Gear transmission parts such as gears, sprockets, ring, rack, etc. are commonly used in various types of equipment parts, which damage the main form of tooth wear and broken teeth. Worn or broken teeth after manual arc welding methods available to repair, not only in time to ensure normal operation, and can save a lot of spare parts costs, with significant economic benefits. This article describes the part of gear transmission parts welding repair success stories, for reference. First, the gear shaft welding repair broken teeth
Heavy material Herringbone gear shaft reducer plate mill is 50SiMnMoB steel, modulus m = 30mm, the number of teeth z = 24, tooth width b = 300mm, maximum outer diameter of φ914mm, total length of 2.75m, unit weight 7.722t. The average service life of the gear shaft is from 1 to 1.5 years, the damage in the form of wear and tear, peel injury, broken teeth and the like. The current domestic production of only a few manufacturers can. The plant has been using welding methods to repair a broken tooth multiple, maximum break size of 200mm × 40mm × 45mm scrap gear shaft, concrete repair process is as follows:
(1) with a hand wheel at the bottom surface of broken teeth grinding is good, it does not allow the presence of any cracks. Heating the workpiece before welding, using far infrared radiation heater 24 evenly mounted on the top surface of all the teeth, and wrapped with asbestos cloth. Heated for about 6h, workpiece temperature controlled at about 300 ℃.
(2) selection φ4mm of E308-16 (A102) electrode and φ4mm the E8515-G (J857) alternately surfacing welding, before welding electrodes should be carefully dried.
(3) first with E308-16 electrode backing weld, thickness 4mm, then the E8515-G welding electrode 16 ~ 20mm thick, followed by E308-16 welding rod 3mm thick buffer layer, and finally with the E8515-G After surfacing welding the teeth part. Welding process to make the workpiece is always in a heated state, and put in the shelter, the interlayer temperature is maintained at about 300 ℃, each solder layer to (hot) hand hammer hard hit more than 30 times at each surfacing . Entire welding process should be carried out continuously, once completed. (4) after welding to insulation 4h, then slow cooling.
(5) In order to get a better profile accuracy, it should make use of the wheel manual carefully polished.
Welding repair of the gear shaft were ultrasonic testing and hardness testing, are in line with quality requirements.
Second, the inner ring of welding repair
50t crawler cranes walking connection with the upper part of the adoption of the platform slewing ring, the inner ring outer diameter φ1400mm, thick 135mm. During the air-tooth, due to the malfunction of the machine will be one of the teeth of thick milled to half, the need for welding repair. 5CrMnMo inner ring of material is steel, poor weldability. After the ring gear is quenched, while the tooth defects after welding is not allowed to make the appropriate heat treatment, so need to choose the hardness of which corresponds to the electrode and using the heat affected zone no cracks in welding technology. Specific welding process is as follows:
