Pairs of cutout couplings are commonly used on dual drives, having an auxiliary prime mover (usually an engine or turbine) for emergency use. The changeover is performed at standstill by disengaging the coupling on the primary driver and engaging the coupling on the standby drive. With one cutout coupling, a unidirectional drive can be disconnected to permit partial system reversal. The first unit of a tandem drive can be similarly cut out.
Slide couplings are an inexpensive exposed bolt coupling with varying slide capacities. They are commonly used on applications such as disc refiners in the pulp and paper industry, bridge drives on overhead traveling cranes and where the magnitude of thermal shaft growth precludes use of standard Series "F" couplings.
Brakewheel couplings accommodate misalignment between connected equipment and eliminate the need for double shaft extensions on motors and gear units for applications requiring shoe-type brakes.
High speed gear couplings are generally used in applications that require higher speeds than standard Series "F" type couplings.The basic difference includes steel pilot rings, fitted gears and matched-marked (serial numbered) assemblies, couplings are dynamically balanced.Fasteners are weigh balanced.Couplings can be either grease lubricated or continuous oil lubricated.
The two flex-halves are electrically insulated from each other to prevent the flow of stray shaft currents from one machine to another. These couplings are not intended to withstand high potentials, short circuits or static changes. They will protect against the pitting of precision bearings and shafting, which occurs in generator exciter drives.