Effects of time-varying friction coefficient on hypoid gear dynamics

This paper develops a generalized 3-dimensional 14-DOF dynamic model for hypoid gear which considers the time-varying friction coefficient and lubrication situation. We propose a mixed elastohydrodynamic lubrication(EHL) friction model of hypoid gear tooth contact to reflect the realistic lubricant situation in gear transmission system consisted of full film contact and asperity contact. Under the mixed lubrication condition, the effects of time-varying friction coefficient on gear dynamic is analyzed. The load sharing coefficient is used to calculate the instantaneous friction coefficient at each contact point along the contact path. Friction coefficient model based on mixed elastohydrodynamic lubrication(Mixed EHL) is incorporated into the dynamic model to predict the dynamic mesh force and transmission error with constant and time-varying friction coefficient. The simulation results under a wide range of speed and load show that the time-varying friction coefficient has a marginal effect on the dynamic response.     

Profile Precision of Hypoid Gears Controlled by Coordinate Measurements

The geometrical model of profile error is put forward to describe the tooth surface precision of hypoid gears. The influence of each machine tool setting error on profile error is investigated respectively, and the research of the associativity and compensativity among the machine tool errors are made. The setting errors of machine tool, the optimal modifying parameters and their value are got from the measurement coordinates of hypoid gear real tooth surface, and the adjusted manufacturing shows the geometrical precision of the tooth surface is improved effectively.     

The Analysis of Bending Deformation of Cutter Tooth and Gear Tooth During Shaving Process

In this paper,the variation pattern of the contact point on cutter tooth and gear tooth is analyzed during gear shaving process. According to the shaving force measured by dynamometer, the deformation of cutter tooth and gear tooth at the contact point is calculated by appying the three dimension finite element method. The deformation curve of cutter tooth and gear tooth are obtained by analying deformation in shaving domain. It is the basis of studying relation between shaved amount and deformation.     

Intensity Comparative Analysis Based on Ideas Between Involute Gear and Double Involute Gear

Modeler and simulation modules in Ideas software are used to build the finite element models on involute gear and double involute gear with accurate tooth shape, and with the same design parameters and under the same loads, finite element contact analysis has been done. At last, the contact stress and bending stress on the two types gear transmission at the different meshing positions are solved out, and comparative analysis and study have been done. At the same time, that the ladder-shape tooth on the double involute gear how to influence contact stress and bending stress is emphatically analysed. All above offer the theoretical foundation that bring the double involute gear with ladder-shape tooth into the industry.     

Study of Modern Applied Technology for Design and Manufacture of Spiral Bevel and Hypoid Gears

A new method of computing the cutter specifications and machine settings for the manufacture of spiral bevel and hypoid gears is studied. And a software system which includes the program models of new and old methods is developed. The system can perform the computations such as blank dimensions,cutting and grinding settings,tooth contact analysis and under cut check of SGM,SFM,SGT,SFT,HGM,HFM,HGT,HFT cutting methods. The new method can allow the user to give the position and length of contact pattern,the direction of contact path and the relative anglar acceleration. The system can be easily operated.     

Dynamic optimization design of marine gear transmission system

A dynamic model of transmission system for a marine gear is established considering time-varying mesh stiffness, mesh damping and tooth composite error. The solution efficiency is improved by taking contact line length change of gear pair instead of instantaneous gear mesh stiffness change and making mesh damping and tooth surface equivalent to viscous damping. Multi-objective dynamic optimization design is put into practice to improve the marine gear transmission system using vibration acceleration and mass as target function. The results show that the optimization method can effectively reduce the vibration level and mass of marine gear.     

Research on analysis of force and contacting stress for the discrete teeth harmonic drives

Mechanical analysis for the discrete teeth harmonic drive gear pair is carried out. The force on discrete teeth is calculated based on the deformation coordination equation,and the contact stress of meshing pair is obtained by Hertz equation. According to transmission periodicity of the discrete gear harmonic wave and the input angle values of continuous sampling wave generator,the distribution of discrete teeth harmonic drive meshing force and contract stress in rigid tooth profile,tooth wave generator and discrete teeth is obtained. By studying the top cutting phenomena in rigid tooth profiles,the change trend of meshing force and contact stress on the contact surface is found,and positions for high meshing force and high contact stress in transmission are also found,in order to provide reference for further intensity and structure optimization design.     

Tooth contact analysis of helical beveloid gear with parallel axis

The study object of this paper is helical beveloid gears with parallel axis. Based on the gear Mshing Principles and the tooth-surface equations of pinion and gear,the mathematical model of tooth contact is developed under standard installation and installations with center distance error,axis error and multiple error respectively. The MATLAB solver is used to obtain the contact trace and the transmission error under different installing conditions and the comparative analysis is made. The results indicate that this gear drive is sensitive to axis installation errors,it forms the edge contact and cause the periodic transmission error. It can provide the foundation for designs and analysis of this gear transmission.     

Mothematical Model for Planing of Precise and Hardened Gear

In this paper, the mathematical model for gear planing of precise and hardened gear is established. The computational charts and results for the tooth edge height,cutter edge contact length and cutter area are given out to improve the present planing technique.     

Numerical simulation of the internal dynamic excitation of a spiral bevel gear transmission

A 3-D geometry model and a static/dynamic finite element (FE) model of a spiral bevel gear transmission are established. Using ANSYS software, the mesh stiffness excitation of a tooth pair is calculated via the static contact FE method. Using LS     

Coupled Thermo-Elastic Contact Finite Element Method and It''s Application in Gearing

A new finite element method is presented in this paper to analyze the thermo- elastic contact problem with heat input on meshing tooth faces. The computational model of meshing gear has been established and the frictional heat input on meshing tooth faces is estimated. In addition, 2-D finite element analysis program for this kind of problem is listed. The test and practical examples are given to show the validity and versatility of this method.     

Transmission model of higher-order elliptical bevel gearing and motion simulation for interference checking

Higher-order elliptical bevel gear is a typical form of the noncircular bevel gear transmission.Space spherical coordinate system of the bevel gear meshing is set up based on the meshing theory of space transmission.The varying relationship among the pitch curve,tooth profile and mesh lines are analyzed,and the equation of the gear tooth surface is developed with matrix method based on space coordinate transformation.The basic parameters of the noncircular bevel gear such as transmission ratio,modulus and the number of teeth are designed,and detailed analysis of the influence of the eccentricity on the relevant parameters is carried out as well.By using discrete numerical method and three-dimensional software,the mathematical model of the tooth profile and virtual physical model of the noncircular bevel gear are established,and then simulation on its motion and interference checking are performed.Finally,the approach for design,calculation and generation of the tooth profile is obtained and its correction has been verified by experiment.     

The machine setting reverse method of spiral bevel gear

The profile error correction of spiral bevel gears is difficult. To solve this problem, the inspected method of spiral bevel gears tooth surface is studied in 3906 gear measuring center. The grids of tooth surface is measured by measurement software. Taking reference tooth surface as the goal, a method of machine setting reverse using approximation algorithms is proposed, and a mathematical model is build. At last, a reverse example based on grinded spiral gear is given. The result shows that the cutting machine setting of bevel gear tooth surface can be exactly calculated.     

Contact analysis of a new style planetary reducer with a double crank and internal gear board

To address the problems of low carrying capacity and short life of bearings in current ring reducers, a new type of ring reducer is proposed which consists of a two stepped transmission. One is a planetary transmission, and the other is an N type planetary transmission with a low tooth number difference. Based on the analysis of structural features, the transmission principle, and a transmission load situation, a contact finite element model of the new type of ring reducer is set up, and the stress value and the actual pairs of meshing teeth are derived by calculation. Based on gear modification research theory, the second stage transmission gear pairs of the new reducer are modified on its teeth profiles. Results demonstrate that the load capacity of transmission gear pairs have been enhanced greatly.     

Dynamic Optimization of System Parameters For the Epicyclic Gear Drive with Internal Tooth

The epicyclic gear drive with internal tooth has been analysed,the formula has been also deduced for computing the inertial force and change of contact force,and the dynamic optimization of system parameters for the force of bearing has been carried,it has given a reliable proof to reduce the dynamic load and prolong the life of bearing of three ring type reducer.     

Bending Stress Analysis on Backlash Adjustable Worm Transmission

The full name of variable tooth thickness plane worm gear transmission is. Backlash adjustable plane worm gear with variable tooth thickness enveloping worm transmission, which is a new kind of accurate power transmission that is intervenient between traditional motion transmission and power transmission. Tooth surface equations of the variable tooth thickness plane worm gear transmission are deduced based on the theory of engagement. Basing on the result, the authors create a finite analysis model of backlash adjustable variable tooth thickness plane enveloping worm with perfect tooth shape by using I-DEAS software, and then has done finite element analysis of backlash adjustable variable tooth thickness plane enveloping worm transmission. Finally, the author drew a conclusion about distribution of principal stress and load distribution between teeth, which offer some references for strength and performance analysis of worm transmission.     

Influence of Motorcycle Noise on Gear Transmission

The study of motorcycle's acoustic signal shows that gears noise take a great proportion on the whole acoustic of motorcycle.So how to control the noiseof gears is very helpful for reducing the whole motor's acoustic.This paper discusses the engine matching with transmission system in reason,primary transmission and gear geometry design parameter & the mend of tooth body(tooth form & tooth direction) how to influence the acoustic of motorcycle.The study shows that the gear transmission System's matching with engine in reason can notable improve the efficiency of motorcycle.In the meaning time the exactly choosing the primary transmission gear geometry design parameter and the mend of primary transmission gear's tooth body can effectively reduce the acoustic of motorcycle.This paper has engineering practice sense.     

The Research on Stiffness of Double Involute Gear with Ladder shape Teeth

The stiffness of the tooth with different profile parameters,meshing stiffness and the coefficients of loading distribution allowing for no error are calculated and analyzed on double involute gear with ladder shape teeth for the first time,and the results are made comparison with traditional involute gear;The stiffness of the double involute gear and the meshing stiffness are both increased,and the coefficients of loading distribution are basically unchanged.The energy integration method is also put forth to solve stiffness approximately by linear approximating the tooth profile curve.     

Analysis on tooth root stress and influencing factors of crossed beveloid gears with small shaft angle

In order to accurately calculate the tooth root stress of spatial crossed beveloid gears with small shaft angle, an exact geometry-based numerical computation method is proposed based on the spatial gearing theory and the finite element theory. Using the proposed method, the mathematical tooth surface model and the mesh model of a crossed beveloid gear pair with small shaft angle is created and the tooth root stress distribution is analyzed. Then the influences of the key design parameter which is the clearance coefficient, torque load, offset error, shaft angle error, pinion axial position error and gear axial position error on the tooth root stress are investigated. The results show that the increasing of the clearance coefficient can decrease the maximum tooth root stress. The root stresses distribute smoothly along the tooth width direction at a light torque load level. For heavy torque load level, the root stresses are parabolic in shape. Also, the existence of offset error and shaft angle error can increase the maximum value of the root stress obviously and the positive and negative value of the errors can change the position of the maximum root stress along opposite direction. For the pinion and gear axial position errors, they have less effect on root stress distribution.     

Analysis of Radial Force for Compound Gear Pump with Three Idle Gears

Based on the investigation of engaging points' displacement of gear pump with three idle gears ,the radial components of instantaneous hydraulic pressure and the engaging force of the compound pump are analyzed .The research comes to the conclusions that the instantaneous radial forces acting on center and inner gears can be balanced so long as the center gear has triple times tooth ,and the idle gear of even tooth makes less radial hydraulic pulsation than those of odd ones. [WT5HZ]