Theoretical And Experimental Research On Loaded Meshing Of Involute Cylinder Worm-drive

The worm-drive provides a simple solution in power transmission application and possesses some characteristics with large drive ratio, small volume and so on. It can operate smoothly and steadily, so its noise is small. The worm-drive is widely used in modern industry, especially the ordinary cylinder worm-drive in machine tool manufacturing sector. Main disadvantages of worm dives are lubrication and wear problems due to relatively high sliding at the tooth contacts. The ordinary cylinder worm-drive has almost become an exclusive selection in general low speed transmission work-platform and continuous graduation mechanism. The involute cylinder worm gear is one of the ordinary cylinder worm gears. Because of the specificity of the machine tool for this worm gear, its machine tool is not extensively developed in our country. The deep research on the involute worm gear is lack in our country. The central content of this thesis is theoretic and experimental analysis on involute cylinder worm gear under the coupling of the load and the mounting errors. The thesis involves mainly in several aspects of this worm drive as follows:1. Tooth surface equations and contact line equations of the involute worm gearing are established according to its machining methodology. Meshing characteristics in rigidity condition are studied. These characters include the inductive normal curvature along the contact line on the worm surface, the first and the second limit lines during the engage of the worm gear, and the influence of the intersect angle between the contact line the relative velocity of the worm and the gear on transmission performance.2. Solid model of the involute worm gearing solid model with drive ratio 1/50 is built by using IDEAS-5.0, then the elastic contact analysis is proceeded on the basis of contact FEM. The dynamic evolution image of the area of the contact zone, the load sharing among instantaneous meshing tooth pairs, the distribution of the contact force, and tooth stress are obtained.3. After considering the coupling of the mounting errors and elastic deformation, the meshing influences of the error of the center distance, the setting parametric error in the axial direction, and the intersect angle between the two axes on transmission performance are investigated.4. On the basis of the engage efficiency and lubricious conditions, theoretical transmission efficiency with the different drive ratios (1/50 and 6/31) of involute cylinder worm gears is analyzed. At the same time, the change trend of engage efficiency and transmission efficiency with different design parameters is discussed. The experimental investigation on transmission efficiencyof this worm drive and lubrication oil temperature is carried out using electrometric method. The test results verify the theoretical analysis.