Lord Corporation

Teresa L Forehand

K Andrew Kintz

Daniel E Barber

A magnetorheological fluid comprising a mixture of soft and hard iron particles, an organic based carrier fluid, and optional additives such as anti-friction, anti-wear, or surfactants unexpectedly have improved durability when used in devices for control vibration and/or noise, for example, shock absorbers, elastomeric mounts, dampers, and the like.

High durability magnetorheological fluids

The invention provides a magnetorheological device employing narrow design gap and containing a magnetic-responsive composition exhibiting reduced off-state forces and good performance. Specifically, this invention is directed to a magnetorheological device of defined gap, and employing a magnetic-responsive composition characterized by comprising non-sperical magnetic-responsive particles of average number diameter distribution (d) from 6 to 100 microns and at least one friction-reducing additive that reduces the interparticle friction between the magnetic-responsive particles.

Magnetorheological composition

What is disclosed is a magnetorheological fluid useful for incorporating within the working gap of magnetorheologically controllable linear or rotary devices. The MR fluid includes a carrier fluid component and a magnetic responsive particle component characterized by Dof 2 &#x3bc;m up to and including a Dof 5 &#x3bc;m, a Dof 8 &#x3bc;m up to and including Dof 15 &#x3bc;m; a Dof 25 &#x3bc;m to and including a Dof 40 &#x3bc;m; and further characterized by least squares regression (R) particles size against log normal cumulative volume percent of greater than or equal to 0.77. Optional preferred additives included therewith include thixotropic agent or viscosity modifier, dispersant or surfactant, antioxidant, corrosion inhibitor, and one or more lubricants.

MR fluid for increasing the output of a magnetorheological fluid device

The invention provides a magnetorheological composition having reduced off-state forces and good performance. Specifically, this invention is directed to a magnetorheological composition that may comprise non-sperical magnetic-responsive particles and at least one friction-reducing additive that reduces the interparticle friction between the magnetic-responsive particles.

Magnetorheological devices, including damping devices, rotary devices, and haptic systems constructed with said devices are disclosed. The devices contain dry magnetically-responsive particles, or MR fluids containing the magnetically responsive particles. The magnetically soft particles characterized by a single process yield population of atomized particles having a cumulative 10%, 50% and 90% by volume, fraction within specified size, i.e., Dof from 2 up to and including a Dof 5 &#x3bc;m, a D8 &#x3bc;m up to and including a Dof 15 &#x3bc;m, a Dof 25 &#x3bc;m up to and including a Dof 40 &#x3bc;m, and characterized by a least squares regression of log normal particles size against cumulative volume % fraction of greater than or equal to 0.77.

Growing community of inventors

Raleigh, NC, United States of America

Teresa L Forehand