Gear Tooth Profile Research Articles

Study on modular modeling and performance evaluation of a conical gear for marine transmission system

Conical involute gears, which are also known as beveloid gears, are the involute gears with cone-shape gear body rather than cylindrical gear body. Generally, conical gears are used in anti-backlash transmission systems and marine transmission systems. In marine transmission system, in order to obtain optimal propulsive force, 7–14 degree inclination angle was needed. In this paper, a 7 degree cone angle conical gear used in 375 kW class marine power transmission system was selected as research objective. And in order to establish the design theory of conical gear, a design system named conical gear modular modeling system was developed. The prototype conical gear was developed by the above design system to be used to simulate in a certain condition. The simulated and optimized prototype conical gear was manufactured which is as a specimen to complete a series of performance tests which contains gear tooth profile test and contact rate test. As the results, the developed conical gear can well meet the performance requirements of the 375 kW class marine power transmission system.

헬리컬기어의 전달오차예측 비교에 관한 연구

In recent years, world is faced with a transportation energy dilemma, and the transportation is almost dependent on a single fuel – petroleum. However, Hybrid Electric Vehicle (HEV) technology holds more advantages to reduce the demand for petroleum in the transportation by efficiency improvements of petroleum consumption. Therefore, there is a trend that lower gear noise levels are demanded in HEV for drivers to avoid annoyance and fatigue during operation. And meshing transmission error (T.E.) is the excitation that leads to the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in the whole gearbox. In this paper, the analysis of gear tooth profile and lead modification is firstly presented, and then, the different transmission error of no mesh misalignment and mesh misalignment under one loaded torque for the 1st gear pair of HEV gearbox was investigated and compared. At last, the appropriate tooth modification was used to minimize and compare the transmission error of the gear pair with mesh misalignment under the loaded torque.

A precision generating grinding method for face gear using CBN wheel

In order to improve the machining accuracy and production efficiency of face gear, a generating grinding method for face gear using cubic boron nitride (CBN) wheel is studied in this paper. The mathematical model of the CBN wheel profile is derived based on face gear grinding principle and theory of gearing. Taking the demands of machine motion during face gear grinding into account, a five-axis face gear grinding machine is developed. Then, the mathematical model of the ground face gear and the grinding method are proposed based on the structure of the machine. For reducing the face gear tooth profile errors induced by installation errors, an error analysis model of face gear grinding is established; the effects of installation errors on tooth profile errors are analyzed. The CBN wheel was manufactured, and the grinding experiments were performed on the self-developed grinding machine. The processing parameters of face gear grinding were amended according to the tooth flank measurement results obtained from coordinate measuring machine. The ground tooth profile deviation was reduced significantly after processing parameters amendment. Experiment results demonstrate that the generating grinding method is an effective approach to achieve the precision grinding of face gear.

Profiles of gear teeth

Parametric equations are derived for the tooth profiles of involute and cycloid gears, and the corresponding geometric constructions are presented. The results may be used in the automated design of transmissions.

Surface Quality and Accuracy Characteristics of Spiral Bevel Gear by Electrochemical Mechanical Finishing

Spiral bevel gears (SBG) are the core transmission elements for realizing intersection shaft driving. Owing to the outstanding advantages of finishing efficiency and capability, electrochemicalmechanical finishing (ECMF) is used to finish the tooth surfaces of SBG for improving surface quality and accuracy.The forming ECMFmethod is put forward, the influence of processing parameters on the surface roughness is studied, and the influence of the forming ECMF method on the accuracy of SBG’s tooth profile is studied experimentally. The results indicate that the surface roughness R a is reduced from 1.6 μm to 0.05 μm. After finishing, the dimensional accuracy between teeth can be enhanced by 1∼2 grades compared with the technical specifications before finishing and the accuracy of gear teeth profile are also improved.

A Methodology for Longitudinal Tooth Flank Crowning of the Helical Gear on a CNC Honing Machine

The gear honing is the most economical way for hard finishing an involute helical gear after hobbing and heat treatment or after shaving and heat treatment. The gear honing can also be applied to the modification of gear tooth surfaces to compensate for the distortions that occur during heat treatment process. Most published papers on the technology of gear honing describes on the principle of generated gear surface. However, the longitudinal tooth flank crowning of a helical gear with honing has not been investigated yet. Therefore, in this paper, we proposed a novel method for longitudinal tooth flank crowning of work gear surfaces by setting a crossed angle between the honing cutter and work gear axes as a linear function of honing cutter's traverse feed in the honing process. A mathematical model for the tooth profile of work gear honed by a standard honing cutter is also established. Three numeral examples are presented to illustrate and verify the merits of the proposed gear honing method in longitudinal crowning.

Prediction of tribological performance of electrochemical honed bevel gears teeth profile

Gears with involute teeth profile lack appropriate finishing technique for final finishing. Electrochemical honing (ECH) is evolved as a promising gear finishing technique for its micro–removal characteristic. This paper discusses the precision finishing of bevel gears by electrochemical honing process; its prospective features and capabilities. The characteristic features of the process were critically evaluated by optimisation controlled ECH process involving three key input parameters (i.e., current, rotating speed and electrolyte concentration) and employing improvement in bearing ratio as process performance parameter to predict tribological performance of gear teeth profile. The present study shows that the input parameters have significant influences on process performance and the values predicted by developed mathematical model are in close proximity of the actual experimental results.

Kinematic Modeling for the Nutation Drive Based on Screw Theory

The paper describes a study of a relative screw motion of a pair of internal and external spiral bevel gears with double circular-arc tooth profile in a nutation drive by screw theory and focuses on the kinematic modeling for the nutation drive. According to the instantaneous screw motion theory, the meshing function of the nutation drive for the kinematic modeling is developed based on the gear meshing theory and the coordinate system transformation between a crown gear and an internal or an external spiral bevel gear. The equations for the tooth profile of the crown gear, internal and external spiral bevel gears are further obtained based on the standard double circular-arc tooth profile and equal strength principles. Finally, the controllable precision three dimension modeling method for the tooth profile of the external and internal spiral bevel gears is further proposed.

Research on the Variable Ratio Gear Modeling and Transmission Ratio Test Method of Rack and Pinion Variable Ratio Steering Gear

A new modeling method for the variable ratio gear of the rack and pinion variable ratio steering gear was proposed in this paper. It was based on the characteristic that variable ratio gear pair meshing tooth profile surface are the envelope surface of each other and established a variable ratio gear three-dimensional model by simulating the gear machining process in CATIA and using Boolean subtraction operation. According to the related test standard of the variable ratio steering gear transmission ratio, a test bench was design and build, and the correctness of this modeling method was verified by comparing the designed variable ratio curve and the steering gear sample designed and processed by this method.

Parameter Design of Tooth Profile for Internal Cycloid Gear Pump with Multi-Teeth Difference

Based on the principle of gear engagement, the equation of rotor tooth profile has been reduced in this paper and has drawn the actual cycloid tooth profile by MATLAB software, the data obtained from MATLAB Workspace is processed by EXCEL, so the parameter drawing of the full gear tooth profile curve is very easy in AutoCAD software platform. This design method has high accuracy and convenient to processing in CNC machining center.

Study on the Characteristics of Oval Gear

For the problem of generating oval gear tooth profile and driving characteristic, desgin the tooth profile of oval gear by the conversion method of tooth profile, and get its three-dimensional modal by Pro/E. The transmission characteristics of a pair of ovate gear are researched; it would help to further study wire cutting of the oval gear based on the involute profile ,which got by the conversion of method of tooth profile, and the driving characteristic help to study other characteristics of oval gear as well as the application in the machinery.

Study of Formed Milling Cutter for Involute Gear with Small Numbers of Teeth

After its addendum modification and tangent modification of involute gear with fewer teeth, its addendum becomes pointed, which results in the bigger difference between the tooth profile of involute gear with fewer teeth and that of the standard. The equation of tooth profile is deduced in condition of pointed addendum of involute gear with fewer teeth and its 3D mathematic model is built. Based on the principle of form milling machining, relative position between the gear and workpiece is found when form machining. Then contact lines of cutter and workpiece are derived and revolution surface and axial section of formed cutter are obtained. Simulating machining is made after the cutter model is built in 3D software. It’s found that the gear obtained by simulating machining coincides fully with that built based on equation of tooth profile, which shows the validity of form milling machining.

Pitch deviation measurement of an involute spur gear by a rotary profiling system

This paper presents surface-profiling based gear pitch deviation measurement for an involute spur gear. A rotary profiling system, which consists of an air-bearing spindle and a displacement sensor with a diamond stylus, is employed to measure gear pitch deviation. In measurement of gear pitch deviation, an eccentric error between a gear axis and a motion axis of the rotary stage in the profiling system would affect accuracy of gear profile measurement. In this paper, at first, the influence of the eccentric error on measurement of gear pitch deviation is estimated in computer simulation based on a geometric model of the profiling system. After that, a new scanning method named “opposite-direction dual scanning method” is proposed so that a steep profile of gear flank surface with a local slope of up to 90° can be measured by the developed rotary profiling system. For compensating distortions in the measured gear tooth profile, which are induced not only by the eccentric error but also by a probe offset introduced by the proposed scanning method, a self-calibration and compensation method is applied. To verify the feasibility of the proposed method, measurement of gear pitch deviation of a master involute spur gear with a certificate data is carried out. Measurement uncertainty of the proposed method is also analyzed.

The Gear Tooth Profile Form of the Mining Truck Wheel Edges Reducer Based on RomaxDesigner

When the wheel of the wheel edges reducer working, single tooth meshing and bidentate meshing alternately, Gear meshing dislocation, mutation load, speed fluctuations, engaging-in and engaging-out impact will inevitably appear. This paper take the wheel hub reducer based on 60t AC drive articulated dump truck as the research object, use romaxdesigner model and motion simulation analyze the wheel edges reducer. through the analysis obtain the stress and the longevity of gear. According to the simulation results correct the gear for the purpose of improving the bearing capacity of the gear and reducing meshing noise.

Research on NC Technologies of Loxodromic Normal-Arc Bevel Gear

Normal circular-arc spiral bevel gear is a new type gear based on Bertrand conjugation principle. Normal circular-arc bevel gear selects directrix on the basis of paying attention to machining planning process. When the directrix serves as loxodrome, the formed tooth profile surface not only has fine transmissibility like general arc bevel gear, but also is convenient to machining. Starting with differential geometry, the geometry nature and inner relationship of Bertrand conjugation surface are studied. Then the normal circular-arc surface id put forward which is a typical Bertrand surface; the conjugation theory of loxodrome normal circular-arc bevel gears is studied. The characters of loxodrome line are analyzed. The tooth profile of loxodrome normal circular-arc bevel gears, the primary condition the directrix line must be satisfied, the relative curvature of the conjugating surfaces, the relations between non-interventional condition and curvature axle of the directrix line is provided; the NC machining theory of normal circular-arc bevel gears is studied, including the designing and manufacture of the tool, the movement of the machine, the adjustment of the tool under the condition of tangency and non-interventional condition and so on.

Joint dynamic analysis of space manipulator with planetary gear train transmission

SUMMARYJoints of space manipulators are usually simplified as torsional springs in modeling motion equations, and the nonlinear behaviors of the reducer in the joints are generally neglected. In this study, a dynamic model of a space manipulator that considers the joints that are transmitted through a typical 2K-H planetary gear reducer is developed using the Lagrangian method. The backlash clearances, gear tooth profile error, and time-variant meshing stiffness are integrated into the process. The simulation results show that the backlash clearances lead to the accumulation of positioning errors in the space manipulator when the joints rotate back and forth. The tooth profile error is the main cause of severe acceleration fluctuations and meshing force impacts. These fluctuations influence torque instability, which may accelerate gear system failure.

English

This paper discusses the experimental investigation to find out the optimal electrolyte composition in improving the surface quality of the gear teeth profile during surfacing finishing of bevel gears by the electrochemical honing process. In this study, AISI 1040 was used as the workpiece material, mixtures of sodium chloride and sodium nitrate in different ratios were used as the input parameter, and the percentage improvement in the surface roughness and material removal rate of the process were used as measures of process performance. The experimental runs were designed according to the Mixture DOptimal design. The analysis of the experimental outcome was carried out and 80% NaCl + 20% NaNO3 was found to be theoptimal electrolyte composition to conduct the confirmation experiments. The finding of the study establishes the process for precision finishing of bevel gears.

Parameters Design of Shaving Cutter with Novel Relief Portion

Shaving cutter is the most important tool for the refinement manufacture of gears with high precision and manufacturing efficiency. In this study, design parameters of shaving cutter are studied considering the strength of shaving cutter and the tooth profile of shaved gears. The finite element analysis and Taguchi method are adopted to analyze the shaving process for the optimum shaving cutter design parameters. The main objectives are due to increase the strength of shaving cutter and reduce the concavity phenomenon of the generated tooth profile.

Parametric Modeling of Involute Spur Gear Based on AutoCAD

This paper, taking the involute spur gear as a research object and using the LISP module embedded in AutoCAD, studies how to realize the drawing of two-dimensional graphics of the involute tooth profile and keyway of spur gear effectively and efficiently. The study, using the commands, such as stretch and Boolean operation of AutoCAD after programming, has realized the parametric modeling. By using this method, one can model them quickly, and lay the foundation of the assemble and analysis for the next step.

Mathematical Model of Topology Modification of Tooth Surface and Error Characteristics

In order to analysis the processing performance of the CNC grinding machine, the master profile error distribution characteristics of gear grinding tooth error analysis method based on statistical process control techniques. Tooth profile error topology control charts, analysis of the tooth length direction and the tooth height direction of the error distribution, respectively, corresponding to establish the mean - range control chart. Control charts to achieve real-time distribution of the gear grinding process tooth profile error, error change trend analysis and prevention. Calculate the machine's process capability index, derived CNC grinding processes. Finally, analysis the main causes of tooth profile error and take appropriate measures to reduce the tooth profile error by the cause and effect diagram.