A hydraulic drive system is disclosed. The hydraulic drive system includes a body housing, a rotor assembly, a motor assembly, and an engagement assembly. The first rotor assembly is attached to a first side of the body housing, while the first motor assembly is disposed inside the body housing and includes a first motor actuator. The engagement assembly positions the first motor actuator to engage and disengage with the first rotor assembly.

A vehicle includes a tandem axle system having an inter-axle differential and clutching assembly, a forward or first axle assembly, and a rear or second axle assembly. The inter-axle differential and clutching assembly includes a differential mechanism having first and second side gears and a clutch mechanism having a clutch member and an actuator assembly. At least one of the first axle assembly and the second axle assembly is in selective driving engagement with the inter-axle differential and clutching assembly.

A drive unit for a hybrid vehicle capable of improvement of fuel efficiency during HV running is provided. The drive unit includes an engine, a first motor, a second motor, a first planetary gear unit, a second planetary gear unit, a first engagement unit, and a second engagement unit. In a case where an operation state of the vehicle is high vehicle speed and a low driving force in which a requested driving force is small, by bringing the first engagement unit to an engaged state and the second engagement unit to the disengaged state, a first state where a gear ratio which is a rotation number ratio between an input element and an output element of a complex planetary gear unit becomes a first gear ratio 2 smaller than 1 is set. In the case of a low vehicle speed and a high driving force in which the requested driving force is large, by bringing the second engagement unit to the engaged state and the first engagement unit to the disengaged state, a second state where the gear ratio becomes a second gear ratio 1 larger than 1 is set.

Methods and systems are provided for an electromagnetic pulse disconnect assembly. In one example, an electromagnetic disconnect assembly includes an electromagnetic coil assembly including an electromagnetic coil, an armature cam including an annular ring and a plurality of bidirectional cam ramps extending in an axial direction from the annular ring, where the annular ring is adapted to have face-sharing contact with the electromagnetic coil assembly when the electromagnetic coil is energized and be spaced apart from the electromagnetic coil assembly when the electromagnetic coil is de-energized, and a cam follower a plurality of radially extending guides arranged around a circumference of the cam follower and spaced apart from one another via a plurality of elongate apertures, each of the plurality of elongate apertures adapted to receive one of the plurality of bidirectional ramps of the armature cam. The assembly may further include a latching system.

A form-locking shift element may include a first shift-element half and a second shift-element half which are engageable with each other by moving at least the first shift-element half. A method for determining an operating condition of the form-locking shift element may include monitoring a position of the first shift-element half with a sensor, and, when a value of a signal generated by the sensor is greater than an applicable value and when the first shift-element half is actuated and displaced towards an engaged operating condition, determining that the shift element is sufficiently engaged to transmit a torque at the form-locking shift element. The applicable value corresponds to a defined overlap between the first and second shift-element halves that is less than an overlap when the first shift-element half is in the engaged operating condition.

A drive switching mechanism of a utility vehicle includes: a two-wheel drive and four-wheel drive switching device that switches between two-wheel drive and four-wheel drive of the utility vehicle; and a control unit that controls the drive switching mechanism. The two-wheel drive and four-wheel drive switching device switches between two-wheel drive and four-wheel drive by using a first clutch. The control unit permits the two-wheel drive and four-wheel drive switching device to switch from two- wheel drive to four-wheel drive when a rotation difference of the first clutch becomes equal to or smaller than a predetermined value.

A hybrid drive vehicle having: at least one driving wheel; an internal combustion engine provided with a drive shaft; an electric machine provided with its own shaft; a gearbox which transmits motion to the driving wheel; a disengagable coupling which acts as a synchroniser and is interposed, to establish a disconnectable mechanical connection, between the drive shaft and the shaft of the electric machine; and a transmission shaft interposed, to establish a permanent mechanical connection, between the shaft of the electric machine on the opposite side to the coupling and the gearbox.

Methods of controlling a tandem axle assembly in a vehicle, the tandem axle assembly including an inter-axle differential (IAD), one or more side gears, and a front tandem axle assembly having a pair of front tandem axle half shafts selectively connected to a pair of front tandem axle wheel hub assemblies. When a determined speed of the vehicle is greater or equal to a predetermined speed, the IAD may be locked, the tandem axle wheel hub assemblies may be disconnected from their respective tandem axle shafts, and/or the IAD may be moved out of engagement with the one or more side gears. When a determined speed of the vehicle is less than a predetermined speed, the IAD may be unlocked, the tandem axle wheel hub assemblies may be connected to their respective tandem axle shafts, and/or the IAD may be engaged with the one or more side gears.

A method for accelerating a vehicle driving forward, in which the vehicle has a propulsion system including a combustion engine with an output shaft (2a), a gearbox (3) with an input shaft (3a), an electric machine (9) comprising a stator and a rotor, and a planetary gear comprising a sun gear (10), a ring gear (11) and a planet wheel carrier (12). When accelerating the vehicle the torque of the electric machine is controlled and the rotational speed of the combustion engine is controlled until the components of the planetary gear have the same rotational speed and may be interlocked.

A four-wheel drive vehicle includes a dog clutch that selectively interrupts transmission of a drive force to a propeller shaft, first and second multi-plate clutches that selectively interrupt transmission of the drive force from the propeller shaft to left and right rear wheels, first and second pistons that press the first and second multi-plate clutches, and a hydraulic circuit that supplies hydraulic oil to first and second cylinder chambers. During a transition to a four-wheel drive mode, torque transmitted through the first multi-plate clutch increases the speed of rotation of the propeller shaft so as to engage the dog clutch, and the second multi-plate clutch is kept from transmitting torque to the propeller shaft.