Device converts railway track vibrations into energy
Engineers in the US have developed an innovative energy harvester that has the potential to save millions of pounds in energy costs for railways while reducing carbon dioxide emissions.
The device, created by a team from New York's Stony Brook University, works by converting the irregular, oscillatory motion of train-induced railway vibrations into regular, unidirectional motion, in the same way that an electric voltage rectifier converts AC voltage into DC.
Professor Lei Zuo and graduate students Teng Lin and John Wang, from the university's Department of Mechanical Engineering, believe the invention could save more than $10million (approx £62m) in track-side power supply costs for railways in New York State alone, along with a reduction of 3000 tons per year of CO2.
"Our invention can harness 200W of electric energy from train-induced track deflections to power track-side electrical devices such as the signal lights, cross gates, track switches and monitoring sensors," noted Professor Zuo.
"By using two one-way clutches, the mechanical motion rectifier converts the irregular up and down vibration motion into unidirectional rotation of the generator, thus breaking the fundamental challenge of vibration energy harvesting and offering significant advantages of high efficiency and high reliability."
In addition to the economic and environmental benefits of the device, Zuo believes the most important technical breakthrough comes down to the team's efforts to synergistically integrate the fly wheel into the energy harvesting system to further increase energy conversion efficiency and stable power output.
Another important feature, he says, is the implementation of the MMR in one shaft design. This is said to increase the energy converting efficiency to more than 70%.
