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.     

Force Analysis on Meshing Surface and Stress Research of the Cone Roller Enveloping Worm Gearing Transmission

By using the finite element elastic contact analysis method combined with the I-DEAS engineering analysis software, this paper studies the strength of the cone roller enveloping worm gearing,which is a new type of worm gearing transmission,on SUN-4 working station. It also analyzes loading distribution among meshing gears, the contact force distribution along the contact line ,the bending stress distribution and the contact stress distribution of the cone roller enveloping worm gearing with three-tooth meshing instantaneously. Besides,it provides the theoretic basis in the further researches for the new type of worm gearing transmission.     

Study on Mismatched Engagement of Hourglass Worm Gearing with The Worm Generated by A Cone and The Wheel Generdted by A Straight Profile Hob

A method to make the hourglass worm gearing with the property of mismatchedpoint contact has been proposed.The worm and the hob of the worm gearing is generated by a coneand a straight line located on the cone respectively. The basic principle of the worm gearing has beenanalysed. The formulas for calcultating the machining parameters has been obtained. And the toothcontact of the worm gearing has been investigated.The result shows that this worm gearing could getopint contact well.     

THEORETICAL INVESTIGATION AND PARAMETER OPTIMIZATION ON ROLLING CONE ENVELOPING HOURGLASS WORM GEARING

In this paper, a new high - strength worm gearing, named'rolling cone enveloping hourglass worm gearing' is proposed. With such a new type of worm gearing, the motion form between meshing tooth surfaces is changed in nature. A systematic theoretical study. a lot of numerical calculations and parameter analyses have been done. Based on these analyses,the optimum design of worm gearing is obtained. It is shown that this worm gearing possesses the virtues of high efficiency, large load capacity, long life -span and easy meanufacture.     

contact stress and steady thermal analysis of herringbone gears in a gas turbine

To obtain the distribution characteristic of contact stress and the bulk temperature on the surface of herringbone gears, parameter modeling of gears was carried out by parametric design language. A numerical simulation was given to calculate the contact stress field and the steady thermal field by combining heat transfer theory, tribology theory, and mesh theory. The distribution of contact stress, the bulk temperature and heat flux also were analyzed. The analysis results show that the distribution of the load along the contact line possesses regularity. The heat flux along the tooth depth direction decreases first and then increases. The effect of thermal conduction of the tooth is stronger than that of convective heat transfer. The conclusion indicates that the finite element emulation method can be used to estimate the transmission performance of herringbone gears.     

A Solid Modeling and Geometric Analysis of Hourglass Worm Gearing

Based on the theory of conjugate surface and computer graphics, a solid modeling method of hourglass worm gearing is presented. Assembly simulation of worm gearing is carried out, clearance and interference between meshing tooth surfaces are analyzed, and effects of machining and modification of assembling parameters on meshing and contact between tooth surfaces are investigated.     

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.     

THEORETICAL INVESTIGATION OF SPHERE RE-ENVELOPING HOURGLASS WORM GEARING

On the condition of avoiding the"undercutting,"and "sharpening" of worm tooth, it is now regarded as an important subject in the field of meshing principle studying of the "multiple-thread small reducation ratio" hourglass worm gearing with developable tooth surfaces to reduce the gorge pitch circle diameter of worm, raise meshing efficiency and strength of the wheel tooth and improve the unresonable structure of the pair. In this paper, a new type of hourglass worm gearing with developable tooth surfaces -"Sphere Re-nveloping Hourglass Worm Gearing" is studied. It shows that 4a satisfied result to above subject can be obtained if this worm gearing is applied.     

Effect of Tooth Modification on Double Enveloping Worm Gearing

A method of modifying the double enveloping worm gearing with developable tooth surface has been proposed to reduce the sensibility of the worm gearing to the manufacturing errors. The tooth contact and kinematic precision of the modified worm gearing with manufacturing errors has been investigated by the TCA method. The results show that by the modification, the edge contact resulting from the manufacturing errors is avoided or effectively relieved,and the kinematic error of the worm gearing is obviously reduced.     

Contact Analysis of worm gearing under the Condition of the Errors and the Load

The contact analysis on the double enveloping hourglass worm gearing is very important to control its efficient contact zone and contact quality. Nevertheless, current meshing analysis under the rigid condition cannot really reflect its tooth-surface contact. In this paper, the contact Finite Element Method is used to analyze the tooth contact of double enveloping hourglass worm gearing under the manufacturing error and the elastic deformation caused by the load. The load sharing among the contact tooth pairs and variations of contact zone are investigated. As compared with the result of rigid analysis, the contact zone is obviously shifted. This analysis method can provide a base for the conjugating control of the double enveloping hourglass worm gearing.     

Study of Tooth Contact and Kinematic Precision on Cone-Generated Double Enveloping Worm Gearing

The tooth contact and kinematic precision of cone-generated double-enveloping worm gearing with machining and assembling errors have been investigated. The influence of different errors on driving quality has been discussed. The assembling method to reduce or eliminate the influences of machining errors on tooth contact and kinematic precision has been proposed.     

Worm wheel grinding method of convex pitch line non-circular gear

To overcome the precision machining difficulty of non-circular gear, a convex pitch curve of non-circular gear and worm grinding method is presented. Firstly, worm wheel is reduced to rack cutter and a rack machining convex pitch curves of non-circular gears sport model is set up. Then based on the structure of CNC worm wheel grinding machine tools and machining principle, electronic gear box of machine tools is designed and active and following axes are planned. At the mean time, the synchronous coefficient of machine tools between synchronization is deduced by machining principle of equal arc-length, and interaction models of grinding are established. At last, the worm wheel manual presetting cutter methods with non-circular gear are given and worm grinding wheel mounting angle, axial position and axial location parameter can be adjusted along the gear.     

Analysis and Discussion on Klinglnberg'' s Cyclo-Palloid Bevel Gear

Because of their machining characteristics,Klinglnberg' s sprial bevel gears have the advantage over Gleason' s in many ways,so that they are more and more widely used. This paper analyzes the meshing and machining properties of the gears and deduces the equations,normal curveture and contact ratio of tooth surface. It also lays a solid foundation for spreading and importing the Klinglnberg' s machine,and developing klinglnberg' s gears.     

Design and experimental validation of a novel double ring plate gear reducer

A novel double ring plate gear reducer (DRPGR) is designed and its experimental validation is conducted. By using the closed graph method, the modification coefficients of internal gearing in DRPGR are determined. Based on this, the overall structure of the reducer is designed and its kinematics simulation is achieved. With APDL programming language of ANSYS, a 3D finite element (FE) model of DRPGR is established, and its modal analysis and loaded tooth contact analysis (LTCA) are conducted respectively. The modal analysis reveals that the lower natural frequencies of DRPGR are much higher than the input frequency and the lower modes can be classified as vertical and horizontal bending of input and output shafts. The LTCA indicates that three pairs of gear teeth contact simultaneously at rated output torque. Due to the multi teeth contacts, the maximum stress is much lower than the permissible stress of internal gearings. The experimental tests of the prototype validate that DRPGR is adapted to both single driven and dual driven work condition. When single droved, DRPGR can eliminate the kinematic uncertainty by non 180 degree phase difference design. DRPGR claims a better dynamic performance in dual driven work condition. The efficiency of DRPGR increases with the increment of output torque and the reducer has an excellent short term overloaded capacity. The experimental results validate that the proposed method can be used to guide the design of that kind of reducer.     

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.     

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.     

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.     

Accurate mathematical models for relief grinding of gear hob cutters

A mathematical model for accurate relief grinding of gear hob cutters along radial directions is presented based on the analysis of grinding geometry. Both the design and manufacturing models of gear hob cutters are carefully derived and presented. By employing the plane envelope theory, the reference contour of the grinding wheel is determined in order to attain the design tool profile precisely. The tooth profile error model after regrinding is also given to confirm the grinding parameters. The model provides accurate solutions for both the tool profile and the sectional contour of the grinding wheel. It is simple and straightforward and can be used to produce high precision hob cutters systematically. Two numerical examples are presented to illustrate the effectiveness of the proposed method. The model computing results indicate that the proposed method is practical, precise and reliable. The method provides valuable reference for the design and machining of hob cutters.     

Study on ZK Worm Gearing with the Property of Controllable Mismatched Contact

A methed to modify the cone-generated cylindric worm gearing(ZK-Wormgearing)with the proprty of controllable mismatched contact has been proposed.The basic principleof the modification has been analysed.The contact state of the worm gearing could be modified bychanging the contact position and the curvature modification amount,which could be realized conveniently by changing the geometric parameter and the setting parameter of the grind wheel in wormmachining.     

Parameter Design for Machining Quenched Internal Helical Gears by EDM

Aiming at the problem of machining quenched internal helical gears, a method and its equipment are discussed and designed, which is used for machining quenched internal helical gears by EDM. Its characteristic and principle are proposed. The modifying design of the electrode gear and the calculating method of its modification coefficients is presented. Analyzing for the error of the machining equipment is done. The results show that this problem can be solved by EDM, the electrode gear is the modification gear of machined gear and the machining accuracy can be improved by controlling errors.