A processing method for rough cutting hourglass worm on general NC lathe

Abstract

The manufacturing method of two spatial-orthogonal rotary axis linkage is usually used to cut hourglass worm. However, the traditional processing method of roughing tooth groove depends on the special machine, specific tool, and its processing efficiency is lower. To avoid these defects, a processing method of the rough cutting hourglass worm on general NC lathe without C-axis functions was presented in the paper. Based on the forming principle of the hourglass worm and the traditional processing steps, the machining principle of the new approach was elaborated. Key techniques such as the shape of the blade, the contours of tooth groove, tool path loop and the variable lead of worm, etc. were discussed. Macro-program of the new method was programmed based on Fanuc oi mate-tc CNC system, and tooth groove of the hourglass worm were trial manufactured on general NC lathe. Addendum axial pitch and a normal tooth thickness of the trial model were measured. It is noted that measurement results can satisfy the technological requirement. In conclusion, the new processing method of roughing hourglass worm is feasible and efficient.

Research on equaling design and machining method of roughing allowances of a dual-cone enveloping toroidal worm

“…Toroidal worm surfaces also can be machined on an ordinary CNC lathe with XZ without B axis and C axis. By setting the worm rotating speed constantly and using the layered machining method, the turning tool is moved to machining points continuously by producing an arc spiral line along X and Z (He,et al, 2011;Dong, et al,2016;Qiu, et al, 2019). In order to obtain the uniform contact line, the non-uniform rational B-spline curve is used for the parametrically fitting of contact lines for points on the discrete worm surfaces (Ding, et al, 2019).…”

A novel specific four-axis linkage method for processing the hourglass worm

“…4,5 In identical dimensions of a worm pair, the number of simultaneous meshing teeth of the hourglass worm gears is more than the number of the cylindrical worm pair. 6–8 In aspect of microcosmic engaging performance, hourglass worm drives have a greater radius of induced normal curvature, distribution of the instantaneous contact line nearly tooth height direction, larger lubrication angular, 9 etc. Therefore, the bearing capacity and transmission performance of the hourglass worm gears is outstanding, and then they are widely used in metallurgy, mining, petroleum, and other heavy-duty transmission applications.…”