Diesel engine crankshaft trunnion after wear?

Diesel engine crankshaft trunnion after wear? 2020 - 03 - 27 miller ab. hoogstraten b ( Think that watch network/possess. you Shanghai information technology co. , LTD. Technical director) When diesel engine run some years later, the crankshaft main trunnion or crank pin diameter of axle may lead to wear and tear, until beyond the allowable limit of manufacturers specifications, this is just needs to be repaired. A shipowner in ship repair and found 3 # auxiliary engine crank pin diameter of axle excessive wear, then through two sales way to purchase a second-hand pieces, a professional company in the wear of the crank pin diameter of axle please take way to restore the original size of metal coating, then supply to install and use on the ship. Unfortunately, about half a year later, owner's email from claims that the lubricating oil filter found metal scrap, further examination found that auxiliary 3 # crank pin diameter of axle surface metal loss damage ( See attached figure 2) , and put forward the claim. Supplier after receiving the insurance policy, check the product number, used to provide find shipowners' claim number is wrong, the crankshaft suppliers, of course, do not accept such claims, and inform maintenance. System. its found after checking again, provide product number of the original photographs, provided the 1 # auxiliary engine crankshaft seal number, in fact, a defect of the crankshaft is really at the beginning of repaired 3 # auxiliaries, flight check again after providing the correct # 3 auxiliary engine crankshaft seal number the photos. Due to the delay some time during this processing, suppliers and citing a warranty, rejected the insurance policy. After repeated representations, find the original metal coating manufacturers, but according to the manufacturer may be slippery oil shortage of oil or complex factors, such as poor lubrication, and put forward please professional organization test, if test results prove to be the coating of the metal loss, only agreed to free coating again. And owners could not accept this kind of coating again, to claim the whole new crankshaft, the price does not poor. Dealers in line with the responsible attitude to customers, send professionals in ship by domestic port of embarkation do the inspection, due to the round of name change, then carefully check the history of the name of vessel certificate to replace, and seal number on the crankshaft, confirm the identity of the owner's narrative situation and the current state of the offer, is indeed had once repaired crankshaft offers. Then the whole crankshaft made a comprehensive inspection, found only 3 # cylinder crank pin diameter of axle surface metal loss damage, its corresponding 3 # cylinder crank shaft bearing damage (obviously See figure 1) , other parts are found no damage or anomalies, crank pin for all five cylinder trunnion were measured, and only 3 # cylinder crank pin diameter of axle is smaller than other crank pin diameter of axle was 0. The diameter of the 27 mm, other crank pin diameter of axle are nearly the same. Look carefully damage surface and the test results, according to the size can clearly determine damage caused the original metal coating fall off. At the same time, the fusion of metal on the busbar took the sample and bring back the damaged bearing, so that necessary component analysis to determine whether the coating of the metal. Figure 1, figure 2, in fact, for the crankshaft trunnion after wear, should adopt a more reliable way to repair, even with small size, English name is undersize, that is, according to the actual size of crankshaft trunnion after wear and tear, Less than the original size) And then customize a corresponding matching the inner hole of smaller size of the bearing shell, or a thick wall bearing shell, of course, narrowing the range of the undersize size should be in the diesel engine model allows range. Using metal coating method to restore the original size, there is a huge risk, the metal coating process is reliable and the actual metal coating and the adhesion strength of the original forging steel material enough, it depends on the surface cleaning workers operating and the influence of temperature control and so on a series of technological process, in a word, the repair method is not preferred. For intermediate dealers, absolutely not directly involved in the business trade, it is not independent enough of trade disputes, and even suffered big losses. In addition, this example warned us crew, to the problem of the quality assurance issue insurance policy must be timely and accurately the necessary information in writing, otherwise, missed the warranty period, brings to the after-sales service handles the passive situation.