Round the harm of failure analysis

The harm of fault analysis of 2019 - 05 - 16 rounds of the existence of the fault, not just to round against itself, more important is that it will cause some harm does more harm than wheel for itself. Round 1, bring about harm to its own fault flange and tread of harm caused by the eccentric wear surface after eccentric wear, easy to cause the wheel diameter difference is too big, cause the body center of gravity to small wheel diameter side, exacerbating the tread mill. Bring about the dangers of brim abrasion overrun the brim abrasion overrun can lead to rim root section after thinning, the strength drops, the rim root are prone to cracks and defects, still can make between flange and rail travel between increase, reduce the carrying amount of the safety of the wheel, and contributed to the wheel to the lateral movement, climbed up the tongue rail when through the switch, causing derailment or rolling tongue rail, and after the abrasion overrun, when through the curve, not only increased the operation also intensifies the flange abrasion resistance. Bring local concave wheel tread scratches and the harm of the overrun after tread scratches and local concave overrun, under the wheel of circular arc surface will appear larger local plane, make the wheel to can't smooth scrolling, increased the impact of the wheel to vibrate, when the wheel diameter is 840 mm, scratch depth of 2 mm, its chord length is 82 mm, that is to say, the plane was involved in the 82 mm rolling, vehicles per mile, run the plane hit the rail is about 2700 times or so. Imagine a heavy 60 t gondola car, plus the weight of 20 t, total about 80 t, 10 t of each wheel weight, this is under stationary state, if the vehicle runs at a speed of 80 km per hour, the blow of rail vibration, and other parts of the vehicle on is an extremely serious test. Bring the tread stripping, defect transfinite harm occurs, stripped and defect transfinite tread, not only increased the wheel on the impact of vibration, is more serious is that as the vehicle running, stripping and defect parts are growing, especially after defect, when the defect location relative to the rim of the distance is less than 1508 mm, through curve can occur when the vehicle derailment caused the traffic accident. Bring about the dangers of radial plate hole crack damage overrun vehicles spokes plate hole is convenient hoisting, after using for a long time, but the wheel on the radial plate hole of crack damage is very serious, especially when the wheel rim after many rotary cut processing of thinning, radial plate crack damage fault is easy to occur. In recent years, the wheel cracks caused by radial plate crack damage accident. My homework once a worker found wheel disk crack along major fault, 1000 mm is in jeopardy, if leak will inevitably cause the wheels split, vehicle derailment, overturning accident. 2, by the wheel of the fault caused by other fault bring big components fracture vehicle swing bolster, side frame beam and big parts is the place where the stress is concentrated. When the wheel to scratch, recessed, stripping, defect in the limited time, increased the impact of the car body vibration, when faced with large defect of parts, cargo loading overweight, easy to make large parts stress concentration and fracture occurred. Pillow fracture, side frames, such as: broken shaft of cold and so on, and cause traffic accidents. Bring about damage to the rail wheel to scratch, recessed, stripping, defect in the time limit, will intensify the blow for rail. Especially in the two seams of rail, because instead of a cast, a splint rivets and connection, when bear big blow, prone to crack damage or make rivet on rivet hole broken, rail displacement occurs, the derailment caused, after another round of other parts wear overrun, may also damage the tongue rail, bifurcation point, etc. Bring cause bearing fault rolling bearing is the most closely with the wheel to contact parts, when the wheel to scratch, recessed, stripping, defect after limit of bearing load and alternating load increases, the bearing running an exception occurs, and gradually developed to keep the crack damage, roller broken, outer ring crack damage, etc. , can guide the hot axle and cause traffic accidents. Bring about brake beam failure of brake beam is the vehicle in running and wheel is very frequent contact with accessories, when encounter have overrun the wheel pair, brake beam on the impact and vibration power will increase, causing the brake beam pillar crack damage, the girder crack damage, trunnion weld, broken, such as fault, endangers safety. Bring other malfunctions in addition to the above situation, wheel failure may also cause of coupling beam is loose, fall off, hook tail box after plate is loose, fall off the hook tail box plate fall off, causing accidents such as train separation, may also cause displacement caused bodywork tilt transfinite goods weight, damage to buildings or driving equipment, and in the empty pillow spring came out, missing, bolster spring, was caused when the heavy car axle box spring break fault and driving safety, etc. （ Source: the resources of railway vehicle platform)