Shifting gears to power the world with wind

Shifting gears to power the world with wind

Hansen Transmissions expands to meet growing worldwide demand

Sometimes people change the world without you even knowing it. When an o-ring failed on the ill-fated Challenger shuttle flight in 1986, it put in stark relief how small things can be so fundamental to the success of greater goals. It was also the 1980s that saw a far less dramatic (but no less important) change in public perception – how we generate electricity. After the first oil crisis a decade earlier, countries started looking for alternatives to fossil fuels.

The first wind farms took root in California, largely on the back of generous tax credits, but also through the realisation that wind is abundant. Not only this, but the technology is attractive because it is both renewable and non-polluting. With a similar realisation sweeping Europe at the time (specifically Denmark, Germany, Spain and Belgium), early wind turbines came in two flavours: Overly massive and inefficient (Europe) or flexible and fragile (US). An early (and seemingly minor) participant in the wind business was Hansen, then an industrial gearbox manufacturer. The gearbox is the part of the turbine that people never see, yet it’s one of the most critical components in the success of a technology that is to play an increasingly vital role in weaning us off oil.

While early turbines generated mere kilowatts, today’s giants have a 1.5-3.5 megawatt capacity, with a rotor disc area the size of a football field. However, the scaling up of machines and their components has also caused problems, in particular with gearboxes, which are exposed to lots of vibrations and movements inside the turbines. The blades of the turbine are attached to a rotor hub in the centre, which connects to a drive shaft. Because this shaft spins quite slowly, a gearbox is required to turn a second shaft at speeds high enough to generate electricity.