Reduction of Vibration in Spur Gears by an Asymmetric Tooth Profile With High Contact Ratio

2017 ◽  
Author(s):  
Ryo Fujikawa ◽  
Kiyotaka Ikejo ◽  
Soichi Ibaraki ◽  
Kazuteru Nagamura
Keyword(s):  
Thrust Force ◽  
Spur Gear ◽  
Tooth Profile ◽  
Spur Gears ◽  
Gear Pair ◽  
Contact Ratio ◽  
Mesh Stiffness ◽  
Gear Drive ◽  
Gear Drives ◽  
Helical Gear Pair

Gear drive is a mechanism transmitting a power and a motion through the teeth contact. The number of teeth in contact changes during a mesh cycle. That raises a discontinuity of the mesh stiffness, and causes a gear vibration. The discontinuity implies a direct relationship with the contact ratio of the gear pair. In general, the high contact ratio more than two decreases the discontinuity of the mesh stiffness. Therefore, the increase of the contact ratio is able to reduce the vibration and the noise in the gear drives. An adoption of a helical gear pair is a method to obtain two or more contact ratio. However, that provides a thrust force and a difficulty to machine and assemble. For a spur gear pair, though it is possible to increase the contact ratio by stretching the tooth depth, the tooth thickness may reduce or be excessively sharp at the tooth tip on the addendum circle. In this study, we designed and made a high contact ratio spur gear pair with an asymmetric tooth profile. The gear pair has a large tooth depth to increase the contact ratio, and the asymmetric tooth profile to prevent the sharpness of tooth at the tip circle. In the running test, the vibration and the noise were measured. Consequently, we succeeded in a reduction of vibration and noise in spur gear drives with the asymmetric tooth profile.

Prediction of Spur Gear Mesh Stiffness Associated with the Tooth Corrosion

2015 ◽  
Vol 799-800 ◽  
pp. 570-575
Author(s):  
Zheng Min Qing Li ◽  
Qing Bin Zhao ◽  
Xiao Zhen Li
Keyword(s):  
Spur Gear ◽  
Mesh Stiffness ◽  
Gear Mesh ◽  
Gear Drive ◽  
Corrosion Effect ◽  
Proposed Model ◽  
Stiffness Model ◽  
The Stability ◽  
Gear Drives ◽  
Gear Mesh Stiffness

In this study, a mesh stiffness model of spur gear drives considering the tooth corrosion effect, which is based on Ishikawa model, is proposed. The fidelity of mesh stiffness based on the proposed model is checked by comparing the result with a benchmark result from the reference and the effect of the tooth corrosion on mesh stiffness is analyzed. The prediction indicates mesh stiffness is insensitive to the tooth corrosion, but this conclusion has a signification for assessing the stability of inherent properties of a spur gear drive when the tooth corrosion is produced.

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.

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.

Mesh stiffness evaluation of an internal spur gear pair with tooth profile shift

2016 ◽  
Vol 59 (9) ◽  
pp. 1328-1339 ◽  
Author(s):  
ZaiGang Chen ◽  
WanMing Zhai ◽  
YiMin Shao ◽  
KaiYun Wang
Keyword(s):  
Spur Gear ◽  
Tooth Profile ◽  
Gear Pair ◽  
Mesh Stiffness ◽  
Stiffness Evaluation

Estimation of loss factor based on the load share model in improved bending strength spur gear drive system

2020 ◽  
Vol 235 (1) ◽  
pp. 33-45
Author(s):  
R Ravivarman ◽  
R Prabhu Sekar
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Loss Factor ◽  
Bending Strength ◽  
Spur Gear ◽  
Gear Pair ◽  
Gear Drive ◽  
Root Region ◽  
Share Model ◽  
Gear Drives

This paper demonstrates the prediction of loss factor for non-standard gear drives with equal stresses in the root region of the pinion and wheel. This implementation of equal stresses in the root region is achieved in the described model of a spur gear drive with higher transmission ratio using non-standard rack cutter. The aim is to discover the optimal modification point in the tooth profile by varying values of tooth thickness with at most balanced stresses in the gear pair considered for the study. A loss factor is predicted along the path of contact for a complete meshing cycle using finite element method. This paper studies and compares the distinct models and thereby identifies the suitable and appropriate models. The predicted loss factor includes the distribution of load sharing effect during the meshing which is excluded in the compared models. The gear pair is analyzed, and the loss factor is predicted for influence over the major drive parameters. It was observed that the approach employed facilitate substantial enhancement in the efficiency which is confined by the detailed parametric study and numerical simulation of the balanced stresses in the drive.

Comparison on torsional mesh stiffness and contact ratio of involute internal gear and high contact ratio internal gear

2019 ◽  
Vol 234 (7) ◽  
pp. 1423-1437
Author(s):  
Yanzhong Wang ◽  
Delong Dou ◽  
E Shiyuan ◽  
Jianjun Wang
Keyword(s):  
Spur Gear ◽  
Finite Element Models ◽  
Contact Ratio ◽  
Mesh Stiffness ◽  
Gear Drive ◽  
Single Tooth ◽  
Dimensional Finite Element ◽  
Internal Gear ◽  
Tooth Pair ◽  
Input Torque

The mesh stiffness and contact ratio of gear drive are very important factors which have a great impact on the dynamic load. Contact ratio also affects the fluctuation and the mode of change of the mesh stiffness. In this research, a novel high contact ratio internal gear with a circular arc contact path is introduced. However, the irregular tooth profile of non-involute gear usually causes the numerical calculation to be more complex. To get the torsional mesh stiffness of a pair of internal spur gear, the two-dimensional finite element models of involute internal gear and high contact ratio internal gear are presented and compared. In addition, the influence of input torque on torsional mesh stiffness and contact ratio are analyzed. The mesh stiffness of a single tooth pair and the effect of different engagement positions on mesh stiffness are obtained and compared. Finally, experimental measurement of contact ratio is established by strain gauge technique. It is shown that the torsional mesh stiffness increases with the increase of input torque, and the greater the contact ratio, the smoother the gear drive.

The Synthesis of Tooth Profile Shapes and Spur Gears of High Load Capacity

1970 ◽  
Vol 92 (3) ◽  
pp. 543-551 ◽  
Author(s):  
A. O. Lebeck ◽  
E. I. Radzimovsky
Keyword(s):  
Bending Strength ◽  
Load Capacity ◽  
High Capacity ◽  
High Hardness ◽  
Spur Gear ◽  
Speed Ratio ◽  
Spur Gears ◽  
Gear Pair ◽  
Contact Ratio ◽  
High Load Capacity

In this work a method is presented for the synthesis of high capacity noninvolute spur gears and tooth profiles. Two gear capacity criteria are used in the synthesis: (1) the capacity based on maximum allowable Hertz stress and (2) the capacity based on the bending strength of the tooth. These capacity criteria are related to a generalized noninvolute gear geometry which includes the factors number of teeth and contact ratio. It was found that there are certain optimal relationships which exist among the noninvolute parameters which lead to a solution, for a maximum capacity noninvolute gear pair. For a speed ratio of one to five it was found that a significant capacity advantage exists for the synthesized noninvolute gear pair (compared to a 20-deg involute spur gear pair) for moderate as well as high hardness values. For a speed ratio of one to one a capacity advantage was found for moderate hardness but the advantage decreased significantly for high hardness.

A Dynamic Model for Addendum Modified Gear Pair

1994 ◽  
Author(s):  
Jao-Hwa Kuang ◽  
John Yu
Keyword(s):  
Dynamic Load ◽  
Spur Gear ◽  
Friction Model ◽  
Time Varying ◽  
Spur Gears ◽  
Gear Pair ◽  
Load Modeling ◽  
Mesh Stiffness ◽  
Load Response ◽  
Fundamental Resonance Frequency

Abstract This investigation presents a dynamic tooth load analysis of spur gear pair with addendum modification. The time varying mesh stiffness and Dowson’s tooth friction model are employed in this dynamic tooth load modeling. The effects of various magnitudes of the addendum modification on the fundamental resonance frequency and dynamic load response of the engaged gear pair are analyzed. A particular emphasis has been placed on the effect of addendum modification on the dynamic load of spur gears.

The Torque Responses in Spur Gearing

1998 ◽  
Author(s):  
Ah-Der Lin ◽  
Jao-Hwa Kuang
Keyword(s):  
Fourier Expansion ◽  
Spur Gear ◽  
Time Varying ◽  
Gear Pair ◽  
Contact Ratio ◽  
Mesh Stiffness ◽  
Frequency Spectra ◽  
Stiffness Model ◽  
Close Form ◽  
Input Torque

Abstract In this study, the frequency spectra of a meshing spur gear pair are derived. A two-step mesh stiffness model is assumed to account for the time varying stiffness during the teeth engagement. The analytic load of this simplified gear pair system is used to derive the corresponding Fourier expansion series of the transmitted torque in close form solutions. Numerical results have shown that the frequency spectra of the transmitted torque are dominated by the mesh stiffness alternation and the contact ratio of a gear pair. Furthermore, the amplitude modulation introduced by a harmonic input torque has also been investigated.

Optimization of fillet stress to enhance the bending strength through non-standard high contact ratio spur gears

2015 ◽  
Vol 230 (7-8) ◽  
pp. 1139-1148 ◽  
Author(s):  
P Marimuthu ◽  
G Muthuveerappan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Parametric Study ◽  
Bending Strength ◽  
Spur Gear ◽  
Gear Ratio ◽  
Spur Gears ◽  
Contact Ratio ◽  
Element Analysis ◽  
Gear Drives

The present study aims to determine the improvement in the bending strength of the non-standard high contact ratio spur gears based on the balanced (optimum) fillet stress of the pinion and gear. The average number teeth in contact is more than two for high contact ratio gear drives. In the non-standard high contact ratio spur gears, the rack cutter tooth thickness factor is more than 0.5, whereas the standard rack cutter tooth thickness factor is 0.5. The maximum fillet stresses of the pinion and gear is not equal for non-standard high contact ratio spur gear drives when the gear ratio increases. In order to avoid the fatigue failure of the gear, the fillet stresses of the pinion and gear should be balanced. This balanced stress is predicted as the optimum fillet stress. Hence, the present study focuses to optimize the fillet stress with respect to the rack cutter tooth thickness factor of the pinion and gear through finite element analysis. Also, a parametric study is carried out to obtain the influence of some gear parameters, such as gear ratio, teeth number in the pinion, pressure angle, addendum height and corrected gear drives (S+, S− and So) on the optimum fillet stress with respect to the rack cutter tooth thickness factor of the pinion and gear.

Sign in / Sign up

Export Citation Format

Share Document