Authors: Kotov A.V., Krol D. G., Ph. D. in Phys. And Math., Assoc. Prof.
This article is a translation of the original work of the same name, which was written in Russian and published in a peer-reviewed journal. I decided to prepare and publish its English version for several reasons. First, science and engineering thinking have no language barriers. Publishing a translation is a step towards drawing attention to my research from a wider audience, including foreign colleagues, engineers and researchers who may find the proposed method useful. Second, publishing the article in English helps increase the visibility of the blog itself in foreign search engines. This means that my developments and findings are more likely to reach those who truly need them. I am open to discussion, feedback and professional dialogue with anyone who finds the topic of my research relevant. I will be glad if this material proves useful beyond the Russian-speaking audience.
Introduction. The problem of ensuring high efficiency and reliability of lever mechanisms is directly related to minimizing losses in their kinematic pairs, which, in turn, depend on the pressure angle [1, 2]. Exceeding the pressure angle beyond the recommended optimal value leads to an increase in friction losses and radial loads in the joints of the lever mechanism, which results in increased wear, jamming, and a decrease in the overall efficiency of the mechanism [3].
Traditionally, the synthesis of mechanisms based on the pressure angle is classified as a kinematic design task and is solved using graphical or analytical methods, which include constructing position and velocity plans [4 – 6]. Such synthesis can precede force analysis and provide additional qualitative and quantitative assessment of the potential force loading of the mechanism under study. However, formulating and solving this problem often requires cumbersome calculations and graphical constructions, which complicates the possibility of algorithmization and optimization [7].

The application of vector analysis or complex number theory for describing the kinematics of planar lever mechanisms is a well-established and effective approach [8, 9]. It allows for uniform, compact, and minimal analytical expressions to calculate the positions and velocities of all characteristic points and links of the mechanism. At the same time, the potential of vector analysis and complex numbers for solving kinematic synthesis problems, in particular optimization of pressure angles in joints, has not been fully explored. In this regard, the development of a methodology for the rapid assessment of pressure angles at the stage of mathematical modeling, based on this apparatus, retains its scientific and practical relevance.
