Contact stress analysis of skew conical involute gear drives in approximate line contact

2009 ◽  
Vol 44 (9) ◽  
pp. 1658-1676 ◽  
Author(s):  
Szu-Han Wu ◽  
Shyi-Jeng Tsai
Author(s):  
S H Wu ◽  
S J Tsai

A novel design for skew conical involute gear drives in approximate line contact is proposed. Such a drive has a contact ellipse with a large major-to-minor-axis ratio, which allows it to overcome the weakness of conical gear drives for application in power transmission. This gearing design approach is characterized by reduced edge contact sensitivity and increased surface durability. The edge contact sensitivity that can arise with this kind of gear drive due to assembly or manufacturing errors is evaluated by analysing the value of the shift of the line of action caused by such errors. The surface durability is evaluated by calculating the Hertz stress. Some guidelines are developed based on the analysis of the influence of the gearing parameters on the edge contact sensitivity and the surface durability made possible using this design approach for conical gear drives in the approximate line contact. The guidelines are summarized and, finally, a practical example is given to demonstrate the feasibility of the approximate line contact design.


Author(s):  
Mircea Napau ◽  
Ileana D. Napau ◽  
Ioan Napau ◽  
Vistrian Maties ◽  
Ana A. Napau-Stoica ◽  
...  

The virtual simulation methods used in the gear industry allow for the prediction of requirements in the gears manufacturing process, as well as, prediction of their mesh before they are manufactured. The aim of this paper is to present an approach regarding the virtual simulation of multi-tooth contact analysis of worm-face gear drives used in the automotive industry. The methods presented in this paper are intended to reduce the process development phase of gearboxes, having as components, worm-face gear drives and thus saving large amounts of time and money. A procedure has been developed in order to simulate the idle multi-tooth contact, in a worm-face gear drive with localized contact, as a combinative algorithm of using a virtual manufacturing method and the power of MathCAD software. Virtual simulation of loaded multi-tooth contact analysis has been carried out together with the contact stress analysis by FEA method using ANSYS software. The FEM models have been developed by Computer Manufacturing Simulation (CMS) method. 3D CAD examples illustrating the idle contact pattern on face gear teeth flanks are presented for both directions of rotation of the driving worm. Numerical results related to the loaded multi-tooth contact analysis and contact stress analysis, respectively, are also provided in order to illustrate the developed approach.


Author(s):  
Layue Zhao ◽  
Robert C Frazer ◽  
Brian Shaw

With increasing demand for high speed and high power density gear applications, the need to optimise gears for minimum stress, noise and vibration becomes increasingly important. ISO 6336 contact and bending stress analysis are used to determine the surface load capacity and tooth bending strength but dates back to 1956 and although it is constantly being updated, a review of its performance is sensible. Methods to optimise gear performance include the selection of helix angle and tooth depth to optimise overlap ratio and transverse contact ratio and thus the performance of ISO 6336 and tooth contact analysis methods requires confirmation. This paper reviews the contact and bending stress predicted with four involute gear geometries and proposes recommendations for stress calculations, including a modification to contact ratio factor Zɛ which is used to predict contact stress and revisions to form factor YF and helix angle factor Yβ which are cited to evaluate bending stress. The results suggest that there are some significant deviations in predicted bending and contact stress values between proposal methods and original ISO standard. However, before the ISO standard is changed, the paper recommends that allowable stress numbers published in ISO 6336-5 are reviewed because the mechanisms that initiate bending and contact fatigue have also changed and these require updating.


2013 ◽  
Vol 57 (1-2) ◽  
pp. 40-49 ◽  
Author(s):  
Seok-Chul Hwang ◽  
Jin-Hwan Lee ◽  
Dong-Hyung Lee ◽  
Seung-Ho Han ◽  
Kwon-Hee Lee

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