2 degree of freedoms 1 2-degree-of-freedom motor 1 2-degrees-of-freedom (DOF) motor 1 Ball screws 1 Degrees of freedom (mechanics) 1 Electric motors 1 Energy efficiency 1 Fasteners 1 Force 1 Industrial robots 1 Magnet screw Magnetic force 1 Magnetic forces 1 Magnetic gear 1 Magnetism 1 Multi-2-degree-of-freedom 1 Permanent magnet motor 1 Permanent magnet motors 1 Permanent magnets 1 Radial-gap machine 1 Rotors 1 Screws 1 Service robots 1 Stators 1 magnet screw 1 magnetic gear 1 multi-DOF 1 radial-gap machine 1