The Roughness of the Contact Surfaces of Plastic Cylindrical Gears with a Circular Tooth during Additive Shaping

The article discusses the problems of using FDM technologies in the formation of plastic gears with circular teeth. It is shown that additive technologies are becoming increasingly important in the manufacture of non-standard parts. The role of such an important parameter as the roughness of the side surface of the teeth, which has a significant impact on the durability of gearing, is emphasized. The method for calculating the configuration of liquefied material layer on a solid flat surface is proposed. This method is based on a model of the interaction of the internal three-dimensional state of liquid material layer, a two-dimensional material film, and a material line closing it. The state and shape of the liquid layer on a flat surface was analyzed under the assumption of the validity of the Yungi equation, connecting the wetting angle with the values of surface tensions. The dependences, allowing calculating the amount of irregularities of the lateral surface of the circular teeth of plastic cylindrical gears, are given.