GB170946A - Improvements in and relating to the cooling of dynamo-electric machines - Google Patents

Abstract

170,946. Nobuhara, K.. July 31, 1920. Armatures and field magnets, cooling; dynamos and motors, cooling; casings; commutators.-A dynamo-electric machine in which the working parts are enclosed in an air-tight casing is cooled by passing the cooling-liquid, preferably oil, through passages in the heat-generating parts, whereby the liquid is distributed in the form of a spray over the rotor and stator. The rotor and commutator of the machine are mounted on a hollow shaft 4, the interior of which communicates through radial holes 10, 22, 23 respectively with recesses 6, 9 in the rotor, an annular recess 18 in the commutator, and a space 20 at the extreme end of the commutator. Other radial holes connect the recesses 6 with the air-ducts 8 and the recesses 9 with the space within the casing 1. The recesses 9 at the ends of the rotor are in communication through axial passages 40. The space 20 communicates with the interior of the machine through axial holes 19 formed in the commutator segments. Axial holes 24 are also formed in the commutator end ring 17. A dished plate 26 is attached to the end cover 3, leaving between it and the cover a space 27. The cooling-liquid is kept in circulation by a pump 30, which draws the liquid out from the bottom of the casing and forces it through a cooling-chamber 31 into the hollow shaft 4, the space 27, and pipes 28 provided with sprinklers 29 for distributing the liquid over the field poles 15. The surface of the liquid in the casing is just below the lowest point of the rotor when the machine is at rest. The liquid forced into the space 27 passes out of it in the form of a cylindrical film of liquid, thereby sealing the clearance 25 and only allowing the internal gas to escape when an accidental rise of temperature occurs.