I did searched google.. the only answer that i have found that it is a brushless DC motor which doesn't make sense.
INTP, no, the point is that its described in the literature about the system as a stepper motor,that is what makes little sense. As I said, this is custom, unknown quantity, I'd avoid itwithout better information. It could be 3-phase stepper, brushless, variable reluctance, active, alinear actuator, a servo, who knows? Dead cheap at a flea-market it would be interesting, as a workingset of four, its really only interesting for its intended function.