A vehicle differential disconnect assembly can include a differential case, a differential gear set, and a torque distribution device. The differential gear set is carried within the differential case. The torque distribution device transfers torque between the differential gear set and side shafts of the accompanying vehicle driveline. The torque distribution device can include a clutch pack and an actuator assembly. The clutch pack is located at a first side of the differential case relative to the differential gear set, and the actuator assembly is located at a second side of the differential case relative to the differential gear set. The actuator assembly has a mover that transmits movement to the clutch pack when the actuator assembly actuates and deactuates the clutch pack.

A vehicle driving force distribution device includes: a differential gear; a driving force transmission device; and a case member having a first accommodating chamber accommodating the differential gear and a second accommodating chamber accommodating the driving force transmission device. The case member has a first flow passage that allows lubricating oil to flow from the first accommodating chamber into the second accommodating chamber, and a second flow passage that allows lubricating oil to flow from the second accommodating chamber into the first accommodating chamber. In a two-wheel drive mode, lubricating oil flows from the second accommodating chamber into the first accommodating chamber through the second flow passage. In a four-wheel drive mode, lubricating oil flows from the first accommodating chamber into the second accommodating chamber through the first flow passage.

A vehicle driving force distribution device includes: a differential gear; a driving force transmission device; and a case member having a first accommodating chamber accommodating the differential gear and a second accommodating chamber accommodating the driving force transmission device. The case member has a first flow passage that allows lubricating oil to flow from the first accommodating chamber into the second accommodating chamber, and a second flow passage that allows lubricating oil to flow from the second accommodating chamber into the first accommodating chamber. In a two-wheel drive mode, lubricating oil flows from the second accommodating chamber into the first accommodating chamber through the second flow passage. In a four-wheel drive mode, lubricating oil flows from the first accommodating chamber into the second accommodating chamber through the first flow passage.

A control apparatus for a hybrid electric vehicle includes: an engine control portion for controlling an operation state of an engine; and a driving-mode control portion for controlling the vehicle so as to realize selected driving mode or modes. The driving modes include a main-drive-wheel driving mode in which a drive power is distributed to main drive wheels, and an all-wheel driving mode in which the drive power is distributed to the main and auxiliary drive wheels. When the all-wheel driving mode is selected in the main-drive-wheel driving mode with the engine being in a stopped state, the engine control portion is configured to maintain the stopped state of the engine until completion of switching from the main-drive-wheel driving mode to the all-wheel driving mode, and to start the engine after a predetermined operation is executed by the driver of the vehicle to drive the vehicle.

A four-wheel drive vehicle includes: a drive-power distribution device for distributing a drive power from an engine to main and auxiliary drive wheels with a drive-power distribution ratio between the main drive wheels and auxiliary drive wheels; and a control apparatus for controlling an electric motor such that the drive-power distribution ratio becomes a target distribution ratio value, by setting an electric-current command value for driving an electric motor. The control apparatus is configured, in a drive-power transmitted state in which the drive power is transmitted to the drive-power distribution device, to execute a command-value reduction control operation for causing the electric motor to be driven with the electric-current command value being set to a value smaller than in a drive-power non-transmitted state in which the drive power is not being transmitted to the drive-power distribution device.

A four-wheel drive vehicle includes: a drive-power distribution device for distributing a drive power from an engine to main and auxiliary drive wheels with a drive-power distribution ratio between the main drive wheels and auxiliary drive wheels; and a control apparatus for controlling an electric motor such that the drive-power distribution ratio becomes a target distribution ratio value, by setting an electric-current command value for driving an electric motor. The control apparatus is configured, in a drive-power transmitted state in which the drive power is transmitted to the drive-power distribution device, to execute a command-value reduction control operation for causing the electric motor to be driven with the electric-current command value being set to a value smaller than in a drive-power non-transmitted state in which the drive power is not being transmitted to the drive-power distribution device.

A drive control apparatus includes a circuitry configured to operate a differential lock device of a differential device in timings which are different between a two wheel drive state and a four wheel drive state. The differential device is disposed between one of a pair of front wheels and a pair of rear wheels of the vehicle and configured to transmit a driving force from a drive source to the one of the pair of front wheels and the pair of rear wheels. The differential lock device is configured to lock a differential rotation of a pair of output members of the differential device that are differentially rotatable with respect to each other, and configured to respectively output the drive force.

A drive control apparatus includes a circuitry configured to operate a differential lock device of a differential device in timings which are different between a two wheel drive state and a four wheel drive state. The differential device is disposed between one of a pair of front wheels and a pair of rear wheels of the vehicle and configured to transmit a driving force from a drive source to the one of the pair of front wheels and the pair of rear wheels. The differential lock device is configured to lock a differential rotation of a pair of output members of the differential device that are differentially rotatable with respect to each other, and configured to respectively output the drive force.

A four-wheel drive vehicle includes: (a) main drive wheels and auxiliary drive wheels; (b) a rotating machine as a drive power source; (c) a drive-power distribution clutch configured to allocate a part of a drive power outputted to the main drive wheels from the drive power source, to the auxiliary drive wheels, so as to distribute the drive power to the main drive wheels and the auxiliary drive wheels with a drive-power distribution ratio between the auxiliary drive wheels and the main drive wheels, such that the drive-power distribution ratio is variable with an engaging force of the drive-power distribution clutch being controlled; and (d) a control apparatus configured, when determining that a heat load of the drive-power distribution clutch is large during deceleration running of the vehicle, to limit a regenerative torque of the rotating machine, as compared with when determining that the heat load is small.

A four-wheel drive vehicle includes: (a) main drive wheels and auxiliary drive wheels; (b) a rotating machine as a drive power source; (c) a drive-power distribution clutch configured to allocate a part of a drive power outputted to the main drive wheels from the drive power source, to the auxiliary drive wheels, so as to distribute the drive power to the main drive wheels and the auxiliary drive wheels with a drive-power distribution ratio between the auxiliary drive wheels and the main drive wheels, such that the drive-power distribution ratio is variable with an engaging force of the drive-power distribution clutch being controlled; and (d) a control apparatus configured, when determining that a heat load of the drive-power distribution clutch is large during deceleration running of the vehicle, to limit a regenerative torque of the rotating machine, as compared with when determining that the heat load is small.