A magnetic coupling comprising a first member having a first array of magnetic field generating elements, the first member being arranged to produce first moving magnetic field, an array of electrical conductors fixed relative to the first member, and a second member having a second array of magnetic field generating elements, the second member being arranged to produce second moving magnetic field, wherein the first and second members are arranged for relative movement therebetween, wherein the array of conductors is arranged to inductively couple with the second moving magnetic field to produce a torque to bring the first and second moving magnetic fields into synchronous relative movement.