OBRABOTKAMETALLOV MATERIAL SCIENCE Том 23 № 3 2021 EQUIPMEN . INSTRUM TS Vol. 6 No. 1 2024 Introduction Domestic enterprises in various industries use a variety of process equipment, including weaving machines. Modern weaving machines have several unique features, including a close relationship between technical condition, productivity, and product quality. An essential feature of the process equipment is also the high kinematic complexity of the main mechanisms’ movement and the dynamic intensity of the machines’ operating modes [1–5]. One of the trends in the development of modern mechanical engineering is focused on improving existing and creating new high-performance equipment for weaving production. The increase in dynamic tension combined with that of operating speeds places higher requirements on the design of individual elements and assemblies, including drives that ensure intermittent movements of the machine’s working bodies [1, 6–9]. Currently, the production of a mass assortment of fabrics for consumer needs, including strong ones, is carried out mainly on shuttleless looms [2–18]. Shuttleless looms off er several advantages, including small dimensions, high performance, and automated fabric production processes. They are used to manufacture cotton, silk, wool, linen, technical, and other types of fabrics [3, 4, 9, 19]. One of the most important requirements for modern machines is that the followers are required to perform movements that accurately correspond to a specifi c law. This requirement is sometimes not feasible if simple part connections, such as levers, are being used. Therefore, shuttleless looms use cam links with various contour surfaces obtained using mathematical dependencies in their mechanisms. Compared with other transmission mechanisms, they have a number of advantages. The cam can be shaped to meet the kinematic and dynamic requirements of the developer. This allows for easy adaptation. The design of a cam is simple, allowing for precise execution of the required follower motion [1, 4, 10, 12, 19–25]. However, fabric formation on such machines can present several challenges, including increased vibrations and accelerated wear of mechanisms. These factors reduce the performance and quality of the fabric. In this regard, when designing machine mechanisms, it is important to consider dynamic characteristics, which depend on the smoothness and continuity in the graphs of the followers’ kinematic characteristics [10–12, 19–43]. The industrial use of shuttleless looms indicates that it is not possible to increase performance without considerable changes in defi nite mechanisms. First of all, it is necessary to modernize the mechanisms directly involved in the formation of fabrics. These include a mechanism designed to move the warp threads, i.e., a heddle lifting mechanism. The process of fabric formation on shuttleless looms is similar to that on shuttle looms: shed opening, picking of the weft thread, shed closing, battening of the weft thread to the cloth fell, and then the cycle repeats [40]. In the process of weaving, the warp threads bend around the weft threads and move from one side of the fabric to the other. Each main overlap on one side of the fabric corresponds to a weft overlap on the other. The pattern is created by various interlacing. This function is performed by a heddle lifting mechanism [40, 43]. Signifi cantly, there are a large number of shuttleless looms in the factories of the Russian Federation. Even a small reduction in the size of a machine can allow for more equipment to be placed in the factory, resulting in a signifi cant increase in performance per unit of production area. Consequently, reducing the dimensions of the shuttleless loom by reducing the size of the heddle lifting mechanism is an urgent and practical task. The purpose of the work is to reduce the dimensions of the loom by changing the design parameters of the heddle lifting mechanism. To achieve this goal, the following tasks were solved: – to analyze the possibility of changing the size of the kinematic scheme of the mechanism; – to develop a synthesis technique for the lever mechanism; – to select the necessary parameters for the synthesis of the cam pair and perform the synthesis; – to present the methodology of kinematic analysis and establish criteria for objectively evaluating the proposed solution. Research Methodology Consider the constructive scheme of the mechanism of the remission motion as shown in Fig. 1. It includes drive cams (7), a shaft with rollers (6), a connecting link (10), an eccentric mechanism (11), a double-arm lever (1), and a horizontal rod (9). As can be seen from the diagram, an eccentric
RkJQdWJsaXNoZXIy MTk0ODM1