GB195764A - Improvements in and connected with the cooling or ventilating of enclosed electric motors - Google Patents

Abstract

195,764. Evans, D. A., and Hodgson, H. Jan. 9, 1922. Motors, cooling.-To prevent condensation of moisture within an enclosed electric motor particularly when working submerged in water, air is circulated in a closed circuit within the water-tight casing, and heat insulation is arranged between the field-magnet carcase and the casing so that there is no direct cooling of the magnet &c. from the outside. The field magnet b, Fig. 1, is surrounded by a lagging f of asbestos &c., and an annular space, r is provided between the magnet and the outer casing q. Heat insulation g may also be placed between the field frame and the end covers h, j. A fan s draws in air through perforations in the cover h into passages w, x. A deflector z directs air on to the magnet windings e, and a fan y drives the air through apertures v into the space r where cooling of the air by direct contact with the outside casing takes place. The stuffing-box n prevents entry of water into the motor. Perforated containers filled with hygroscopic material may be placed inside the end cover t to absorb moisture. In a modification, Fig. 2, the end cover h and fan s are dispensed with. Entry of water is prevented by a stuffing-box consisting of a casing 1 having its end walls fitted with white-metal or other packing-rings 2. Two flanged bronze sleeves 3 are kept in tight contact with the packing-rings by a spring 4. According to the Provisional Specification, one of these flanged rings may be fixed. In another modification, the end cover j is formed with radial pockets for affording free communication between the fan delivery and the entrance to the jacket space r, and the cover has an annular groove to receive the overhang b<2> of the magnet frame b.