Rotary actuator with coil winding portions having opposing current flow directions

A rotary actuator assembly, comprising:

• a first subassembly comprising a first magnetically conductive core, an electrically conductive coil including a plurality of windings wrapped over the conductive core, and a first central aperture;
• a second subassembly comprising a second magnetically conductive core, at least one magnet rigidly connected to the second magnetically conductive core, and a second central aperture;
• and
• a shaft subassembly received in the central apertures of the first and second subassemblies and having at least a first portion that is rigidly connected to one of the first and second subassemblies, wherein the first and second subassemblies are spaced from the central apertures of each other by an air gap, and wherein transmission of an electric current through the electrically conductive coil induces rotation of the one of the first and second subassemblies and the first portion of the shaft subassembly relative to the other of the first and second subassemblies.

A head positioning assembly for a data storage drive, comprising:

• at least one recording head configured to read data from and/or write data to storage media;
• a first travel carriage configured to move the at least one recording head in a lateral direction relative to the storage media;
• and
• a rotary actuator that rotates the at least one recording head about an axis that is perpendicular to the storage media, wherein the rotary actuator comprises:
• a first subassembly comprising a first magnetically conductive cylindrical core having an inner surface and an outer surface and an electrically conductive coil including a plurality of windings wrapped over the inner and outer surfaces of the cylindrical core;
• and
• a second subassembly comprising a second magnetically conductive cylindrical core and at least one magnet rigidly connected to the second magnetically conductive cylindrical core;
• wherein one of the first and second subassemblies is non-movable relative to the first travel carriage, wherein the other of the first and second subassemblies is non-rotatable relative to the at least one recording head, wherein the second subassembly is spaced from the first subassembly by an air gap.