LORD Magneto-Rheological (MR)
After investing in more than a decade of intensive research and development, we hold the world’s most extensive patent portfolio on MR fluid formulations, devices and systems. We have developed additives, lubricants and suspension aids to keep iron particles in place while preventing them from grinding away at seals, gaskets and metal components. We also have compiled a body of scientific data through aggressive lifecycle testing and installed commercial applications that clearly demonstrate the effectiveness, durability and performance of MR fluids, devices and systems.
MR, DEVICES & FLUID (MRDF)
We have the expert knowledge, resources and commitment to work with you for a successful launch of your application. MR technology makes it possible for engineers to design a wide range of devices and systems with far greater flexibility. The result:
- Improved Performance
- Reduced Part Count and Complexity
- Smaller Package Size
- Less Weight
Whether you are in the conceptual or prototyping stage of your application, we stand ready to be your development partner in:
- Magneto-Rheological (MR) Fluid and Technology
- Steer-By-Wire and Haptic Control
- Advanced Controllable Suspensions
- Vehicle, Cab, and/or Seat Suspensions
- Active Suspensions and Systems
- Smart Materials and Structures
- Adaptive Motion Control
- Passenger Restraint and Safety Systems
- Magnetic Devices and Design
- Fan Clutch
- Seismic Protection
- Human Prosthetics
MR technology has moved out of the laboratory and into viable commercial applications for a diverse spectrum of products. Applications include:
- Automotive Primary and Secondary Suspensions
- Seat Suspensions
- Steer-By-Wire Devices
- Vehicle, Cab, and/or Seat Suspensions
In contrast to conventional electro-mechanical solutions, MR technology offers:
- Quick response time (less than 10 milliseconds)
- Real-time, continuously variable control of damping
- Simple design (few or no moving parts)
- Consistent efficacy across extreme temperature variations
- High dissipative force independent of velocity
- Greater energy density
- Minimal power usage (typically 12V, 1 Amp max current; fail-safe to battery backup, which can fail-safe to passive damping mode)
- Inherent system stability (no active forces generated)
In contrast to conventional electro-rheological solutions, MR technologies:
- Are 20-50 times stronger
- Are significantly less sensitive to contaminants and extremes in temperature
- Can be operated directly from low-voltage power supplies
MR technology can provide flexible control capabilities in designs that are far less complicated and more reliable than those based on ER technology.
WHAT IS MAGNETO-RHEOLOGICAL (MR) FLUID?
A typical MR fluid consists of 20-40 percent by volume of relatively pure, 3-10 micron diameter iron particles, suspended in a carrier liquid such as mineral oil, synthetic oil, water or glycol. A variety of proprietary additives, similar to those found in commercial lubricants to discourage gravitational setting and promote particle suspension, are commonly added to LORD Corporation’s state-of-the-art MR fluids to enhance lubricity, modify viscosity and inhibit wear. For most engineering applications, a simple Bingham plastic model is effective in describing the essential, field-dependent fluid characteristics.
MR fluids made from iron particles exhibit maximum yield strengths of 50-100 kPa for applied magnetic fields of 150-250 kA/m. MR fluids are not highly sensitive to moisture or other contaminants that might be encountered during manufacture and usage. Further, because the magnetic polarization mechanism is unaffected by temperature, the performance of MR-based devices is relatively insensitive to temperature over a broad temperature range (including the range for automotive use).
MR fluids are usually applied in one of two modes. MR fluid operating in valve mode, with fixed magnetic poles, may be appropriate for hydraulic controls, servo valves, dampers, and shock absorbers. The direct-shear mode with a moving pole, in turn, would be suitable for clutches and brakes, chucking/locking devices, dampers, breakaway devices and structural composites.