This paper proposes a mathematical model of a CNC rotary table driven by a worm gear. The CNC rotary tables are generally utilized as rotary axes of 5-axis machining centres. In this study, a mathematical model which can simulate dynamic behaviours of rotary table is proposed. The model consists of inertia of motor, spur and worm gears, and table. Axial displacement of the worm is also consider...

The performance of a circularly polarized edge truncated elliptical patch microstrip antenna has been investigated experimentally in free space and has been compared with the performance of a conventional elliptical patch antenna. Extensive optimizations in feed locations and in edge lengths along major and minor axes of conventional elliptical patch antenna have been carried out to achieve bes...

Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or ...

Dual-ball-screw feed drive systems (DBSFDSs) are designed for most high-end manufacturing equipment. However, the mismatch between dynamic characteristic parameters (e.g., stiffness and inertia) P-PI cascade control method reduces accuracy of DBSFDSs owing to structural changes in motion. Moreover, controller always same even though two axes have different characteristics, it is difficult tune ...