A New Approach To Design Multi-Stage Gear Drives Using Simulated Annealing Algorithm

Abstract

The research on the design of gear drives is mainly focused on dimensional design of single-stage gear drives. Recently, however, the need for designing multi-stage gear drives has been increased with more applications of the gear drives in high speed and small space. The design of multi-stage gear drives is a time-consuming process, because it includes some more complicated problems that are not needed to consider in the design of single-stage gear drives. The design problems include not only dimensional design but also configuration design; we have to determine number of reduction stages, to set gear ratios and to configure gear drive elements. There is no definite rule or principle for these types of design problems. Thus the design practices largely depend on the ‘sense’ and the experiences of the designer (mostly done by trial and error).

We propose a new and generalized design algorithm to support designer at the preliminary design phase of multi-stage gear drives, which integrates dimensional design and configuration design process. The proposed design algorithm consists of four steps. In the first step, the user determines number of reduction stages. In the second step, gear ratios of every stage are determined using random search method, and the ratios are used as the basic input for dimensional design of gears in the next step. The dimensions of gears are determined in the third step using generate and test method. The strength and durability of each gear is guaranteed by the bending strength and pitting resistance rating practices using AGMA rating formulas. In the final step, configuration design is carried out using simulated annealing algorithm; the positions of gears and shafts are determined to minimize the geometrical volume (size) of a gearbox while avoiding interferences between them. These steps are carried out iteratively until a desirable solution is acquired.

In order to validate the availability, the proposed design algorithm is applied to the preliminary design of 4-stage gear drives. The design solution shows considerably good results in both aspects of dimensional and configuration design.