It’s humanity to ask: ‘Which is much better?’ Even if the answer is usually ‘neither’, since each has its pros and cons.
People will still question whether it’s iPhone or Android, PlayStation or Xbox, manual or dual-clutch automated. The very same holds true of engines, and possibly next it’ll be EV electric drives: radial flux or axial flux?
Like the other stuff, each has its minuses and pluses– only in this case, the differences are most likely more clear cut. The radial flux motor is the familiar cylindrical shape and the axial flux is shaped like a biscuit tin, and on shape alone they provide themselves to different installations.
Due to the fact that it’s higher in length but smaller in diameter, the traditional radial flux is a natural fit in between two wheels on a single axle. Axial flux is higher in size and exceptionally brief in length so it’s perfect for sandwiching between an engine and transmission for hybrid drives. There’s very little future for that concept in the UK any more, but in EVs axial flux motors can likewise work in sets mounted close to the wheels as drive systems, or as wheel motors, or stacked one behind the other to make multi-rotor units.
Like radial flux motors, they can be designed to work at low voltage (48V) for scooters and small city EVs or, in the future, autonomous pods, in addition to at high voltage for any kind of EV up to supercars. UK-based company Saietta has actually developed a new axial flux traction (AFT) motor to fit mass production and bring expenses down. It can be scaled in size to power anything from a scooter to a bus.
Making use of basic moderate steel in the disc-like rotor with permanent magnets connected helps minimize expense, as does the modular building and construction, which provides itself to a high level of automated assembly– the secret to minimizing and producing big numbers cost. The motor is sealed and water cooled and, like other axial flux motor designs, is ‘yokeless’, missing the large, heavy frame supporting the stator windings of a standard radial flux machine. The absence of yoke is one of the features that minimizes weight and increases power density.
Like all kinds of Air Conditioning simultaneous electric motor, the magnets on the rotor of an axial flux motor are drawn in to the rotating field developed by a surrounding ring of separate electromagnets in the stator. The switching of the magnets making the field turn isn’t dead smooth therefore the rotor suffers from a minor ‘torque ripple’ referred to as ‘cogging’ as it turns.
Although the result is usually decreased digitally, Saietta motors have 96 electromagnets in the stator, the high number and smaller increments helping minimize it to a minimum. Saietta was just recently the recipient of an Advanced Propulsion Centre grant to help develop production procedures to produce 150,000 motors a year and sees prospective in producing wheel motors for autonomous pods along with traditional automobiles. It will sign up with other axial flux motor developers such as established YASA and Belgium firm Magnax in moving electric motor technology forward.
Hyundai’s take on motors
UK-based company Saietta has created a new axial flux traction (AFT) motor to suit mass production and bring costs down. The motor is sealed and water cooled and, like other axial flux motor styles, is ‘yokeless’, missing the bulky, heavy frame supporting the stator windings of a traditional radial flux maker. Like all types of A/C synchronous electrical motor, the magnets on the rotor of an axial flux motor are attracted to the rotating field produced by a surrounding ring of different electromagnets in the stator. Saietta was just recently the recipient of an Advanced Propulsion Centre grant to assist develop production procedures to produce 150,000 motors a year and sees potential in producing wheel motors for self-governing pods as well as conventional lorries.