University of Nevada

Other

The University of Texas System

Gregory Hitchcock

Faramarz Gordaninejad

Alan Fuchs

Xiaojie Wang

Barkan Mehmet Kavlicoglu

Mei Xin

Krishna Kiran Bangrakulur

Jacob Elkins

Qi Zhang

A damper/strut that can provide variable damping and spring energy storage and dissipation. One embodiment includes an adjustable magnetorheological damper and a mechanically adjustable fluid spring in association with an internal accumulator. A combination of internal and external electromagnets generate the magnetic fields required to activate internally maintained magnetorheological material so that its apparent viscosity undergoes the desired change for a given disturbance. By controlling the strength of the magnetic fields generated in the device, the damping capacity and energy storage of the compressible liquid spring can be affected to provide a semi-active damper that can both dissipate and store energy. The proposed devices can be coupled with a sensor feedback and a control system to provide fast and accurate response force for a variety of engineering applications.

Controllable compressible fluid damper

Variably controllable motion-damping devices are disclosed that utilize a magneto-rheological fluid (MRF). One configuration of such a device includes a first valving region and a second valving region connected to the first valving region. Between the first and second valving regions is a plate having a first surface adjacent the first valving region and a second surface adjacent the second valving region. At least one of the first and second surfaces is treated to impart a significantly increased shear yield stress to columnized MRF particles passing over the surface, compared to an otherwise similar untreated surface. An MRF is contained in the first and second valving regions such that the MRF can flow through the first and second valving regions. Motion of a first object relative to a second object is damped by causing flow of MRF through the first and second valving regions. A magnet produces a magnetic field within at least one of the valving regions. MRF flow is constrained by the magnetic field and the treated surface sufficiently to damp the relative motion.

Controllable magneto-rheological fluid devices for motion-damping

Novel magnetorheological elastomer compositions are provided. The magnetorheological elastomers (MREs) may have aligned or randomly arranged magnetizable particles in a thermoset or thermoplastic matrix. The magnetizable particles may be coated to reduce corrosion and/or improve bonding between the particle and the matrix. The magnetizable particles may be flake-shaped. The MREs may have matrices selected from the group consisting of hydrogenated nitrile rubbers, butyl rubbers, ethylene-propylene copolymers and terpolymers, ethylene-acrylic copolymers, fluorinated elastomers, silphenylene-siloxanes, silarylene-siloxanes, poly(carborane-siloxane-acetylene)s and blends thereof. The MREs may also have matrices selected from the group consisting of styrene-butadiene block copolymers, copolyesters, polyamides, polyether block amides, polyolefin-elastomers other than polyalpha olefins, chlorinated polyethylenes, ionomers, chlorosulfonated polyethylenes, blends thereof, and blends of thermoplastic polyurethane with polyvinyl chloride (PVC), polyvinylindene fluoride (PVDF), polycarbonate, or acrylonitrile butadiene styrene (ABS).

Tunable magneto-rheological elastomers and processes for their manufacture

A tunable vibration isolation device comprising a magneto-rheological elastomer (MRE), and methods of using such a device, are provided. By manipulating a magnetic field within the MRE the device's stiffness is controlled. The vibration isolator can be constructed to provide shock absorption in one, two and three dimensions. Coupling the tunable device to a sensor feedback and a control system provides fast and accurate vibration isolation and energy dissipation for shock events in a variety of applications.

Controllable magneto-rheological elastomer vibration isolator

The disclosed device is directed toward magneto-rheological fluid encasement device. The magneto-rheological fluid encasement device comprises a body having at least one containment element defining an interior and an exterior. A magneto-rheological fluid is disposed in the interior of the at least one containment element. At least one magnetic field is in operative communication with the magneto-rheological fluid.

Magneto-rheological fluid encased in flexible materials for vibration control

The disclosure describes a magnetorheological fluid control valve. The magnetorheological fluid control valve comprises an electromagnetic coil having a first end and a second end. A first arm is magnetically coupled to the first end of the electromagnetic coil. A second arm is magnetically coupled to the second end of the electromagnetic coil. The second arm has a passage. A ferromagnetic rod having a diameter less than that of the passage is disposed in the passage and magnetically coupled to the first and second arms. A first manifold is coupled to the second arm at one end of the passage. A second manifold is coupled between the second arm and the first arm at an end of the passage opposite the first manifold. A magnetorheological fluid is disposed in the passage.

Growing community of inventors

Reno, NV, United States of America

Gregory Hitchcock