Research And Analysis On The Hoisting System Of Large Horsepower Tractor

In order to solve the problem of clamping stagnation valve and cylinder scoring in the working process of tractor hydraulic lifter, the research method of this article uses a combination of theory and experiment. The principle and structure of the hydraulic system of tractor are analyzed, study on the occurrence mechanism and failure form of tractor raiser, based on summing up the development process of tractors in China. The 3D tractor lifts model built by using SolidWorks software, and the finite element analysis of one Dongfanghong tractor lifter, put forward the improvement scheme. In this paper, the specific work contents and research results include:1. Analysis of the working principle of tractor lifter. This paper analyzes the types of tractor hydraulic system, control method of tractor hydraulic system, working principle, performance and characteristics.2. Study on the formation mechanism of tractor lifter. Through analysis of types and cause of fault in the lifter, Put forward the technical scheme for solving the problem of clamping stagnation valve and cylinder scoring. The main research results include:(1) The influence factors on the reliability of lifter include: hydraulic oil cleanliness, control valve spool and valve cover with clearance, the working temperature of hydraulic oil;(2) Experimental study shows that the main control valve spool and the valve sleeve with the gap of 0.010-0.015 mm, can significantly reduce the clamping stagnation valve;(3) By increasing the filtering device and the auxiliary hydraulic oil, hydraulic oil to reduce cycle times, reduce the temperature of the hydraulic oil, ensure the working reliability of tractor lifter;(4) In the work, to avoid continuous, long time high load field operations, to ensure that the hydraulic oil in the normal operating temperature range.3. Built the 3D modeling and assembly modeling of tractor lifter. A large tractor lifter was designed by using Solidworks software, 3D modeling and assembly modeling of parts. Through the model of the assembly interference check assembly interference and motion of the lifter. The 3D modeling and assembly modeling of parts was built by using Solidworks software, designed a kind of supporting with large tractor lifter. Through the model of the assembly interference check assembly interference and motion of the lifter.4. The finite element analysis and Study on assembly process of tractor lifter based on the SolidWorks simulation software.Using SolidWorks simulation software module was carried out on the analysis of stress and strain of lift cylinder. Analysis shows that the lifter in the cylinder scoring positions are mainly located in the area around the connecting bolt. The maximum stress and maximum deformation of the cylinder are increased with the increase of cylinder wall thickness difference. When the wall thickness difference is 3.1mm, the maximum deformation of the cylinder is 0.076 mm.The assembly process of lifter assembly of test results show that the lifter assembly and in cylinder scoring position and cylinder position and vertical direction, hole and hole in cylinder bottom deformation 0.005-0.02 mm, cylinder cavity diameter of ?110mm not change significantly.Through the deformation of finite element analysis and test results of the hydraulic lifter assembly process, the improvement scheme of oil cylinder is put forward. And the dynamic test on the prototype of the improved. The test results show that the deformation of the cylinder is reduced from 0.01-0.04 mm to 0-0.01 mm under the rated load, and the deformation is obviously reduced.