The Driving Axle Development And Experimental Research Of 5T Wheel Loader

This article is based on the project "drive axle with large reduction ratio used on 5-ton wheel loader" carried out by XCMG, with the purpose to enable the machine to better handle heavy-duty applications through increasing the speed ratio of the drive axle in transmission system and to meet customer's requirements on machine towing performance. The theoretical analysis and test made are as follows:1. A statement on the current development situation of the wheel loader drive axle and the content and the purpose of this article.Wheel loader performances mainly consists towing performance, travel performance, steering performance and reliability performance. While towing performance reflects the machine's working capacity under traction. Towing performance parameter is one of the basic influencing parameters of the whole machine.The current reduction ratio of the drive axle on 5-ton wheel loader is between 22 and 23.5, which is comparatively smaller. And it leads to a small traction (usually below 14.5t) which is not suitable for heavy-duty applications. After analysis, we choose to design and develop an improved drive axle with a 26.11 speed ratio to improve the machine traction.2.According to the basic theory of engineering machinery, we selected and designed the axle proposal and design calculation.Through analogy method, the overall structure of the drive axle with large reduction ratio, overall reduction ratio, the speed ratio distribution between the master reduction gear and the hub reduction gear is finalized according to the wheel loader overall performance requirement on traction force, speed and connections.Calculation on the gear roots bending strength as well as the gear face contact strength of the master reducer's spiral bevel gears. The max. bending stress and max. contact stress are verified as the max. torque. The spiral bevel gears meet the design requirements. 3. The optimized design on the planet wheel of the axle.Setting up of the planet wheel mathematical model, and optimization on the planet wheel by practical software. The total volume after optimization has reduced by 9%.4.Strength stiffness analysis of axle housingThe housing initial stress, strain, movement, partial distortion simulation results is obtained after static force FEM analysis under condition of the full loading static bending. Then the following sensitivity analysis and design parameter setting, and finally is to finalize the structure parameter optimization in the dangerous area. The accordance with reality proves the correctness of the axle housing model. The highest stress is reduced by 9% and housing weight reduced by 0.5% after optimization. The analysis is evidence of axle weight reduction, which provides valuable reference for design and improvement.5.Bench test study on axle housingThe vertical bending stiffness, vertical bending static strength and vertical bending fatigue tests have been done for three types of housing in XCMG lab center. The results show that:the three types of housing all meet the requirement of JB/T5927-1991《Construction Machinery Axle Testing Technical Index》with the lowest fatigue life should not be less than 200.000 times.6. Fatigue life test on the drive axleThe endurance test on the newly-designed drive axle was performed on the power transmission test stand in XCMG Transmission Test Lab.First, after testing with load according to Mp 503,000 times, the drive axle ran stably with no failure, meeting the standard requirements.In order to come up with the final fatigue life, we increased the load by 5% each time, based on the Mp and tested with each load 100.000 times respectively till the drive axle gear failed due to fatigue. Total 866,600 times tests had been conducted, far above the standard.This drive axle has met the design standard after the phase of pilot run, test and strict installation assessment and entered the phase of mass production.