Thermally efficient, liquid cooled housing for dynamoelectric machine

Abstract

An annular, cast housing for a dynamoelectric machine defines a single internal, circumferential, liquid coolant circulation passage having a main portion of flat, rectangular cross-section having a width extending axially across the housing and a length extending circumferentially around a majority of the housing and, at opposite ends of the main portion, transitional portions narrowing in width from opposite axial sides so that the transitional portions pass each other on the narrowing sides and smoothly convert from the flat, rectangular cross-section to a circular cross-section. The transitional portions end in conduits substantially aligned with each other and oriented in substantially opposite directions. The housing provides an array of cast, continuous, radial pillars connecting inner and outer annular walls so as to improve the efficiency of heat transfer from the walls to the liquid coolant by (1) increasing the conduction of heat from the inner annular wall to the outer annular wall, where heat transfer to the liquid coolant is more efficient due to higher liquid coolant velocity in circumferential circulation, (2) providing increased surface area for heat transfer to the liquid coolant, and (3) obstructing straight-through fluid flow paths to perturb fluid thermal boundary layers.