Abstract:

To enhance the comprehensive transmission performance of hypoid gears with high reduction ratios, a design method for significantly inclined contact lines based on active tooth surface design technology is proposed. Initially, multiple tooth surface imprints with varying degrees of contact line inclination are preset, along with their corresponding major axes of contact ellipses and lengths of contact lines. The pinion conjugate tooth surface is then modified with a parabolic shape to achieve a tooth surface that meets the preset parameters. Subsequently, by integrating Tooth Contact Analysis (TCA) and Load Tooth Contact Analysis (LTCA) techniques, the transmission error amplitude (TE), amplitude of loaded transmission error (ALTE), tooth surface load distribution, root bending stress amplitude, and tooth surface flash temperature amplitude are obtained for each tooth surface. The impact of changes in contact line length on these performance parameters is analyzed. Based on the findings, a final target modified tooth surface is selected, and its comprehensive performance is analyzed and compared with the original tooth surface. A case study demonstrates that for a hypoid gear pair with a gear ratio of 5:75, under conditions of significantly inclined contact lines, the longer the contact line, the smaller the tooth surface contact stress, and the root bending stress and tooth surface flash temperature also decrease accordingly. The edge contact condition of the target tooth surface is mitigated, with the maximum root bending stress reduced by 12%, and the contact stress distribution becomes more uniform. The highest tooth surface flash temperature decreases by 6.3%, enhancing the scuffing load capacity. The modified target tooth surface exhibits superior contact zone performance, improved load capacity, and significantly enhanced comprehensive transmission performance.

Key words: high reduction hypoid gear, active design, modification, load tooth contact analysis, loaded transmission, tooth flash temperature