Date: Mar 01, 2010 Source: DARPA Success Stories (
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Technical Challenge Addressed:
The DARPA SBIR project developed revolutionary new motor technology to overcome the physical and performance limitations of conventional direct drive motors used for robotics and other servomotor motion control applications, such as magnetic resonance imaging (MRI), spacecraft turbines, thrust vector control, autonomous underwater vehicle propulsion, motor/alternator for hybrid electric vehicles, and constant velocity motors for applications where smooth, precise control is necessary. Conventional motors or gear motors do not provide smooth motion control, and at high loads their efficiency decreases. Also, their torque output is not the desired smooth, linear, proportional function of the amount of current applied. The SBIR challenge was to eliminate these limitations by developing a new type of SEMA motor with revolutionary coils and stators, designed to provide smooth, high torque motion and speed control along with economical manufacturing methods.
Technology Description:
SEMA technology was developed and demonstrated under the DARPA SBIR and was further developed and applied to a variety of applications through subsequent SBIRs, STTRs, a spin-off company, and private funding. SEMA technology is based on an axial gap (disk) direct current motor without brushes or contacts to wear out, spark, or cause losses. It employs a permanent magnet that produces a magnetic field in a specially designed coil inside an ironless stator that is segmented into groups of pole-pairs. These innovations eliminate phase mutual inductance, magnetic saturation of the iron core, and hysteresis or lagging in magnetization when the amount of current is varied; and reduce resistance losses in the coil wires while avoiding torque pulsations. The results are higher power density, superior efficiency, faster and smoother response, better control, higher torque at low-speed operation, and reduced noise, as compared to conventional motors.
Motors based on SEMA architecture may be operated at constant or variable speed, or reversed in a steady or intermittent state, and can be controlled precisely in a quiet, continuous manner. SEMA motors provide extremely high peak torques, and SEMA generators provide extremely high peak currents. They eliminate torque oscillations (cogging) and minimize low torque ripple. Independent tests demonstrated efficiency as high as 98 percent. SEMA motors and generators range from 3 to 33 inches in diameter and from fractional to 200 horsepower output. They are easier to manufacture than conventional motors, since they are modular and entail simpler coil and stator designs. SEMA machines are best suited for applications where efficiency, size, weight and smooth operation are important.
Lessons Learned & Best Practices:
- Understand the value of marketing in a small, innovative company, and present proposition in technical and business terms.
- Technology licensing is a time-honored and proven approach to leverage the innovation of a small company while capitalizing on the production and marketing capabilities of a larger company.
- Develop a mutually effective relationship with a larger potential partner that bridges differences in culture and practices, and provides an excellent return on investment for both companies.
Economic Impact:
Based on its initial DARPA SBIR success, has received more than 20 SBIRs and STTRs from federal agencies, including the Department of Defense (DoD), National Aeronautics and Space Administration (NASA), and Department of Energy (DOE). The SEMA technology is patented. A sister company, Lynx Motion Technology, was formed to license SEMA for manufacturing, and several other companies sell the technology under license agreements. Private investment and development funding continues to flow to develop SEMA technology and related products.
Applications:
SEMA motors and generators have been in production since 1999 for a wide variety of applications, which include magnetic resonance imaging control; aerospace applications, such as spacecraft turbine replacement and thrust vector control; autonomous underwater vehicle propulsion; motor/alternator for hybrid electric vehicles; constant velocity motors for various commercial applications; and a servo motor for an industrial welding robot with over one million cycles of endurance testing.
Partnering & Collaboration:
The DOE projects include providing a SEMA traction motor for an electric hybrid vehicle under the Future Truck program, and grants for other automotive applications and research activities. KAT was a recipient of a 2000 Tibbetts Award from the Small Business Administration for its SBIR/STTR success.
KAT received a $267,000 SBIR/STTR Commercialization Enhancement Program grant from the State of Indiana to commercialize its proprietary CL1 Controller. The company also received a $1.9 million grant from the Indiana 21st Century Fund to develop and commercialize advanced SEMA technology, working with Honeywell Aerospace. The two companies are jointly developing multi-slice motors (each slice is a motor), in which slices are electrically separated but working together mechanically to provide flexibility and redundancy.
KATÆs subsidiary, Lynx Motion Technology Corporation, has established strategic business partnerships and relationships with several commercial companies. Bodine Electric Company is licensed to manufacture its e-TORQÖ motors, while several other companies are licensed to sell SEMA motors and generators. SEMA licensee, Lexel Imaging Systems, developed and delivered a propulsion motor for a Navy unmanned undersea vehicle in August of 2008.
