Magnetics Business & Technology - January/February 2020 - 25

INDUSTRY NEWS

MR fluid powertrain mounts dampen vibration
simplicity of the damper is complimented by the speed and sophistication of the controlling mechanism. One thousand times per
second, sensory inputs are read, damping forces are calculated,
and resulting damping forces are applied.
BWI also makes innovative powertrain mounts using MR fluid
that isolate vibrations from the vehicle's body while also providing
enhanced powertrain motion control. Unlike conventional hydraulic mounts which provide peak damping at a single frequency
and

amplitude, its MR mounts can provide high damping over a broad
frequency and amplitude range.

Using MR fluid to change the damping rate in real time,

the mounts
may be "firmed up" with high levels of lateral acceleration for more
direct cornering, or "softened" to maximize comfort during
straight
ahead driving. The original MR powertrain mounts were engineered
for performance and configured for premium sports car applications. They prevented large transient powertrain movements in the
frequency range of 2-22 hz from reaching the chassis. The second-generation design retains this capability while also providing
isolation from smaller amplitude movements in the critical comfort
range of 30-150 hz, enabling the technology to be applied to touring
vehicles where superior levels of refinement are required.

field causes the particles to align into fibrous structures in the direction of the magnetic flux. The strength of the bond between the particles in the structures is proportional to the strength of the applied
magnetic field, so changing the current provides real-time variable
damping with a very large range of force variation.
LORD Corporation, recently acquired by Parker Hannifin (see next
article), is a primary supplier of magnetic fluids to BWI.
For more info, see www.bwigroup.com.

The Pioneer In
Advanced Magnetics
www.intemag.com
800-421-6692
info@intemag.com

With over 60 years of technical magnet expertise, Integrated
Magnetics specializes in design-to-specification & build-to-print:
* Off-the-shelf magnets
* Custom magnets
* Custom magnetic assemblies
* Custom electrical machines -
servo motors, actuators,
LVDTs, RVDTs & more.

Engineering Expertise * In-House Production Facilities
Environmental Testing * Assembly * Class-1000 Clean Rooms
Machining * Milling * Turning * Grinding * Winding
EDM * Chemical Cleaning * Inspection & Test
Each mount contains an electromagnetic coil that can generate a
variable magnetic flux across the fluid passages. When the coil current is turned off, the MR fluid is not magnetized, the iron particles
are randomly dispersed within the fluid, and the fluid behaves like
conventional hydraulic oil. When the coil is energized, the magnetic

www.MagneticsMag.com

US Based Manufacturer with
Plants in Culver City, CA
Tucson, AZ & Nogales, Mexico

January/February 2020 * Magnetics Business & Technology

http://www.bwigroup.com http://www.intemag.com http://www.MagneticsMag.com

Magnetics Business & Technology - January/February 2020

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