ELECTRIC MOTOR BEARING UNIT EXPLOSIONPROOF SEAL (VERSIONS) Russian patent published in 2004 - IPC

FIELD: electrical engineering; explosionproof motors. SUBSTANCE: proposed bearing unit explosionproof seal of electric motor contains cover forming slot explosionproof clearance with shaft, flame cutoff bushing installed on shaft and two thin-walled bushings with segments rigidly secured by one end in ring groove of bearing cover and provided with longitudinal cuts. One of bushings, namely, outer one, is furnished with bend on other end fitted with clearance in bore of flame cut off bushing. Bushings are installed so that their cuts are displaced relative to each other. Design peculiarity of seal is that segments of thin-walled bushings are manufactured of bimetal with expansion coefficient of inner layer material less than that of outer layer and surface of flame of flame cut off bushing pointed to bend is made with radius of curvature R=L+δ, where L is length of segment of thin-walled bushing and δ is explosionproof clearance between bend of outer thin-walled bushing and flame cut off bushing. EFFECT: improved reliability of motor in service. 3 cl, 3 dwg