GB159862A - Improvements in or relating to means for preserving an electric motor against the action of an injurious surrounding medium whilst ensuring lubrication and cooling of the motor - Google Patents

Abstract

159,862. Longue, R. March 4, 1920, [Convention date]. Motors, cooling; casings; insulation.-Electric motors are rendered immune from the action of deleterious surrounding media and are cooled by being immersed in a liquid contained in a casing having relief means for equalizing the outside and inside pressures, as, for instance, when the liquid expands with heat, of such a nature as to prevent entry of the external fluid medium or exit of the contained liquid. In the form shown in Fig. 1, the motor is contained in a metal case 1 having a. stuffing-box 2, through which the motor shaft 3 projects, and a flexible diaphragm 5. The case is filled with oil, and as the diaphragm equalizes the pressure when the oil expands, there is no leakage at the stuffing- box. If lubricating oil be employed in the case, it serves as a lubricant for the motor as well as an insulator. The diaphragm may be replaced by a piston floating on the surface of the oil in an open tube extending upwards from the lower part of the casing. When the motor is to be submerged in water, the open tube 8, Fig. 3, extends downwards from the casing 1, and in consequence of the difference in density between the oil and the surrounding water, the oil remains at the upper part of the tube.