| 摘要 |
PURPOSE:To enable to perform control of rotation of cooling fan in three stages corresponding to the change of ambient temperature by installing two sets of oil returning hole mechanism and pumping mechanism in the partition separating rotor chamber from oil reserving space. CONSTITUTION:When shaft 12 rotates together with pulley by the start of engine, shearing force is generated in the working oil in labilince L composed between circular projects 13a... projecting inner surface of case 13 and projections 11a... of rotor 11 combined with the former, and by this case 13 and cover 15 are rotated. In this case, when the temperature of engine is low, valve plate 17 is retained in the position in contact with stopper 27 by bimetal 26. Accordingly, plate 17 opens only the second pumping hole 23, and the shearing force obtained by the work within L becomes minimum. When the temperature of engine becomes moderate, plate 17 opens the first pumping hole 20 and the second oil-returning hole 21, and thus the necessary shearing force being obtained. |
