Patent ID: 8141689
Filing Date: 2012-03-27
Classification: F16F

Abstract:
1. A magnetorheological (MR) damper assembly containing MR fluid comprising; a cylinder defining a central longitudinal axis, a first MR piston end plate, a second MR piston end plate, a MR piston core coaxially aligned with said central longitudinal axis and disposed longitudinally between and attached to said first MR piston end plate and said second MR piston end plate, a piston ring attached to said first and second MR piston end plates and including a first longitudinal end extending perpendicularly to said central longitudinal axis adjacent said first MR piston end plate and a second longitudinal end extending perpendicularly to said central longitudinal axis adjacent said second MR piston end plate and said piston ring being disposed radially outwardly from said MR piston core to define a MR passageway therebetween, a surface portion of said piston ring in sliding engagement with said cylinder defining at least one surface groove having a narrow circumferential extent and an open end and a closed end and extending from said open end and being open to one of said longitudinal ends of said piston ring to said closed end terminating said surface groove before reaching said other longitudinal end for receiving MR fluid and providing lubrication between said surface portion of said piston ring and said cylinder.