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

Abstract

To improve the flexibility of hourglass worm processing equipment, a specific four-axis linkage method for processing hourglass worm, which is called CZXB method, is presented in the paper. Based on the forming principle of the hourglass worm, machining principle and the traditional processing method were elaborated in detail. And then, the CZXB method that aims to apply four feed-movements linkage to simulate the conjugated rotary motions between the worm and its worm gear was proposed. According to the basic theory of rigid body kinematics, the scientific and feasibility of the CZXB method were demonstrated. Based on the computer numerical control machining simulation system, VERICUT, a virtual model of the machine tool with CZXB function, was established. A multi-thread hourglass worm was taken as an example to simulation processing by the CZXB method. Trial manufacturing was performed: tooth grooves of the hourglass worm were cut out by the traditional method, and tooth surfaces of the hourglass worm were finishing machined by the CZXB method. The result shows that machining center distance of the CZXB method is less than center distance of the worm gear pairs. Implementing the CZXB method can significantly enhance the flexibility of machining equipment of the hourglass worm.