Brushless DC Rotary Motor Improves Efficiencyin Fuel Cell Applications

ThinGap, Ventura, California

The designers and manufacturers of fuel cells are continually striving to improve the efficiency of their products. A design challenge facing the engineer relates to reducing the power demands of the many electrical systems that support fuel cell operation. Blowers, compressors, and pumps are necessary for fuel pump operation, but are considered parasitic electrical loads. Since they require power from the fuel cell itself they impact overall system efficiency. To be truly effective in fuel cell applications, the motors used to drive the pumps must be lightweight, compact, and as efficient as possible in order to provide more energy for the intended application.

This patented electromotive coil technology eliminates the iron core and wire windings of conventional motors. The result is an innovative motor with excellent power conversion efficiencies, higher power-to-weight ratios, and lighter weight. The technology is applicable to brush as well as brushless DC motors.

The use of precision-machined copper sheets produces a design with higher copper-packing density and higher copper-to-total-volume ratio than conventional models. The motor's freestanding coil design also enables the reduction in the air gap between the permanent magnet and magnetic return structure, allowing fuller utilization of the available magnetic flux density. No complex, costly iron lamination stacks are required.

High inertia gives the motor the ability to operate over a larger dynamic range, which is always a desirable feature in fuel cell applications. The high inertia thus gives the motor the ability to push through the power stroke at lower speeds. The motor also features smooth, quiet operation, and low heat generation.

A "thick coil" ironless armature displays a mechanical ruggedness due to a denser, multi-layer construction that creates a robust and very rigid structure. The lower electromotive coil resistance leads to lower winding resistance and higher motor power efficiencies. The air gap is minimized, which enhances the magnetic field and air gap flux density, enabling high torque in a lightweight package.

ThinGap Motor Technologies, 2140 Eastman Avenue, #112, Ventura, CA 93003. For more information, contact ThinGap at (805) 477-9741 or e-mail info@thingap.com. Visit ThinGap on-line at www.thingap.com.