Comparative Analysis of the Energy Consumed by Needle Bar Mechanism and the Mechanism Driving the Feed Dog of a Top Drive Sewing Machine

Abstract


 
 
 
 The paper focuses on the energy consumed by two mechanisms of sewing machine for straight lockstitch (stitch line 301): needle driving mechanism and the transporting mechanism. The first mechanism - needle driving, is a simple structure, but it is the most dynamic one. The second – to moving the fabrics, is the most complicated mechanism of the sewing machine. A comparative analysis of the energy consumed by the two mechanisms for the implementation of their propulsion is made. The correct work of the machine, the seam quality and the quality of the entire sewing product depend to a large extent, on the workings of these two mechanisms. The needle is driven by a slider-crank mechanism, while for the movement of the connected details, at the distance one step is done by a working part – a feed dog. It is attached to a carrier and its trajectory is a closed planar curve, close to the ellipse. The feed dog receives the horizontal and vertical component of its motion from two conditionally separate kinematic chains that have a common drive.The aim is analytical research and comparative analysis of the energies of needle bar mechanism and a mechanism driving the feed dog of the sewing machine. The energy consumed by each of the links of chains, of the chains themselves and total energy consumed by each of the two mechanisms for a full turn of the main shaft of the machine was studied. A comparative analysis of the energies and their distribution was carried out during the working process and the free movement of each of them. The results of the comparative analysis are presented in graphs and diagrams. It can be seen that the energy consumed by the needle mechanism is significantly greater than that of the transport mechanism. This fact is due to the much higher speeds of the links of the first one.