Abstract: The invention relates to a magnetic rotary coupling with outer magnetic devices on a rotary outer coupling member and an inner magnetic device on a rotary inner coupling member. The inner magnetic device includes permanent magnets spaced radially out from the axis, each such magnet having a magnetic axis perpendicular to a radius from the axis. The outer devices include permanent magnets having magnetic axes approximately radial with respect to the axis. Pole faces of the outer member are aligned with faces of opposite polarity of the inner member magnets to minimize the lengths of the flux loops linking the inner and outer magnets. A high-permeability shield bridges the outer poles of the outer member to reduce the total reluctance further, thereby maximizing the torque that can be transmitted between the inner and outer members.