Self-pivoting drive with internal gears for spherical-form motion simulators

A surface-moving mechanism comprising

• a pair of wheels for frictionally moving a surface;
• an separate axle for each of the said wheels, each wheel rigidly mounted on its associated axles;
• a pivoting frame supporting the two axles, the axles being mounted for rotation within the pivoting frame, and with the centerline of each axle passing through the axis of rotation of the pivoting frame;
• for each axle a pivoting-frame-mounted drive shaft, hereinafter called “transfer shaft;”
• a concentric pair of drive shafts, hereinafter called “longitudinal shafts,” with axis coinciding with the axis of rotation of the pivoting frame, each longitudinal drive shaft associated with one of the transfer shafts mounted on the pivoting frame;
• for each axle, a rotation-transfer mechanism by which rotation of the transfer shaft associated with the axle effects corresponding rotation of the axle;
• for each longitudinal shaft, a rotation-transfer mechanism by which rotation of the longitudinal shaft effects corresponding rotation of the transfer shaft;
• a fixed frame;
• a pair of motors mounted in the fixed frame, each motor associated with one of the longitudinal shafts;
• a thrust bearing between the fixed frame and the pivoting frame, said thrust bearing providing for rotation of the pivoting frame relative to the fixed frame, with the longitudinal drive shafts passing through the center of the thrust bearing;
• for each longitudinal shaft, a mechanism by which the longitudinal shaft is rotated by the motor associated with the longitudinal shaft;
• and
• an angle encoder mounted on the fixed frame, said angle encoder determining the angle of rotation of the pivoting frame relative to the fixed frame.