Motor windage losses reduction system - operates by encapsulating end windings to give smooth contour and casing is filled with thermally conducting material

摘要

The system is used with slotted armatures, and is intended to reduce the windage losses, principally from the end windings. The ends of the coils (5) are covered with an encapsulating medium (8) which is given a smooth external contour to minimise windage losses when the motor is running. The encapsulation is normally loaded with thermally conducting material in order to maintain the cooling of the winding ends. The encapsulation can also, and with advantage, be extended to cover the armature core and slots (2, 4) thereby reducing the windage effects of the slot openings. The encapsulation may be applied by spraying or casting. The filling material is typically glass fibres, or glass balls with a diameter of hundredths of a millimeter in order to facilitate flow during application.