Patent ID: 8123012

Claim:
A rotational coupling device, comprising: a rotor coupled to an input shaft for rotation therewith, said input shaft disposed about a rotational axis and said rotor defining a first clutch engagement surface; a field shell disposed about said input shaft and fixed against rotation; an electrical conductor disposed within said field shell on a first side of said rotor; a brake plate spaced axially from and coupled to said field shell, said brake plate defining a first brake engagement surface; an armature disposed axially between said rotor and said brake plate on a second side of said rotor opposite said conductor, said armature coupled to an output member and defining a second clutch engagement surface and a second brake engagement surface; a permanent magnet coupled to one of said brake plate and said armature, said magnet urging said armature into engagement with said brake plate; and, a removable shim disposed axially between said brake plate and said field shell, at least a portion of said shim having a first axial dimension configured to approximate an anticipated decrease in axial dimension in at least one of said rotor, said armature and said brake plate resulting from wear during engagement of said first and second clutch engagement surfaces and engagement of said first and second brake engagement surfaces.