Tooth Profile Modifications for Optimum Dynamic Load in Spur Gears Based on Pseudo-Interference Stiffness Estimation Method

2005 ◽  
Author(s):  
Monsak Pimsarn ◽  
Kazem Kazerounian
Keyword(s):  
Contact Stress ◽  
Gear Tooth ◽  
Estimation Method ◽  
Spur Gear ◽  
Rigid Body Dynamics ◽  
Gear System ◽  
Hertzian Contact ◽  
Bending Fatigue ◽  
Gear Mesh ◽  
Hertzian Contact Stress

A systematic methodology combining optimization, three dimensional analytical rigid body dynamics and a novel method, namely, Pseudo-Interference Stiffness Estimation method (PISE) [1]- [2], is proposed to dramatically reduce gear design time and improve the spur gear system dynamic performance. The main aim of this methodology is to search for the pro les of tooth crowning and shaving that eventually lead to the optimum dynamic tooth load in the gear mesh. An example of the detailed design study is numerically investigated. The results show that the dynamic tooth load can be reduced to up to 50 percent of its original value. However, this reduction is only valid at the operating ranges of the design load and design speed. It is also found that the effect of pro le modi cation on the dynamic response of the gear system was mostly observed to be a reduction in the peak dynamic tooth load at the resonance speed. Later, the investigation of gear tooth durability was conducted to validate an improvement of gear life. The rating factors given in AGMA publication, Hertzian contact stress, bending fatigue stress, ash temperature and PV index are employed in gear durability determination. The results show that, with the reduction of 50 percent in dynamic tooth load, the reductions in PV index, bending fatigue, Hertzian contact stress, and ash temperature can be achieved up to 64, 58, 28 and 39 percent, respectively.

scholarly journals Design And Analysis Of An Open Differential

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Subhajit Konar ◽  
Vijay Gautam
Keyword(s):  
Contact Stress ◽  
Rear Wheel ◽  
Gear System ◽  
Hertzian Contact ◽  
Differential Motion ◽  
Differential Gear ◽  
Wheel Drive ◽  
Hertzian Contact Stress ◽  
Left And Right ◽  
Good Agreement

An automobile differential gear system is used to establish a differential motion between left and right driving axle which provides a smooth turning of the vehicle. When a vehicle takes a turn then the wheels at outermost position requires to cover a large distance than that of the innermost wheels. This speed variation can be achieved by using a differential gear system. It also transmits the power from the propeller shaft to each axle. A rear wheel drive vehicle requires a differential at the rear axle while all-wheel drive vehicle requires differential gear system for each and every axle. In this paper, an open differential is designed for a leading automobile and analysed the ability to work without failure. The analysis was done using the modified Lewis equation, Hertzian contact stress equation and AGMA equations. The analytical results were compared with results obtained by FEA. It is observed that results obtained from Lewis criterion are more conservative as compared to AGMA. The results obtained from modified Lewis, Hertzian contact stress and AGMA are in good agreement with the results obtained from FEA.

Evaluation of Mechanical and Thermal Stresses in Polymer Gear Teeth through Simulation Approach

2013 ◽  
Vol 302 ◽  
pp. 468-473 ◽  
Author(s):  
Per Lindholm ◽  
Jian Qin
Keyword(s):  
Thermal Properties ◽  
Thermal Stresses ◽  
Material Selection ◽  
Gear Tooth ◽  
Gear Wheel ◽  
Spur Gear ◽  
Contact Forces ◽  
Mechanical And Thermal Properties ◽  
Gear Mesh ◽  
Tensional Stress

One way to achieve lightweight and lubricant-free drive train is, among others, to convert conventional steel to polymer composite materials. This paper describes a part of this endeavor by taking a spur gear pair as a study object. One of the steel gear wheel is replaced with three different materials including Victrex PEEK 650G, Victrex PEEK 650CA30 and Luvocom PEEK 1105-8165 while keeping the gear geometry unchanged. Mechanical stresses and thermal properties are two major criteria for material selection at this stage. Therefore carbon fiber filled PEEK (Victrex PEEK 650CA30) and PEEK filled with thermal conductive minerals (Luvocom 1105-8165) are chosen to benchmark each of the criterion. The evaluation is done by modeling the gear mesh and analyzing the contact forces and heat generated in the gear tooth. The results show surface temperature on the tooth flanks, root tensional stress and contact pressure during the tooth mesh. The work suggests a guideline of materials selection. Depending on actual application a compromisation between mechanical and thermal properties often needs to be considered within the tolerance boundary in order to obtain optimized results. This work only deals with material selection. Gear design such as optimization of tooth geometry for polymer gears is out of the scope of this study and will not be discussed.

Dynamic Analysis of Gear Mesh for Gear Pump Based on ANSYS Workbench

2013 ◽  
Vol 706-708 ◽  
pp. 1290-1293 ◽  
Author(s):  
Lei Zhao ◽  
Qing Qing Lv ◽  
Li Quan Yang
Keyword(s):  
Contact Stress ◽  
Gear Tooth ◽  
Corrosion Damage ◽  
Structure Design ◽  
Gear Pump ◽  
Three Dimension ◽  
Tooth Contact ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Ansys Workbench

Based on the FEA software ANSYS Workbench, the soft body dynamics performance of the gear pump gear mesh of a hydraulic pump company was analyzed. In the practical engineering applications, gear pump gear teeth are effected by alternating pressure in the two working cavity. It can cause pitting corrosion damage for gear tooth, and even cause tooth crack and fracture. At first, a three dimension finite element models of the gear pump gear teeth was established. In the start-up process, the gear pump tooth mesh deputy of tooth contact stress strain and dynamic characteristics of gear teeth was analyzed. Obtain the velocity curves, acceleration curve and tooth contact stress and strain dynamic curves of the tooth of gear pump. Providing a new analysis method for gear pump of gear Structure design and having a practical application value.

Planar Tooth Profile Synthesis for Relative Curvature

2017 ◽  
Author(s):  
Zhiyuan Yu ◽  
Kwun-Lon Ting
Keyword(s):  
Contact Stress ◽  
Tooth Profile ◽  
Hertzian Contact ◽  
Rolling Motion ◽  
Special Cases ◽  
Systematic Methodology ◽  
Hertzian Contact Stress ◽  
Curvature Theory ◽  
The Given ◽  
Tooth Pair

This paper is the first that uses the new conjugation curvature theory [1] to directly synthesize conjugate tooth profiles with the given relative curvature that determines the Hertzian contact stress. Conjugation curvature theory offers a systematic methodology to synthesize the relative curvature for a tooth pair. For any given relative curvature between the contact tooth profiles, a generating point can be located on an auxiliary body. Under the rolling motion among the pinion pitch, the gear pitch and the pitch on the auxiliary body, the generating point will trace fully conjugate profiles on the pinion and gear bodies with the given relative curvature at the instant of the contact. Full conjugation throughout the contact of the profiles is guaranteed with the three instant centers remaining coincident [1]. The methodology is demonstrated with a planar tooth profile synthesis with given relative curvature. One may find that the Wildhaber-Novikov tooth profile, which is known to have low relative curvature and Hertzian contact stress, and its variations become special cases under such methodology.

scholarly journals Optimal Tooth Numbers for Compact Standard Spur Gear Sets

1982 ◽  
Vol 104 (4) ◽  
pp. 749-757 ◽  
Author(s):  
M. Savage ◽  
J. J. Coy ◽  
D. P. Townsend
Keyword(s):  
Optimal Design ◽  
Objective Function ◽  
Design Space ◽  
Spur Gear ◽  
Gear Ratio ◽  
Contact Ratio ◽  
Bending Fatigue ◽  
Gear Mesh ◽  
Compact Design ◽  
Center Distance

The design of a standard gear mesh is treated with the objective of minimizing the gear size for a given ratio, pinion torque, and allowable tooth strength. Scoring, pitting fatigue, bending fatigue, and the kinematic limits of contact ratio and interference are considered. A design space is defined in terms of the number of teeth on the pinion and the diametral pitch. This space is then combined with the objective function of minimum center distance to obtain an optimal design region. This region defines the number of pinion teeth for the most compact design. The number is a function of the gear ratio only. A design example illustrating this procedure is also given.

Hertzian Contact-Stress Deformation Coefficients

1969 ◽  
Vol 36 (2) ◽  
pp. 296-303 ◽  
Author(s):  
Duane H. Cooper
Keyword(s):  
Contact Stress ◽  
Digital Computer ◽  
Approximate Calculation ◽  
Transcendental Equation ◽  
Contact Stresses ◽  
Elliptic Integrals ◽  
Hertzian Contact ◽  
Stress Deformation ◽  
Hertzian Contact Stress

Formulations are given for the coefficients λ, μ, ν defined by Hertz in terms of the solution of a transcendental equation involving elliptic integrals and used by him to describe the deformation of bodies subjected to contact stresses. Methods of approximate calculation are explained and errors in the tables prepared by Hertz are noted. For the purpose of providing a more extensive and more accurate tabulation, using an automatic digital computer, these coefficients are reformulated so that a large part of the variation is expressed by means of easily interpreted elementary formulas. The remainder of the variation is tabulated to 6 places for 100 values of the argument. Graphs of the coefficients are also provided.

Optimization of Tooth Bending Fatigue Characteristics of Spur Gear Pairs Using a Gear Dynamics-Based Approach

2015 ◽  
Author(s):  
Yalın Öztürk ◽  
Ender Ciğeroğlu ◽  
H. Nevzat Özgüven
Keyword(s):  
Fatigue Life ◽  
Gear Tooth ◽  
Spur Gear ◽  
Bending Fatigue ◽  
Gear Dynamics ◽  
Optimization Study ◽  
Fatigue Life Estimation ◽  
Fatigue Characteristics ◽  
Profile Optimization ◽  
Operational Range

A gear tooth profile optimization study is performed with the target being defined as the maximization of tooth bending fatigue life for a selected operational range, where the operating torque and speed ranges are defined along with their corresponding durations. For this purpose, a nonlinear lumped gear dynamics model is combined with the S/N curve of the gear material in order to estimate tooth bending fatigue life of the spur gear pair. The differences between the predicted lives of the optimally modified and non-modified gear pairs are presented based on example spur gear pairs. The proposed tooth bending fatigue life estimation is compared with the standard AGMA procedure.

On Dynamic Tooth Load and Stability of a Spur-Gear System Using the State-Space Approach

1985 ◽  
Vol 107 (1) ◽  
pp. 54-60 ◽  
Author(s):  
A. S. Kumar ◽  
T. S. Sankar ◽  
M. O. M. Osman
Keyword(s):  
State Space ◽  
Dynamic Load ◽  
Initial Conditions ◽  
Gear Tooth ◽  
Spur Gear ◽  
The State ◽  
Gear System ◽  
Computational Time ◽  
Steady State Condition ◽  
The Stability

In this study, a new approach using the state-space method is presented for the dynamic load analysis of spur gear systems. This approach gives the dynamic load on gear tooth in mesh as well as information on the stability of the gear system. Also a procedure is given for the selection of proper initial conditions that enable the steady-state condition to be reached faster, conditions that result in considerable savings in computational time. The variations in the dynamic load with respect to changes in contact position, operating speed, backlash, damping, and stiffness are also investigated. In addition, the stability of the gear system is studied, using the Floquet theory and the well-known stability conditions of difference systems.

Tooth Surface Fatigue Strength of Normalized Steel Conical Involute Gears

2000 ◽  
Author(s):  
Tatsuya Ohmachi ◽  
Koji Iizuka ◽  
Hidenori Komatsubara ◽  
Ken-ichi Mitome
Keyword(s):  
Fatigue Strength ◽  
Contact Stress ◽  
Testing Machine ◽  
Hertzian Contact ◽  
Tooth Surface ◽  
Paper Test ◽  
Surface Fatigue ◽  
Involute Gears ◽  
Conical Gears ◽  
Hertzian Contact Stress

Abstract The tooth surface fatigue strength of the conical involute gear is evaluated in this paper. Test gears are straight intersecting-axis conical gears. The material of the test gear is normalized steel. The power circulating testing machine is used in this experiment. The circulating torque is kept constant and the number of times of contact is 107. The tooth surface life is evaluated by the pitting area rate. The critical value of the circulating torque is found between 147 N·m and 157 N·m. For critical torque, the pitting area rate does not progress over 4%. The Hertzian contact stress of the test gear is calculated at the circulating torque. The contact stress should be evaluated in consideration of the wearing effects.

Sign in / Sign up

Export Citation Format

Share Document