A hydraulic control device for a vehicle is provided wherein a determination of “base neutral” is made when a difference between a command hydraulic pressure and an actual hydraulic pressure of a hydraulic clutch is within a predetermined minute value range, and when the difference is out of the minute value range, a determination of “base raising” is made if the command hydraulic pressure is larger than the actual hydraulic pressure, and a determination of “base lowering” is made if the command hydraulic pressure is smaller than the actual hydraulic pressure. The determination of “sub raising” is made when an inclination of command torque subjected to low-pass filter processing is positive for a predetermined time or more, and the determination of “sub lowering” is made when the inclination is negative for the predetermined time or more, whereby a rising or dropping tendency of the command torque is determined.

A vehicle includes a powertrain having a powerplant and a clutch that selectively couples the powerplant to an axle. A controller is programmed to, in response to the powertrain being in a power-limiting routine, command a torque to the powerplant based on an error between a target slip of the clutch and a slip of the clutch.

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a controller that controls the engagement and disengagement of the dog clutch and the friction clutch. In this clutch control device, when there is a request to engage the dog clutch from a disengaged state, the controller, during the engagement control of the friction clutch, first controls the engagement of the friction clutch, monitors the change gradient of the clutch rotational speed difference of the dog clutch and starts engagement of the dog clutch upon determining that the gradient of the clutch rotational speed difference is no longer decreasing.

A method to estimate an amount of force in a clutch pack of a clutch actuation system. The method includes engaging an actuation motor to apply a set point force to the clutch pack and monitoring a position of the actuation motor when the set point force is applied. Additionally, the method includes determining one or more clutch clamping curves and one or more clutch releasing curves based on a relationship between the position of the actuation motor and an amount of torque applied by the actuation motor at position of the actuation motor. The method further includes modeling one or more frictional characteristics of the clutch actuation system and estimating an amount of clamping and releasing force within the clutch pack by using a control unit. The amount of torque applied to the clutch pack between the clutch clamping and releasing curves at the set point force is maintained.

A work vehicle including an articulated vehicle chassis having a front frame portion and a rear frame portion pivotally coupled together at a generally vertical pivot axis. The front frame portion carries a front axle and the rear frame portion carries a rear axle. A steering system includes at least one steering cylinder connected between the front frame portion and the rear frame portion. A power plant provides motive power to the work vehicle, and a transmission receives power from the power plant and provides power to the front axle and rear axle. The work vehicle further includes a secondary clutch interconnected between the transmission and the rear axle. The steering system is configured to disengage the secondary clutch to provide reactive steering, whereby the front frame portion tows the rear frame portion. The rear frame portion freely articulates relative to the front frame portion.

Methods and systems are provided for operating an electromagnetic pulse disconnect assembly for selectively engaging two rotating components of a vehicle drivetrain. A disconnect assembly is needed that is not powered by vacuum diverted from an engine of the vehicle, as modern engines are being developed to reduce vacuum production and remove vacuum lines for powering peripheral devices such as disconnects. An electromagnetic pulse disconnect assembly is provided that operates via pulses of electrical current and includes an electromagnetic coil for translating a clutch ring assembly and a latching ring assembly to selectively couple two rotating components.

Methods and systems are provided for operating an electromagnetic coil assembly. As one example, a method comprises responsive to energization of an electromagnetic coil of an electromagnetic coil assembly, translating the electromagnetic coil along a central axis of the electromagnetic coil assembly toward a magnetic armature while maintaining the armature fixed along the central axis. The electromagnetic coil assembly may be utilized within various clutching, braking, or lever applications.

A control device for a power transmission mechanism is provided, performing control so that a driving wheel reliably obtains torque when a vehicle is started. In a vehicle having a power transmission mechanism that includes a power transmission path transmitting power from a power source to a first driving wheel and a second driving wheel, and a power transmission element arranged in the power transmission path between the power source and the second driving wheel, a control device for a power transmission mechanism includes a control section controlling a fastening force of the power transmission element so as to control power transmission capacity of the power transmission mechanism from the power source to the second driving wheel, wherein when the control section acquires that the vehicle transitions from a traveling state to a stop state, the acquisition triggers the control section to increase the power transmission capacity.

A multimode clutch may be adapted for selectively connecting and disconnecting front and/or rear axles from respective internal combustion engine and electric motor powertrains connected to such front and rear driving axles in a through-the-road hybrid vehicle. For example, the engine may be part of a front axle driven powertrain connected to the front wheels, while the motor may be part of a separate rear axle driven powertrain connected to the rear wheels, or vice versa. By selective disconnection of an axle not being actively driven, a real time reduction in parasitic losses may be achieved, leading to higher overall operating efficiencies. The multimode clutch offers greater flexibility over the use of standard friction clutches; each multimode clutch may provide four distinct operational modes for accommodating a wide diversity of driving conditions. For example, bi-rotational freewheeling of the rear axle may occur whenever the motor is not in use.

A power transmission device of a four-wheel drive electrically driven vehicle comprises a transverse engine that is supported on one right side surface of two side surfaces of the gear case, and a motor that is supported on the other left side surface of the two side surfaces of the gear case. The power transmission device includes a transfer case that is supported by a gear case and the distributes power from a power source between the left and right front wheels and the left and right rear wheels. The transfer case wraps around from the side surface to a rear surface of the gear case, as seen from above, and outputs power to the left and right rear wheels from the rear surface side of the gear case.