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 vehicle propulsion system includes a prime mover having a coolant inlet and coolant outlet, a coolant flow controller having a flow control inlet in communication with the prime mover coolant outlet, and a flow control outlet in communication with the prime mover coolant inlet, and a controller that determines a coefficient based upon a power of the prime mover, and that provides a coolant flow command signal to the coolant flow controller based upon the power of the prime mover.

Method and systems for determining when to cancel coolant stop. An initial coolant temperature value is measured. The initial coolant temperature value is used to create Multiple Control Valve (MCV) opening thresholds. A first threshold is generated for MCV opening threshold for engine speed. A second threshold is generated for MCV opening for intake air mass flow. A comparison is made between the first threshold and the currently measured engine speed and/or a comparison is made between the second threshold and the currently measured intake air mass flow. The comparison(s) are then used to determine when to cancel coolant stop and open the MCV.

Examples of techniques for controlling temperature of a coolant fluid at an inlet of an internal combustion engine are disclosed. In one example implementation, a method includes receiving, by a processing device, total fuel burned data indicating a total amount of fuel burned by the internal combustion engine. The method further includes receiving, by a processing device, engine speed data indicating an engine speed of the internal combustion engine. The method further includes calculating, by the processing device, a radiator flow rate to achieve a temperature set-point at an inlet of the engine based at least in part on the total fuel burned data and the engine speed data. The method further includes adjusting, by the processing device, a radiator flow based at least in part on the radiator flow rate.

Upon a valve rotation angle of a flow rate control valve exceeding a radiator-flow-path closed position during changing of the valve rotation angle of the flow rate control valve in an opening direction of a radiator flow path from a closed state of the radiator flow path, a cooling water starts to circulate through the radiator flow path, and an outlet water temperature or an inlet water temperature of an engine starts to drop. The radiator-flow-path closed position is learned as a valve rotation angle of the flow rate control valve immediately before the outlet water temperature or the inlet water temperature starts to drop during changing of the valve rotation angle of the flow rate control valve in the opening direction of the radiator flow path from the closed state of the radiator flow path.

A system includes an engine block having a plurality of cylinder-piston combinations. At least one of the cylinder-piston combinations includes a cylinder, a piston positioned in the cylinder and coupled to a connecting rod, the piston having an internal cooling gallery about a circumference of the piston, an oil jet for introducing coolant into the cooling gallery, and at least one pressure sensor positioned within the piston to detect pressure fluctuations within the cooling gallery. The system includes a processor having a program coupled thereto. The processor is configured to detect cyclical pressure fluctuations within the cooling gallery, via the at least one pressure sensor, during a linear motion of the piston within the engine block, determine pressures that occur during the detected cyclical pressure fluctuations, and determine a fill ratio of coolant within the cooling gallery based on the determined pressures.

An engine cooling system includes a coolant circulation path, which circulates coolant between the water jacket and the radiator of an internal combustion engine, a pump, a control valve, which is provided in the coolant circulation path, and a controller. The controller executes a warming-up promotion control and a pressure relaxation control. In the pressure relaxation control, the controller controls the aperture ratio of the radiator port such that the lower the temperature of the radiator, the lower becomes the engine rotational speed at which the aperture ratio of the radiator port is increased.

A coolant circulation system includes a coolant circuit including a water jacket, a motor-driven pump, an outlet liquid temperature sensor, and a controller. The controller executes variation determination control for driving the motor-driven pump to determine whether a variation in the temperature of the coolant in a diesel engine is equal to or less than a predetermined value based on an outlet temperature detected by the outlet liquid temperature sensor. The controller executes circulation stop control on condition that it is determined that the variation in the temperature of the coolant is equal to or less than the predetermined value. The controller changes the period during which the circulation stop control is executed in accordance with the outlet liquid temperature detected at the start of the circulation stop control.

An engine coolant system includes a variable-opening valve having a plurality of tubes in fluid flow communication with an engine block and a radiator. The coolant system also includes an electrically-powered pump arranged to cycle coolant through the radiator and the engine block to regulate an engine temperature. The coolant system further includes a controller programmed to store a baseline relationship between pump speed and pump power draw using a nonlinear scale. The controller is also programmed to detect a steady state operating condition of the pump, and identify an operational relationship between real-time pump speed and a pump power draw. The controller is further programmed to detect a coolant leak based on a deviation between the baseline relationship and the operational relationship.

A system for determining a remaining useful life of a cooling component operatively connected to a prime mover. A controller performs a thermal strain analysis that includes determining the power output of the prime mover based upon sensor signals, determining a temperature output of the prime mover based upon the power output, determining a temperature at each of the plurality of analysis locations based upon the temperature output, determining a temperature difference based upon the temperature at each respective one of the plurality of analysis locations, and determining a thermal strain based upon the temperature difference. The controller repeats the thermal strain analysis at time intervals over a period of time, determines an accumulated damage for the cooling component based upon the thermal strain from each thermal strain analysis, and determines a remaining useful life of the cooling component based upon the material characteristics and the accumulated damage.