| 摘要 |
PURPOSE:To enable an escape to be promptly attained from a slip condition by providing the second resistance plate to be arranged adjacent to a pair of first resistance plates and several blocks to be arranged in an operating chamber with these first and second resistance plates serving as a single block, in the case of a viscous coupling built in a power transmission system for a vehicle or the like. CONSTITUTION:Silicone oil, interposing between a pair of first resistance plates 7 and rotating with the first resistance plate 7, generates a static pressure, and silicone oil, interposing between the first and second resistance plates 7, 8, generates a dynamic pressure, with the dynamic pressure between the first and second resistance plates 7, 8 relatively lower than the static pressure between the pair of first resistance plates 7. While the larger is a difference between relative rotary speeds of the first and second rotary members 1, 5 the larger difference is generated between these static and dynamic pressures. Accordingly, the first resistance plate 7 is moved toward the second resistance plate 8 against urging force of a spring 13 by this differential pressure, reducing a clearance between the first and second resistance plates 7, 8. Thus increasing shearing force of the silicone oil, this shearing force is transmitted to a rear wheel as torque. |
