A hydraulic supply system provides hydraulic power to functional systems of a work vehicle and includes first and second hydraulic circuits. The first hydraulic circuit includes a first fluid pump operable to generate a first hydraulic fluid, a pressure storage reservoir coupled with the first fluid pump, and a first port coupled with the first fluid pump and with the pressure storage reservoir operable to store a reserve hydraulic fluid. The first port delivers a boost hydraulic fluid from the first circuit for use by the work vehicle to operate a first functional system of the work vehicle. The second hydraulic circuit includes a second fluid pump that generates a second hydraulic fluid, and a second port coupled with the second fluid pump delivers the second hydraulic fluid from the second hydraulic circuit for use by the work vehicle to operate a second functional system of the work vehicle.

A utility vehicle includes: a power unit that outputs drive power; a drive shaft that receives the drive power transmitted from the power unit; a front axle that receives the drive power transmitted from the drive shaft; a right front wheel connected to the front axle; a left front wheel connected to the front axle; a right clutch configured to disable power transmission from the drive shaft to the right front wheel; a left clutch configured to disable power transmission from the drive shaft to the left front wheel; a clutch actuator that actuates the left clutch and the right clutch; and a controller that controls the clutch actuator.

A utility vehicle includes: a pair of front wheels; a pair of rear wheels; at least one front wheel power source configured to drive the front wheels and not to drive the rear wheels; at least one rear wheel power source configured to drive the rear wheels and not to drive the front wheels; and a controller that controls the front wheel power source and the rear wheel power source. Upon receiving a predetermined two-wheel drive command, the controller brings the front wheel power source into a non-operative state while allowing the rear wheel power source to drive the rear wheels. Upon receiving a predetermined four-wheel drive command, the controller brings the front wheel power source into operation while allowing the rear wheel power source to drive the rear wheels.

A hydraulic supply system provides hydraulic power to functional systems of a work vehicle and includes first and second hydraulic circuits. The first hydraulic circuit includes a first fluid pump operable to generate a first hydraulic fluid, a pressure storage reservoir coupled with the first fluid pump, and a first port coupled with the first fluid pump and with the pressure storage reservoir operable to store a reserve hydraulic fluid. The first port delivers a boost hydraulic fluid from the first circuit for use by the work vehicle to operate a first functional system of the work vehicle. The second hydraulic circuit includes a second fluid pump that generates a second hydraulic fluid, and a second port coupled with the second fluid pump delivers the second hydraulic fluid from the second hydraulic circuit for use by the work vehicle to operate a second functional system of the work vehicle.

A clutch device includes a plurality of clutches; a plurality of cylinder chambers provided to respectively correspond to the clutches; a pump configured to discharge a hydraulic fluid; a plurality of control valves each of which is configured to control the hydraulic fluid supplied from the pump to a corresponding one of the cylinder chambers; and an oil passage that distributes the hydraulic fluid discharged from the pump, to the control valves. The oil passage includes at least one split point at which the hydraulic fluid discharged from the pump splits. At least one check valve is provided between the at least one split point and at least one control valve among the control valves, the at least one check valve being configured to block a flow of the hydraulic fluid in a direction from the at least one control valve toward the at least one split point.

A method for controlling a vehicle including a main transmission and a hydraulic transmission, in which, in the absence of a setpoint on the brake, and when the hydraulic transmission is activated, a hydraulic pump of the hydraulic transmission is controlled in such a way as to establish a predetermined pressure inside a hydraulic circuit of the hydraulic transmission, and in the event of a setpoint applied to the brake, the hydraulic transmission is then controlled according to an acceleration setpoint applied to the vehicle. If the acceleration setpoint is greater than or equal to an acceleration threshold value, and the speed of travel of the vehicle is less than or equal to a speed threshold value, the hydraulic transmission is controlled in such a way as to apply a tractive force. If the acceleration setpoint is less than the first threshold value, the hydraulic transmission is disengaged.

A power transmission device include: a differential having three rotational elements; and a connection switching device that selectively switches a connection relationship among an input shaft, a first output shaft, a second output shaft, and the three rotational elements. Further, the connection switching device selectively fixes any one rotational element to a fixing member, the second power source is coupled to rotational elements other than the rotational element fixed to the fixing member, the differential can be switched between modes including a first mode where any one rotational element among the three rotational elements is coupled to the input shaft, one of the remaining rotational elements is fixed to the fixing member, and the other is coupled to the first output shaft, and a second mode where the three rotational elements are respectively coupled to the second power source, the first output shaft, and the second output shaft.

Systems, apparatus, and methods to control fluid associated with vehicle clutches are disclosed. A disclosed apparatus includes a drive unit assembly for a vehicle. The drive unit assembly includes a housing and a clutch in a cavity of the housing. Rotation of a drum of the clutch expels a fluid from the cavity. The apparatus also includes a vehicle controller configured to disengage the clutch via an actuator. Actuation of the actuator reduces a flow of the fluid into the cavity. The vehicle controller is also configured to maintain engagement of a vehicle transfer device operatively coupled between a vehicle transmission and the drum such that the drum continues to rotate for a time interval during which the clutch is disengaged.

An alternative traction control system, in addition to a primary traction control system, is associated with an agricultural machine in which a user selectable input can allow wheels of an the agricultural machine to spin freely, such as for clearing debris from tires, until a predetermined deactivate condition occurs. Such a deactivate condition could comprise, for example, reaching a maximum rotation speed and/or temperature threshold with respect to a wheel. To minimize the risk of damage to propulsion components which may be caused by excessive rotation speeds and/or temperatures, upon reaching such a threshold, operation can return from the alternative traction control system to the primary traction control system. Such a system can therefore allow an on the fly change that would permit an operator to selectively spin the tires without damaging mechanical aspects of the agricultural machine.

A utility vehicle includes: a pair of front wheels; a pair of rear wheels; at least one front wheel power source configured to drive the front wheels and not to drive the rear wheels; at least one rear wheel power source configured to drive the rear wheels and not to drive the front wheels; and a controller that controls the front wheel power source and the rear wheel power source. Upon receiving a predetermined two-wheel drive command, the controller brings the front wheel power source into a non-operative state while allowing the rear wheel power source to drive the rear wheels. Upon receiving a predetermined four-wheel drive command, the controller brings the front wheel power source into operation while allowing the rear wheel power source to drive the rear wheels.