A fan drive system includes a hydraulic pump, a hydraulic motor that rotates a fan on the basis of hydraulic oil supplied from the hydraulic pump, a data acquisition unit that acquires an actual fan speed of the fan, a target amount determination unit that determines a target fan speed of the fan on the basis of a state of an object to be cooled of the fan, and an estimating unit that estimates a state of the hydraulic pump or a state of the hydraulic motor on the basis of a change of a feedback amount that indicates a difference between the target fan speed and the actual fan speed.

A working machine includes a prime mover, a hydraulic pump driven by power of the prime mover, a cooler including a cooling fan rotated by either the power of the prime mover or hydraulic fluid delivered from the hydraulic pump, and a controller configured or programmed to perform a reduction control for reducing a target fan rotation speed that is a target rotation speed of the cooling fan in response to reduction of an actual prime mover rotation speed that is an actual rotation speed of the prime mover, and to perform, after the reduction control, a restoration control for restoring the target fan rotation speed. The controller is configured or programmed to make a difference between a reduction rate of the target fan rotation speed in the reduction control and an increase rate of the target fan rotation speed in the restoration control.

A cooling system for a utility vehicle comprises a first fluid circuit including a first fluid such as hydraulic oil and a second fluid circuit including a second fluid such as a coolant or lubricant. A heat exchanger couples the first and second fluid circuits enabling transfer of heat from one of the first and second fluids to the other. A fluid cooler in the first fluid circuit has a fan arranged to direct an airflow towards it, which fan is a hydraulically driven device connected in the first fluid circuit and driven by flow of the first fluid.

A vehicle includes a chassis, tractive elements configured to support the chassis, a primary driver configured to output mechanical energy to at least one of the tractive elements to drive the vehicle, a coolant circuit, a fan assembly, and a controller. The coolant circuit includes a thermal energy interface configured to transfer thermal energy from the primary driver to coolant and a radiator configured to receive the coolant. The fan assembly includes a hydraulic pump coupled to the primary driver, a hydraulic motor fluidly coupled to the hydraulic pump, a fan coupled to the hydraulic motor and configured to provide air flow to the radiator, and an actuator configured to vary a displacement of at least one of the hydraulic pump and the hydraulic motor. The controller is configured to control the actuator to vary a speed of the fan based on telematics data.

Provided is a technique for improving the cooling efficiency of a vehicle heat exchange system configured to cool a cooling liquid discharged from each of a plurality of heat sources. The vehicle heat exchange system comprises a high-temperature side radiator unit and a low-temperature side radiator unit, the high-temperature side radiator including: a first high-temperature side radiator that faces a first fan and is connected to a high-temperature side discharge pipe; a second high-temperature side radiator that faces a second fan and is connected to a high-temperature side supply pipe; and a high-temperature side connection pipe for supplying the cooling liquid from the first high-temperature side radiator to the second high-temperature side radiator, and the low-temperature side radiator unit including: a first low-temperature side radiator that is arranged to face the second high-temperature side radiator on the upstream side of the cooling air flow, and is connected to a low-temperature side discharge pipe; a second low-temperature side radiator that is arranged to face the first high-temperature side radiator on the upstream side of the cooling air flow, and is connected to a low-temperature side supply pipe; and a low-temperature side connection pipe for supplying the cooling liquid from the first low-temperature side radiator to the second low-temperature side radiator.

A fan control system includes a tank, a pump, a hydraulic motor, a fan, and a control valve. The control valve is adapted to selectively direct a flow of hydraulic fluid from the pump through the control valve into a pressure control chamber of the hydraulic motor or from the pressure control chamber to the tank to vary the control pressure therein to move the hydraulic motor's swashplate between forward and reverse positions. The control valve is adapted to selectively direct hydraulic fluid from the pump into the pressure control chamber such that the control pressure therein is pressurized to an idle pressure to move the swashplate to an intermediate position between the forward and reverse positions such that the output shaft rotates at an idle rate which is less than the rotational speed of the output shaft when in the forward mode.

A construction machine having a frame and at least one compaction member is provided. The machine also includes a propulsion system having a hydraulic motor adapted to rotate the compaction member. The propulsion system also includes a hydraulic pump fluidly coupled to the hydraulic motor via a high pressure line and a low pressure line. The high pressure line allows flow of a fluid at high pressure from the hydraulic pump to the hydraulic motor. The low pressure line allows flow of the fluid at low pressure from the hydraulic motor to the hydraulic pump. The propulsion system further includes a hydraulic valve fluidly coupled to the low pressure line and a casing of the hydraulic motor. The hydraulic valve selectively allows flow of a portion of the fluid at low pressure from the low pressure line to the casing for cooling of the hydraulic motor.

A hydraulic system is provided to selectively and independently route pressurized fluid to one or more operational systems of a machine. The hydraulic system is capable of switching fluid flow in operation from one of the operational systems to another of the operational systems in the event of hydraulic drive power being required by the latter one of the operational systems. The hydraulic system is also configured to continue supplying a nominal amount of fluid to support one or more auxiliary functions, for example, a lubrication system for bearings associated with the former one of the operational systems while routing the pressurized fluid to the latter one of the operational systems. A recirculation and anti-cavitation arrangement is also provided to allow recirculation of fluid to a hydraulic motor in the former one of the operational systems when pressurized fluid is being routed to the latter one of the operational systems.

A fan drive system includes a hydraulic pump, a hydraulic motor that rotates a fan on the basis of hydraulic oil supplied from the hydraulic pump, a data acquisition unit that acquires an actual fan speed of the fan, a target amount determination unit that determines a target fan speed of the fan on the basis of a state of an object to be cooled of the fan, and an estimating unit that estimates a state of the hydraulic pump or a state of the hydraulic motor on the basis of a change of a feedback amount that indicates a difference between the target fan speed and the actual fan speed.

Agricultural machines such as sprayers can be improved by providing a control system configured to adjust an engine cooling package fan with variable speeds, to thereby minimize parasitic losses, based on progress of the HVAC system for attaining a desired temperature in the operator cab. In one aspect, as a gap between actual and desired temperatures (temperature differential) in the cab minimizes, the cooling package fan can be variably adjusted to increase or decrease in speed, depending on heating or cooling occurring in the cab, respectively. However, if a temperature of an area in the engine compartment reaches a predetermined threshold, such variable speed control can cease, and the cooling package fan can instead be controlled to cool the area.