Development And Application Of A New Technology Of Highway Type Drive Axle

Commercial vehicle power assembly includes an engine, a gear box, a driving axle.The driving axle is not only a part of vehicle power but also the most terminal of the power transmission which is very significant. With the rapid development of the highway and the perfect of laws and regulations in our country, the domestic commercial vehicle company have developed their own highway products rapidly, the development of highway driving axle is imminent. In the future, the direction of highway driving axle development is "Safety,High Reliability,High Efficiency,High comfort,High mileage", or simply "4H+S" for short, which is conform to the trends of internation.First of all, this paper expounds the background and significance of the research and describes the development situation of bridge at home and abroad, and also explains the source and task of the project. To enhance the competitiveness of existing products and build a new kind of highway drive axle, we analysis different technical route, finally we choose the MeiChi as the technical route. According to the contrastive analysis, we confirm the target of the research:the ability of the torque need to be increased by 10%, the mass need to be lighten by 220Kg per set, the noise should has been reduced by 3dB,and the mechanical efficiency should has been increased by 2.3%, the maintenance mileage of the wheel edge has been increased by thirty thousand km, finally we should achieve the goals of "Safety,High Reliability,High Efficiency,High comfort,High mileage".Based on the advanced technical route abroad, associated with domestic situation, we make the constrastive analysis for the main reducer assembly,axle housing assembly,wheel edge assembly respectively(including the brake assembly), and determine the program of the development. The original main reducer assembly has many disadvantages such as the heavy weight, too many components, unreasonable spatial arrangement and low transmission effiency. The new main reducer assembly arrange the interaxle differential below the cylindrical gears instead of up to the gears. We combine the cylindrical gears with the axle shaft gear, and we cancle the guide bearing by adding the length of the cone bearing's bracket. According to the innovation of the structure and technology, we solve the problem the original main reducer assembly remained. The problem of the axle housing assembly is to light the weight, the original section have been optimized from 150×160×14 to 150×160×12, we achieve the goals of weight-lighten. The innovation of the wheel edge assembly has mainly three points. First of all, the lubrication methods have been changed from grease lubrication to oil lubrication which increase the period of the maintenance; secondly the high grade ductile iron has been adopted for wheel hub, and we can light the weight without performance degradation. The brake assembly use the double-metal process to achieve the goals of weight lighten and life lengthen. Thirdly the new design of the brake assembly appear on the structure optimization and weight-lighten, the tradional structure brake has been changed to the quick-change-lighten brake based on the technical route of MeiChi. The goals of shortening the time of maintence has been achieved as well as the weight-lighten.According to the theoretical optimal design, the tested drive axle achieve the primary goals via road test,bench test,small-batch sales, and promote the competitiveness greatly.