What are the requirements for the dimensions of garbage trucks? The bearing shell is a small part, but its dimensional tolerance and processing precision are very high. Although the various axles produced by various garbage trucks are slightly different, they generally meet the following requirements. The inner surface of copper-lead alloy bushings must not have visible lead lines, cracks, slag inclusions and air holes. The babbitt alloy bushes used in gasoline engines have low hardness and can be manually repaired. Especially when the crankshaft out-of-roundness is between 0.03 and 0.04mm, and no crankshaft grinder is used to grind the crankshaft, the triangular scraper can be used to scrape the alloy layer so that the contact surface with the crankshaft journal reaches more than 75%. The use of diesel engines, the surface of the bush is a common fault. The bushings are mainly caused by dirt such as metal impurities in the lubricating oil. Especially for newly assembled garbage truck diesel engines, the use of pistons and other moving parts will wear down some of the metal powder; cylinders, pistons, connecting rods, crankshafts and other parts are not clean and have impurities, and powder and fine impurities are trapped in the lubricant. As the lubricant oil passage enters into the crankshaft main bearing bush and the connecting rod, it will cause the bearing bush to pull and damage the formation of the oil film on the bearing bush, which will accelerate the wear of the crankshaft journal. MDF Plywood CNC Router Machine,Multi Spindles CNC Router,CNC Wood Router Fangzheng CNC Machine Tool Co., Ltd. , http://www.jsedmmachine.com
The method of repairing and scraping the bearing bush is only used in field operations and lack of processing equipment. Now when the crankshaft journal wear exceeds the limit, the crankshaft grinding machine can be used to increase (ie thicken) the type of bearing bush. Solved, very convenient. Moreover, due to the high hardness of copper-lead alloy bearings and aluminum-based alloy bearings, manual scraping is very difficult. Now when repairing the garbage truck diesel engine, almost no bearing bushes are repaired, but the crankshaft is ground to the repair size (that is, 0.25 to 0.50 mm in size), and a standard enlarged (thickened) type bearing bush can be used.