The Research On Increasing The Overall Positional Precision Of The Gear Of Intermediate Shaft In Auxiliary Box

Transmission is one of the key components in the automobile power transmission system, and its performance has a decisive influence on the performance of the vehicle. Twin countershaft transmission designed by The American Eaton Corporation in the 50 s to 60 s last century has becoming the most popular transmission of heavy trucks in our country because of its characteristics such as strong bearing capacity and low failure rate etc. In years of working in domestic it proved that the main form of failure type of this transmission is the gear-hit in Auxiliary Box, of which countershaft assembly consists of a pair of gears and a pair of countershaft by pressing and welding. The processing difficulty is mainly reflected in the gear tooth precision, welding strength, the influence of the total thermal deformation on the gear tooth direction and the tooth pitch error, and so on. The gear tooth precision is the most critical factor, if the correct implementation of the vice-box on the teeth cannot be correctly realized; the gear meshing bad will lead to serious damage to the gear boxThis thesis takes countershaft assembly of heavy duty truck transmission as the research object. The research on increasing the overall positional precision of the gear of intermediate shaft in auxiliary box was conducted. The research objective is to solve the problem of gear tooth beating phenomenon to achieve the lifting of the overall performance of the truck. The following several aspects of the study were carried out.1. Analysis on the phenomenon and influence factors of gear tooth beating phenomenon. According to the market feedback, the law of the occurrence of gear tooth beating phenomenon was analyzed in detail; and the causes and main influencing factors of this phenomenon were analyzed.2. Study on pressing technology of the auxiliary box countershaft. Study on the optimization of positioning and clamping mode of the pressing fixture for the auxiliary box countershaft was conducted. On the basis of the existing pressing fixture, the upgrading and improvement of the pressing installation precision were conducted to stabilize the process quality.3. Study on welding process of the auxiliary box countershaft. Analysis of technological characteristics of the auxiliary box countershaft using different welding methods was conducted. Research on how to meet the requirements of welding quality, and make the deformation as small as possible was conducted. And the corresponding process test was carried out.4. Research on increasing the overall positional precision of the gear of intermediate shaft in auxiliary box. Through the analysis of shaft position characteristics of auxiliary box countershaft after pressing and welding process, based on many rounds of trial and error, finally the change law of the position degree was got.Through this research, the transmission intensity was improved; the major defect was prevented, so much more economy effects produced for our guests. Research on this issue,is also the conclusion and research of the structure of “The press fitting and welding of the Gear of Intermediate shaft in Auxiliary Box ”,it can also provide some Reference resources for more researchers, on this point this issue has its own social benefits.