Design and Development of a Heddle Shaft Mechanism for Air-Jet Weaving Machines

Air-jet weaving is the most productive weaving procedure. However, it is also the most energy-intensive procedure. In order to save energy newly developed high-volume-low-pressure relay nozzles can be used. The application of these nozzles requires changes in the heddle shaft movement. The design and development of a suitable mechanism to drive the heddle shaft is presented. After the determination of requirements a structural synthesis is conducted. The outcome of the structural synthesis is a set of mechanisms which in principal can solve the motion task. Subsequently a dimensional synthesis is performed to determine the kinematic parameters of each structure. The different mechanisms are then compared to each other. The most suited mechanism is a combination of a linkage and a cam mechanism. In order to improve the dynamic behavior of the heddle shaft mechanism a Fourier analysis of the shaft motion is carried out. The Fourier series of the shaft motion is then truncated and the disk cam profile is redesigned in order to drive the shaft with the desired harmonic motion. The result of the design and development process is a new heddle shaft mechanism for air-jet weaving machines with high-volume-low-pressure (HVLP) relay nozzles.