1. It balances the engine, making the actual motor more efficient and
2. It takes the energy from the motor and temporarily stores it until it is used by the propulsion system, ie through the gearbox.
Function 1 is still important. If the engine is not smooth, you will destroy everything around it and even the motor itself. Clearly in a car this is not acceptable and as the speeds increase (not just road speed, but engine revs) this becomes even more important.
This is a classic flywheel from an engine – a Fidanza model. Image from tunersports.com.
You see flywheels on most machines – especially agricultural ones as they help to deliver the power to another labour saving machine. Often old mills and factories had huge flywheels in them and today they are seen as things of great beauty.
This is an example from newsandstar.co.uk and used at Carrs Flour Mill in the UK.
But what about today? Ricardo, a British engineering firm had just released their second generation kinetic storage system when I last wrote on the topic. They had developed a hermetically sealed carbon fibre flywheel system that was light and compact that took the technology a step further, so much so, they had applied for 9 patents! The developments partly funded by the UK Government were with Allison Transmissions and other partners to improve the efficiency of buses.
Torotrak, one of the partners with Ricardo and Allison has recently bought Flybrid Automotive to further develop the systems used in race cars. The Flybrid system, also made of carbon fibre, spins at 60,000 rpm to store “lost”energy.
This is the Flybrid system – a mechanical battery! Image from flywheelcapacitor.com.
Earlier this year, Ricardo announced the TorqStor, an evolution designed for construction equipment that saves fuel by reusing energy that would have been wasted otherwise.
So this technology is now leaping ahead and getting smaller and more reliable. Soon household uses will start to appear as developers realise that any flow of air or water could turn a device that converts the energy into a “mechanical” battery. So we literally go full circle back to water wheels and windmills that did this centuries ago! And that is why the world still turns after billions of years…..