Estimation of tooth form factor for normal contact ratio asymmetric spur gear tooth

2015 ◽  
Vol 90 ◽  
pp. 187-218 ◽  
Author(s):  
R. Prabhu Sekar ◽  
G. Muthuveerappan
Keyword(s):  
Form Factor ◽  
Gear Tooth ◽  
Spur Gear ◽  
Contact Ratio ◽  
Normal Contact ◽  
Tooth Form

scholarly journals Selection of Pressure Angle based on Dynamic Effects in Asymmetric Spur Gear with Fixed Normal Contact Ratio

2019 ◽  
Vol 69 (3) ◽  
pp. 303-310
Author(s):  
Benny Thomas ◽  
K. Sankaranarayansamy ◽  
S. Ramachandra ◽  
Suresh Kumar S.P.
Keyword(s):  
Gear Tooth ◽  
Transmission Error ◽  
Spur Gear ◽  
Dynamic Factor ◽  
Spur Gears ◽  
Contact Ratio ◽  
Normal Contact ◽  
Pressure Angle ◽  
Side Pressure ◽  
Static Transmission Error

Asymmetric spur gears are finding application in many fields including aerospace propulsion and automobile which demand unidirectional or relatively higher load on one side of the gear flank. Design intend to maximise the load carrying capacity of the drive side of asymmetric gear by increasing the pressure angle is achieved at the expense of coast side capacity. Multiple solution for coast to drive side pressure angle exist for a given contact ratio and each of these have relative merits and demerits. In the present work asymmetric spur gears of theoretically equal contact ratio as that of corresponding symmetric gears are selected to investigate the change in gear tooth static transmission error and dynamic behaviour with coast and drive side pressure angle. Study shows that dynamic factor of normal contact ratio asymmetric spur gears below resonance speed are relatively lower than corresponding symmetric gears of same module, contact ratio, number of teeth, coast side pressure angle and fillet radii. Results also show that, coast and drive side pressure angle can be suitably selected for a given contact ratio to reduce the single tooth and double tooth contact static transmission error and dynamic factor of asymmetric spur gears.

Further Evaluation of Spur Gear Tooth Profile Designs Used in Heavily Loaded Transmissions

2011 ◽  
Author(s):  
Nihat Yıldırım ◽  
Hakan I˙s¸c¸i ◽  
Abdullah Akpolat
Keyword(s):  
Gear Tooth ◽  
Transmission Error ◽  
Spur Gear ◽  
Tooth Profile ◽  
Design Parameters ◽  
Preference Order ◽  
Spur Gears ◽  
Tooth Root ◽  
Contact Ratio ◽  
Practical Applications

Aerospace applications require special procedures for component design and manufacturing. Spur gears of different designs, because of their simpler geometries, are used in vital units-transmissions of helicopters and alike aerospace vehicles. In this study, performances of various profile designs of previously researched low and high contact ratio spur gears with some realistic design parameters are studied. Effects of the realistic parameters of variable tooth pair stiffness, relief shape, and adjacent pitch error on Transmission Error (TE), tooth loads and root stresses are presented; composition of these parameters determines the efficiency of the gearbox assembly. Detail of minimization of tooth root stress through optimized/proper design of relief is described. More comprehensive comparison of the gear tooth profile design cases is done to be able to guide aerospace transmission designers for practical applications with realistic parameters for each of the design cases. A preference order is done among the design cases, depending on effect of some design parameters on the results such as tooth loads, tooth root stresses, TE curves and peak-to-peak TE values.

A Method for Determining the AGMA Tooth Form Factor from Equations for the Generated Tooth Root Fillet

1986 ◽  
Vol 108 (2) ◽  
pp. 270-279 ◽  
Author(s):  
M. A. Lopez ◽  
R. T. Wheway
Keyword(s):  
Form Factor ◽  
Iterative Procedure ◽  
Gear Tooth ◽  
Critical Section ◽  
Tooth Root ◽  
Bending Stress ◽  
Tooth Form ◽  
Computer Generation ◽  
Tooth Section

The determination of the AGMA tooth form factor requires that the dimensions of the critical tooth section, at which the maximum bending stress is deemed to occur, be found. Critical section dimensions have traditionally been measured from a scaled generated layout of the tooth profile. The layout procedure, however, requires very careful drafting, and even then it is difficult to achieve really satisfactory accuracy because of the complex operations required to produce the fillet curve, with the added difficulty of estimating the point of tangency with the Lewis iso-bending stress parabola. Although a number of analytical methods are available for computing the critical section dimensions, their solution has generally been cumbersome, or convergence on the correct solution remained a problem. This paper presents equations for the gear tooth root fillet curve which have been derived from an analysis of the relative motion between a rack cutter and gear tooth during the generating cycle. An improved iterative procedure is used to find the critical tooth section dimensions from these equations. A further application of the root fillet equations, which is also covered, is in the computer generation of tooth profiles for assessment of the final tooth shape.

Influence of Pressure Angle on Load Sharing Based Stresses in Asymmetric Normal Contact Ratio Spur Gear Drives

2013 ◽  
Vol 465-466 ◽  
pp. 1229-1233 ◽  
Author(s):  
P. Marimuthu ◽  
G. Muthuveerappan
Keyword(s):  
Parametric Design ◽  
Load Sharing ◽  
Spur Gear ◽  
Contact Model ◽  
Contact Ratio ◽  
Element Analysis ◽  
Normal Contact ◽  
Gear Teeth ◽  
Pressure Angle ◽  
Gear Drives

The aim of this paper is to investigate the influence of pressure angle on drive and coast sides in conventional design asymmetric normal contact ratio spur gear, considering the load sharing between the gear teeth pair. The multi pair contact model in finite element analysis is used to find the load sharing ratio and respective stresses. It has been found out that the predictions through multipoint contact model are in good agreement with the available literature. A unique Ansys parametric design language code is developed for this study. It is found that, the maximum fillet stress decreases up to the threshold point for drive side (35o) and coast side (25o) pressure angles, beyond this point it increases. The load share based maximum fillet and contact stresses are lower in the high pressure angle side than that of the low pressure angle side, when it is loaded at the critical loading points.

Search method applied for gear tooth bending stress prediction in normal contact ratio asymmetric spur gears

2018 ◽  
Vol 232 (24) ◽  
pp. 4647-4663 ◽  
Author(s):  
Benny Thomas ◽  
K Sankaranarayanasamy ◽  
S Ramachandra ◽  
SP Suresh Kumar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Gear Tooth ◽  
Search Method ◽  
International Organization ◽  
Spur Gears ◽  
Bending Stress ◽  
Contact Ratio ◽  
Element Analysis ◽  
Normal Contact

Various analytical methods have been developed by designers to predict gear tooth bending stress in asymmetric spur gears with an intention to improve the accuracy of predicted results and to reduce the need for time consuming finite element analysis at the early stages of gear design. Asymmetry in the drive and coast side of asymmetric spur gears poses difficulty in direct application of well-known procedures like American Gear Manufacturers Association and International Organization for Standardization in the prediction of gear tooth bending stress. In earlier works, ISO-6336-3 methodology was suitably modified and adapted to predict asymmetric spur gear tooth bending stress. This approach is based on certain assumptions on the location of critical section which could introduce error in the predicted maximum bending stress. The present work is to analytically predict gear tooth bending stress in normal contact ratio asymmetric spur gears based on a more rigorous analytical approach. This includes a fundamental study on the gear tooth orientation used to define the coordinate system, determination of maximum bending stress by search along the fillet profile and to obtain stress profile along the fillet. Gear tooth bending stress obtained from the present work using Search method is compared against the results obtained from earlier adapted International Organization for Standardization method and Finite Element Analysis. This study recommends a new coordinate system and method for analytical prediction of gear tooth bending stress in normal contact ratio asymmetric spur gears.

scholarly journals Geometry and design of spur gear drive associated with low sliding ratio

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110125
Author(s):  
Wei Sheng ◽  
Zhengminqing Li ◽  
Hong Zhang ◽  
Rupeng Zhu
Keyword(s):  
Gear Tooth ◽  
Tooth Wear ◽  
Spur Gear ◽  
Transmission Efficiency ◽  
Contact Ratio ◽  
Gear Drive ◽  
Solid Models ◽  
Tooth Surfaces ◽  
The Relationship ◽  
Cubic Function

The relative sliding between tooth surfaces is the main cause of tooth wear and power loss, which directly affects the transmission efficiency and durability of gear. The aim of this paper is to provide a method to design such spur gear with low sliding ratio (LSR). Based on kinematics, differential geometry and contact path, the general mathematical models of the generating rack, the pinion and the mating gear tooth profiles are established in turn. Then, according to the relationship between the contact path and sliding ratio, a contact path described by a cubic function is proposed to construct a spur gear drive with low sliding ratio. In order to ensure the continuity of action and non-interference, solid models of the mated gear pair are established, and the motion simulation is carried out by an example. Moreover, the effects of the contact path function coefficients on sliding ratio, tooth shape, and contact ratio are analyzed. Meshing efficiency and tooth wear of LSR gear drive are evaluated by comparing with those of the involute gear drive. The results show that, this LSR spur gear drive has higher transmission efficiency and better anti-wear performance.

Enhancement of wear resistance on normal contact ratio spur gear pairs through non-standard gears

Wear ◽  
2017 ◽  
Vol 380-381 ◽  
pp. 228-239 ◽  
Author(s):  
R. Prabhu Sekar ◽  
R. Sathishkumar
Keyword(s):  
Wear Resistance ◽  
Spur Gear ◽  
Contact Ratio ◽  
Normal Contact
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