Although the electric motor in question is the small one of an old corded electric string trimmer/edger, it has me wondering about the electric motor/s of hybrids and EVs.
In the case of my fourteen year old B&D corded trimmer, despite being careful not to run it non-stop, it began running hot this year. Last time using it a few days ago it suddenly made a deep chugging noise so I released the trigger within a couple of seconds. Checked to see if the string lines were messed up (again ), they weren’t and the housing was only warm, not hot. Gave it and me a few minutes rest before trying it again. Motor then made a high pitched whine similar to a jet engine turbine whine but the spool no longer spins.
So either some connection to the spool is broken or binding, or the electric motor is failing. (I’ll get it sorted out and if need be will get a new, this time cordless, trimmer.)
But all this has me wondering about several things:
What is the key design difference between small electric motors that do not tolerate continual “on” use while others can run non-stop for anywhere from hours to weeks?
When an electric motor of any size or function fails what is the most common cause? Do they simply seize up, “burn out”, or something else?
Are small electric motors such as those on yard tools and some mowers, on sewing machines, etc. basically the same in form and function as a vehicle alternator or the small generators on early decades of cars?
I’m looking for a layman’s explanation as I know very little about electrical systems.