Abstract: An electric motor comprising a rotor, a stator and a field weakening device. The rotor has a plurality of magnets mounted thereto, and the stator is located adjacent to the rotor and has a plurality of slots defined therein. The slots define raised teeth and are wound with electrical wiring to generate a magnetic field when the wiring is energized with current. The field weakening device is made from a highly magnetically permeable material and a comparatively lower magnetically permeable material. The field weakening device is disposed between the rotor and the stator and is selectively movable between a first position to align the highly magnetically permeable material between the teeth of the stator and the magnets of the rotor and a second position to align the comparatively lower magnetically permeable material between the teeth of the stator and the magnets of the rotor.

Abstract: An electric motor comprising a rotor, a stator and a field weakening device. The rotor has a plurality of magnets mounted thereto, and the stator is located adjacent to the rotor and has a plurality of slots defined therein. The slots define raised teeth and are wound with electrical wiring to generate a magnetic field when the wiring is energized with current. The field weakening device is made from a highly magnetically permeable material and a comparatively lower magnetically permeable material. The field weakening device is disposed between the rotor and the stator and is selectively movable between a first position to align the highly magnetically permeable material between the teeth of the stator and the magnets of the rotor and a second position to align the comparatively lower magnetically permeable material between the teeth of the stator and the magnets of the rotor.

Abstract: A method and apparatus for chucking tires to be tested in a tire testing apparatus. A lower chuck assembly or spindle includes a lower rim that is engageable with a bead region of the tire to be tested. An upper chuck assembly includes an upper rim that is engageable with an upper bead region of the tire to be tested. The upper rim is reciprocally movable towards and away from the lower rim. A plurality of sensors associated with the movable rim monitors the closing distance between the upper rim and the side wall of the tire that is being chucked, during the chucking process. A controller controls the movement of the upper rim in response to the distance data obtained from the sensors.