Yes, you are correct. But what if you understand how to use physic to create a permanent magnet motor that would run for 100 years before it lost its magnetism. Don't laugh. In the 5th grade, I entered one in our science fair after my science club teacher said physics says it impossible. I told him I knew how and would bring it tomorrow and set it on his desk. Made it out of an elector set A-frame with an axle through an oak meal round box top. It was a ferrous wheel of magnets with an opposing larger magnet on a thread wood spool. Set it on his desk with the attractive poll in front of it to get it started spinning and then spun the spool around to opposing polls and it kept spinning. I left his 6th-grade class and went back to my 5th-grade class and said "NOTHING".
At first recess, I opened his door looked at it, and said. "Looks like it is still spinning to me!" And shut his door. At lunch, I said "Hey Mr. Fox appears physic, and the science community is WRONG as it looks perpetual to me.
The next recess he told me to come in before my next well-thought-out smart-ass comment!
After more than 60 years of telling others how you could make a 3 turbine with 10 cylinders each permanent magnet motor, I'm going to make it myself. Chuck's brother makes customized handicap vehicle controls in his machine shop.
Here is how you can make one. I'm been too busy living life to the fullest but running out of life, need to do this before I die.
Just in case here is how you could build your own...
In the 5th grade, I realized that all disks have only one 90 degrees timing point. That is exactly like an armature of an AC motor.
For a permanent magnet motor, you time the attractive side but not to its at-rest state at 90 degrees like you do with opposing coils and magnets in AC motors. I'm timing these cylinders at 33 degrees offset. They are always trying to get back to 90 and at rest but can't because of timing gears.
The other property of a disk I realize is the magnet field changes direction away from each opposing cylinder allowing the other difference from an AC motor. You create a slight dwell that is a gap in the magnetic fields. That is done by spacing the alternating rows of magnets on each turbine to the position where the next row is on the opposing cylinder attracting it by a 33 degree offset.
Any 5th grader who studied electricity and electromagnets, like I did, at the library and did not know science said it's impossible could make one.