scholarly journals Effect of pressure angle on contact ratio of asymmetric involute spur gear teeth

2014 ◽  
Vol 1 (12) ◽  
Keyword(s):  
Spur Gear ◽  
Contact Ratio ◽  
Gear Teeth ◽  
Effect Of Pressure ◽  
Pressure Angle

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.

scholarly journals Analysis on Meshing Characteristics and Transmission Error of Elliptic Gears

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Changbin Dong ◽  
Yongping Liu ◽  
Yongqiao Wei ◽  
Beibei Yun ◽  
Dawei Li ◽  
...  
Keyword(s):  
Great Influence ◽  
Transmission Error ◽  
Spur Gear ◽  
Analysis Model ◽  
Contact Ratio ◽  
Cylindrical Gear ◽  
Pressure Angle ◽  
Object Based ◽  
Meshing Characteristics ◽  
Eccentricity Error

As an important parameter to distinguish noncircular gear from cylindrical gear, eccentricity is very important for the meshing characteristics and transmission error of noncircular gear. In order to study the transmission characteristics of the elliptic gear, a pair of elliptic gear in the reversing device of a new type of drum pumping was taken as the research object. Based on the analysis of the transmission pressure angle and instantaneous contact ratio of the elliptic gear, the eccentricity error was introduced into the analysis model of transmission error. The influences of the eccentricity on the transmission pressure angle, instantaneous contact ratio, and transmission error were analyzed, and the analysis accuracy is verified by the finite element method. The results show that the eccentricity has a great influence on the transmission pressure angle, instantaneous contact ratio, and transmission error of the elliptic gear, and the eccentricity error has a significant influence on the transmission error. In order to ensure the normal meshing condition of the elliptic gear, the eccentricity should be less than 0.7071, and the maximum instantaneous contact ratio is 1.809. The research results can provide some guidance for the following noncircular spur gear transmission test and transmission error research.

Studies on the Dynamic Performance of a Spur Gear With Hollow Teeth

1992 ◽  
Author(s):  
A. Ramamohana Rao ◽  
B. Srinivasulu
Keyword(s):  
Damping Ratio ◽  
Dynamic Performance ◽  
Spur Gear ◽  
Dynamic Loads ◽  
Response Analysis ◽  
Spur Gears ◽  
Contact Ratio ◽  
Mesh Stiffness ◽  
Direction Parallel ◽  
Gear Teeth

Abstract Performance of spur gears largely depends on the magnitude and nature of variation of dynamic loads occuring between mating teeth. Variable tooth mesh stiffness is one of the primary sources causing parametric excitations resulting in dynamic loads. The usual method of varying the mesh stiffness to reduce dynamic loads is to use high contact ratio and profile modified gears. In this paper, a new type of tooth design to improve the dynamic performance of spur gears is presented. In this, a through hole is drilled in each tooth in a direction parallel to the gear axis. The diameter of the hole and its position on the tooth centre line are variable. Such a gear is called a hollow gear. Dynamic analysis is carried out for the mesh of hollow pinions mating with solid gears. The results are compared with solid pinions (no holes in teeth) meshing with solid gears. Finite element method is used for the analysis. For estimation of the dynamic load variation in hollow-solid and solid-solid gear meshes, a model incorporating the varying mesh stiffness and damping of gear teeth is used. Governing differential equations are solved using unconditionally stable Newmark-beta algorithm. The dynamic loads obtained are used as an input time varying loads for the determination of dynamic fillet and hole stress response of solid and hollow gear teeth whichever is applicable. Modal superposition technique is used for transient response analysis. The study shows that for the same damping ratio, dynamic loads in hollow-solid meshes are nearly the same as in a solid-solid mesh. In reality, the dynamic loads in a hollow-solid mesh are less than a solid-solid mesh due to its inherent higher material damping.

scholarly journals Compliance and Stress Sensitivity of Spur Gear Teeth

1981 ◽  
Vol 103 (2) ◽  
pp. 447-459 ◽  
Author(s):  
R. W. Cornell
Keyword(s):  
Closed Form Solution ◽  
Time History ◽  
Peak Stress ◽  
Spur Gear ◽  
Stress Sensitivity ◽  
Form Solution ◽  
Sensitivity Analyses ◽  
Spur Gears ◽  
Contact Ratio ◽  
Gear Teeth

The magnitude and variation of tooth pair compliance with load position affects the dynamics and loading significantly, and the tooth root stressing per load varies significantly with load position. Therefore, the recently developed time history, interactive, closed form solution for the dynamic tooth loads for both low and high contact ratio spur gears [1] was expanded to include improved and simplified methods for calculating the compliance and stress sensitivity for three involute tooth forms as a function of load position. The compliance analysis is based on Weber [2] and O’Donnell [3] but with an improved fillet/foundation compliance analysis. The stress sensitivity analysis is a modified version of the Heywood method [4] but with an improvement in the magnitude and location of the peak stress in the fillet. These improved compliance and stress sensitivity analyses are presented along with their evaluation using test, finite element, and analytic transformation results, which showed good agreement.

The Undercutting of Hobbed Spur Gear Teeth

1983 ◽  
Vol 105 (1) ◽  
pp. 122-128 ◽  
Author(s):  
R. G. Mitchiner ◽  
H. H. Mabie ◽  
H. Moosavi-Rad
Keyword(s):  
Spur Gear ◽  
Gear Teeth ◽  
Pressure Angle ◽  
Number Of Teeth ◽  
Minimum Number ◽  
Straight Portion ◽  
Base Circle ◽  
Tooth Flank ◽  
General Method

A general method is presented for the determination of the minimum number of teeth that can be cut in a spur gear without undercutting by a rounded-tooth tip hob. The minimum number of teeth to produce undercutting was investigated for three trochoid/tooth-profile relations: (1) trochoid tangent to the involute profile at the base circle, (2) trochoid tangent to a straight portion of the tooth flank, and (3) trochoid intersecting the involute profile at the base circle. It was found that in order to avoid undercutting, the minimum number of teeth cut into a gear occurs when the trochoid is tangent to the involute at the base circle. There is no set of hob parameters such that the trochoid intersects the involute profile at the base circle nor does the case of the trochoid being tangent to a straight flank exist. A set of figures representing the variation of the amount of undercutting versus the number of teeth, radius of hob-tooth tip, hob addendum, cutting pressure angle, and the corresponding derivatives are included for a typical gear.

Influence Gearing Parameters on the Tooth Deformation of Spur Gears

2015 ◽  
Vol 816 ◽  
pp. 27-30 ◽  
Author(s):  
Silvia Medvecká-Beňová ◽  
Peter Frankovský ◽  
Robert Grega
Keyword(s):  
Spur Gear ◽  
Spur Gears ◽  
Gear Teeth ◽  
Pressure Angle ◽  
Number Of Teeth ◽  
Basic Parameters

Gear teeth are deformed due to the load. The tooth deformation of spur gears is not constant for all examined teeth of gears. Tooth deformation is depends on the shape of the teeth, on the basic parameters of examined spur gear, such as the number of teeth, module gearing, pressure angle, gearing width, correction and modification of gearing.

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.

An Evaluation of Stresses and Deflection of Spur Gear Teeth Under Strain

1974 ◽  
Vol 96 (1) ◽  
pp. 85-93 ◽  
Author(s):  
G. Chabert ◽  
T. Dang Tran ◽  
R. Mathis
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Static Load ◽  
Simple Calculation ◽  
Spur Gear ◽  
Spur Gears ◽  
The Finite Element Method ◽  
Gear Teeth ◽  
Pressure Angle ◽  
Maximum Stresses

This paper aims at an evaluation of the stresses induced by a static load applied to gear teeth. For spur gears of different ratios with 20-deg pressure angle and standard addendum proportions, the stresses and deflections are computed by the finite element method. Formulas are drawn allowing a simple calculation of the maximum stresses, and the results are compared with what is given by ISO and AGMA standards related to the strength of gear teeth.

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