Abstract:
A controllable damper (470) for resisting movement between two relatively moveable members includes a first member and a second member coupled for relative movement having a working space between them, and a controllable medium retaining structure, for example, an absorbent matrix (30), to hold a controllable medium only in the working space. A cage (86) preferably supports the matrix. A field generating coil (88a, 88b) is mounted to one of the first and second members to generate a field acting on the first and second members and the controllable medium in the working space. The rheology change in the medium produced by the field results in resistance to relative movement of the first and second members. A device according to the invention may be used in apparatus, such as washing machines, exercise equipment, air supported tables, and a range of other apparatuses that would benefit from controlled damping or braking. Devices including a two-piece outer housing (78a, 78b) are described.
Abstract:
A magnetorheological material containing a carrier fluid and a magnetically active particle. The particle has been modified so that the surface of the particle is substantially free of contamination products. The contamination products are removed from the surface of the particle by abrader processing, chemical treatment or a combination thereof. Magnetorheological materials prepared using the particles from which contamination products have been removed exhibit significantly enhanced magnetorheological effects.
Abstract:
A friction damper (10) a housing (12) including a cavity (17) formed therein; a first member disposed in said cavity and movable in said cavity (17); a second member (60) disposed in said cavity; an intermediate member (40) between the first (50) and second members (60), the first member being in frictional engagement with the intermediate member (40); and at least one magnetic field generator mounted to magnetically couple the first and second members thereby maintaining the first member in frictional engagement with the intermediate member and wherein the first member is movable against the intermediate member to generate a damping force.
Abstract:
The invention provides a magnetorheological grease composition which contains magnetic-responsive particles, a carrier fluid and thickening agent. The composition according to the invention contains an effective amount of thickening agent to provide a composition of proper consistency with good properties and little settling of the magnetic-responsive particles.
Abstract:
Magnetorheological fluid compositions that include an aqueous carrier fluid, magnetic-responsive particles and an additive selected from bentonite or hectorite. This fluid exhibits excellent stability and is easy to re-disperse. Preferably, all the ingredients are inorganic.
Abstract:
A controllable vibration apparatus such as a linear fluid damper in which an electrical connection to a controllable valve, preferably located in the piston assembly, is made through a single-strand electrical conductor. In one embodiment, the piston and piston rod (24a) are preferably used as the source of low potential (ground or retun electrical path). An accumulator assembly (44a) preferably including a flexible diaphragm (76a) thereon can be used to provide separation of the fluid-containing chambers from a pressurized accumulator chamber. In magnetorheological (MR) fluid dampers, a special sealing system including a defined relationship between surface finish on the piston rod and magnetically soft particle size is described which enhances life of the seal system. A metal bushing (36a) with a friction-reducing surface treatment is used in combination with an energized lip seal (38a) to prevent escape of the magnetic particles from the damper and support side loads. The magnetically controlled valve can be formed from separate top (80a) and bottom (85a) pole pieces that are spaced from an outer annular ring (82a) to define a fluid passageway. The top pole piece and the annular ring can be secured together by bridging elements such as non-magnetic welds, spot welded plates, or alternatively, formed as a single unit using powdered metal processes such as PIM or MIM. The coil assembly (88a) can be configured with axially-extending pins (94a, 96a) to easily connect with a conductor. An elastomeric element (98a) provides electrical and fluid sealing engagement against the single-strand conductor. Push-on connectors (83a) preferably make the connection between the single-strand conductor and the axially extending pins. In a two single-strand conductor version, one single-strand carries the incoming current and the other the outgoing current. 00000
Abstract:
A magnetorheological material containing a carrier fluid and a magnetically active particle. The particle has been modified so that the surface of the particle is substantially free of contamination products. The contamination products are removed from the surface of the particle by abrader processing, chemical treatment or a combination thereof. Magnetorheological materials prepared using the particles from which contamination products have been removed exhibit significantly enhanced magnetorheological effects.
Abstract:
A magnetorheological material containing a particle component and a carrier fluid having a change in viscosity per degree temperature ( DELTA eta / DELTA T ratio) less than or equal to about 9.0 centipoise/ DEG C over the temperature range of 25 DEG C to -40 DEG C. The magnetorheological material exhibits a substantial magnetorheological effect with a minimal variation in mechanical properties with respect to changes in temperature. The magnetorheological material is advantageous in that it provides for the design of devices that are smaller, more efficient and consume less power.
Abstract translation:含有颗粒组分和载体流体的载体流体或载体流体混合物的磁流变材料,其粘度/度温度变化(DELTA eta / DELTA T比)小于或等于约16.0厘泊/℃,在约 25℃至-40℃。磁流变材料具有显着的磁流变效应和优异的润滑性能,相对于温度变化的机械性能变化最小。 磁流变材料的优点在于它提供了更小,更有效和消耗更少功率的装置的设计。
Abstract:
A magnetorheological material containing a carrier fluid, a particle component and a thixotropic additive to provide stability against particle settling. The thixotropic additive can be a hydrogen-bonding thixotropic agent, a polymer-modified metal oxide, or a mixture thereof. The utilization of a thixotropic additive creates a thixotropic network which is unusually effective at minimizing particle settling in a magnetorheological material.