Abstract: An improved magnetorheological fluid damper is provided which effectively provides a smooth transition, without a sharp break in the damper force/velocity curve, between very low damping forces near zero damper velocity to higher damping forces at higher piston velocities while maintaining desirable maximum force levels. The damper includes a piston assembly, including a magnet assembly and a flow gap extending through the piston assembly to permit fluid flow between the chambers. The force/velocity optimization feature includes a groove or passage open to the flow gap, positioned in series with a part of the flow gap in a magnetic circuit generated by the magnet assembly and dimnensioned/sized to permit fluid flowing through the passage to experience a magnetorheological effect less than a magnetorheological effect experienced by fluid flowing through the flow gap but not through the groove. Preferably, the passage is formed in an inner annular surface of a flux ring positioned around a piston core.

Abstract: A novel and improved magnetorheological fluid damper is provided which effectively secures a flux ring to a piston core in a manner which prevents relative axial and radial movement between the flux ring and the core throughout operation while minimizing the size of the piston assembly yet providing effective damping. Several connector devices are disclosed for both axially and radially securing the flux ring relative to the piston core at one end of the piston assembly in a simple manner without increasing the length of the piston assembly. The connector device may include an outer portion brazed to the flux ring, an inner portion connected to the piston core, bridge portions extending between the outer and inner portions, flow passages formed between the bridge portions and an inlet cavity formed adjacent an annular flow gap to permit unimpeded, enhanced laminar flow through the flow gap by improving the damping effect.

Abstract: A rotary damper for use in an automotive vehicle. The rotary damper includes an outer casing having a main chamber and a pair of piston orifices, the main chamber and the piston orifices being filled with a damping fluid, a pivotable cam located in the main chamber and attached to an arm for transferring the rotary movement of the arm to the cam. The damper also includes a pair of pistons, each located in its own orifice, and connected to opposite sides of the cam. When the ami transfers the rotary movement to the cam, each piston is moved in opposite directions in its respective piston orifice to damp the rotary movement of the arm.

Abstract: A magnetorheological fluid damper is provided which permits effective control of damping while minimizing assembly size and costs by including a thin-walled insert in a flow gap formed between a flux ring and a piston body. The insert may include a thin-walled tubular insert having a generally smooth cylindrical shape for increasing the shear surface area. Alternatively, a corrugated insert may be provided having corrugations formed by edges extending axially along the insert. The corrugations may be formed in a variety of locations, sizes, shapes and spacings along the axial extent of the insert and the circumference of the insert. The corrugations advantageously effectively align the insert within the flow gap and also function to securely connect the flux ring to the piston body without the use of other devices such as plates thereby reducing the size and cost of the assembly.

Abstract: A snap ring closure system is particularly useful in securing a rod guide in an end of a tube of a hydraulic damper. The snap ring closure system utilizes an end cap or rod guide having a double-lobed groove and a peripheral flange about its outer end. The double-lobed groove includes an outer lobe and an inner lobe of a lesser depth than the outer lobe. A groove is formed on the tube and is positioned to design with the doubled-lobed groove when the end cap is inserted in the tube. The end cap includes a first snap ring in the outer lobe which expands outwardly into the tube groove when the cap is first inserted. The cap is secured by engagement of the first snap ring with the inner more shallow lobe. A second snap ring is placed between the flange and the end of the tube to remove any play between the end cap and tube.