Electromagnetically operated friction clutch e.g. for IC engine cooling fan - uses variable spacing between rotor disc and permanent magnetic disc to control clutch slip

摘要

The friction clutch allows direct transmission of the rotation of a drive shaft (5) to the fan wheel (2) using a rotor (6) attached to the drive shaft via a spring (7) cooperating with an armature ring (11) attached to the fan hub (18). A conductive rotor disc (15) lies at a variable spacing (S1) to a permanent magnet disc (14). A mechanical adjustment facility is provided by a bimetal disc (18) between the drive shaft and the rotor disc for determining ths spacing (S1) and hence the variable slip of the clutch. Pref. the bimetallic disc allows the slip to be matched to the cooling requirement. ADVANTAGE - Provides variable drive for cooling fan dependent on engine temp.