Digital Modeling And Error Influence Analysis Of Straight Profile Hourglass Worm Gear

As a kind of advanced and reliable worm drive and precision worm drive,hourglass worm gear is widely used in metallurgy,machinery,chemical industry,military project,transportation and many other industries.Due to the constraints of the design and manufacturing process,the excellent performance of the hourglass worm gear can not be fully utilized,which leads to the fact that it has not been applied in our country.According to the demand of Yancheng Pacific Machinery Manufacturing limited company,Jiangshu,the thesis researches the tooth surface equation of hourglass worm gear,digital modeling,he influence of machining error on the profile of worm,the influence of installation errors on contact state.The main research work of this paper is as follows:1.The establishment of the tooth surface equation of the straight profile hourglass worm gear.According to the principle of spatial meshing,the tooth surface equation of the worm is deduced based on the conjugate surface theory and the tooth surface equation of the worm gear is established by using envelope method.It proves a special phenomenon of the typical hourglass worm gear: first line reproduction,establishes axial section equation of the straight profile hourglass worm and proves that the tooth profile of worm axial section is straight line.It simulates turning tool' cutting edge and hob' cutting edge by MATLAB software.2.Solid modeling of worm gear.According to the tooth surface equation of the straight profile hourglass worm gear,it solves the worm tooth surface equation and the gear tooth surface equation by MATALB software,divides the worm tooth surface and the gear tooth surface into data point cloud and obtains the discrete model of straight profile hourglass worm tooth surface and gear tooth surface.Based on the idea of reverse engineering,using UG software completes the solid modeling of the worm gear.3.The digital modeling of straight profile hourglass worm gear.Based on the idea of virtual machining and the two development platform of UG,this paper studies the digital modeling of the straight profile hourglass worm gear and disposes the smooth treatment of worm gear tooth surface.Based on the ADAMS software,the dynamic simulation analysis of the straight profile hourglass worm gear is carried out.4.Error analysis of the straight profile hourglass worm gear.It studies the influence of machining center distance error on the profile of worm gear and the distribution of contact line.The finite element model of the worm gear is established,and the influence of the center distance error on the contact state of the straight profile hourglass worm gear is analyzed.It analyses the shape of the worm and determines the accuracy of the turning tool and the hob cutter shape.By using virtual machining method,the actual shape of worm gear can be seen from the design stage,and the design and manufacturing efficiency of the hourglass worm can be improved.Through the analysis of the center distance error,it is indicated that the worm gear is very sensitive to the error and machining and installation error should be strictly selected and control.