Isolator for use with engine that is assisted or started by an MGU or a motor through an endless drive member

An isolator for isolating a device driven by an engine via an endless drive member, comprising:

• a shaft adapter that is connectable with a shaft of the device;
• a rotary drive member that is engageable with the endless drive member;
• a first isolation spring arrangement that is positioned to transfer torque between the shaft adapter and the rotary drive member;
• and
• a position-based damping structure that is positioned to transfer torque via a frictional damping force between the rotary drive member and the shaft adapter at a selected amount of relative movement therebetween, wherein the selected amount of relative movement is selected to be less than a maximum permitted amount of flexure of the first isolation spring arrangement;
• wherein the damping structure includes a first spreader member and first and second force transfer members, wherein the selected amount of relative movement between the rotary drive member and the shaft adapter drives the spreader member circumferentially into engagement with the force transfer members, which in turn transfer force from the spreader member into an axial force on first and second friction members respectively to generate the frictional damping force.