Posted inElectric Vehicle / Technology

Regenerative shock absorber for EV

Electric Truck, LLC (ET) has exclusively optioned commercial rights to a technology from Tufts University that can recharge the batteries of any hybrid electric and electric-powered vehicle while it is driven. The regenerative electromagnetic shock absorber technology was developed by Tufts engineering professor emeritus Ronald Goldner and colleague Peter Zerigian within the School of Engineering and received additional support in subsequent years from Argonne National Laboratory.

At the SAE Government/Industry Meeting in Washington in 2001, Goldner, Zerigian and J.R. Hull from Argonne presented a paper estimating that the percentage of recoverable power/energy for a 2,500 lb vehicle that employs four optimized design regenerative magnetic shock absorbers and whose average speed is 20 meters/s (45 mph) on a typical US highway is likely to be between 20% and 70%.

The shock absorber uses an electromagnetic linear generator to convert variable frequency, repetitive intermittent linear displacement motion to useful electrical power. The Goldner device uses superposition of radial components of the magnetic flux density from a plurality of adjacent magnets to produce a maximum average radial magnetic flux density within a coil winding array.

Due to the vector superposition of the magnetic fields and magnetic flux from a plurality of magnets, a nearly four-fold increase in magnetic flux density is achieved over conventional electromagnetic generator designs with a potential sixteen-fold increase in power generating capacity. As a regenerative shock absorber, the disclosed device is capable of converting parasitic displacement motion and vibrations encountered under normal urban driving conditions to a useful electrical energy for powering vehicles and accessories or charging batteries in electric and fossil fuel powered vehicles.
– Goldner et al. Patent# 6,952,060

The linear generator comprises an assembly of magnet arrays, high magnetic permeability spacers and coil winding arrays with an innovative magnet-spacer-coil configuration and geometry which uniquely provides for vector superposition of the magnetic fields.

Unlike conventional devices, such as a linear motion generator, a regenerative shock absorber, or a reciprocating linear motor, the Goldner device provides substantially more uniform and higher average radial magnetic flux density throughout coil winding volumes, according to the inventors, resulting in the increase in electrical power regeneration.

In their patent filing, the inventors claim that the regenerative electromagnetic shock absorber system is capable of peak power generating capacity of between about 2 to 17 kW, average power generating capacity ranging from about 1 to 6 kW, and power contribution efficiencies ranging from 8-44% for passenger vehicles traveling at relatively moderate speeds on typical roads encountered under normal urban driving conditions.

For rough roads with bump slopes as high as 0.10 and displacement velocities greater than 1.0 m/s, they claim that the system may generate nearly 50 kW of peak power and nearly 16 kW of average power with a power contribution efficiency approaching 70%.

It is anticipated that, with devices fabricated with high permeability materials having a saturation magnetization of greater than 2.5 Tesla, even greater peak and average power outputs and power contribution efficiencies may be realized from additional increases in radial magnetic flux density in the coil windings.
– Goldner et al. Patent# 6,952,060

Since the technology actively uses the weight of a vehicle for energy recovery, it could help speed the expansion of the hybrid and battery electric vehicle market from cars to vehicles of greater size, weight and payloads, such as SUVs, pickup and delivery trucks, mail trucks, school and city buses and other light and medium duty trucks.

– from greencarcongress. 23 Nov 2008

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