The Structures And Technical Measures For Quality Assurance Of Gear

In modern machine building area, the most important thing is to improve the qualityof production, for the machine power is getting larger, while the size and weight of themachine are getting smaller and lighter, so that a requirement of higher strength andprecision for the important part, gear, is put forward. Correspondingly,in recent years, thegear with hard tooth surface is widely applied in our country, of which the precision isneeded to be increased to5-6degree. This is very difficult in practice. To solve thisproblem, taking the gear with high precision and hard tooth surface as example, thetechnology to control the quality of gear was studied. Our research has not only academicsignificance, but also practical values.A concept of optimization of technical process is proposed. It is not enough only toget the part, it is also needed to know the information of error changes during themachining processing, and according to the information, an optimum technique can be got,which considers all the influence factors and makes it sure to get the request size precisionand strength. To improve the efficiency of tests and decrease the cost, a method of gearmodel test is used in our researches.In this paper, the effects of structure, materials, machining, heat treatment andmeasurement on the quality of product were analyzed by using mathematical statisticsmethod, the structure-technic classification of parts were carried out and the relationshipbetween the structure of parts and technologies and production organizing was set up bysystem analysis method.Aiming at the minimum deformation after heat treatment, that how to reasonablydesign the structure of part using system analysis method was studied, and a model of heattreatment of gear was presented based on the quantitative estimation of structure and heattreatment deformation, so that an optimal structure was determined and verified by tests.Taking the gear as a typical example, the effects of structure and technics on theprecision were researched. After classifying the gears with different structures, theinfluence of geometry characteristics on the heat treatment deformation of gear models was estimated by using probability and mathematical statistics, and the precision valuescaused by the structure of part were calculated and analyzed with large number of data,tables and figures. Our works have very important significance on the improvement of theprocessing precision of gears with hard tooth surface.