THERMAL STABILIZATION UNIT FOR DRUM-AND-SHOE BRAKES AND METHOD OF THERMAL STABILIZATION Russian patent published in 2004 - IPC

FIELD: mechanical engineering; heavily-loaded drum-and-shoe brakes. SUBSTANCE: proposed unit includes brake drum, brake shoes and forced cooling devices whose nozzles are mounted in friction linings and on the outside of brake drum rim. Novelty of invention consists in availability of air cooling devices made in form of nozzles and provided over width and length; nozzle have shape of truncated pyramids with unequal-sided trapezium in base; their cross-sections increase on side of pinching drum rim with flange as far as its free edge. Each two rows of nozzles are interconnected by means of longitudinal passages and gaps between nozzles are connected with transversal slotted holes in linings, thus forming closed circulating loop for compressed air. Novelty of proposed method consists in observing pressure ratio of 1.225: 1 for compressed air circulating in loops of multi-jet ejectors of friction linings of brake shoes on side of pinching of rim with flange and ratio of 1:0.8 on side of free edge of rim. This ensures taking air in different amount from space between friction pairs through transversal slotted holes of friction linings and forced delivery of air flowing around outer surface of drum rim to space between friction pairs. EFFECT: improved operating parameters; enhanced reliability; increased service life of friction units. 3 cl, 7 dwg