The Direct Gear Design® approach is one of the many gear designing methods available to improve load carrying capacity of the gear pairs. For customized gear pairs, the direct gear design approach is more advantageous over conventional design. In this paper, a parametric study is carried out for asymmetric high contact ratio spur gears based on load sharing method to determine the improvement in load carrying capacity. A finite element model for multi-pair contact is adopted to determine the non-dimensional fillet and contact stresses which quantify the load carrying capacity of the gear pairs. The results of direct designed symmetric and asymmetric high contact ratio spur gears are compared with the conventional symmetric high contact ratio spur gears. Also, the influence of gear parameters such as addendum pressure angle, gear ratio, teeth number and backup ratio of non-dimensional stresses is analyzed in detail. The results show significant improvement in gear pair performance for all parameters analyzed. © 2015 Elsevier Ltd. All rights reserved.

G. Muthuveerappan

Design

finite element method

Gear teeth

Gears

Load limits

Loads (forces)

CONTACT RATIO

Conventional design

DESIGNING METHODS

GEAR DESIGN

GEAR PARAMETER

Load sharing

Parametric study

PRESSURE ANGLES

SPUR GEARS

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Mechanism and Machine Theory

The aim of this paper is to determine the effect on direct design asymmetric high contact ratio spur gear based on tooth load sharing. A unique Ansys parametric design language code is developed for this study. The load sharing based bending and contact stresses are determined for different drive side contact ratios. In addition to that the location of critical loading point is determined. Because the critical loading point for high contact ratio spur gear not lies on fixed point like normal contact ratio spur gears namely highest point of single tooth contact. In conclusion an increase in drive side contact ratio leads to increase in the load sharing based bending stress and decrease in the contact stress at the critical loading point. © (2014) Trans Tech Publications, Switzerland.

Applied Mechanics and Materials

Effect of drive side contact ratio on direct design asymmetric high contact ratio spur gear based on load sharing

In a given size of symmetric involute gear designed through conventional approach, as the load carrying capacity is restricted at the higher pressure angle due to tipping formation, the use of the asymmetric toothed gear to improve the fillet capacity in bending is examined in this study. Non-standard asymmetric rack cutters with required pressure angles and module are developed to generate the required pinion and gear of a drive with asymmetric involute surfaces and trochoidal fillet profiles. The respective profiles thus generated are optimized for balanced fillet stresses that are equal and possibly the lowest also. For this study of optimization, several non-standard asymmetric rack cutters are designed to accommodate different combinations in the values of pressure angle, top land thickness ratio, profile shift, speed ratio and the asymmetric factors. However for any drive with a given center distance and a speed ratio, only two non-standard asymmetric rack cutters, one for the pinion and other for the gear are used to generate a required numbers of pinion and gear with different cutter shift values for the purpose of optimization. The influence of these parameters on the maximum fillet stress has been analyzed to suggest the optimum values of these parameters that improve the fillet capacity in bending. The optimization of the asymmetric spur gear drive is carried out using an iterative procedure on the calculated maximum fillet stresses through FEM for different rack cutter shifts and finally the optimum values of rack cutter shifts are suggested for the given center distance and the speed ratio of an asymmetric gear drive. Comparisons have also been made successfully with the results of the AGMA and the ISO codes for symmetric gears to justify the results of the finite element method pertaining to this study. © 2007 Elsevier Ltd. All rights reserved.

Optimization of asymmetric spur gear drives to improve the bending load capacity

Extinction and Re-Ignition Predictions Using Eddy Dissipation Concept and Flamelet Generated Manifold Models for a Premixed Piloted Turbulent Jet Burner

Direct Gear Design

Area of Existence of Involute Gears

Investigation of load carrying capacity of asymmetric high contact ratio spur gear based on load sharing using direct gear design approach

Journal	Data powered by TypesetMechanism and Machine Theory
Publisher	Data powered by TypesetElsevier Ltd
ISSN	0094114X
Open Access	No