A clutch device for a vehicle fan includes a drive-side clutch element and an output-side clutch element. The clutch device includes a locking mechanism configured between the drive-side clutch element and the output-side clutch element so that a rotary connection established between the drive-side clutch element and the output-side clutch element is released when a drive-side rotational speed reduces in comparison with an output-side rotational speed.

A clutch device for a vehicle fan includes a drive-side clutch element and an output-side clutch element. The clutch device includes a locking mechanism configured between the drive-side clutch element and the output-side clutch element so that a rotary connection established between the drive-side clutch element and the output-side clutch element is released when a drive-side rotational speed reduces in comparison with an output-side rotational speed.

A cooling fan device includes an electronic control unit that controls an engagement rate of a fan clutch. The electronic control unit executes a first calculation process that calculates an air conditioner requested engagement rate, a second calculation process that calculates, as a first guard value, a value of an engagement rate at which a fan rotation speed increases at a specified speed and an upper limit guarding process that sets a value of the air conditioner requested engagement rate to the first guard value when a calculated value of the air conditioner requested engagement rate in the first calculation process exceeds the first guard value. The electronic control unit further controls the engagement rate of the fan clutch based on a value of the air conditioner requested engagement rate after execution of the upper limit guarding process.

Disclosed are active engine compartment venting systems, methods for making and using such systems, and vehicles equipped with an active engine compartment vent and control logic for operating the vent. A method is disclosed for regulating operation of an active venting device fluidly coupled to a vent in an engine hood of a motor vehicle. The method includes a vehicle controller determining if a calibrated vehicle venting condition exists, and determining if a calibrated vehicle speed condition exists. Responsive to determining that the calibrated vehicle venting condition exists, the controller commands the active venting device to transition to an open state and thereby unobstruct the vent and allow venting fluid flow therethrough. Conversely, in response to determining that the calibrated vehicle speed condition exists, the controller commands the active venting device to transition to a closed state to thereby obstruct the vent and restrict venting fluid flow therethrough.

Disclosed are active engine compartment venting systems, methods for making and using such systems, and vehicles equipped with an active engine compartment vent and control logic for operating the vent. A method is disclosed for regulating operation of an active venting device fluidly coupled to a vent in an engine hood of a motor vehicle. The method includes a vehicle controller determining if a calibrated vehicle venting condition exists, and determining if a calibrated vehicle speed condition exists. Responsive to determining that the calibrated vehicle venting condition exists, the controller commands the active venting device to transition to an open state and thereby unobstruct the vent and allow venting fluid flow therethrough. Conversely, in response to determining that the calibrated vehicle speed condition exists, the controller commands the active venting device to transition to a closed state to thereby obstruct the vent and restrict venting fluid flow therethrough.