will cause the thrust discs 16 and 16 39 to be drawn toward one of the solenoids 22 and 22 39 this is the so called 34 negative spring 34 effect of the constant magnetic field provided by the permanent magnets 32 and 32 39 the active control electromagnetic coils 24 and 24 39 positioned about the shaft 16 and 16 39 within the coil housings 26 and 26 39 are controlled by a servo circuit to counteract the 34 negative spring 34 effect and produce a 34 positive spring 34 that is a high stiffness restoring force which keeps the thrust discs 18 and 18 39 centered between the solenoids 20 and 20 39 the reference numbers 30 and 30 39 identify exemplary magnetic flux paths of flux generated by the active control electromagnetic coils 24 and 24 39 each of the electromagnetic coils 24 and 24 39 is capable of generating an axially polarized controllable electromagnetic field wherein the flux path 30 and 30 39 is directed across the air gaps 28 and 28 39 and conducted peripherally around the electromagnetic coils 24 and 24 39 and the permanent magnets 32 and 32 39 in use the radially polarized constant flux magnetic fields generated by the permanent magnets 32 and 32 39 tend to cause the thrust discs 18 and 18 39 to displace from a true centered position between the solenoids 22 and 22.