| 摘要 |
<p>It is possible to more effectively reduce extraordinary noise of a fan and promote warm-up idling by restricting the occurrence of 'corotation' on the fan side to a short period of time after the start of an engine. Similarly, in relation to a specified small amount of oil sealed in a compartmented receiving chamber, it is also possible to restrict the 'corotation' of the fan remarkably effectively that would be caused when an abrupt transition is made from a low-speed operating state to a high-speed operating one by virtue of inlet and outlet in the receiving chamber, efficient pumping function in a dam and the construction of the receiving chamber, thereby making it possible to accelerate heat radiation effect. The thickness of a driving disc is made as thick over the whole surface on its peripheral side as confronts the dam, and the interior of the driving disc is formed into a receiving chamber having a radial wall protruding radially from the inner circumferential surface thereof. Furthermore, a small-diameter hole is formed between the radial walls at a position located slightly inwardly of the circumferential side surface of the back wall portion of the driving disc confronting an oil reservoir, and a through hole in the vicinity of the center of the front side wall of the driving disc.</p> |
