Optimization Design Of Matching On Loader’s Engine And Hydraulic Transmission Box And Bench Test

With the increasing and development of the infrastructure construction, traffic construction and mine exploitation, the demand of construction machinery, such as loaders, has grown rapidly under the globalization of world economy. Hydraulic transmission box’s dynamic performance determine the loader’s dynamic property, worked efficiency, and working life, which is the most important part of the loader’s driving device. The optimization of the matching of the hydraulic transmission torque converter and engine power is very important to the optimization of loader’s starting characteristic, the performance of stage changeover and fuel economy label. In this paper, we finished the power matching and optimization between the engine and SD50loader hydraulic transmission box, and designed the experimental platform to test the performance of SD50loader hydraulic transmission box.In this paper, the structure and principle of operation of SD50loader hydraulic transmission box is explained, that the speed change of loader relay on the cooperation between hydraulic converter and free-wheeling clutch. The relationship between the common work characteristics of engine and hydraulic converter and power performance of loader is expatiated. The basic principles of the matching work between the converter and engine is determined. Then select the Cummins6CT8.3-C215engine, and YJ355L single-phase torque converter and YJSW315-6single-stage two-phase torque converter to be the example of matching work.The common work characteristics of SD50applicable d engine and hydraulic torque converter is analyzed and studied systematically, a simplified mathematical model of engine’s output torque and hydraulic torque converter’s input characteristic is established, and the characteristic curves of engine and hydraulic torque converter are fitted by Matlab. Detailed analysis is carried out when hydrodynamic torque converter and engine work together, and the mathematical equations to compute power matching are established through setting the engine torque characteristics’ mathematical model. At last, it can be see that YJSW315-6single-stage two-phase torque converter is the better choice to SD50loader hydraulic transmission box. After that, the optimized design of the converter is carried out, which can make the loader has more excellent dynamic performance.The performance test rig of SD50is designed to test its power performance, which is open-type test rig with a main test bench, measuring apparatus and accessory system. Then in accordance with the relevant national standards and industry standards, the specific test programs and methods is designed.