Patent ID: 6390252
Filing Date: 2002-05-21
Classification: F16F

Abstract:
A damping device, comprising:a hollow tube containing a magnetorheological fluid, a piston assembly slidably mounted in said hollow tube to form a first chamber positioned on one side of said piston assembly and a second chamber positioned on an opposite side of said piston assembly, said piston assembly including a radially central portion and an annular ring radially surrounding the radially central portion and defining therebetween a substantially annular flow gap extending between said first and said second chambers and defining a flow path through the piston assembly, and a magnet assembly adapted to generate a magnetic field extending across said substantially annular flow gap, said radially central portion, said annular ring and said substantially annular flow gap each including a first end positioned adjacent said first chamber and a second end positioned adjacent said second chamber; and laminar flow enhancing means mounted on said piston assembly and positioned adjacent said first and said second ends of said substantially annular flow gap for enhancing laminar flow and minimizing turbulence in said substantially annular flow gap, wherein said laminar flow enhancing means includes a respective flow opening . positioned adjacent each of said first and said second ends of said substantially annular flow gap, said respective flow opening having a funnel-shaped cross-section defined by an outer annular curved surface on the respective axial end of the annular ring extending outwardly from said substantially annular flow gap toward said hollow tube and an inner annular curved surface on the respective end of the radially central portion extending inwardly from said substantially annular flow gap toward a longitudinal axis of said piston core.