the clutching device such that a torque transmitted by the clutching device vanishes at least temporarily during the sweep, and disengaging the clutching device during the sweep. The present document further relates to an electric driveline for carrying out the method.

A vehicle driving system 1 includes a first motor/generator M/G1 which is mechanically connected to either of front wheels Wf and rear wheels Wr of a vehicle, a second motor/generator M/G2 which is electrically connected with the first motor/generator M/G1, and a flywheel FW which is mechanically connected with the second motor/generator M/G2 and which stores kinetic energy. The second motor/generator M/G2 is mechanically connected to the other of the front wheels Wf and the rear wheels Wr of the vehicle.

At the time when a hydraulic actuator is operated to engage a dog clutch, after it is detected that a hydraulic pressure for operating the hydraulic actuator is higher than or equal to a predetermined hydraulic pressure, it is determined whether the dog clutch is not engaged. Therefore, non-engagement determination due to insufficient hydraulic pressure for operating the hydraulic actuator is prevented. Thus, at the time when the hydraulic actuator is operated to engage the dog clutch, it is possible to prevent consumption of time to engage the dog clutch due to unnecessary re-engagement operation.

Provided is a control device for a four-wheel drive which can maintain driving stability while restraining noise and vibration. A control device includes: a second control device that, when at least one of front wheel has slipped, engages a dog clutch after rotating a propeller shaft by a rotational force transmitted via first and second friction clutches; and a third control device that, if a predetermined condition is satisfied when the front wheels are not slipping, engages the dog clutch after rotating the propeller shaft by the rotational force transmitted via the first and second friction clutches. The time required to synchronize the dog clutch by the third control device is longer than that required to synchronize the dog clutch by the second control device.

The present document relates to a method of disengaging a clutching device. The method comprises sweeping an output torque of an electric motor drivingly connected to the clutching device such that a torque transmitted by the clutching device vanishes at least temporarily during the sweep, and disengaging the clutching device during the sweep. The present document further relates to an electric driveline for carrying out the method.

At the time when a hydraulic actuator is operated to engage a dog clutch, after it is detected that a hydraulic pressure for operating the hydraulic actuator is higher than or equal to a predetermined hydraulic pressure, it is determined whether the dog clutch is not engaged. Therefore, non-engagement determination due to insufficient hydraulic pressure for operating the hydraulic actuator is prevented. Thus, at the time when the hydraulic actuator is operated to engage the dog clutch, it is possible to prevent consumption of time to engage the dog clutch due to unnecessary re-engagement operation.

A selectable one-way clutch includes an engagement mechanism. The engagement mechanism is configured to be switched between an engaged state and a disengaged state. The engaged state is a state in which relative rotation between a first and a second members in one of a positive rotational direction and a reverse rotational direction is restricted. The disengaged state is a state in which the relative rotation between the first member and the second member in both of the positive and the reverse rotational direction is permitted. The electronic control unit is configured to apply torque to the one of the first member or the second member by using a motor such that relative rotation in the other one of the positive or the reverse rotational direction is generated between the first member and the second member when the engagement mechanism is switched from the engaged state to the disengaged state.

A transfer for a four-wheel drive vehicle, the vehicle including a driving source, main/auxiliary drive wheels, and a power transmission member, the transfer includes: a ring gear being supported so as to rotate around a rotation axis, and configured to drive the power transmission member; an input shaft extending through an inside of the ring gear, being supported so as to rotate concentrically with the ring gear, and being configured to receive part of the driving force; a disconnect mechanism; and an actuator configured to change the disconnect mechanism between a connection position and a disconnection position, the connection position being a position at which the ring gear and the input shaft are coupled to each other so as not to relatively rotate, the disconnection position being a position at which relative rotation between the ring gear and the input shaft is allowed.

A selectable one-way clutch includes an engagement mechanism. The engagement mechanism is configured to be switched between an engaged state and a disengaged state. The engaged state is a state in which relative rotation between a first and a second members in one of a positive rotational direction and a reverse rotational direction is restricted. The disengaged state is a state in which the relative rotation between the first member and the second member in both of the positive and the reverse rotational direction is permitted. The electronic control unit is configured to apply torque to the one of the first member or the second member by using a motor such that relative rotation in the other one of the positive or the reverse rotational direction is generated between the first member and the second member when the engagement mechanism is switched from the engaged state to the disengaged state.

A transfer for a four-wheel drive vehicle, the vehicle including a driving source, main/auxiliary drive wheels, and a power transmission member, the transfer includes: a ring gear being supported so as to rotate around a rotation axis, and configured to drive the power transmission member; an input shaft extending through an inside of the ring gear, being supported so as to rotate concentrically with the ring gear, and being configured to receive part of the driving force; a disconnect mechanism; and an actuator configured to change the disconnect mechanism between a connection position and a disconnection position, the connection position being a position at which the ring gear and the input shaft are coupled to each other so as not to relatively rotate, the disconnection position being a position at which relative rotation between the ring gear and the input shaft is allowed.