Sinusoidal Gears and Alternative Method of Tooth Generation

Over the last several decades, gearing development has focused on improvements in materials, manufacturing technology and tooling, thermal treatment, and coatings and lubricants. In contrast, gear design methods have remained frozen in time, as the vast majority of gears are designed with standard tooth proportions. This over-standardization signif

Direct Gear Design

The methodological principles for the functional-oriented technological process planning are presented in the article. The introduction of a comprehensive system for ensuring the engineering product’s life cycle requires taking into consideration the operating conditions of the most loaded parts in the product not only at the design engineering stage, but also at the stage of the technology planning. Computer Aided Forming (CAF) system that implements the relationship between the technology of forming products with the conditions of their potential exploitation should be added to the integrated CAD/CAE/CAPP/CAM system. The results of simulation of power, temperature and stress-strain parameters are the basis for developing predictive models of influence of the structure and parameters of the functional-oriented technological process on the formation of the wear parameters and corrosion resistance of the machined product. It is proved that the residual stresses reflect the interference pattern of the fluctuation tensile (frictional and thermal) and compressive (force) loads, the dynamic picture of the deep thermal effects of the formation process and the peculiarities of the structural-phase transformations. It is shown, that the specific value of the strain component of roughness increases as a result of increased cutting speed and reduction of feed, which contributes to the formation of the surface microrelief with significant values of the reduced valley depth. This reduces the concentration of oxide products on the functional surface, resulting in increased product’s corrosion resistance.

Computer-Aided Conception for Planning and Researching of the Functional-Oriented Manufacturing Process

In many gear drives, the tooth load on one flank is significantly higher and is applied for longer periods of time than for the opposite one. An asymmetric tooth shape reflects this functional difference. Design intent of asymmetric gear teeth is to improve performance of the primary drive profiles at the expense of the performance off the opposite coast profiles. The coast profiles are unloaded or lightly loaded during a relatively short work period. Asymmetric tooth profiles also make it possible simultaneously to increase the contact ratio and operating pressure angle beyond the conventional gear limits. The main advantage of asymmetric gears is contact stress reduction on the drive flanks, resulting in higher torque density (load capacity per gear size). The paper presents an application of the Direct Gear Design® method to asymmetric tooth gears. This is an alternative approach to traditional design of involute gears, separating gear geometry definition from the generating (tooling) rack to maximize gear drive performance. The paper describes asymmetric tooth and gear mesh characteristics, limits of asymmetric tooth gearing, tooth geometry optimization, analytical and experimental comparison of symmetric and asymmetric tooth gears, and implementation of gears with asymmetric teeth.

http://www.akgears.com/pdf/Direct%20Gear%20Design%20for%20Asymmetric%20Tooth%20Gears.pdf

Direct Gear Design for Asymmetric Tooth Gears

Improvement of Loading Capacity of Internal Spur Gear With Using Asymmetric Trochoid Profile

The use of the finite element analysis (FEA) is an effective method for studying the surface layer deformation appeared from inherited residual stresses. This paper is devoted to the analysis of the effect of residual stresses to the service properties of parts and the development of a cutting-induced residual stresses simulation using the DEFORM software. The influence of residual stresses on the operational properties of machined parts is investigated. The fatigue strength of the product, which is provided as the result of forming in the cutting process of the surface layer structure, residual stresses and deformations, is used as a criterion for the decision-making about optimal structure and parameters of the functionally-oriented technological process. The causes of the occurrence of machine-induced residual stresses for different workpiece materials have been analyzed. The simulation model of residual machining-induced stresses is described. The functional dependence of the stress-strain state reflects the interference pattern of the frictional, force loads and the variable process of the deep thermal effects. It is proved, that the compression part of this cycle is determined by external load, and tensile—by residual stresses.

Sinusoidal Gears and Alternative Method of Tooth Generation

References

Direct Gear Design

Computer-Aided Conception for Planning and Researching of the Functional-Oriented Manufacturing Process

Direct Gear Design for Asymmetric Tooth Gears

Improvement of Loading Capacity of Internal Spur Gear With Using Asymmetric Trochoid Profile

Simulation Study of Cutting-Induced Residual Stress

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