...and Dyson’s solution: The DDM
Dyson’s DDM digital motor took over a decade to develop – the work of Dyson’s Malmsbury-based team of 45 motor specialists, and protected by 15 patents.
Unlike a conventional motor, the DDM uses a PCB to digitally switch between polarities up to 3000 times a second. No carbons, and no contact between moving and stationary parts.
Since there are no carbon brushes, the Dyson engineers didn't face conventional speed/performance restrictions. The motor used in the Airblade hand-dryer, DC12, and DC22, can run at 88,000 rpm, and the DDM Version 2, found in the DC30/31/31 Animal handhelds, runs at 103,000 rpm!
It’s half the size and half the weight of a conventional motor, which means the appliances built around it can be much lighter and more compact. Thus, the power-to-weight ratio is far more efficient than any conventional domestic appliance motor.
The self-regulating software utilised by the DDM is also self-diagnosing, and certain DDM-machines can actually recognise a fault in the system, and communicate their findings over the phone to the Dyson Service Centre!
The DDM is manufactured on an entirely automated production line in a clean-room environment, and no human hand ever touches it before it’s placed within the cleaner.
The DDM uses a 3-dimentional impeller made of carbon fibre-reinforced PEEK, similar in design to a car turbocharger. It spins with just a 0.3mm tolerance between the blade tip and the impeller housing. Although engineeringly-complex, it’s physically simple – a one-piece construction which can’t fail like a conventional fan.
Dyson used the techno-friendly Japanese market as a dry-run for the Digital Motor, where it’s been used in the DC12 canister since 2004. With a lifespan equivalent to over 1000 hrs of constant use, the rate of failure was so low that Dyson are now happy to use it in the DC22 Motorhead in the US.
