Automobile connecting rod crank bearing inspection

The role of the crankshaft is accept the connecting rod transmits to the force, to produce around its own axis of the torque, and output. After bearing support within the crankcase, crankshaft is mainly composed of the crankshaft front-end, a number of back-end crank, crankshaft, etc. A machine at work, crankshaft, combination of inertia force and centripetal force to the crankshaft bending and changing load. Set in the secondary cheng to raise, to cope with the crankshaft stop cleaning and inspection of the remaining homework, when the crankshaft wear reaches a certain level, should stop to change or to stop the grinding. 1. Crankshaft bending tests put the crankshaft on the v-shaped iron, using dial indicator to measure the crankshaft radial beat garden. Crankshaft maximum radial beat is greater than zero. 3 mm, such as beyond the maximum, should change or end of the crankshaft crankshaft cold-press correction. 2. Check the main journal and crank pin ( 1) Check the main journal and the surface of the crank pin, there should be no apparent strain or ablation. USES micrometer measuring the main journal and the diameter of the crank pin. The different models of a machine specification different diameter size. Toyota corolla 1. 6 litres of models launched machine specification values of 47 main journal diameter. 988-48. 000 mm, crank pin diameter specification values for 43. 992-44. 000mm。 According to the measured diameter is beyond the scope of the specification, main journal or crank pin should be checked for radial beat garden. ( 2) Check the crank shaft and crank pin separately with the dial indicator of radial beat quantity of the maximum are 0. Beyond the maximum 004 mm, according to the measured values should be changed or to stop the grinding crankshaft treatment. 3. Crankshaft bearing way to check the inspection method is similar to that of a connecting rod bearing, is still in plastic gauge stop check, different specification is clearance and maximum. Toyota corolla 1. 6 litres models launched machine specification clearance of 0. 016-0. 039 mm, the maximum value of 0. 05mm。 According to the measured values beyond the maximum, should change bearing, if necessary, change the crankshaft. Change parts, should refer to the model of maintenance manuals. 4. Crank shaft axial clearance check device good main bearing cover, and according to the rules of the torque tighten bearing cap bolts. Use dial indicator to measure the crankshaft to move along the axial volume. Different models of a machine with different values its specification. Toyota corolla 1. 6 litres of models launched machine crankshaft axial clearance specifications to 0. 04 ~ 0. 14 mm, maximum value of 0. 18mm。 According to the measured values is greater than the maximum, the complete set of change the thrust washer. 5. The crankshaft gear when advertent items ( 1) The main journal of upper and lower axis promise in situ device, shall not adjust the device location. ( 2) Should take organic oil groove on the bearing device to the cylinder block, device shall not daub oil on the surface of the bearing contact with the cylinder body; Cylinder block on the insulation from the bearing and interval of the insulation is 0. 5 ~ 1. 0 mm, and the equal distance. ( 3) Bearing installed on the crankshaft bearing cap, device shall not apply the oil on the surface of the bearing contact with bearing cover. Bearing insulation from cover while under interval of the insulation is 0. 7 mm, and the equal distance. ( 4) Thrust bearing with one side of the tank should be outward device. ( 5) Have forward mark on the bearing cover, should be installed in the correct direction; Device before, should be apply a thin layer of oil on the main journal. ( 6) Bearing cap bolts should be 2 ~ 3 times from middle to both ends tighten respectively, each, in the wake of a bearing cap bolts should turn the crankshaft.