A: the crankshaft bearing outside running round repair technologies - bearing knowledge

Two-stroke motorcycle engine crankshaft bearing and the bearing seat is interference fit, which is often said that the tight fit. This is different from four stroke engines. In the process of engine to replace the crankshaft, because the operation is not standard, hitting hard hit, with iron Lang off hard by repeated after remove the crankcase, caused by the widening is bearing hole loose bearing, bearing cylindrical with crankshaft rotation, namely 'outside running round' fault. Crankshaft bearing 'outside running round' affect the accuracy and the dynamic performance of engine crankshaft, serious when crankshaft produce large noise, the ignition time changing, motorcycle driving weakness, fuel consumption is quite high, scooter hundreds of kilometers around 6 l; Cylinder, piston ring, excessive wear, Eccentric wear) 。 So the crankshaft bearing 'outside running round' is not a small thing, should be taken seriously. At ordinary times when meeting 'outside running round' bearing fault, mostly adopt the method of blunt nest repair ( Around the bearing seat with infant several fossa) ; Has also been used within the crankcase bearing seat, spear a few small pit point in order to increase the friction, and the crankshaft bearing is not 'outside running round'. Have used welding method to repair: is on the outer periphery of the crankshaft bearing, electric welding with welding a few small points, make bearing cylindrical. Also have use: soldering iron in bearing cylindrical soldering, to increase the diameter of the bearing repair methods. And USES: in the crankcase bearing holes around the mat method to fix the copper sheet. These measures as an emergency treatment can also be in the past, but as the regular repair of the engine, the problem is much more. Major ills is: it reduces the assembly precision of the engine crankshaft, the crankshaft alignment within the prescribed; The crankshaft rotational resistance is big, the engine driving weakness, serious overheating; Cylinder, piston ring, shorten service life. In the process of repair at ordinary times the following method ideal: ( 1) Crankshaft bearing 'outside running round' are mostly the crankshaft bearing is wear. Mild bearing wear, can give bearing seat around daub is on A small amount of A, B glue, adhesive live between cylindrical bearings and bearing seat ( Note: when the glue liquid can not put too much, otherwise will be bearing to stick to death) 。 ( 2) Plating method is used to exclude 'outside running round' bearing fault. With the two with the same iron bearing outside diameter, middle place a phi 6 mm holes, the ball bearing blocks with plate and screw in case of bearing ball of the electroplating, plating electroplating factory will cylindrical bearing copper plating. Bearing the electroplating, bearing cylindrical plating thickness can be up to O. 14mm。 Plating bearings cylindrical method, to repair the crankcase bearing severe wear of fault is very effective, and the plating bearing outer circle method to repair the two-stroke engine, its biggest characteristic is the crankshaft installation precision, long service life. Although electroplating bearing the cost of a little higher, but for repair import two-stroke water-cooling engine crankshaft bearing 'outside running round' in terms of fault, the price is fairly cheap. ( 3) When the crankshaft bearing severe deformation (crankcase Such as bearing hole is oval) With the above two methods can't solve, only USES the set of methods to eliminate. Method is: in the crankcase bearing hole boring computer processing, boring big crankcase bearing hole, and then use the aluminium alloy or other metal processing a new bearing sleeve, there will be a new bearing casing pressure and hot pressing method crankcase inside the bearing seat, and then install the crankshaft bearings. This method although cost is higher, but the engine maintenance assembly accuracy is quite good, and also can once and for all.