General Electric Company

Frederick J Armstrong

James Pellegrino Alexander

Lynn E Bradtmueller

Ronnie G Smitley

Robert A Susdorf

Motor for commercial and industrial applications such as golf carts and lift trucks. Features include a thin shell; stator; stator winding; and rotor. Rotor laminations have equally circumferentially spaced semi-closed slots having area for receiving conductors, and the ratio of the number of rotor lamination slots to the rotor outer diameter (measured in inches) is greater than 14.0. In one construction, this ratio is about 15.75; the ratio of the outer diameter to the rotor slot length is from about 9.04 to about 9.16; and the ratio of rotor slot depth or length to rotor slot opening width is from about 10.8 to about 12.5. Cylindrical stator lamination has a given outer diameter and a certain bore diameter determined by the distance between opposing poles. Through-bolt holes are located in the yoke, proximate the outer periphery thereof, and centered with respect to each pole. The ratio of stator pole neck minimum width to two times the yoke thickness or width is from about 0.809 to about 1.009. Methods of assembling motor components are also revealed.

Electric motor with optimum core dimensions

A preferred process includes arranging field yoke segments, pole face segments, and one or more pieces of ceramic magnet material so that the yoke segments and pole face segments can be relied upon to establish low reluctance paths for magnetic flux associated with the ceramic magnet material. The process includes holding the ceramic magnet material sandwiched between the yoke pieces and pole pieces within a cavity of a casting fixture; admitting a molten metallic material to the cavity and adjacent to the yoke, pole, and ceramic material pieces; permitting the molten material to solidify; and thereafter removing the field assembly from the cavity with the ceramic pieces completely surrounded and encased by the pole pieces, yoke pieces, and solidified material. In a more preferred form, molten aluminum at a temperature of at least about 660.degree. C is used as the molten metallic material even though the resulting thermal shock causes a fracturing or shattering of the ceramic material. In this form, the process includes fracturing the ceramic material because of the thermal shock caused by exposing it to the molten aluminum. After solidifying, the solidified material, along with the yoke and pole pieces, holds the ceramic material fragments together so that the fragmented ceramic material may be used as a permanent magnet portion of the field assembly.

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Fort Wayne, IN, United States of America

Frederick J Armstrong