The Definitive Guide to Electric Motors – PART 3
In the third section of our guide to Electric Motors, we take you through the small motors you use every day and advancements in electric vehicle technology.
Where Are They?
Electric motors are used in an absolutely incredible number of objects – in fact it would be incredibly difficult to get through your day without using one. Take this average day for instance.
You’re woken by a call from your friend. Since you had your phone on silent, the only way you’ll be woken by it is thanks to the tiny electric motor contained within your phone. Later on, you’ll know there’s been an important development on Twitter when your phone buzzes like crazy in your pocket.
You can have a shower thanks to the electric motor which powers the pump to push domestic water supplies into your house, and dry your hair with an air flow generated by an electric motor powering a fan.
When you get downstairs, the milk for your cereal is perfectly cold already thanks to the fridge. How did the fridge get cold? Electric motors pump a refrigerant gas into the back of your appliance, forcing the cold air to circulate. There’s also another motor powering the fan inside the fridge, as well as in the blender, food processor and oven hood.
Still half asleep, you make your way to the bathroom to brush your teeth. You might well have an electric toothbrush – the motor should be evident in this one. It could be the exact same type of motor that’s in a mobile phone or pager, as all it needs to do is make the body of the toothbrush vibrate. Next you go to feed the fish, whose aquarium water is pumped around by an electric motor, and then use the electric motors in your computer’s fans to keep it cool while you use it to order more fish food.
You drive to work every day, not knowing how much you rely on the smallest electric motors. They power the fans which heat or cool your car’s interior; they move the windshield wipers, and open and close the windows. By the time you arrive at work you’ve already made use of a dozen or so electric motors, without even being aware of it.
Industrial Uses of Electric Motors
Of course, there are many different types of electric motors. Large-scale electric motors are commonly used for powering industrial appliances, from small lathes, to cars and all the way up to cruise ships.
Lathes were one of the first tools to take advantage of the power of electric motors. Although simple versions of the machine have been around since the times of Ancient Egypt they were originally powered by hand; the Romans later improved upon the design with the use of pedals, and many hundreds of years later they were driven by horses and then water and steam. It wasn’t until the late
19th century that single electric motors began to replace line shafting as the driving power source, thereby providing electrical power to the world’s oldest power tool. Lathes are used today for a wide variety of products, from pottery, gun barrels, pool cue sticks and woodwind instruments.
Submarines and cruise ships also make use of electric motors for greater maneuverability. In the case of cruise ships, electric motors are placed in pods named azimuth thrusters, which allow for 360 degree rotation. In some newer cruise ships, a combination of diesel and electric propulsion is used by connecting the main engines to generators which produce electricity for the electric motors – which turn the propellers. Submarines use electric motors for two purposes; on the surface, they are used to generate electricity for the ship, while when submerged the electric motors are powered by batteries.
Wheel hub motors were first popularised by Ferdinand Porsche, and consist of an electric motor driving the wheel from a hub. Electric bicycles commonly use this technology still, and it is also used for driving wheels in assembly lines. Despite the fact that they were originally produced to be used in vehicles, they were seldom used after the rise of the internal combustion engine.
Electric motors for vehicle propulsion isn’t as new an idea as you might think – in fact they have gone through a few periods of popularity. They were first used in the mid-19th century when Walter C Bersey introduced a fleet into the streets of London, and by the beginning of the 20th century they were frequently used for commercial electric automobiles. Electric cars were much quieter and had less smell and vibration than gasoline-driven vehicles; additionally they didn’t require the manual effort of turning a hand crank. Because of this they were marketed as “women’s cars”, which may have affected their popularity.
Unfortunately as the 20th century progressed, electric cars saw a decline in popularity. The new road infrastructure made the comparatively short distances achievable by electric cars redundant, and gasoline became much more affordable. When the electric starter was invented by Charles Kettering in 1912, the advantage of an easy start became useless, and use of mufflers made the vehicles much more quiet. Henry Ford’s mass production of gas-powered cars soon meant that the electric car cost around twice as much as it’s fossil fuel burning counterpart.
After this time in the UK, electric vehicles were primarily used as milk floats, forklift trucks and golf carts – vehicles that only travelled short distances and were required to not make much noise. Even since then, a huge amount of milk floats have been converted to internal combustion engines to increase the speed and distance they could travel, in order to accommodate more homes.
Nowadays, electric vehicles are a lot more advanced. Improved lithium-ion batteries have meant that a car can now travel as far on a fully-charged battery as a fully-filled tank. They can also be charged in minutes now as opposed to hours, and research is going into solid-state battery technology which will improve the efficiency and safety of these cars.
At the turn of the 21st century, the global economic recession, concerns about the environmental impact of cars and increased international tensions once again highlighted the need to move away from traditional fossil fuel sources. In his 2011 State of the Union address, President Obama expressed his goal of having one million plug-in electric vehicles on US road systems by 2015 in order to reduce their dependence on oil.
Tesla Motors, named after the Hungarian physicist who was instrumental in the development of the electric motor, released their first Roadster car with an AC electric motor based on Tesla’s 1882 design. It was the first production car to make use of lithium ion battery cells and had a range greater than 200 miles per charge, making it the first modern electric car to be capable of highway use. In June of 2014 the company made their patents open source to enable a rush in the production of electric cars.
2014 saw the first official Formula E Championship, started in Beijing. Each of the participating cars must comply to restrictions that they are one-make, single-seaters, driven by a team of two drivers. In the first year all drivers were required to start with the base point of the Spark Renault SRT_01E, a super lightweight carbon fibre and aluminium car which complies with FIA crash tests. McLaren provides the power train and electronics system, while Williams Advanced Engineering are providing the 200kw batteries (equivalent to 270bhp). The fixed ratio five-speed paddle shift sequential gearbox is provided by Hewland.
Each of the cars will be restricted in power to “race mode” which is 150kw, with extra boosts allowed for voted drivers who are able to increase to 180kw for five seconds at a time. During the race each driver needs to take one pit stop in order to change cars – it’s estimated that the cars take around fifty minutes to charge from flat to full.
As of the second season, the championship will be opened up to other car manufacturers, provided that they work to the FIA’s technical specifications. The idea of Formula E – other than pushing the boundaries of racing technology – is that the research and development of electric vehicles will create more interest and investment in sustainable mobility. A study by Ernest & Young, commissioned by Formula E, predicted that between 2015 and 2040 the competition could aid in selling 77 million EVs around the world, save four billion barrels of oil and save 25 billion Euros in healthcare.
It’s easy to take for granted the amount we actually use electric motors on a daily basis, but with increasing developments in electric vehicles and EV motoring, electric motors may see a resurgence in popularity once more.