Import bearings from several aspects of installation and maintenance

When the imported bearing inside diameter greater than 70 mm, or the interference fit is large, with heating method makes the bearing hole expansion, such easy installation to save time and avoid damage caused by the force is too large. It is enough. More than 120 ℃ tempering occur will cause the bearing, the lower hardness and precision of the ring. A, commonly used heating method has: 1, the heating method: electric heating board will import bearing placed in a temperature of 100 ℃ hot plate on a few minutes, this method is most convenient, such as reverse it a few times can make the bearing heated evenly, and the efficiency is high, size bearing can use this method. 2, electric furnace heating method: the bearing in the automatic temperature control of the closed electric furnace heating, uniform heating, accurate temperature control, heat fast, suitable for the occasion of a batch of heating a lot of bearing. 3, induction heating method: using the induction heater can be fast, reliable and clean the bearing heated to the required temperature, which are particularly suitable for the inner ring of the tight fit, just because of the heated inner ring, and the outer heat is small, so can be a drag on the shaft, also easily into a hole. 4, light bulb heating method: using the 50 w light bulb heating bearings, can guarantee the heating temperature about 100 ℃, the smaller the bearing can be directly on the bulb, larger bearings taper enclosure may be placed on a light bulb, conical cover can prevent heat losses, bulb and heated evenly. Conical cover can be adjusted up and down, in a certain heating range that can adapt to different size of bearing. If the far infrared light bulb, pay attention to the light bulb direction should be down, so as to avoid of infrared radiation is bad for the eyes. Imported pump this bulb can be energy saving. Bulb heating method is suitable for small and often do not need; To the bearing heating, light bulbs still can make lighting at ordinary times, moreover does not need any other equipment. 5, oil tank heating method: this is a widely used traditional heating method, the bottom of the tank from 50 to 70 mm in a metal mesh, bearing on the Internet, large bearing to hoist hooks. Bearing should not be placed directly on the bottom of the channel, in case of contact with the bottom of the channel bearing parts of the local heat is too high, or dirt into the bearing groove bottom sediment. Oil tank heating method of the key points are as follows, should use no corrosive thermal stability good mineral oil, it is best to transformer oil, oil, and the container should be kept clean. The size of the tank capacity should be heated and bearing and oil amount, if the container is too small, in continuous operation, one into the bearing oil temperature will drop quickly, the effect is bad. Second, the main points of the heating installation method: (1) to control the heating temperature appropriate, high temperature damage about the imported bearing, temperature is low enough ring expansion, the effect is not significant. 80 ~ 1000 ℃ heating temperature of the thermal expansion of the inner ring diameter, this to have the bearing of the over surplus quantity of the ordinary, is enough. (2) once you reach the required heating temperature, be about to install as soon as possible, so as to avoid cooling and installation difficulties. (3) bearing during cooling in the width direction also have shrinkage, therefore when installation to a certain pressure inner ring to the shoulder pressure, and with a very thin feeler attempt after cooling test, whether inside the gap between end face and shoulder. All in all, requires skilled, quick and accurate adjustment. ( 1) Decomposition, cleaning crank shaft components, ensure that the crankshaft internal oil clean and smooth. ( 2) Crankshaft for inspection, if there is any crack, must be replaced. Carefully check the crankshaft main journal, connecting rod journal and transition arc of all surface must not have scratches, burns and touch. ( 3) Check the crankshaft main journal and connecting rod journal, according to the grades of repair repair after dimension overrun. The crankshaft journal repair standard as follows: ( 4) Check the crankshaft journal and the hardness of connecting rod journal requirements, must conform to the technical requirements. Otherwise, it should be to deal with, in order to meet the use requirement. ( 5) Crankshaft thrust and radial circular runout, facing the main journal public axis radial runout, must conform to the technical requirements. Otherwise, must be corrected. ( 6) Connecting rod journal axis, within the span of main journal public axis parallelism must conform to the technical requirements. ( 7) Before and after the crankshaft gear with crack, damage, severe wear, should replace the crankshaft. ( 8) Crankshaft counterweight bolt if there is any crack, must be replaced. Crankshaft after replacement of balance or balance blocks of bolt, because of the dynamic balance test on crankshaft assembly, to ensure that the unbalance in conformity with the technical requirements. ( 9) Flywheel and pulley bolts if there are any cracks, scratches or elongation than the limit, to replace. ( 10) Carefully check the shock absorber of crankcase stand feet, such as, rubber aging, cracks, deformation or damage of crack, must be replaced. ( 11) When assembling crankshaft, pay attention to the main shaft tile, thrust tile installation. Check the axial clearance of the crankshaft and tighten the Lord according to the requirement to import bearing cover the vertical and horizontal bolt.