Imagine running errands on an e-bike, e-scooter, or e-skateboard and leaving your car at home. That’s a look into the future of micromobility. In fact, in many cities around the world the trend toward micromobility has become a reality.
With e-mobility becoming more popular, more research is being poured into improving performance, lowering cost and opening the market to others. Much of that research begins with the e-motor design.
Let's take a look at the e-bike motor design trends you can expect in 2021 and 2022 as the electrification of transportation continues.
3 E-Scooter, E-Skateboard, & E-Bike Design Trends Impacting the Future of Micromobility
From the designer’s and buyer’s standpoints, these are the trends that matter most for the next few years:
- Motor performance
- Battery size/range
1. Motor Performance
Motor performance in an e-bike, e-scooter, or e-skateboard design is defined as the ability to climb hills, acceleration supporting battery life, and so on.
Traditionally, laminations made from electrical steel have been the material of choice for e-motor design. But, with soft magnetic composites (SMCs) made from powder metal, you can dramatically reduce core losses and eliminate the heat buildup that plagues laminations.
In some tests we’ve performed on steel lamination assemblies, we’ve found that about 20% of the motor’s power goes toward cooling. With laminations, you have to provide for plenty of cooling to combat significant core losses.
What does it mean for you if you switch to soft magnetic composite? You can put more of the battery’s effort toward eliminating the need for pedal power rather than cooling the stator.
When you achieve a drastic increase in the motor’s efficiency, the improvement of the battery is compounded. If you can optimize the motor to provide less strain on the battery, you can have your cake and eat it, too.
Linear Labs’ revolutionary electric motor is a recent, real-life example of this success. The tech start-up's founder cites massive torque, high efficiency, and lack of gearbox as the dominant forces in their motor improvements.
2. Battery Size & Range
The value of the electric vehicle has always come with an asterisk: the short battery range.
Engineers are attacking this through changing the size of the battery, but have you overlooked improving the motor’s performance?
The competition to create a lighter-but-more-powerful motor between the major mid-drive manufacturers -- Bosch, Yamaha, Brose, Shimano -- continued in 2020.
Where does powder metallurgy fit in the middle of this battlefield? Think of a brushless DC motor: The type of metal and the ability to create unique shapes in the stator significantly impacts the battery's life.
Although the motor's efficiency highly depends on the winding, the windings also play a role in performance and price. The more windings you need, the higher labor and production investment you’ll make.
Fortunately, you don't have to stick to the traditional winding methods. The e-bike motor design is taking on a new shape thanks to the adoption of powder metallurgy.
Electric motor manufacturers can take advantage of materials such as soft magnetic composites (SMCs) to improve magnetic performance while still leveraging the unique shape-making abilities inherent to powder metallurgy. Since SMCs also allow compact winding and geometry, e-bikes, e-scooters, and e-skateboard manufacturers can take advantage of this by pre-winding to make it easy to slip over components.
The faster the motor response, the more horsepower a driver will get. More power means you can use a smaller motor to achieve the same goal.
Since SMC improves magnetic performance, that component can now reduce the need for frequent recharges, making e-mobility more appealing to skeptical consumers. How does a 20% increase in battery range sound?
It's short-sighted to look at the expense of individual components instead of the entire process.
If you take a lamination out of your e-motor design and put an SMC in, the SMC is going to cost more. However, the SMC provides an opportunity to reduce the overall motor’s cost, alongside the increase in battery range -- and happier customers.
Powder metallurgy reduces the cost of electric motor production by first eliminating the need for expensive operations. As discussed earlier, with compact pre-winding available and ease of unique complex shapes made easy, you can save on material.
You should be asking yourself (and your manufacturer), "How can we optimize not only our bike's performance, but also our design and manufacturing flow?" By flow, we mean fewer steps. For example, instead of stuffing wires into slots on an electromagnetic component, you pre-wind. Now you've made things so simple that you don't need elaborate, extra processes to produce a great part.
The Electric Motor Hub
The future of micromobility is a broad market waiting to be unlocked for the general public. There are massive opportunities in the motor design of an e-scooter, e-skateboards, e-bike, and even an e-motorcycle.
There's a lot to learn about enhancing electric motor design. Stay updated on any new developments by regularly checking the Electric Motor Hub for Engineers: