A viscous clutch (20; 20) includes a rotor (26), a housing (24) that at least partially surrounds the rotor, a center shaft (22) rotationally fixed to the housing, a mounting disk (30) rotationally fixed to the rotor, a working chamber (38) defined between the rotor and the housing, a reservoir (36) for holding a supply of shear fluid, an electromagnet (34), a valve assembly (32) to selectively control flow of the shear fluid between the reservoir and the working chamber, and a flux guide (54) operatively positioned between the electromagnet and the armature. At least a portion of the mounting disk extends outside the housing. The valve assembly including an armature (32-3) that is selectively movable in response to magnetic flux generated by the electromagnet, and the magnetic flux is transmitted between the armature and the electromagnet along a flux circuit. The flux guide extends through the mounting disk.

A valve system (44) for reducing morning sickness effects in a viscous clutch (20) having a reservoir (38) with a bore (46-1) includes a valve element (44-1), a counterweight portion (44-2), a pivot (44-3), and a biasing member (44-4). The pivot is located in between the valve element and the counterweight portion, and the valve element and the counterweight portion are configured to commonly move about the pivot between open and closed positions. The biasing member is configured to bias the valve element to cover the bore in the closed position by default. The counterweight portion is configured to counteract the biasing member under centrifugal loading such that the valve element at least partially uncovers the bore in the open position.

A viscous clutch (20; 20) includes a rotor (26), a housing (24) that at least partially surrounds the rotor, a center shaft (22) rotationally fixed to the housing, a mounting disk (30) rotationally fixed to the rotor, a working chamber (38) defined between the rotor and the housing, a reservoir (36) for holding a supply of shear fluid, an electromagnet (34), a valve assembly (32) to selectively control flow of the shear fluid between the reservoir and the working chamber, and a flux guide (54) operatively positioned between the electromagnet and the armature. At least a portion of the mounting disk extends outside the housing. The valve assembly including an armature (32-3) that is selectively movable in response to magnetic flux generated by the electromagnet, and the magnetic flux is transmitted between the armature and the electromagnet along a flux circuit. The flux guide extends through the mounting disk.

A valve system (44) for reducing morning sickness effects in a viscous clutch (20) having a reservoir (38) with a bore (46-1) includes a valve element (44-1), a counterweight portion (44-2), a pivot (44-3), and a biasing member (44-4). The pivot is located in between the valve element and the counterweight portion, and the valve element and the counterweight portion are configured to commonly move about the pivot between open and closed positions. The biasing member is configured to bias the valve element to cover the bore in the closed position by default. The counterweight portion is configured to counteract the biasing member under centrifugal loading such that the valve element at least partially uncovers the bore in the open position.