In 2018, British company Equipmake announced that it would use a magnet arranged like an spoke to make it cheaper to manufacture a new generation of motors, and that they could use cheap materials and standard manufacturing processes to make motors with a power density of 9kW/kg,media reported. By contrast, the company says its competitor’s best permanent magnet motors still only reach a power density of about 5 kW/ kg. Now, the company has decided to take advantage of additive manufacturing to see how far they can roll out their technology, and the results could be revolutionary.
Equipmake expects its upcoming Ampere motor to weigh less than 10 kg (22 lb) and generate 220 kW (295 hp) of power at 30,000 revolutions per minute, meaning it can provide a power density of more than 20 kW / kg, four times the power density of a permanent magnet motor of a similar size.
All advances in electric vehicle technology must be compared to Elon Musk’s technology, which is far ahead in mass production. The latest information we can find from Tesla was six years ago, so there’s no doubt that things have improved, but at that time the Model S motor weighed 32 kg (70 lb) and powered 270 kW (362 hp). This is equivalent to a power density of about 8.4 kW / kg, which makes Equipmake’s claim about its competitors somewhat questionable, but the Ampere motor will still effectively provide more than twice the power output at a given weight. What’s more, this will greatly reduce the weight of the car.
Equipmake says its 3D printing technology,” which works with Bristol-based additive manufacturing specialist HiETA, allows it to use fewer metals in its designs to combine parts into complex shapes that milling or casting is impossible. It also preserves the excellent cooling capacity of the spoke magnet design and reduces inertia for extremely high rotational speeds.
Equipmake hopes to launch and run its first prototype within 12 months.