Analysis of the influence of the displacement of the gear rack profile of the pair evolution gearing on the quality indicators of the transmission
Date
2023-02-28
Journal Title
Journal ISSN
Volume Title
Publisher
Видавництво Львівської політехніки
Lviv Politechnic Publishing House
Lviv Politechnic Publishing House
Abstract
The article is devoted to the study of the influence of the modification of the paired
evolute gearing with convex-concave contact on the quality indicators of transmission, namely, the
contact pressure and the speed of slippage in the engagement. Previous studies of evolute gears showed
the presence of characteristic zones on the side surface of the tooth, which have worse values of quality
indicators than in similar involute gear. One of the ways to remove these zones or to reduce their
impact on the load capacity of the transmission is to modify the tooth profile, which will be
implemented by shifting the profile of the processing gear rack. A displacement factor is added to the
equation of the rail profile curve, which has the same value for the gear and wheel teeth, but the
opposite sign. On the basis of the developed equation, the side profiles of the teeth of the gear and the
wheel were constructed. Several values of the rack displacement coefficient with a positive and
negative sign for the gear teeth are considered. The results of the research allow us to evaluate the
influence of the amount and direction of the rail displacement on the curvature of the tooth profiles,
the contact pressure in engagement along the height of the tooth, and the relative and absolute speed
of sliding. Themodifications of the profile of the processing toothed rack proposed in thisworkwill expand
the existence of paired evolute gears with a different set of quality indicators. This will make it possible to
design gears with rational values of contact pressures and slip speeds when they are used in heavily loaded
transmissions created for specific operating conditions. Gears with relatively high slip speeds can be used
in road and construction equipment transmissions, which are characterized by lowshaft rotation frequency,
in which the speed of slip between the teeth does not have a significant effect on the life or efficiency of
the transmission. Otherwise, gears with relatively low slip speeds are very relevant when they are
implemented in the transmission of modern and promising vehicles with a hybrid or fully electric power
unit, especially in the case of passenger cars with high-speed electric motors.
Description
Keywords
gearing, rack displacement, convex-concave contact, paired evolute gearing, profile curvature, contact pressure
Citation
Analysis of the influence of the displacement of the gear rack profile of the pair evolution gearing on the quality indicators of the transmission / Roman Protasov, Ľuboš Magdolen, Jan Danko, Olena Lanets, Borys Vorontsov // Ukrainian Journal of Mechanical Engineering and Materials Science. — Lviv : Lviv Politechnic Publishing House, 2023. — Vol 9. — No 2. — P. 66–74.