A new approach to enhance the manufacturing accuracy of the cylindrical worm using measured circular-arc helicoidal profile data

This paper presents a new approach to enhance the production accuracy of a cylindrical worm using measured circular-arc helicoidal profile data. In an attempt to enhance the accuracy of the base structure for measuring and manufacturing the cylindrical worm, a swinging measurement head is designed and utilized as the probe to measure the free surface of the worm. Some annoying errors introduced by a misaligned layout configuration and excessive contact point excitation coming from a traditional measurement head are mathematically characterized and represented. By combining both the layout error equation and the measurement operation equation, a diagnostic model is systematically derived in terms of adjustable machine-tool system parameters. This diagnostic model can then be used to improve the machining accuracy of the worm in real production processes. To illustrate the effectiveness of the proposed approach, an industrially used worm is selected for use in measuring the geometric parameters. These measured parameters are then incorporated into the layout error and the diagnostic models to produce a cylindrical worm of better accuracy. The experimental results indicate that the analytical solution agrees well with actual measurement data of the enhanced cylindrical worm. The proposed method is proved to be practical and applicable to enhancing the manufacturing accuracy of various key components of industrial machines.