Whirlpool bought Maytag, and has been the OEM manufacturer for Kenmore for some time. They use the same motors because they're all made by the same company!
I've had washers and dryers by all three makes, and my favorites (or my wife's favorites) were the Whirlpools. We had a gas dryer, which worked great. The Maytags (Neptune series) were the worst.
Thanks — LOVE my Whirlpool washer (15 yrs old) and just had the transmission replaced instead of buying a new machine. LOVE my matching gas dryer too! LOL.