Round off the causes and prevention of shaft kiln

Rotary kiln roller and 2020 - the cause of the broken shaft and prevention 07 - 19 Wang Zhanguang ( Jiaozuo strong cement) Wheel and axle are key components of rotary kiln, and other supporting wheels supporting the full weight of the rotary kiln, not only high value manufacturing cycle is long, and change is difficult, once appear, shaft fracture, will bring a lot of damage to the production of enterprises, must attach importance to it and now he elaborates the reasons and prevention of the shaft fracture. One, the reason of roller shaft broken wheel and axle generally USES the hot or cold pack, close together of shaft and the wheel, as contained a supporting shaft will receive a lot of pressure, make it produce a great friction, or it will as the roller rolling elongation, and the shaft of the loose. Due to the roller by shaft kiln for supporting the all weight, so the bearing by the large shear stress, and at the same time as the wheel is rotating parts, but also by the alternating stress. Not only so, friction and temperature stress, the stress is more complex. Below the influence of other aspects from the Angle of the force, expounds the reasons of shaft fracture. 1, cooperate to be not reasonable roller roller and shaft and shaft with interference quantity to zero point six per thousand to one over one thousand of the diameter of axle, to ensure that the roller shaft will not produce and loose, but the amount of interference can make the shaft in the roller hole end of neck, to produce stress concentration, the shaft fracture is not difficult to imagine in this occurrence, that is the case. 2, fatigue fracture due to the complexity of roller bearing, if the roller and the shaft as a whole to consider, the axis of bending stress and the maximum shear stress in the corresponding roller Kong Duan department, this is under the action of alternating load fatigue, so the fracture should occur in the end of roller and shaft parts. 3, manufacturing defect axles generally need by ingot or round steel forging, machining, heat treatment process is complete, once appear between defects and failed to check out, such as impurities in ingot, the forging, heat treatment, such as insect skin appear in the micro cracks, these defects not only make the bearing load capacity is limited, also produce stress concentration, so as the source, once the expansion of crack and fracture is inevitable. 4, high temperature stress or improper mechanical rotary kiln tile heating is a kind of common failures, improper operation and maintenance, supporting wheel could produce surface crack. When big tile heating, the temperature of the shaft must be very high, then if the shaft rapid cooling, due to the shaft of the internal cooling slowly, only through a sharp contraction in the shaft surface crack to release huge contraction stress, surface crack produces stress concentration at this moment, in under the action of alternating stress, crack once appear, ring to expand, and reached a certain degree of fracture occurs. Roller bearing is too big, too, such as improper adjustment, the shaft or some section of the axial force is too large, easy to cause the fracture of shaft. Second, when the shaft fracture prevention said the reasons of shaft fracture, now talk about prevention method according to the reasons. 1, roller and shaft tolerance area take a different amount of interference for roller and the shaft interference quantity is very big, so the thermal cooling roller inside Kong Duan department after tightening, caused the shaft at the neck, the stress concentration is too large, so in the process of design, manufacture, installation, to the ends of the wheel inner hole ( Range of about 100 mm) , gradually reduce the amount of interference from inside to outside, to ease the necking phenomenon, reduce the amount of can be gradually reduced to a third to half of the over surplus quantity of the middle, so as to avoid or reduce the necking phenomenon. 2, a comprehensive inspection to eliminate defects defects will decrease the axial bearing capacity, also can produce stress concentration and fracture accident often cause, the harm is great, must attach importance to it, for supporting shaft, must find out defects in advance, such as inspection before processing to the material selection, choose the material that is no problem; Will inspection in processing so as to eliminate the defects, the quality of the inner axis, guarantee the accuracy of the shaft at the same time, eliminate the crack source and source of stress concentration. 3, rational adjustment of the kiln, reduce the additional load more grassroots shaft through the roller supporting the full weight of the kiln, the load is very large, improper installation or maintenance adjustments, can produce partial load. Away from the center line of the kiln does not agree, will cause a roller bearing is too large; When the wheel axis and the center line of the kiln uneven row, can make the shaft of a lateral force. Improper stress is too large to cause big fever, also because somewhere axial stress, damage to the shaft, so the maintenance of kiln adjustment must pay attention to, avoid or reduce the additional load, make the kiln fast running. In the process of maintenance, to avoid hot on axis, welding, to avoid shaft grinding wheel grinding, to reduce the damage to the shaft. 4, during the operation of hot shaft not cold kiln in operation, due to some reason caused big fever, at this time in order to reduce production losses, some units often take rapid cooling, it is easy to cause shaft surface micro cracks, so take slow cooling way, makes every effort to avoid a sharp cooling. Conclusion, the above is only for the reasons of shaft fracture and the prevention of opinions, supporting shaft fracture is the result of the comprehensive causes more, in mind at the same time, due to my level is limited, in this paper, we have less than or inappropriate place, still hope readers to comment. Thank you very much! （ Source: wisdom cement)