Spherical induction motor

#This document relates generally to motors and more particularly to spherical induction motors.

#Spherical motion is associated with many important applications. For example, robotic wrists and shoulder joints and positioning mechanisms for antennas, sensors, detectors, and cameras can all utilize a spherical rotor to facilitate spherical motion and improve performance. Despite these important applications, no motor has previously been designed that can rotate a spherical rotor continuously through arbitrarily large angles among any combination of three independent axes via an induction principle.

#In accordance with the teachings herein, systems and methods are provided for an induction motor. An induction motor includes a spherical rotor and a plurality of curved inductors positioned around the spherical rotor. The plurality of curved inductors are configured to rotate the spherical rotor continuously among any combination of three independent axes.

#FIG. 1 depicts two example implementations of a spherical induction motor.

#FIG. 2 depicts an application of a spherical induction motor in the form of a dynamic balancing mobile robot.

#FIG. 3 depicts another implementation of a spherical induction motor in the form of a motorized wheel chair.

#A spherical induction motor, as described herein, provides an ability to rotate a spherical rotor continuously through arbitrarily large angles among any combination of three independent axes. FIG. 1 depicts two example implementations of a spherical induction motor. The implementations each include a spherical rotor 102. The spherical rotors 102 are surrounded by a plurality of curved inductors 104, 106, 108, 110. The curved inductors 104, 106, 108, 110 are positioned around their respective spherical rotor 102. The curved inductors 104, 106, 108, 110 are configured to rotate the spherical rotor 102 continuously among any combination of three independent axes. For example, the plurality of inductors can be positioned in a non-degenerate arrangement so as to provide a set of torque axes, enabling rotation of the spherical rotor among any combination of three independent axes. In the left example, the curved inductors 104 are positioned askew relative to one another along or parallel to a great circle of the spherical rotor 102. In the right example, certain of the curved inductors (e.g., curved inductors 108, 110) are positioned orthogonally to one another.

#As noted above, spherical motion has a wide array of applications. FIG. 2 depicts one such application in the form of a dynamic balancing mobile robot (a ballbot). A ballbot 200 is a robot that is tall enough to interact with people at a reasonable height and is slender enough to maneuver about an area without colliding with things or people. The ballbot 200 balances on a single spherical rotor that is controlled via a drive unit 204 in the form of a spherical induction motor. The drive unit 204 imparts inductive forces on the spherical rotor 202 to cause controlled rotation of the spherical rotor 202 to maintain the balance and stability of the ballbot, even when the ballbot is pushed by an outside force.

#FIG. 3 depicts another application of a spherical induction motor in the form of a motorized wheel chair. In this application, a spherical rotor 302 is controlled via a spherical induction motor 304 according to commands received from a joystick 306. The spherical induction motor 304 may monitor the current rotational velocity of the spherical rotor 302 and the current directional command from the joystick 306 to determine an appropriate inductive force to apply to the spherical rotor 302 to maintain appropriate motion.