Patent ID: 6095305
Filing Date: 2000-08-01
Classification: F16D

Abstract:
An electromagnetic coupling device comprising:a rotor supported for rotation under the influence of a source of power and having a friction surface;an armature having a friction surface spaced from said rotor friction surface by an air gap, said armature including a plurality of apertures extending therethrough;a field core assembly providing an electromagnetic force, said field core assembly mounted relative to said rotor such that actuation of the electromagnetic force causes said armature to be attracted to said rotor and such that said armature friction surface bridges said air gap to come into abutting contact with said rotor friction surface so that said rotor and said armature substantially rotate together; anda plurality of damper assemblies mounted to said armature, each of said damper assemblies including a damper accommodation portion having an aperture corresponding to one of said apertures extending through said armature and a damper member supported by said damper accommodation portion, said damper member having an outside surface disposed opposite said aperture through said damper accommodation portion and an aperture extending through said damper member and corresponding to one of said apertures extending through said damper accommodating portion and said armature;each of said plurality of damper assemblies including a torque transmission pin having a head portion formed at one end thereof, a leg portion formed at an opposed end thereof, and a drum portion extending therebetween, said leg portion being received in a corresponding one of said plurality of apertures in said armature so as to interconnect said damper assembly to said armature, said drum portion being received in said aperture in said damper member;each of said head portions including a stepped inside surface facing said outside surface of said damper member, said stepped inside surface including an upper stage portion disposed in pre-tensioned abutting contact with said outside surface of said damper member and a lower stage portion spaced from said outside surface of said damper member by a predetermined distance which, prior to actuation of said electromagnetic force, is less than said air gap between said rotor friction surface and said armature friction surface such that said electromagnetic force causes said armature to be attracted to said rotor and said damper member to absorb energy at a variable spring rate as contact between said outside surface of said damper member and said stepped inside surface of said head portion increases from said upper stage portion to said lower stage portion and across said predetermined distance.