A heuristic synthesis of multistage planetary gearbox layout for automotive transmission

Abstract

The automatic transmission system is very crucial for the high-speed vehicles, where the planetary or epicyclic gearbox is a standard feature. With the increase in design intricacies of planetary gearbox, mathematical modelling has become complex in nature and therefore there is a need for modelling of multistage planetary gearbox including the shifting scheme. A random search-based synthesis of three degrees of freedom (DOF) high-speed planetary gearbox has been presented in this paper, which derives an efficient gear shifting mechanism through designing the transmission schematic of eight speed gearboxes compounded with four planetary gear sets. Furthermore, with the help of lever analogy, the transmission power flow and relative power efficiency have been determined to analyse the gearbox design. A simulation-based testing and validation have been performed which show the proposed model is efficient and produces satisfactory shift quality through better torque characteristics while shifting the gears. A new heuristic method to determine suitable compounding arrangement, based on mechanism enumeration, for designing a gearbox layout is proposed here. An important finding on automotive gear shift quality due to closer gear ratio is also reported in this work.

Modeling for design simplification and power-flow efficiency improvement in an automotive planetary gearbox: A case example

“…According to this method, the power flow efficiency should be greater than 90 % for a feasible design of the gear ratio. The use of this formula for gearbox enumeration can befound in [32] and [10]. The mathematical expression for the power flow efficiency is provided in Equation (2).…”

Remaining Useful Life Prediction of a Planetary Gearbox Based on Meta Representation Learning and Adaptive Fractional Generalized Pareto Motion

“…A schematic diagram of a planetary gearbox can be seen in Figure 3 [5]. In the planetary gearbox, there are multiple planet gears simultaneously meshing with the sun and ring gears.…”

“…Considering the unit-tounit variability and measurement error, [15] proposed a Brownian-motion-based RUL prediction model. A schematic diagram of a planetary gearbox can be seen in Figure 3 [5]. In the planetary gearbox, there are multiple planet gears simultaneously meshing with the sun and ring gears.…”

“…In the planetary gearbox, there are multiple planet gears simultaneously meshing with the sun and ring gears. The common cause for a planetary gearbox failure is a gear tooth fatigue crack A schematic diagram of a planetary gearbox can be seen in Figure 3 [5]. In the planetary gearbox, there are multiple planet gears simultaneously meshing with the sun and ring gears.…”