A method for controlling a DC pump motor, preferably a brushed DC motor for pumping lubricant, which motor is controlled by a pulse-width modulated (PWM) control signal, wherein current parameters are acquired in an acquisition step and a duty cycle (D) of the PWM control signal (S.sub.PWM) is adapted and/or changed on the basis of the detected parameters in an adaptation step, wherein the acquisition of current parameters comprises at least the acquisition of a current input voltage (U.sub.B).

An agricultural work vehicle according to an aspect of the invention that can monitor a state of the agricultural work vehicle when the agricultural work vehicle performs agricultural work using a working machine which is attached thereto includes: a vehicle body; a working machine that is attached to the front or rear of the vehicle body and performs agricultural work; an engine that generates a driving force for movement of the vehicle body and work of the working machine; and a monitoring device that determines at least one of whether there is an abnormality in a temperature of a coolant for cooling the engine, whether there is an abnormality in a pressure of an engine oil supplied to the engine, and whether there is an abnormality in the engine when the working machine performs work using the driving force.

In a hybrid vehicle, a hybrid type lubrication control valve which is a solenoid valve type turned on/off by electricity is used as a lubrication system component for circulating lubricating oil to a transmission and an engine clutch. A method for diagnosing sticking of a lubrication control valve of a hybrid vehicle includes measuring a drag torque acting on an input shaft of the transmission through an output shaft of the motor by measuring a first drag torque in an off-state of the independent type lubrication control valve and a second drag torque in an on-state thereof; and determining whether or not the independent type lubrication control valve is stuck, on the basis of a torque difference between the first drag torque and the second drag torque. The method can diagnose a stuck state of the hybrid type lubrication control valve using motor speed control, before starting the vehicle.

The invention relates to a method for controlling the oil pressure of an oil pump (40, 140) in a combustion engine (100). The combustion engine (100) comprises a crankcase (11) and a separator (14, 114) for separating oil present in a blow-by gas from the crankcase (11). The method comprises the step (201) of providing oil pressure demand for a set of different engine operation conditions, the oil pressure demand defining the theoretical required oil pressure of the oil pump (40, 140); the step (203) of controlling the oil pressure of the oil pump (40, 140) based on the oil pressure demand for at least one engine operation condition in the set of different engine operation conditions; the step (205) of driving the separator (14, 114) using oil from the oil pump (40, 140), the oil being pressurized based on the oil pressure demand.

An integrated electrical pump comprises a motor, an oil pump driven by the motor, and a pressure control system. The pressure control system controls a hydraulic pressure of the oil pump according to a motor speed of the motor, an oil temperature and a pressure command. An oil pressure control method of the integrated electrical pump is also provided.

A method for determining a degree of loading on a filter medium of a filter device on a vehicle through which a fluid flows includes determining an operating characteristic of the filter device based on at least one operating quantity of the vehicle and comparing a predefined reference characteristic of the filter device with the operating characteristic. The degree of loading is derived from a result of the comparing step.

A lubrication system for an internal combustion engine includes a fluid flow control device at an outlet side of the pump that regulates pressure conditions at the outlet side of the pump upstream of the lubrication circuit in the engine. The fluid flow control device is located in a recirculation path, and opens in response to a fluid pressure at the outlet of the pump exceeding a first threshold to allow the fluid to pass from the outlet side of the pump back to an inlet side of the pump. The recirculation path includes a tuning device that maintains the fluid pressure at engine speeds above the first threshold. In response to engine speeds above a second threshold, the tuning device restricts fluid flow in the recirculation path so that the fluid pressure in the fluid flow path increases.

A system for determining an oil amount in a marine drive includes an oil level sensor that senses an oil level in the sump and temperature sensor sensing an engine temperature. A control module for the system is configured to determine that the engine temperature is greater than a temperature threshold, and that an engine speed exceeds a speed threshold for at least a predetermined time period or that a throttle position exceeds a throttle position threshold. If both such conditions are met, and a threshold drop in engine speed to an idle threshold is detected or a threshold change in throttle position to an idle position is detected, then an oil level in the sump is sampled with an oil level sensor. An oil amount is then determined based on the sampled oil level in the sump.

An apparatus and method for controlling an electric oil pump with a pump control signal generated by an electronic control unit (ECU) of a vehicle. The pump control signal has a variable drive time portion during which the electric oil pump is actuated to supply oil to an engine of the vehicle and a variable cycle time defining a frequency of the pump control signal.

A control device for an internal combustion engine including a piston, an oil jet configured to inject oil toward the piston, and an actuator configured to adjust a supply flow rate of the oil to the oil jet. The control device includes an electronic control unit configured to control the actuator such that the supply flow rate under the same engine load and the same engine rotation speed increases as a degree of deterioration of the oil increases.