Hydraulic oil temperature with the system condition, environment temperature and heat exchange characteristics, is one of the most significant parameters affecting the performance of hydraulic system. Oil temperature directly changes oil viscosity and leakage characteristics, which affects the damping effect on system performance of hydraulic oil ratio, thereby affects the stability of the hydraulic system and dynamic response. At the same time, it also can cause the seal metamorphism and oil oxidation failure, which causes corrosion and formation of sediments, which affect the normal operation of the system, even brings harm to the equipment. Therefore, improving the working performance and reliability control through the analysis of hydraulic oil temperature is necessary.

Transmission system is an important part of combine harvester, and is the main indicator to measure the level of technology. This paper presents the design of a composite hydraulic mechanical transmission system for combine harvester. The system consists of engine, variable pump, quantitative hydraulic motor, planetary reducer, driving wheel, crawler etc. Author analyzes the continuous variable speed regulation characteristics of transmission; determines selection method of hydraulic components and mechanical parameters. Composite transmission system can make the engine is close to full load operation, improve combine harvester productivity and fuel economy. By optimizing the transmission system, combine harvester can reduce speed, increases the torque, realizes continuous variable speed. Practice has proved: this dynamic composite transmission system with fast response, high efficiency, and reliable, low failure rate. At the same time, combine harvester has the advantages of simple operation, forward, backward or turning without shifting, greatly reduce the labor intensity of the operator.

Crawler combine harvester walking system is various transmission technology are organic and reasonable matching, foster strengths and circumvent weaknesses, complementary drive system so as to achieve the best overall. Stepless speed walking is particularly suitable for complex condition changes, the demand of drive system for a more comprehensive, more comprehensive, objective stepless speed walking in transmission system innovation or seek better performance, and as a mechanical transmission device of the planetary gear has the advantages of small volume transfer large torque, high efficiency. The combination of both realizes stepless transmission, and has the advantages of low speed and high torque. Hydraulic drive system is mainly to achieve stepless speed regulation, commutation, planetary gear drive mainly reduce speed, increase the torque to. Composite transmission mode that can greatly improve the transmission ability, expand the scope of speed adjustment. In fact, combine the stepless variable speed running and control technology can greatly improve the performance of the product, especially the effect on production efficiency, durability, controllability, environment adaptability, green characteristics were significantly.

Hydro mechanical stepless speed system is a new conbination system of hydraulic transmission and mechanical transmission, which realizes the stepless speed change through the hydraulic transmission and the mechanical transmission to reduce the speed and torque, and to improve transmission efficiency; through optimizing design, The system can realize the differential steering, increase ground clearance. In this paper, the caterpillar feeding combined harvester is the object, the system is composed by the motor, a variable pump single stage planetary gear, hydraulic machinery stepless speed walking system is of wide speed range, simple structure.

How to make discarded mobile mechanical product implement material and components reuse and recycling economical in its all 1ife was the focus of green design. Aiming at the problems of the traditional design which is not considering recycling resources and the influences to the environment after the end of life of the productions, the concept and content of green design for recycling was introduced, in addition, the tactic of green design for recycling was included. At last, the method of realizing the mobile mechanical productions recycling is pointed out.