Viscous fluid coupling, for driving auxiliary units such as cooling fans

摘要

An operating plate (8) divides a space defined by the housing (4) into a reservoir (5), an operating chamber (6), and has openings (7, 7A) to interconnect them. A rotor (9) is located in the operating chamber and is attached to the drive shaft (2). A valve mechanism (11) closes and opens the connecting openings in the plate depending upon the surrounding temperature of the housing in order to control the amount of flow of viscous fluid. A driven wheel (12) is located between the operating plate and rotor, and annular protrusions (13) formed concentrically on an outer circumferential section of the wheel overlap other annular protrusions (14) on the outer circumferential section of the rotor so that they are interconnected by the viscous fluid.