Abstract: A monotube damper and suspension spring assembly for a motor vehicle includes a tubular housing defining a chamber filled with damping fluid. A piston and piston rod reciprocate within the chamber. In order to compensate for volumetric changes of the chamber due to extension and retraction of the piston rod within the chamber, either the upper seal cover or lower bottom ring assembly is slidable within the housing. A preload is applied either to the housing or to the seal cover to thereby bias these elements to compensate for volumetric changes in the chamber.

Abstract: A damper for damping movement of a shaft, the damper including a housing having an inner surface defining a chamber and a rotor rotatably mounted in the chamber. The chamber is filled with magnetorheological fluid such that when the rotor is moved in the chamber the magnetorheological fluid damps the movement of the rotor. The rotor has an outer surface adjacent to and spaced apart from the inner surface. The damper further comprises shaft coupled to the rotor and an outer magnet adjacent the space between the outer surface and the inner surface for restricting the flow of the magnetorheological fluid in the space between the outer surface and the inner surface.

Abstract: An improved magnetorheological fluid pumping system and method are provided which effectively dispense a predetermined amount of magnetorheological fluid for delivery to a MR device such as a damper assembly, for example, during manufacture. The fluid pumping system includes a pump having inlet and outlet valves, a reciprocally mounted piston, a stroke operator device for controlling the movement of the piston and an electronic controller for operating the stroke operator device and the inlet and outlet valves. Importantly, the inlet and outlet valves include an annular flow gap and a magnetic field generating assembly operable in an energized state to generate a magnetic field across the flow gap to cause magnetorheological fluid flowing through the gap to experience a magnetorheological effect sufficient to prevent flow through the gap and in a de-energized state to permit flow through the gap.

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 monotube suspension damper including a cylinder tube having a fluid chamber and a gas chamber, a piston dividing the fluid chamber into a compression chamber and a rebound chamber, a primary fluid flow path across the piston including flow control valves which throttle fluid flow, a secondary fluid flow path across the piston parallel to the primary flow path including flow control valves which throttle fluid flow, and a tubular connecting rod on the cylinder tube connected to the piston. A valve spool is supported on the piston for linear translation between closed and open positions blocking and unblocking the secondary flow path. A control rod inside of the connecting rod is disposed between the valve spool and a flexible diaphragm exposed to pneumatic pressure in an expansible load leveling chamber between sprung and unsprung masses of the motor vehicle.

Abstract: A damper provides tunable variable rates in both extension and compression operation. A piston is carried in a cylinder tube separating out extension and compression chambers. The piston carries a first valving assembly that is tuned to provide a first damping level when fluid flows through the piston from the extension chamber to the compression chamber and a second valving assembly that is tuned to provide a second damping level when fluid flows through the piston from the compression chamber to the extension chamber. A control valve assembly is mounted to move with the piston. When the control valve assembly is closed, fluid flow between the compression and extension chamber flows substantially only through the first and second valving assemblies and when the control valve is open at least some fluid flows between the compression and extension chambers through a secondary valve assembly without passing through the first and second valving assemblies.

Abstract: A hydraulic mount includes a mounting plate and a wall, with a working chamber defined between the mounting plate and the wall. The mounting plate and the wall are separated by a relatively thick elastomeric element so that the size of the working chamber varies as the elastomeric element is compressed and expanded by operation of the mounting plate and the wall moving closer together and farther apart. A reservoir is defined substantially by the elastomeric element in combination with a relatively flexible diaphragm that extends between the mounting plate and the wall so that the reservoir is generally annular in shape and is positioned around the working chamber. The elastomeric element serves as a separation wall between the working chamber and the reservoir.

Abstract: In a duo-pumping hydraulic mount, two acting pistons are employed, one associated with each working chamber. The pistons are rigidly connected. During operation, internal pressures generated in each chamber are opposite in sign with one being negative and the other being positive. Therefore, to achieve a given pressure differential across the fluid track, the magnitude of the pressure in each working chamber is half what would be experienced in a conventional single pumping mount. Durability is improved by reducing internal pressures and by distributing kinetic loads to two rubber elements so that individual stresses are minimized. An individual load bearing element supports static loads on the mount.

Abstract: A chassis system control method comprising the steps of measuring rotational speed of a plurality of vehicle wheels; estimating, responsive to each wheel rotational velocity, a relative velocity between the wheel and a corresponding corner of a vehicle body; determining a chassis system control command responsive to the estimations; and applying the chassis system control command to control the chassis system responsive to the estimations, wherein need for body to wheel relative position and/or relative velocity sensors is eliminated.

Abstract: A passive magnetorheological clutch includes an input member that is constantly driven at engine speed, or some selected proportion thereof. An output member is journaled on the input member so as to be supported thereon in a nonrotating state and to be concentrically rotatable in concert therewith. A space presented between the input and output members contains a quantity of magnetorheological fluid. The space also contains an engagement mechanism including a permanent magnet and a ferromagnetic ring concentrically positioned with an operative gap therebetween, wherein the operative gap's dimension is variable to effect changes in the magnetic field passing between the magnet and the ring. When an actuator effects a reduction in the distance between the magnet and ring, the amount of magnetic field increases in density adjacent the ring. The resultant torque transfer from the input member to the output member is effected across the operative gap and through the magnetorheological fluid.

Abstract: A damper includes a piston that carries a relatively compact control valve for controlling fluid flow through the piston. The control valve provides a variable amount of damping by regulating damper fluid flow between the extension chamber and the compression chamber of the damper during extension and compression strokes. Pressure regulation across the piston is controlled through two alternate flow paths as determined by the control valve. Damping through the first flow path is relatively soft and is determined according to the deflective characteristics of a single bi-directional annular disc valve. Damping through the second flow path is relatively firm and is determined by the first bi-directional single annular disc and a second bi-directional single annular disc in series.

Abstract: A proportional fluid pressure regulation system is provided using a combination of a proportional valve and a shuttle valve for fluid flow control. A system of fluid pressure regulation is achieved where the desired pressure output is provided by one of two pressure input sources. The two pressure input sources are alternately selected by operation of a pilot operated shuttle valve and a solenoid operated proportional valve. The two pressure sources may comprise a manually actuated vehicle braking system's master cylinder and a power operated fluid pump.

Abstract: A damper includes a piston that carries a relatively compact control valve for controlling fluid flow through the piston. The control valve provides a variable amount of damping by regulating damper fluid flow between the extension chamber and the compression chamber of the damper during extension and compression strokes. Pressure regulation across the piston is controlled through two alternate flow paths as determined by the control valve. Damping through the first flow path is relatively soft and is determined according to the deflective characteristics of first and second single bi-directional annular disc valves in parallel. Damping through the second flow path is relatively firm and is determined solely by the second bi-directional single annular disc.