| 摘要 |
The present invention provides a fan off-revolutions per minute (RPM) reducing method. The fan off-RPM reducing method uses a moving case (30) positioned between an outer case (4) and a rotor (5) to be engaged with the rotor (5) to form an interval. A bimetal (20) scheme is applied when the moving case (30) is a mechanical oil valve (9) releasing and blocking the circulating flow of operating oil. When the moving case (30) is an electronic oil valve (9A), a pulse width modulation (PWM) signal applying scheme is applied. Therefore, regardless of whether the fluid type-fan clutch is a mechanical type or an electronic type, when a fan is rotated at an excessively high speed at the temperature of the cooling water for operation of the fan clutch or there is a clutch off signal for disengagement, the speed of the fan can rapidly be reduced, or off-RPM, which gets near zero, is possible. Furthermore, fuel efficiency can be improved only by improving the off-RPM. |
