Micromotors Are Making Small Beautiful

Online Editor

Micromotors are accelerating the decarbonisation of the transport sector in the sky as well as on the ground. Stewart Goulding examines the evidence

As of the end of February 2021, there were over 215,000 pure-electric cars on UK roads. Transitioning to more environmentally friendly modes of transport and improving fuel economy will be crucial in reducing greenhouse gas emissions from transport. Every single aspect of the sector must be examined to see where improvements can be made – and this includes micromotors, which are supporting the switch to EVs and improving the efficiency of commercial aircraft.

Global transport emissions increased by less than 0.5% in 2019, compared with 1.9% annually since 2000, owing to efficiency improvements, electrification and greater use of biofuels. Nevertheless, the sector is still responsible for 24% of direct carbon emissions, according to the International Energy Agency. Because of this, the decarbonisation of transport has become a crucial part of the UK government’s climate crisis strategy.

Last year, the government released its Decarbonising Transport: Setting the Challenge report, which detailed what must be done to reduce transport emissions to reach net zero by 2050. Efficiency improvements in aircraft technology and switching to EVs are two strategies covered in the document, and innovative motor technology can catalyse progress in these areas.

EV’s are Charging Ahead

As part of its decarbonisation strategy, the government has banned the sale of new internal combustion engine (ICE) cars and vans from 2030, enforcing a shift to EVs. Despite EVs producing around 50% less greenhouse gas emissions than ICE vehicles, increasing their adoption has been challenging. Many drivers are reluctant to switch as they believe EVs cannot perform as well as ICE vehicles, or have concerns over the inconvenience of charging.

Micromotors are helping to combat these apprehensions, as they are being used in applications that can make EV charging quicker and simpler. For example, micromotors can be incorporated into an EV charging port to enable electronic opening of the flap, providing easy access for the driver. This design feature also enables the port to be secured at the touch of a button, preventing physical damage and tampering with the internal components.

In the confined spaces of a charging port, a bespoke drive system is often the best option to achieve the maximum performance in the given space envelope. Standardised parts are designed to operate in a variety of applications, and therefore only partially suit most products. Increasingly, companies are offering a bespoke manufacturing service that can deliver custom mechanisms with only the necessary features built in, creating a compact structure that is tailored to the unique requirements of the project.  

A Shifting Gear

Micromotors also play a vital role in EV gear shifts. ICEs require multi-speed transmissions, as they can only operate within a narrow revolutions per minute window in each gear before stalling. On the other hand, the electric motors in EVs have a much larger operating window, so a single-speed transmission can work for both high and low acceleration.

Although EVs do not need a multi-gear system, that doesn’t mean they can’t benefit from it. A single-speed transmission will work for a wide range of acceleration, but there is a degree of trade-off that can impact torque and efficiency. For heavy vehicles such as buses and trucks in particular, a multi-speed transmission can improve the EV’s efficiency and performance, improving uphill travel and acceleration to highway speeds.

However, multi-speed transmissions are larger than single-speed, which can be problematic in commercial vehicles that require maximised space for the carrying of goods or passengers. Fortunately, automotive engineers can make the transmission system more compact by using small and power-dense micromotors in the integrated actuation system.

Every Gram Counts

While there are far fewer travelling commercial aircraft than road vehicles at any given time, planes have a higher fuel consumption rate and should also be prioritised in the transport decarbonisation strategy. For example, a Boeing 747 Jumbo Jet can burn around four litres of fuel every second.

Shedding weight will help bring down this high fuel consumption. For instance, when United Airlines switched its in-flight magazine to a lighter paper stock, it saved over 640,000 litres of fuel a year.

A crucial area where airlines can reduce aircraft weight and improve fuel economy is in motorised systems. Motors are used to add comfort and a touch of luxury across a range of cabin equipment, such as in reclining seats, motorised television screens and electric window blinds.

They are also found on board in safety-critical applications, playing a key role in locking cabin door mechanisms, emergency exits and the pilot’s seat, which must remain in a fixed position during take-off and landing. Motors are also used to adjust the valves that regulate the plane’s air conditioning system.

With a number of motorised systems on board, aerospace engineers can shave many grams from aircraft by switching to more compact alternatives, such as those made by Faulhaber.

In combination with high-performance motor technology, companies are now increasingly working with advanced materials such as titanium, which is known for its incredibly low weight and high strength, in their customised mechatronic solutions, further improving the overall system performance.

There is no doubt that the transport sector can capitalise on advancements in motor technology to reduce greenhouse gas emissions. High-performance micromotors can help accelerate EV adoption and improve the fuel economy of aircraft, assisting the transition to greener travel.

Stewart Goulding is managing director of drive supplier EMS