A controller includes: a control unit configured to calculate a control command value of an opening degree of a solenoid valve to control an opening degree of the solenoid valve; and an acquisition unit configured to acquire an estimated amount and a target amount of a working fluid in a labyrinth chamber, and a rotation speed of a drive shaft. The control unit calculates a final control command value based on a feedback control command value and a feedforward control command value, and controls the solenoid valve, the feedback control command value being calculated based on deviation between the estimated amount and the target amount, the feedforward control command value being used to maintain a rotation speed of a fan constant based on the estimated amount and the rotation speed of the drive shaft.

A system and method for controlling the operation of a vehicle radiator fan motor is provided. One embodiment receives one of a low-speed radiator fan control signal or a high-speed radiator fan control signal from an engine control module; provides a first soft start of the radiator fan motor in response to receiving the low-speed radiator fan control signal, wherein the first soft start is defined by a first increasing power ramp that starts at a zero-power level and ends at a low-speed power level; and provides a second soft start of the radiator fan motor in response to receiving the high-speed radiator fan control signal, wherein the second soft start is defined by a second increasing power ramp that starts at the zero-power level and ends at a high-speed power level.

A control system that uses an algorithm to control the fan speed in a cooling system for an engine is disclosed. The algorithm is adapted to maintain a cooling medium at a set temperature instead of an operating temperature range of the cooling medium. The algorithm is also adapted to maintain a cooling medium at a set temperature and to build a cooling safety margin in response to an engine output torque percentage that is below an output torque percentage setpoint.

Thermal management systems for vehicle engines which include hybrid fan drives with viscous clutches and electronic motors, particularly brushless DC motors (BLDC). One embodiment incorporates a pulley driven, electronically controlled viscous clutch mechanism and an internal rotor BLDC motor. Another embodiment includes an engine crank mounted electronically controlled viscous clutch mechanism with a tethered electric motor, particularly a BLDC motor. A further embodiment is an engine block mounted electronically controlled viscous clutch mechanism with an integrated external rotor BLDC motor.

A control method for a fan of a work vehicle includes supplying, when an engine is started, a first current to a solenoid of a variable relief valve such that the hydraulic fluid flows by a first flow rate, supplying, when a rotational speed of the engine becomes larger than a first rotational speed threshold value, a second current larger than the first current to the solenoid such that the hydraulic fluid flows by a second flow rate smaller than the first flow rate to reduce the rotational speed of the fan, and supplying, when the rotational speed of the engine becomes larger than a second rotational speed threshold value that is larger than the first rotational speed threshold value, a current to the solenoid to change the rotational speed of the fan, the current corresponding to a temperature of liquid flowing in the work vehicle.

To enhance responsivity of temperature sensor detecting an engine temperature. A temperature sensor component 40 includes a metal washer 42. The temperature sensor component 40 transfers the engine temperature to a sensor body 46 via the heat transfer washer 42. A cylinder portion 8 of a cylinder block 64 has two bosses 30. The washer 42 of the temperature sensor component 40 is fixed to the boss 30 together with the electronic control unit 20.

A system for efficient machine control may include feedback devices for identifying operating conditions of a work machine and a controller for controlling a primary system and an auxiliary system. The controller may calculate a total energy loss by adding a primary system energy loss based on power requests from the primary system to an auxiliary system energy loss based on support requests from the auxiliary system. The controller may adjust a setting of the auxiliary system, repeat the calculating of the total energy loss, and compare the result to a previously calculated total energy loss until further adjustment of the setting fails to reduce the total energy loss. The controller may then send control requests to the auxiliary system based on the setting used when the total energy loss failed to reduce.

A system for efficient machine control may include feedback devices for identifying operating conditions of a work machine and a controller for controlling a primary system and an auxiliary system. The controller may calculate a total energy loss by adding a primary system energy loss based on power requests from the primary system to an auxiliary system energy loss based on support requests from the auxiliary system. The controller may adjust a setting of the auxiliary system, repeat the calculating of the total energy loss, and compare the result to a previously calculated total energy loss until further adjustment of the setting fails to reduce the total energy loss. The controller may then send control requests to the auxiliary system based on the setting used when the total energy loss failed to reduce.

A clutch device for a clutch system has an input member that rotates at a first speed. A friction drive system is disposed between the input member and an output member. The clutch device is selectively movable by a fluid actuator assembly, between an engaged position in which the friction drive system drives the output member to rotate at the first speed, and a disengaged position in which a viscous drive system rotates the output member at a second speed slower than the first speed. A variable viscous fluid supply assembly includes a viscous fluid storage chamber, a valve, and a valve actuator that selectively drives the valve to move between an open position and a closed position to control an amount of viscous fluid available to the viscous drive system, thereby varying the second speed.

A fan and a motor drive device thereof are provided. The motor drive device is configured to drive a motor and includes a control management unit and a voltage converter. The control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed ranges, each corresponding to a specific output duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and output a voltage regulating signal, which is a pulse width modulation signal having a duty ratio corresponding to one of the rotation speed ranges in which the target rotation speed signal transmitted from the ECU falls. The voltage converter is connected between a power source and the motor, and is configured to regulate a voltage outputted to the motor in response to the voltage regulating signal having the specific duty ratio outputted from the control management unit, to regulate a rotation speed of the motor.