For several years, I had the pleasure of being able to attend Parker Hannifin’s Chainless Challenge competition, a research and design contest that the company sponsored for several different engineering universities. In it, students were charged to create a bicycle that would use fluid power to increase the speed and power of bicycles traveling on a course. Having witnessed about three or four of these competitions, I can say that most students chose to go with hydraulics as their mode of power; only one team that I can remember worked with pneumatics, and the design—featuring countless plastic bottles, or accumulators—was cumbersome to say the least. And it just wasn’t as effective as its hydraulic counterparts except for short bursts of power.
So I was pleasantly surprised to see this cool new design that uses an air motor to boost power, coming from a couple of avid cyclists in Rio Rancho, N.M. Trever Skilnick and Aviad Cahana have created NuAira, where they are prototyping and in the process of patenting this ultra-pneumatic, high-pressure (4500 psi) compressed air system that uses a carbon fiber tank for storage.
In their design, says Skilnick, “The 2ndwind Ultra-lite Pedal Assist is mounted within the wheel hub and allows the rider to achieve and maintain a higher average speed or to surmount obstacles. The wheel-centric design breaks the weight/performance paradigm by achieving an ultra-light, yet powerful propulsion mechanism with incredible performance. The total system (powered hub, bottle, throttle and ancillary equipment) adds only 2 lb to the bike of your choice.”
The NuAira design works almost like a rotary vane motor, but is instead flipped inside out and reversed so the wheel turns the proper way. But because the pedal-assist air motor design is currently going through the patent process, Skilnick could not provide too many details on how the design works.
The motor can mounted in the front, rear or on both wheels, and it can be used only when needed (for going up a hill, for example) or to provide consistent pedal-assisting force.
Filed Under: Pneumatic Tips