You would have to check what type of construction the motor uses, but many will use the same drive technology as their "cored" counterparts do. These are simply a motor that is constructed mechanically different from what a motor normally looks like. Often the central ring is just a ring of magnets on a hollow core instead of a shaft.
This is all based on my understanding that you are refering to motors that do not have a driveshaft, but are the ones that are hollow, allowing a shaft to pass through them. I mean the ones that are similar to a shaft encoder, they look like a bearing, being a ring with a central hollow ring that rotates whatever is inserted though it.
I have used them on reduction drives to save space and avoid a coupler, and the ones I used were permanent magnet type, driven the same as a regular permanent magnet motor.