Gear Stress Research Articles

An Approximate Algorithm for Shakedown on Gear Contact

A model of gear contact has been established based on Hertz theory. Local coordinates are constructed on different meshing points because curvature of gear profile is not constant and then distributions of residual stresses and strains are given. Upper and lower bounds for the shakedown limits have been obtained. An approximate algorithm based on a stress invariant hypothesis and a stress/strain relaxation procedure is developed to solve residual stresses and strains accumulation in elastic-plastic stress analysis of gear contact. The steady-state residual stresses of gear under repeat meshing are calculated. The results are useful information for the strength design of gear.

Dynamic Analysis of Planetary Mechanism for the Cutting Part of Coal Shearer

The transmission load on planetary gear to the cutting part of coal mining machine is bigger, and the force is uneven stress while the gear driving. In order to solve this problem, and puts forward the coal mining machine cutting part planetary transmission gear contact dynamic meshing analysis method. This paper build entity modeling of coal minning machine cutting part transmission gear by established 2d model by CAXA and import PRO/E, and by using ABAQUS/Explicit as the simulation platform, assembly and analysis with dynamic meshing contact, get in gear stress of gear tooth distribution, and provide the basis to the gear shape design.

Analysis of the Influence of Fillet Curves on Gear Bending Strength Based on Space Contact

An analytical method was presented on some pairs of gear teeth contacting each other at the same time. First, the software Pro/E is applied to establish two kinds of gear whose fillet curves are typical double circular and single circular respectively. Second, changes of meshing locations is made to get omni-directional contact analysis results. At last a conclusion was drawn that bending stress on dedendum double circular gear is 1.3~1.5 times bigger than that on dedendum single circular gear,that is dedendum single circular gear has better carrying capacity. The study provides a good method for studying gear bending stress.

Meshing Performance Analysis of New Non-Zero-Positive Modification Spiral Bevel Gear

For non-zero-modification spiral bevel gear, its machining parameters could be designed with big contact ratio by Local Synthesis. This design method could make up the shortage of low coincidence degree resulted by increasing mesh angle in the non-zero-positive transmission designing. Taking an example, according to comparing the new with conventional design simulation results, the max root tensile stress of pinion was reduced by 28.36%, and the max root compressive stress was reduced by 23.31%, and the max tooth surface contact stress was reduced by3.5%, and the root stress of gear was a bit decreased under the same load conditions. The conclusions showed that the pinion bending strength was improved obviously, and new tooth profile design and its machining parameters made gear pair possess higher life and reliability.

Modal and stress analysis of gear train design in portal axle using finite element modeling and simulation

The portal axle is a gearbox that is specially designed for off-road driving conditions. It is installed between the wheel and the axle shaft to give higher ground clearance to the vehicle. The modeling and simulation of spur gears in portal axle is important to predict the actual motion behavior. However, gear train design in portal axle is difficult to study comprehensively due to their relatively low cost and short product life cycle. In this study, modal analysis of portal axle is simulated using finite element method (FEM). Modal analysis is simulated on three different combinations of gear train system commonly designed for portal axle. The three gear trains being analyzed are gear train without idler gear, one idler gear and two idler gears. FEM static stress analysis is also simulated on three different gear trains to study the gear teeth bending stress and contact stress behavior of the gear trains in different angular positions from 0° to 18°. The single and double pair gear teeth contact are also considered. This methodology serves as a novel approach for gear train design evaluation, and the study of gear stress behavior in gear train which is needed in the small workshop scale industries.

Gear Stress Analysis and Discrete Optimization for Wheel-Legged Rover

The wheel-legged rover with a double-half-revolution mechanism uses two tandem planetary gear trains to drive. Its virtual prototype model was built in COSMOS Motion software, and the mechanical data of each gears of the wheel-legged rover were obtained by dynamic simulation under the typical working conditions. On this basis, the finite element analysis model of the wheel-leg planetary gear was established and its stress analysis was done. The discrete optimization mathematical model was built with the optimization target of minimizing the rover’s wheel-leg planetary gear volume and the constraint condition of keeping the Mises stress applied on the dedendum under the admissible Mises stress. Based on ANSYS Parametric Design Language (APDL), the optimization design was done for the above gear based on discrete optimization method. The result shows that the optimized gear not only meets the strength requirement, but also its weight is 58% lower than the original, which will provide a new effective method for optimizing the wheel-leg structure of the rover.

Simulation Analysis of Residual Stress of the Plastic Gear Based on Moldflow

Through the orthogonal experiment with Moldflow software, numerical simulation was conducted in different injection molding process parameters. The influence on the plastic gear tooth root residual stress from the mold temperature, melt temperature, injection time, packing time, and packing pressure was explored was explored. The results showed that: The selected process parameters for plastic gear tooth root of the residual stress effects in varying degrees. By optimizing the injection molding process parameters, the residual stress of injection was reduced to improve the quality of injection molding gear.

Fatigue Simulation and Analysis on Planetary Gear of Megawatt Wind Power Yaw Reducer

The new type wind power yaw reducer has been virtually assembled in Pro/E for the operating conditions of the Megawatt wind power yaw reducer. The planetary gear contact model of the new type wind power yaw reducer has been built to simulate the change of the contact stress in the process of planetary gear operation with the interface of Pro/E and ANSYS. The results show that: the initial maximum contact stress of the meshing planetary gear is 395MPa and the maximum stress in the engagement process is 460MPa, but it is still less than the material yield limit of the planetary gear. The results also show that the fatigue life of the gear teeth is 125,800 times, the cumulative fatigue factor is 0.72501 by analyzing the fatigue loads and 42CrMo’s S-N curve of Megawatt wind power yaw drive planetary gear, so it can meet the design and operation requirements for the Megawatt wind power yaw reducer.

Methods for Analyzing Nose Gear During Landing Using Structural Finite Element Analysis

The objective of this paper is to provide a modeling and analysis guide that can be used in determining the stress and displacement behaviors of an aircraft nose gear during landing. The paper outlines themodeling and analysis of the nose gear of an aircraft using finite element analysis. The nose gear was first modeled using computer-aided design software and then imported intofinite element software. The external forceswere determined analytically and the interactions between components were carefully modeled using contact analysis. The tire was modeled using the eye-bar theory. The results obtained in this work are consistent with the Federal Aviation Administration’s recommendations for physical testing.

Fatigue Simulation and Analysis on Planetary Gear of Megawatt Wind Power Yaw Reducer

The new type wind power yaw reducer has been virtually assembled in Pro/E for the operating conditions of the Megawatt wind power yaw reducer. The planetary gear contact model of the new type wind power yaw reducer has been built to simulate the change of the contact stress in the process of planetary gear operation with the interface of Pro/E and ANSYS. The results show that: the initial maximum contact stress of the meshing planetary gear is 395MPa and the maximum stress in the engagement process is 460MPa, but it is still less than the material yield limit of the planetary gear. The results also show that the fatigue life of the gear teeth is 125,800 times, the cumulative fatigue factor is 0.72501 by analyzing the fatigue loads and 42CrMo’s S-N curve of Megawatt wind power yaw drive planetary gear, so it can meet the design and operation requirements for the Megawatt wind power yaw reducer.

Optimized Face Gear and its Bending Stress Analysis

According to the simulation of the face gear in UG, the research established the model of face gear. A perfect model that can be used in ANSYS was obtained through reserve modeling. The blending situation of three models of face gear was analyzed in ANSYS. The blending stresses distribution area and the influence on gear teeth bending stresses of different parameters i.e. modulus, width and number of teeth were discussed. And the discipline of the bending stresses under these parameters was got. It provides a new analysis method to research the characteristics of stress of face gear.

Study on 42CrNiMo Gear Contact Fatigue Strength Experiment

This paper makes study on the 42CrNiMo gear contact fatigue strength, applying the rapid measure method of the gear contact fatigue stress value with a few gear samples to get the estimated value of the gear fatigue limit value precisely and rapidly. And the gear fatigue life curve and fatigue damage accumulation curve are got by MATLAB simulation. Comparing with the traditional test method, this method can reduce the cost and save the time.

Analysis on the Increasing Gearbox Cooling System of Wind Power Generator Based on ADINA

As the core components in the wind power generator set, the maintenance of gear box is very difficult, and its maintenance fee also is extremely high. To prevent gearbox teeth fault injuries in the supernormal heavy load, the driving friction heat distribution and heat transfer characteristics of wind power gear box are studied, the wind power generator increasing gearbox structure characteristics are analyzed. The parametric model of increasing gearbox is completed in UG software and finite element analysis of gear temperature and heat stress is conducted in ADINA software. Through the analysis on the calculation results, the design idea of wind power generator cooling system is summarized, and provides theoretical basis for the design of increasing gearbox cooling system for wind power generator.

Numerical Experiment on Bend Strength Computation of Profile-Shifted Involute Gear

In order to fix on the inner connection of modification coefficient and bend strength, the static analysis of profile-shifted gear is made by applying Finite Element Method, then regression equation that revealed the relation between modification coefficient and bend strength is set up according to the Similarity Theory. Given bend stress of a standard gear, the bend stress of any profile-shifted gear with the same teeth can be calculated from the equation.

Virtual Prototype Modeling and Dynamics Analysis of a Large-Scale Wind Turbine’s Gearbox

With the gearbox of a large-scale wind turbine as a study object, the virtual prototype model of gearbox is created based on UG and ADAMS softwares according to its design parameters such as structure and size. By rigid and flexible dynamics analysis for gearbox, the angular velocity and acceleration curves of the in-out shaft are obtained. Gear meshing forces and flexible body stress cloud using ADAMS are also obtained. It is verified that these results are coincided with the theoretical value through analysis and the simulation results of ADAMS are valid. The simulation results show that the design level of wind turbine gearboxes can be improved using the virtual prototype technology and lay a good foundation for further optimal design.

A Method to Determine the Basic Value of Gear Root Stress Based on FEM

In order to improve the case that the safety margin is a little higher using GB3480 to determine the gear root stress, a method which combines the GB3480 and FEM to determine the basic value of gear root stress is proposed. Using FEM, the comprehensive gear root stress can be figured out firstly based on the accurate tooth profile model. Then the gear root stress can be determined more accurately according to the key coefficients. Using the proposed method, the basic value of the gear root stress for the gears given in this paper is decreased by 11%. The proposed method can provide the useful guide to lightweight design for the gear transmission system.

Analytical Method on Contact Stress of Helical Gear with Asymmetric Involutes

Helical gear with asymmetric involutes is a new kind gear which driving side surface is large pressure angle profile. The numbers of meshing tooth are discussed during helical gear pair meshing process, thus the length of total contact lines is determined easily. It is difficult to calculate contact stress by existing formula because this kind gear is non-standard. A calculating formula is derived which can calculate contact stress of helical gear with asymmetric involutes in this paper. A computer’s software is written in order to calculate instantaneous contact stress of contact line. Contact stress is compared between symmetric helical gear and asymmetric helical gear.

Failure Analysis of Transmission Gear for Heavy Vehicles

For early failure problems, which are broken teeth of the first transmission driving gear in the test, this paper studies the problem in the failure mechanisms such as chemical composition analysis, fracture surface analysis as well as the metallographic structure morphology inspection analysis of failure gear. The results show that the main reasons causing abnormal fracture of the failure gear are the insufficient root shot peening strengthening, the small fillet of the spline groove and the inadequate rim thickness of the rim. This paper uses the finite element method to analyse the contact stress of failure gear and puts forward an improving design method.

Study on the Calculating Method of Bending Stress for Non-Circular Gear

Profiles of non-circular gears and equivalent gears are compared in this paper, and profile differences are specifically investigated. Based on the cantilever beam theory, the calculating method of bending stress for non-circular gear is researched, and computational error by using equivalent gear instead of non-circular gear to calculate the bending stress is analyzed through the comparison of tooth form factors. Simultaneously, the numerical simulation of bending stress of non-circular gear is conducted on the basis of the FEM method. By the fitting curve comparison, the feasibility of using equivalent gear instead of non-circular gear to calculate the bending stress is testified.

Strength Analysis of Logix Gear Based on UG

According to the tooth profile theory of Logix gear, this paper discussed a method of parametric modeling based on UG. By this method, 3D model of Logix gear with different parameters can be easily and quickly built, though tooth profile is complicated. And then, it analyzed the bending stress and contact stress of Logix gear. By comparison with the standard involute gear, it showed that Logix gear has higher bending and contact strength. So it is possible this type of gear can be applied in the case of heavy load. So it provided some practical technical guidance on the research of high strength gear and the application of Logix gear.