A viscous clutch includes an input member, an output member, a working chamber defined between the input member and the output member, a reservoir to hold a supply of a shear fluid fluidically connected to the working chamber by a fluid circuit, a valve that is electromagnetically actuatable to selectively control a flow of the shear fluid along the fluid circuit, a control coil assembly, and a securing mechanism. The control coil assembly includes a modular center hub removably attached to the input member, an electromagnetic coil and a coil bearing rotatably supporting the electromagnetic coil on the modular center hub. The securing mechanism is removably attached to the input member radially inward of the working chamber and the reservoir, and includes a radially outwardly extending flange.

A clutched compressor section of a gas turbine engine coupled to a rotor shaft. The clutched compressor section includes at least one decoupleable rotor stage, the decoupleable rotor stage switchable between a coupled condition and a decoupled condition with a clutch mechanism, the coupled condition coupling the decoupleable rotor stage with the rotor shaft, the decoupled condition decoupling the decoupleable rotor stage from the rotor shaft.

A clutched compressor section of a gas turbine engine coupled to a rotor shaft. The clutched compressor section includes at least one decoupleable rotor stage, the decoupleable rotor stage switchable between a coupled condition and a decoupled condition with a clutch mechanism, the coupled condition coupling the decoupleable rotor stage with the rotor shaft, the decoupled condition decoupling the decoupleable rotor stage from the rotor shaft.

A clutch system is provided. The clutch system includes an outer unit having a surface defining an aperture in the outer unit; an inner unit disposed in the aperture, wherein a shape of the inner unit matches a shape of the aperture; a low melting point material disposed in the aperture between the inner unit and the surface of the outer unit; a heating element; a temperature sensor; and a processor in electronic communication with the heating element and the temperature sensor. The processor is configured to control the heating element thereby changing the low melting point material between a soft state and a rigid state.

A clutch system is provided. The clutch system includes an outer unit having a surface defining an aperture in the outer unit; an inner unit disposed in the aperture, wherein a shape of the inner unit matches a shape of the aperture; a low melting point material disposed in the aperture between the inner unit and the surface of the outer unit; a heating element; a temperature sensor; and a processor in electronic communication with the heating element and the temperature sensor. The processor is configured to control the heating element thereby changing the low melting point material between a soft state and a rigid state.

A viscous clutch head may be replaced by selecting a viscous clutch head and a mount adapter. The viscous clutch head and the mount adapter may be selected from a group of universal modular fan drives and from a group of mount adapters. The mount adapter of a threaded type or a flange and bolt type may be selected. Depending on the viscous clutch head to be replaced, a fan adapter and/or a pilot adapter may also be selected from a group of fan adapters and from a group of pilot adapters. Accordingly, a range of models of viscous fan clutch systems may be replaced by using a limited number of parts. These parts may be stored on a tool cart. As different models of viscous fan clutch systems may be replaced using a limited number of parts, the in-stock inventory of replacement parts may be reduced.

A viscous clutch head may be replaced by selecting a viscous clutch head and a mount adapter. The viscous clutch head and the mount adapter may be selected from a group of universal modular fan drives and from a group of mount adapters. The mount adapter of a threaded type or a flange and bolt type may be selected. Depending on the viscous clutch head to be replaced, a fan adapter and/or a pilot adapter may also be selected from a group of fan adapters and from a group of pilot adapters. Accordingly, a range of models of viscous fan clutch systems may be replaced by using a limited number of parts. These parts may be stored on a tool cart. As different models of viscous fan clutch systems may be replaced using a limited number of parts, the in-stock inventory of replacement parts may be reduced.

A fan-coupling device with a unitary magnetic pole is disclosed. The magnetic pole is of a unitary, ring-shaped construction and includes a choke space and a ridge that promote an increased amount of magnetic flux generated by an electromagnet to travel to a magnetic armature on a fluid flow valve, resulting an increase in the amount of magnetic force that acts upon the valve. This is an improvement over the prior art two-piece magnetic pole structure and over a unitary magnetic pole without the choke space and ridge. The magnetic pole also includes apertures in which protrusions on a sound dampening gasket are inserted to reduce the noise resulting from the armature striking the magnetic pole.

A viscous clutch includes a shaft, a rotor attached to the shaft, a housing located adjacent to the rotor, a working chamber defined between the rotor and the housing, a reservoir used to store a shear fluid, a valve assembly, an electromagnetic coil, and a flux insert in the housing. Selective introduction of the shear fluid to the working chamber facilitates selective torque transmission between the rotor and the housing. The valve assembly regulates flow of the shear fluid between the reservoir and the working chamber, and includes an armature. Selective energization of the electromagnetic coil governs actuation of the valve assembly. A flux circuit is provided that extends from the electromagnetic coil to the armature and back to the electromagnetic coil. The flux circuit passes through the flux insert and through the shaft, and the flux circuit crosses a radial air gap between the flux insert and the armature.

A viscous clutch according to the present invention, which is composed of a main body having a fluid storage chamber of a concave shape formed at a central portion thereof and a cover having a concave fluid operation chamber formed at a central portion thereof, comprises: a fan housing in which the main body is stacked on an upper side of the cover so that an opening of the fluid operation chamber can be covered; a drive shaft which extends in a vertical direction and has a lower end inserted through a bottom plate of the main body; a rotor fixedly coupled to the lower end of the drive shaft so as to be rotatable in the fluid operation chamber; a rotary assembly integrally coupled to the main body so as to cover an opening of the fluid storage chamber; a coil core mounted on an upper surface of the rotary assembly and generating an electromagnetic force when an electric current is applied from the outside; and a valve assembly for opening or closing a fluid outlet according to whether or not an electric current is applied to the coil core.