GB238680A - Improvements in or relating to dynamo-electric machines - Google Patents

Abstract

238,680. Cooper, T. L. R. July 25, 1924. Armatures and field magnets; cooling; insulation.-Dynamo-electric machines with their stator windings enclosed in a fluid-tight chamber have the chamber formed partly with a hard mouldable insulating material such as that known under the registered Trade Mark " Bakelite," thickly covering the back 11 of the stator laminµ as well as end coverings 10 and slot linings 9 of the same material. Each covering 10 is formed with a flange to which at one end the end enclosure 14 is jointed by an oil-proof ring 19, while the other end flange is enlarged, as at 15, for securing the end diaphragm 13. A thin layer 12 of the insulating material may be located on the inner edge of the laminµ. The tightening members 7 may be tubular to allow circulation of the insulating fluid. In another construction, Fig. 3 the parts 9, 20, 23, 24, 25 of the fluid-tight chamber are separately formed and secured together by the same material in plastic form which also fills the slot openings 21. Tie rods 22 pass through each slot opening and are secured to the parts 24, 25. A number of longitudinal keys 31 prevents rotation of the core in the frame 1. Longitudinal circulation passages are formed between the frame and core, and ducts may be formed in the core itself. The stator may be coated and wound before mounting it in the frame, and the rotor may be readily withdrawn. Further slot insulation and troughing is unnecessary. According to the Provisional Specification, the enclosures 13, 14, 18 may be made of the same material as the stator core covering.