Automobile connecting rod crank bearing inspection - bearing knowledge

Is the role of the crankshaft connecting rod under deliver to force, to produce around the axis of the torque itself, and to export. Through the bearing support within the crankcase, crankshaft is mainly composed of the crankshaft front-end, a number of back-end crank, crankshaft, etc. Engine in the work, the common role of crankshaft by centrifugal force, inertia force, causes the crankshaft under bending and torsion load. In the secondary cheng is to maintain, clean and check the maintenance work should be made for the crankshaft when crankshaft worn reaches a certain degree, should be replaced or for grinding. 1. Crankshaft bending tests put the crankshaft on the v-shaped iron, crankshaft radial beat garden quantity is measured with a dial indicator. Crankshaft maximum radial beat is greater than zero. 3 mm, such as more than the maximum value, should replace the crankshaft or cold pressing correction on the crankshaft. 2. Check the main journal and crank pin ( 1) Check the main journal and the outer surface of the crank pin, should not have apparent strain or ablation. With a micrometer to measure the main journal and the diameter of the crank pin. Different models of engine its standard diameter size. Toyota corolla 1. 6 litres models of engine main journal diameter values of 47. 988-48. 000 mm, crank pin diameter standard values for 43. 992-44. 000mm。 Such as the diameter of the measured is beyond the scope of the standard, 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. 004 mm, such as more than the maximum measured values, it should be replaced or on the crankshaft grinding processing. 3. Check the method of crankshaft bearing and connecting rod bearing inspection methods are similar, is still in the plastic gauge to inspect, different standard and a maximum clearance. Toyota corolla 1. 6 litres of car engine standard gap is 0. 016-0. 039 mm, the maximum value of 0. 05mm。 Such as more than the maximum measured values, should be replaced, if necessary, replace the crank shaft. When replacement parts, should refer to the model of maintenance manuals. 4. Crank shaft axial clearance installation inspection of main bearing cover, and in accordance with the provisions of the torque tighten bearing cap bolts. Measured with a dial indicator along the axial movement of the crankshaft. Different models of engine its standard value. Toyota corolla 1. 6 litres models of engine crankshaft axial clearance standard of 0. 04 ~ 0. 14 mm, maximum value of 0. 18mm。 If measured value is greater than the maximum value, the complete set of change the thrust washer. 5. The points for attention during the installation (crankshaft 1) The main journal of upper and lower axis promise in situ installation, adjustment shall be installed. ( 2) With organic oil groove on the bearing should be installed on the cylinder block, when installation shall not daub oil on the surface of the bearing contact with the cylinder body; Cylinder block on the insulation from the bearing and distance of the insulation is 0. 5 ~ 1. 0 mm, and the equal distance. ( 3) Under the bearing installed on the crankshaft bearing cover, installation shall not apply the oil on the surface of the bearing contact with bearing cover. The bearing from insulation cover while insulation distance of 0. 7 mm, and the equal distance. ( 4) Thrust bearing with one side of the tank shall be installed outward. ( 5) Have to mark in the bearing cover, should be installed in the correct direction; Before the installation, should 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.