Tooth Profile Design Research Articles

Design of Gear Tooth Profile Using Free Form Curve for Optimum Stresses

Gear is a key component which finds many applications in numerous engineering sectors and its design plays an important role in a power transmission system. This paper presents the new design concept of a gear tooth profile using free form curve in order to reduce bending stress. The designed tooth profile is tested with a series of simulation results which show the effect in reduction of stress under the variation of face width and speed. The results obtained from simulation test are satisfactory and effective from previous one.

Tooth Profile Design and Meshing Characteristics Analysis of Any Tooth-difference Pure Rolling Movable Tooth Transmission

Tooth Profile Design and Meshing Characteristics Analysis of Any Tooth-difference Pure Rolling Movable Tooth Transmission

クラウン減速機の精度向上のための歯形の設計

Generally, low backlash mechanisms are required for robot joints to perform tasks accurately, so we are proposing a new concept of a low backlash reducer using precessing crown gears. We call it the crown reducer. The features of this reducer are low backlash, high reduction ratio and ease of downsizing which we believe will contribute to the design of small mechanisms such as finger joints of robot hands. This paper describes a design of tooth profile for improvement of accurate motion. Firstly, we propose the clearance of tooth profile for stator gear to avoid increasing input torque. Secondary, we change design of the rotor gear with coaxial double circular gear to single circular gear for reduction of manufacturing cost. Finally, we discuss the effect using manufactured prototype reducers.

Influence of addendum modification on spur gears stability

The aim of the presented research is to develop the new method for studying the influence of main characteristics of spur gears on their stability behaviour. Few different processes and calculations are compiled in algorithm make a method for spur gears stability analysis. In this paper, the main influence factors for spur gears stability are identified and the discussion of appropriate dynamic model of spur gears is given. In order to determine the time-dependent load distribution and mesh stiffness, developed procedure uses verified spur gears model for finite element analysis. The special attention has been devoted to the research and conclusions about the influence of addendum modification on spur gears low-vibration and stability. The discussion is based on comparative study of a series of gear pairs with different addendum modification coefficient in order to select the optimal tooth profile design with gear pair low-vibration and stability as the main aspects.

Upper-bound and finite element analyses of multi-row sprocket during cold semi-precision forging process

The cold semi-precision forging of a multi-row sprocket was investigated using upper-bound (UB) and finite element methods combined with experiments. Based on the design of a new tooth profile for the sprocket, a cold semi-precision forging process and a kinematically admissible velocity field for filling the die cavity were proposed. Using the UB method, the velocity fields of the sprocket billet in the forming process were divided theoretically and calculated. The process of forging a multi-row sprocket was simulated using the FEM package Deform-3D V6.1 to obtain the distributions of the velocity field and the effective stress field in filling the die cavity. Similar to the simulated results, the experiment on cold forging a 5052 aluminum alloy sprocket was successfully performed. By comparing the calculated (UB method), experimental and simulated load-stroke curves, the calculated and simulated results were basically in accordance with the experimental results. The study provides a theoretical foundation for the development of the precision forging of multi-row sprockets.

Design Method for Screw Forming Cutter Based on Tooth Profile Composed of Discrete Points

The forming method has been widely used for manufacturing screw rotors with helical profile. This paper takes the manufacturing of screws for screw pumps as an example and uses the cubic spline interpolation method to obtain the tooth profile of the screw forming cutter according to the tooth profile at any end section of screws composed of discrete points and based on the principle of gearing mesh. Furthermore, this paper studies the space enveloping and geometric characteristics between the screw and cutter during the manufacturing process, combines the shape of the contact line, which is generated due to the cooperative motion of the machine tool, screw, and cutter, with spatial location parameters, and thus innovatively proposes a design method for the screw forming cutter based on discrete points, namely, the form-position geometric method (FPGM). It can be seen after comparing the proposed method with the principle of gear meshing that the cutter-workpiece enveloping solution model, simplified by the FPGM, can overcome the key technical difficulty, i.e., it is difficult to accurately calculate the cusp of the tooth curve; meanwhile, the proposed method can improve the precision of the cutter tooth profile design. Finally, the feasibility and superiority of FPGM are verified by experiments.

Geometric design and simulation of tooth profile using elliptical segments as its line of action

A mathematical model of gear tooth profiles using the ellipse curve, whose curvature is convenient to control by changing the mathematical parameters as its line of action, was built based on the meshing theory. The equation of undercutting condition was derived from the model. A special epicycloidal tooth profile was also presented. An example gear drive with variation of the ellipse parameters was taken to illustrate the proposed method. The contact ratio of the gear drive designed by the proposed method was analyzed. A comparison of the property of the gear drive designed with the involute gear drive was also carried out. The results confirm that the proposed gear drive has higher contact ratio in comparison with the involute gear drive.

Design and Simulation of New Tooth Profile of Flexspline for Harmonic Gear Drive

We focused on the parametric design and simulation of new tooth profile “circular arc-involute-circular arc” for flexspline in this paper. Based on the MATLAB software, the basic tooth profile of hob was designed. According to gear generating cutting principle, the simulation of processing for flexspline tooth profile has been realized. By tooth profile normal method, we calculated flexspline tooth profile which is conjugated with the basic tooth profile of the cutting tool, and gave the contrastive studies on process simulation and theoretical calculation. Results show that they are feasible in solving the new tooth profile of flexspline. When changing the key structure parameters, the different changing regulations of flexspline tooth profile can be gained. The research results are meaningful to improve the capacity of harmonic gear drive.

Calculation method of sliding ratios for conjugate-curve gear pair and its application

The calculation method of sliding ratios for conjugate-curve gear pair, generated based on the theory of conjugate curves, is proposed. The theoretical model of conjugate-curve gear drive is briefly introduced. The general calculation formulas of sliding ratios are developed according to the conjugate curves. The applications to the circular arc gears based on conjugate curves and the novel involute-helix gears are studied. A comparison on the sliding coefficient with the conventional corresponding gear drive is also carried out. The influences of gear parameters such as spiral parameter, gear ratio and modulus on the sliding ratios of gear drive are discussed. Brief description of manufacturing method for conjugate-curve gear pair is given. The research results show that the sliding ratios of gear pair become smaller with the increase of spiral parameter and gear ratio, respectively. And it will be greater with the increase of modulus for the tooth profiles. The meshing characteristics of conjugate-curve gears are further reflected and the optimization design of tooth profiles with high performance may be obtained.

Design and performance analysis of a circular-arc gear pump operating at high pressure and high speed

This paper presents a high-pressure and high-speed gear pump for aerospace application and introduces a circular-arc tooth profile that has no trapping feature and whose gears are in continuous one-point contact in the plane of rotation. Basic dimensions are determined and performance parameters of the gear pump are obtained by structural design of the gear pump. The performance parameters are discussed for different tooth profiles. A disc tool and hob are designed to generate the circular-arc tooth profile. A computer-aided design (CAD) system for the design of the circular-arc gear pump is developed with features of tooth profile design, tool design, and numerical control. The test gears were processed to verify the correctness of CAD system. A study of the outlet pressure of the circular-arc gear pump reveals that the developed high-pressure and high-speed gear pump has low outlet pressure fluctuations.

1P1-B01 クラウン減速機の精度向上のための歯形の設計 : 歯形パラメータに対する出力軸のヒステリシスロス

Generally, low backlash mechanisms are required for robot joints to perform tasks accurately, so we are proposing a new concept of a low backlash reducer using precessing crown gears. We call it the crown reducer. The features of this reducer are low backlash, high reduction ratio and ease of downsizing which we believe will contribute to the design of small mechanisms such as finger joints of robot hands. This paper describes a design of tooth profile for improvement of accurate motion. Firstly, we estimate the effect of tooth profile parameters on the hysteresis loss and the start-up torque. Then, we discuss the effect using manufactured prototype reducers.

Tooth Surface Design for Variable Transmission Ratio Bevel Gearing

A novel CAD method for tooth profile based on the gearing feature has been proposed in this paper, and this method could be applied to the variable transmission ratio and three-dimension situation. The two pitch curves of the two gears can be generated due to the given transmission ratio. The tooth profile curves are formed in each coordinate system of its pitch curve by the gearing process. Finally, the tooth profile could be extracted and translated into a real dimension by CAD method. It is provided a simply thought for tooth profile design to avoid so much complicated mathematical reasoning.

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.

The Tooth Profile Design and Examination of Circular-Arc Gear Pump

This paper presents the circular-arc tooth profile that has no trapped-oil feature and flow fluctuations. The mathematical model of tooth profile and helical surface is obtained by gear engagement theory. The examination of helical surface is by coordinate measuring machining (CMM). The sections that perpendicular to the axis direction of gear are selected to obtain the trajectory of measuring ball by the starting points and end points of measuring ball. The examination process of CMM is simulated by Matlab in this paper.

The effect on dynamics of using a new transmission design for eccentric speed reducers

This paper proposes a new transmission design for eccentric speed reducers that differs from that used with a traditional cycloid speed reducer. The main difference, other than the input and output shafts, is that it uses the internal gear as its fixed part and transmission between the external gear and output shaft occurs via pins connected to a drive plate. In this paper, gearing theory is used to construct a mathematical model of the involute external and internal gears, based on which the trajectory equations, component geometry, and reducer kinematics can be derived. A dynamics analysis model is also constructed and used to test the feasibility of two types of drive plate designs — a cross piece and a round disc, each with a single-gear and double-gear design. The stress results show the infeasibility of the cross drive plate versus the feasibility of the round disc drive plate. An additional kinematic analysis provides evidence that the design of the gear tooth profile also affects the machine transmission and can lead to vibration and stress fluctuation.

Tooth Profile Design and Kinematic Mechanism Simulation of Higher-order Elliptic Gears Based on MAPLE

Tooth Profile Design and Kinematic Mechanism Simulation of Higher-order Elliptic Gears Based on MAPLE

Transmission Theory and Tooth Surface Solution of a New Type of Non-circular Bevel Gears

Non-circular bevel gear is a typical gear mechanism and often applied to the intersecting axes or interlacing axes transmissions. An orthogonal composite-motion bevel gear is put forward based on the combination of cam mechanism and non-circular bevel gear. This new gear pair can implement the rotation of intersecting axes as well as the movement of output axe. The mathematic modeling of conjugate tooth surface is derived based on the equations of spherical involute and the theory of conjugate surfaces. Base on the specific curves of the orthogonal composite-motion bevel gear, the influencing factors and variation is analyzed. According to the motion relationships of the gears and the method of generation, the design of tooth profile is completed according to the instantaneous contact micro planes and the establishment of solid model for the orthogonal composite-motion bevel gear is presented with the application of SolidWorks.

Transmission Theory and Tooth Surface Solution of a New Type of Non-circular Bevel Gears

Non-circular bevel gear is a typical gear mechanism and often applied to the intersecting axes or interlacing axes transmissions. An orthogonal composite-motion bevel gear is put forward based on the combination of cam mechanism and non-circular bevel gear. This new gear pair can implement the rotation of intersecting axes as well as the movement of output axe. The mathematic modeling of conjugate tooth surface is derived based on the equations of spherical involute and the theory of conjugate surfaces. Base on the specific curves of the orthogonal composite-motion bevel gear, the influencing factors and variation is analyzed. According to the motion relationships of the gears and the method of generation, the design of tooth profile is completed according to the instantaneous contact micro planes and the establishment of solid model for the orthogonal composite-motion bevel gear is presented with the application of SolidWorks.

Design Method of Internal Rotary Gear Pump by Parameterized Line Conjugated Tooth Profile

Aiming at the design of line conjugated internal rotary gear pump tooth profile, the model of solving conjugated profile point by tooth profile normal reversal method is established. The methods of solving sliding ratio, meshing angle and pressure angle through meshing line are built. The influence on the pump transmission performance by the distance parameter l is shown. The intact tooth profiles construction method by tooth thickness-parameter k is built, the condition of profile overlap interference and the solution of the interference between addendum and dedendum is given. The models of flow pulsation and trapping is proposed. The results of performance simulation show that this kind of pump have advantages of low flow pulse and hard to trap oil. A design method is provided for system solution of the tooth profile design of line conjugated internal rotary gear pump.

Modification design method for an enveloping hourglass worm gear with consideration of machining and misalignment errors

The influences of machining and misalignment errors play a very critical role in the performance of the anti-backlash double-roller enveloping hourglass worm gear(ADEHWG). However, a corresponding efficient method for eliminating or reducing these errors on the tooth profile of the ADEHWG is seldom reported. The gear engagement equation and tooth profile equation for considering six different errors that could arise from the machining and gear misalignment are derived from the theories of differential geometry and gear meshing. Also, the tooth contact analysis(TCA) is used to systematically investigate the influence of the machining and misalignment errors on the contact curves and the tooth profile by means of numerical analysis and three-dimensional solid modeling. The research results show that vertical angular misalignment of the worm wheel(Δβ) has the strongest influences while the tooth angle error(Δα) has the weakest influences on the contact curves and the tooth profile. A novel efficient approach is proposed and used to minimize the effect of the errors in manufacturing by changing the radius of the grinding wheel and the approaching point of contact. The results from the TCA and the experiment demonstrate that this tooth profile design modification method can indeed reduce the machining and misalignment errors. This modification design method is helpful in understanding the manufacturing technology of the ADEHWG.