After 1980 east windmill, cancelled the adjustment of the crankshaft bearing pad. So, convenient repair, guarantee the assembly quality. When some mechanic devices, some still is not the right thing to do. The following assembly should be how to grasp the firmness, guarantee the high quality of assembly, talk about experience.
EQ6100 engine - 1, the use of nodular cast iron crankshaft and plastic aluminum bearing, with a very good friction pair. This kind of high tin aluminum bearing machining accuracy and roughness by factories guarantee (of high precision, large contact area). Repair, matching with the crankshaft repair at the size of the bearing, to fit up. Fitting clearance of connecting rod bearing generally between 0.040 mm to 0.098 mm, fitting clearance of the crankshaft bearing from 0.04 mm to 0.04 mm. The gap to ensure the normal work of the crankshaft. Practice has proved that in the normal use, the gap is reasonable, good lubrication, and wear too small. According to our statistics, on a team of 10 car driving 100000 km, the maximum number of wear journal under 0.06 mm, roundness and cylindricity error is less than 0.01 mm, bearing wear and tear is small. Fit clearance increases much, therefore, a new bearing can completely finished engine overhaul mileage, there is no need to add adjustment between bearing cover and the seat pad.
Crankshaft bearing in the assembly, the shaft and bearing hole and bearing inner hole tolerance control and adjustment, is the key to the assembly quality. Mastery of the bearing looseness should be: elastic allocate, (gap) close, to a small number of tight and partial loose bearing adjustment. There are two ways for connecting rod bearing (for example) : one is the experience method, according to the provisions of the connecting rod is installed on the shaft neck and shaking, rotational flexibility and laps, determined its pine tight situation; The second is to use outside micrometer measuring shaft neck, with inner dial indicator and outside micrometer to measure (bearing, wrapped in the big end, tighten) according to regulations bearing inner hole diameter. According to the actual data of journal and bearing inner diameter, to allocate shaft bearing looseness. In the end, should make each journal bearing looseness is close to agreement, to ensure the coordination work.
Plastic aluminum thermal expansion coefficient is larger than babbitt, fit clearance is bigger also. Assembly joint trace is not easy to see that, don't doubt it, there will be no more sound. Some maintenance personnel, in accordance with practice, the pursuit of contact area and firmness, the partial loose bearing adopts the cushion cover back or file watts method is wrong. When confronted with a loose, journal and bearing inner hole diameter can be detected, whether the fit clearance is conform to the rules. When cooperate between gap is 0.20 mm, a new bearing should be replaced.
- In a message ： No!
- The next message ： No！
- Back