| 摘要 |
PURPOSE:To aim at smoothly raising the rotational speed of a fan by forming a front chamber having such a shape that the ratio between a displacement of a liquid lead-out opening section and a liquid lead-out amount varies so as to decrease the liquid lead-out amount upon rise-up of the drive force of the fan. CONSTITUTION:A fan casing is sectioned by means of a partition plate 23 so as to define a front chamber 24 having the longitudinal width which increases radially outward and reserves therein liquid 26 having a predetermined viscosity, and a rear chamber 25. Further, a bimetal temperature element 27 drives a liquid lead-out mechanism 32 composed of a center shaft 28, a link 29 and a lead-out pipe 31 in association with a temperature of air passing therethrough so as to lead the liquid 26 from the front chamber 24 to the rear chamber 25. Further, a fluid coupling 35 transmits a torque from a rotary plate 38 fitted on a rotary shaft 33 to the fan casing 21. Accordingly, the liquid lead-out amount is controlled to a slight amount upon rise-up of the drive force of the fan, thereby it is possible to smoothly raise the rotational speed of the fan. |
