机械设备维修)（Maintenance of mechanical equipment)）.doc

机械设备维修)（Maintenance of mechanical equipment)） 1. crane wheel gnawing rail: when the crane running in the wheel flange and track side extrusion and friction, and wheel flange and rail side of significant wear, this phenomenon is called wheel gnawing rail. 1. what is the dimensioning method? What should be paid attention to when using this method to repair the defective parts? Answer: a pair of matched complex components in parts by machining methods will wear parts of the shape, position accuracy and surface roughness of repair, and one relatively simple parts and repair parts corresponding to the dimensions of the new replacement, the ability to work with the Deputy complete recovery, repair method the method of repairing size. Should pay attention to when applying this method to repair failure parts: after repair, parts of the original strength shall not be greatly weakened, when necessary to check the strength or stiffness of the surface heat treatment of parts after repair still retain a certain depth of heat treatment, to ensure that the parts of the original performance. 2. briefly describe the process of repairing mechanical failure parts with thermal spraying technology. Answer: thermal spraying process is as follows: Spray preparation: including workpiece cleaning, surface preparation, surface roughening and preheating processes. Spraying the bonding layer: spraying the bonding layer immediately after the workpiece being treated, spraying the bonding layer can improve the bonding strength between the work layer and the workpiece. The thickness of the bonding layer is generally 0.10 ~ 0.15mm, and the spraying distance is from 180 to 200mm. If the thickness is too thick, the bonding strength of the working layer will be reduced, and the coating thickness will be reduced and the economy will be poor. Spraying work layer: spraying the working layer immediately after spraying with the combination layer. The quality of spray coating mainly depends on the powder fe