Patent ID: 6318519
Filing Date: 2001-11-20
Classification: B60G,F16F

Abstract:
A damper, comprising:a cylinder containing a magnetorheological fluid;a piston assembly slidably mounted for reciprocal movement in the cylinder to form a first chamber positioned on one side of the piston assembly and a second chamber positioned on an opposite side of the piston assembly, the piston assembly having a fluid flow passage therethrough defining a flow gap permitting limited fluid flow between the first chamber and the second chamber and a groove adjacent and open to the flow gap along at least a portion of the flow gap in the direction of fluid flow for parallel fluid flow in the same direction through both the portion of the flow gap and the groove, the piston assembly further including a magnet assembly establishing a magnetic flux circuit through the flow gap and through the groove in series with a region of the flow gap adjacent the groove, the magnetic flux being established through the flow gap and groove transversely to the direction of fluid flow therethrough to cause magnetorheological fluid flowing through the flow gap and the groove to experience a magnetorheological effect affecting the flow of the magnetorheological fluid therethrough, whereby the groove causes the magnetic flux density therethrough to be smoothly reduced from that in the remainder of the flow gap.