Very large excavator roller structure improvement plan

Very large excavator 2018 - roller structure improvement solution 10 - 18 Li Naizhu yue-jin ding canal made red goldfish ( Xugong group mining machinery division) A very large excavator itself quality 400 t, 21 to 25 m3, bucket capacity with the mining truck, mainly used in the large mining ore. Which use harsh working conditions, high reliability requirements for chassis, especially to guide wheel, roller, chain wheel, the durability of the driving wheel and track is very demanding. The main supporting roller machine quality and walking. In the process of walking machine, roller bear huge alternating impact; When broken homework, take more impact. 1. Existing problems of the roller was very large excavator is mainly composed of wheel body, shaft, shaft sleeve and bearing, etc. Due to the initial design without fully considering the bad working condition, as well as the quality of the machine itself great vibration and shock may be produced, the wheel and axle strength can not meet the application requirements, some of the excavator, round body fracture and wheel excessive wear problems roller design experience at home and abroad for reference, we decided to improve. 2. Improved method ( 1) The improvement of wheel body roller wheel body blank contrast before and after improvement is shown in figure 1. Improvement before the roller wheel body blank in left and right wheel body welding and become, as shown in figure 1 a. Because the roller is huge alternating impact load, if the weld quality control does not reach the designated position, wheel body from the middle of weld cracking problems, can cause the wheel body fracture. In view of the wheel body to weld cracking risk, we decided to improve the roller wheel body. Adopts the whole structure can reduce the probability of fracture in the middle, and the wheel body greatly improve its reliability, can also reduce the welding process, economy better. To this end, we decided to welded round of economic restructuring as the integral body, monolithic casting wheel body can use, also can use forging forming. Need to develop mould, casting wheel body would increase the cost of manufacture. Don't have to manufacture of moulds, the forging wheel body and the organization is more dense, long service life, better than casting performance. To this end, we decided to use AISI4340 steel, forging method is used to make wheel blank, as shown in figure 1 b. （ 2) Axle of the roller was to improve the original used the method of making the small and medium-sized excavators roller axle, using bar. Small and medium-sized excavators of the roller shaft diameter is fine, by the bar processing can meet the performance requirements. Very large excavators, bad working condition to the reliability requirement of the shaft is higher, and shaft of 280 ~ 300 mm diameter, bar and mechanical properties can not meet the requirement of the strength. To this end, we decided to adopt material is 42 crmo steel forging blank, then made shaft machining. After forging forming of axle organization more dense, wear resistance, higher reliability. The improved shaft as shown in figure 2. For very large excavator roller after the improvement, from the experimental results, the reliability of the roller was greatly improved. This paper from construction machinery and maintenance 2017 7