A driving force control device 1 for a vehicle V comprises: a D-μ map M1 defining a linear correlation between a driving stiffness D and a maximum road surface μ; a slip ratio calculation circuit 21 for calculating a slip ratio S of one of a pair of front road wheels 10L, 10R; a DS calculation circuit 22 for calculating the driving stiffness D corresponding to a value the slip ratio S calculated by the slip ratio calculation circuit 21; a maximum road surface μ calculation circuit 23 for assigning a value of the driving stiffness D calculated by the DS calculation circuit 22 to the D-μ map M1 to calculate the maximum road surface μ; and a driving force distribution circuit 24 for controlling a driving force, using a value of the maximum road surface μ calculated by the maximum road surface μ calculation circuit 23.

A drive force distribution method and a drive force distribution control device is provided for a front and rear wheel drive vehicle provided with a drive force distribution device that controls a distribution of a drive force generated by a drive force source to main drive wheels and auxiliary drive wheels. A present distribution of the drive force to an auxiliary drive wheel side is increased by a first predetermined amount upon determining the rotational speed difference between the rotational speeds of the main drive wheels and the auxiliary drive wheels has been determined to not be smaller than a predetermined rotational speed difference. The present distribution of the drive force to the auxiliary drive wheel side is reduced by a second predetermined amount when the rotational speed difference has been determined to be smaller than the predetermined rotational speed difference.

A vehicle includes a powerplant, a front axle having first and second wheels and a differential operably coupled to the powerplant. A power-takeoff unit (PTU) is connected to the differential. A rear axle has third and fourth wheels and a gearbox connected to the PTU without a center differential. The gearbox has a first clutch configured to selectively couple the third wheel to the PTU and a second clutch configured to selectively couple the fourth wheel to the PTU. A controller is programmed to determine, during a turn, which of the third and fourth wheels is an outer rear wheel, determine whether there is a positive or negative torque on the outer rear wheel, and disengage, or keep disengaged, the one of the first and second clutches that is associated with the outer rear wheel in response to a negative torque on the outer rear wheel.

A bi-directional overrunning clutch differential is configured to transmit power from an input shaft to a first output shaft and a second output shaft in a vehicle. The differential includes a differential housing having a first bearing seat and a second bearing seat. A first bearing is carried by the differential housing in the first bearing seat, and a second bearing is carried by the differential housing in the second bearing seat. A first retaining ring secures the first bearing in the first bearing seat, and a second retaining ring secures the second bearing in the second bearing seat. A first output hub is carried by the first bearing for rotation relative to the differential housing, and a second output hub is carried by the second bearing for rotation relative to the differential housing.

An actuator is used to longitudinally move a spline sleeve for controlling drive mode of a differential on an off-road vehicle. The actuator's motor rotates an eccentric knob through a drive train including intermediate gears and a worm gear. The eccentic knob is linked to the spline sleeve through a torsion spring carried on a pivot plate, with legs of the torsion spring pushing a slide block, transferring a moment provided by the eccentric knob into a linear slide force. The pivot plate and torsion spring are jointly mounted on the actuator housing by a hub, opposite the rotational axis of the eccentric knob from the slide block. The slide block includes a contact which completes a circuit through conductive pads on the actuator housing, so the position of the slide block can be directly sensed.

Disclosed is a travel control apparatus for a four-wheel drive vehicle in which the states of engagements between a drive output part for secondary drive wheels and left and right secondary drive wheel axles are each changed to a torque transmission state or a torque transmission interruption state. The ratio of rotational speed of the drive output part to the average of rotational speeds of primary drive wheels is greater than 1. When the engagement states corresponding to the secondary drive wheels on the outer and inner sides of a turning locus have been set to the torque transmission state and the torque transmission interruption state, respectively, the engagement state having been set to the torque transmission state is changed to the torque transmission interruption state upon determination that an accelerator pedal is not operated and the magnitude of lateral acceleration is equal to or greater than a predetermined threshold.

A drive device includes a first clutch mechanism that couples or decouples power transmission systems for front and rear wheels, a first electric motor disposed on a front or rear wheel side and coupled to the first clutch mechanism, a second electric motor disposed on the other of the front and rear wheel sides and coupled to the first clutch mechanism, a second clutch mechanism that couples or decouples the first electric motor and front drive shafts, a planetary gear mechanism that distributes output of the first electric motor to the first and second clutch mechanisms, and a third clutch mechanism that limits a difference between a first rotational element that transmits the output of the first electric motor to the first clutch mechanism and a second rotational element that transmits the output of the first electric motor to the second clutch mechanism.

A vehicle caravan comprising electric vehicles configured for coordinated movement and airflow control comprising: a lead vehicle and a chase vehicle, the lead vehicle disposed at the front of the caravan and the chase vehicle disposed behind the lead vehicle in a chase pattern. Each lead and chase vehicle comprising: a vehicle chassis and a front rotatable vehicle drive axle; a selectively movable electric propulsion motor comprising a rotatable motor shaft and a motor axis configured to be oriented in a substantially vertical direction; an air duct configured to direct an airflow to the propulsion motor; an airflow shutter in the front end of the air duct to selectively control the airflow within the air duct; and a vehicle controller; the caravan and the chase pattern configured for coordination of the motor position and the open/closed position of the lead vehicle and the chase vehicle shutters while the caravan is moving.

A vehicle power transfer unit assembly comprises an input shaft, an intermediate shaft at least partially surrounding the input shaft, a central shaft adjacent the input shaft, a peripheral shaft at least partially surrounding the central shaft, a first shift collar, and a second shift collar. The first shift collar is operable between a first position where torque is transferred from the input shaft to the intermediate shaft and a second position where torque is not transferred from the input shaft to the intermediate shaft. The second shift collar is operable between a third position where torque is transferred from the input shaft to the peripheral shaft and a fourth position where torque is transferred from the input shaft to the central shaft.

Disclosed is a travel control apparatus applied to a vehicle which includes two coupling apparatuses individually changing coupling torques between a drive output part for secondary drive wheels and left and right secondary drive wheel axles and in which the ratio of rotational speed of the drive output part to the average of rotational speeds of primary drive wheels is greater than 1. The apparatus generates a yaw moment in a turning direction by using driving force. When a demand of further increasing the yaw moment arises, the control apparatus renders the braking force of the primary drive wheel on the turning locus inner side coincident with a target braking force changing with the travel state of the vehicle and decreases the coupling torque of the coupling apparatus corresponding to the secondary drive wheel on the turning locus outer side. As a result, generation of an anti-spin moment is avoided.