TY - JOUR
AU - Pylypaka, Serhii
AU - Kresan, Tetiana
AU - Volina, Tatiana
AU - Hryshchenko, Iryna
AU - Pshenychna, Liubov
AU - Tatsenko, Oleksandr
PY - 2021/12/21
Y2 - 2024/10/06
TI - Designing an outer toothed gear whose wheel teeth are outlined by the logarithmic spiral arcs
JF - Eastern-European Journal of Enterprise Technologies
JA - EEJET
VL - 6
IS - 7 (114)
SE - Applied mechanics
DO - 10.15587/1729-4061.2021.245121
UR - https://journals.uran.ua/eejet/article/view/245121
SP - 6-11
AB - <p>Toothed gears are the most common mechanical gears in machine building, which are characterized by high reliability and durability, a constant transfer number, and which can transmit high torque. During toothed gear operation, the surfaces of the teeth slide, which gives rise to friction forces and wears their working surfaces. To prevent this, the surfaces of the teeth need constant lubrication. This paper considers the design of a gear tooth engagement, which does not have friction between the surfaces of the teeth since they roll over each other without slipping. The profile of the tooth of such a gear is outlined by congruent arcs, symmetrical relative to the line that connects the center of rotation of the toothed wheel with the top of the tooth. These symmetrical curves at the top of the tooth intersect at the predefined angle. In the depressions of the wheel, adjacent teeth also intersect at the same angle. Such a condition can be ensured by a curve that at all its points crosses the radius-vector emanating from the coordinate origin, also at a stable angle equal to half of the given one. This curve is a logarithmic spiral. If the number of teeth of the drive and driven wheels is the same, then their teeth are congruent. Otherwise, the profiles of the teeth would differ but they could be outlined by congruent arcs of the same logarithmic spiral of the same length taken from different areas of the curve.</p><p>The minimum possible angle at the top of the teeth is straight. At acute angle, the toothed gear operation is impossible. To build gear wheels with a right angle at the top of the tooth, it would suffice to set the number of teeth of the drive and driven wheels. The center-to-center distance is calculated using the derived formula. The transfer number of such a gear is variable but, with an increase in the number of teeth, the range of its change decreases. The algorithm of wheel construction is given.</p>
ER -