Abstract: A damper apparatus includes a housing having a toroidal inner housing surface and a slidably linked piston moveable in the housing having a curved outer peripheral piston surface in engagement with the inner housing surface. A fluid barrier is attached to the housing and located in the housing interior. A flow control passageway and electro-magnetic field control valve defined by either the piston or the damper shaft/arm assembly controls viscosity and passage of magnetic-rheological damper fluid when there is relative rotational movement between the piston and the housing to dampen the forces causing relative rotational movement.

Abstract: A toroidal rotary damper apparatus includes a housing having a toroidal inner housing surface and a piston moveable in the housing having a curved outer peripheral piston surface in engagement with the inner housing surface. A fluid barrier is attached to the housing and located in the housing interior. A flow control passageway defined by either the piston or the fluid barrier controls passage of damper fluid when there is relative rotational movement between the piston and the housing to dampen the forces causing relative rotational movement.