Calculation and Analysis on Crest Thickness of Edge Tooth of Height-Modified TA Worm

摘要

As is well known, the tapering edge tooth may greatly degrade the working performance of a toroidal worm pair so checking its occurrence is always necessary in the process of the design. For this, a mathematical model is established to compute the top thickness of the edge tooth for a height-modified TA worm. Due to the geometric particularities of the height-modified TA worm, the crest thickness of its edge tooth can be obtained semi-analytically and semi-numerically. By means of the above mathematical model, the influence of the quantity of the height modification on the crest thickness of the edge tooth is investigated systematically. The results show that the tapering of the edge tooth will occur more easily when the number of worm thread is more and the transmission ratio is less. Moreover, if the cutter frame moves down, the top width of the edge tooth will decrease. From the viewpoint of avoiding the edge tooth pointing, the selection principle of the height modification amount is also recommended.