Viscous fan coupling with pressure-tight storage chamber

摘要

The coupling comprises a dividing wall (6) which can be made pressure-tight in the contact region with the housing (1). The wall is formed exclusively with the control opening (10) as the connection between the storage chamber (8) and the working chamber (7). On closing the control opening by the valve element as a consequence of backflow of the viscous fluid from the storage chamber to the working chamber, a negative pressure can be produced in the storage chamber. The storage chamber causes a drying-up of the backflow, on attaining a predetermined value.