RESEARCH ON THE GEOMETRY AND FORMATION OF ARCHED TEETH IN NOVIKOV CYLINDRICAL GEARS

Abstract

Improving the meshing of cylindrical gears with arched teeth is a relevant and insufficiently researched scientific and technical direction aimed at improving the quality and load capacity of mechanisms and machines used in various industries. The modern level of development of computer technologies, in particular computer-aided design systems, creates the prerequisites for conducting in-depth research, as well as for developing accurate methods of analysis, synthesis of arched gearing and technologies for manufacturing arched gears in industrial conditions. A common drawback of existing methods of cutting arched teeth is the need to use individual cutting heads for processing gears with different shapes of the displacement line of the initial contour. In some cases, there is a need to use separate tools for forming convex, concave, involute and curved transition surfaces of the depressions between the arched teeth. In addition, the use of such cutting heads does not provide the possibility of cutting barrel-shaped arched teeth with optimal longitudinal profiles of the convex and concave sides, which significantly limits the potential for increasing the load capacity of the arched gear. These technological limitations significantly hinder the widespread introduction of arched gears in modern mechanical engineering. Novikov gears have become widespread due to the fact that the features of their geometry make it possible to significantly increase the contact strength, other things being equal. At the same time, these gears have a number of fundamental disadvantages. The main one is that Novikov gears do not belong to the running-in gears, as a result of which the teeth must be located at a certain angle to the generator, different from 0° and 90°. The presence of such an angle causes the appearance of an axial component of the load in the contact zone. In involute gears, this disadvantage was traditionally eliminated by using chevron wheels. At the current stage of development of gears, designs appear that combine the features of chevron and conventional gears. This is achieved by changing the shape of the tooth along its length with the formation of a curved arched tooth, which creates the prerequisites for more effective use of the advantages of Novikov engagement and increasing the operational characteristics of gears.

Keywords: surface geometry, Novikov gears, arched teeth, running-in method, curved surfaces.