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Investigating the Use of Circle in Gear Cutting as a Substitute to Involute Profile  [cached]
A.D. Kibet,A.M. Muumbo,R.J. Kiprono,S.K. Kimutai
Research Journal of Applied Sciences, Engineering and Technology , 2012,
Abstract: Gears are used in various machines and industries for transportation and transmission of power. Other uses are in consumer electronics and many machines used in homes like the washing machines, electric drills and kitchen appliances. Gears come in different sizes ranging from a module of 0.5 to 100 mm. Currently there is a problem of accurately machining gears. This is due to inaccurate positioning of the blank and cutter. The objective of the study was to investigate and determine the appropriate way of producing quality and accurate gears most economically through the use of a circle as a substitute to involute profile in gear cutting. Two different gears of same dimensional characteristics were cut; one using a Computer Numerical Control machine utilizing circle profile and the other using conventional milling machine. Dimensional comparisons were made of the two cut gears against an actual involute profile to determine the margin of error. The circle involute profile made using CNC was found to be exactly as the true involute profile though an error of 0.078 mm was observed in some sections of the profile. For the hobbing case, it was impossible to accurately machine the actual depth and as such, the intended depth of 7.32 was surpassed by 0.2 mm. The tooth was thicker throughout the length of the profile and the fillet radii lucked homogeneity. The involute circle approach was therefore successful and as such can benefit all CNC users and gear cutters in producing accurate gears cheaply.
Involute Spur Gear Template Development by Parametric Technique Using Computer Aided Design
VS Babu, AA Tsegaw
African Research Review , 2009,
Abstract: There are many methods available for developing profiles of gear and spline teeth. Most of the techniques are inaccurate because they use only an approximation of the involute curve profile. The parametric method developed in this paper provides accurate involute curve creation using formulas and exact geometric equations. In addition, the involute curve by equation technique allows using either Cartesian in terms of X, Y, and Z or cylindrical coordinate systems to create the involute curve profile. Since spur gear geometry is controlled by a few basic parameters, a generic gear can be designed by three common parameters namely the pressure angle (a), the module (m), and the number of teeth (z). Most of the present day CAD systems have no built-in tool for designing such gears. This paper is an attempt in utilizing the concept of parametric technology to develop a template gear. The gear so developed has true involute profile, which is a realistic design. This will allow making changes to the gear design by using parametric input. If one gear file is developed using this parametric technology, with which, different size and variety of spur gears can be created. The specific objective is to design and develop a template spur gear with 3 module, 30 Teeth, 20° pressure angle based on parametric technique by using CATIA V5R14 package. The later portion it is shown how this model may be retrieved and utilized for developing gears of different modules and number of teeth with change in these input parameters.
Coupling Analysis of Heat and Force for Asymmetrical Involute Helical Gear

- , 2015,
Abstract: 通过对非对称渐开线斜齿轮啮合面的分析,得到了啮合面摩擦热流量的分布规律。基于APDL建立了非对称渐开线斜齿轮的有限元温度场分析模型。考虑温度对接触压力的影响,对非对称渐开线斜齿轮进行了热力耦合分析。结果表明:达到热平衡时,非对称齿轮本体温度最大值比对称齿轮低约18%,因而非对称齿轮能有效提高轮齿齿面抗胶合能力;由于本体温度的影响,接触应力增大了约16%,温度引起的热弹变形对齿轮载荷分布和应力产生了较大影响。
The distribution of friction heat flow on meshing surface of asymmetrical involute helical surface was obtained based on the analysis of meshing face. The finite element model for temperature distribution of asymmetrical involute helical gear was established based on APDL. Considering the influence of temperature on the contact pressure, we carried out coupled analysis of heat and force for asymmetric involute helical gear. The results and their analysis preliminarily showed that the maximum bulk temperature of asymmetric gear is lower by about 18% than the symmetrical gear at reaching thermal equilibrium, which could effectively improve the tooth surface scuffing capacity. The contact stress of asymmetrical involute helical gear increased by about 16% due to the influence of temperature distribution
The Comparison of Straight Tooth Bevel Gear and Spiral Bevel Gear about the Stress of Gear Tooth

张钦搏, 宋爱平, 罗超, 张海滨, 王树凤
Instrumentation and Equipments (IaE) , 2016, DOI: 10.12677/IaE.2016.42002
Abstract: 大型的数控龙门加工中心中,卧式主轴头通过一对直齿圆锥齿轮副来作为相交轴的传动部件。其加工中心在高速运转时,直齿圆锥齿轮副会发出大的噪声和冲击,导致加工中心的加工质量和精度下降。为了解决这一问题,提出采用弧齿圆锥轮副代替直齿圆锥齿轮副。基于ANSYS Workbench软件,分析直齿圆锥齿轮副与弧齿圆锥齿轮副的齿跟弯曲应力和齿面接触应力的状况,在此基础上,得出弧齿圆锥齿轮副在传动过程中其轮齿的综合力学性能要优越于直齿圆锥齿轮副相应的轮齿性能。这使得数控龙门加工中心可回转式卧式主轴头在更换前70分贝的噪声降至到60分贝,噪声得到了显著的降低。
In the large CNC gantry machining center, through a pair of straight bevel gear pair, the horizontal spindle head is used as a driving part for intersecting axes. When it in high-speed operation, straight tooth bevel gear pair makes a big noise and impact, which results in a decline in the quality and machining precision of the machining center. In order to solve this problem, it is proposed that the spiral bevel gear pair is used instead of the straight bevel gear pair. Based on ANSYS Workbench software, the status of straight tooth bevel gear pair’s and the spiral bevel gear pair’s the bending stress and contact stress are analysed. On this basis, it is concluded that spiral bevel gear pair, in the transmission process, of the comprehensive mechanical properties of the tooth is superior to the gear's performance of the corresponding straight tooth bevel gear pair. This makes CNC gantry machining center which can be rotary horizontal spindle head dropped to before re-placing 70 decibels of noise to the 60 decibels, which is significantly reduced.
Geometric Modeling and Strength Analysis of Gear with S-Shaped Tooth Profile and Small Number of Teeth

- , 2016, DOI: 10.11784/tdxbz201512003
Abstract: 针对渐开线少齿数齿轮副因齿面接触应力大导致承载能力低而难以广泛应用的问题,提出了一种能够实现 凹凸弧齿廓啮合的基于正弦曲线齿条刀具加工的S 型齿廓.给出了齿条刀具正弦函数的曲线方程,推导了S 型齿廓 数学模型,建立了S 型齿廓少齿数齿轮的几何模型,分析了S 型齿廓的诱导法曲率的计算方法,开展了齿轮副接触 应力的有限元仿真分析,并与渐开线少齿数齿轮作了对比分析.结果表明,相互共轭啮合的S 型齿廓齿轮副具有相 同的齿廓方程形式,能够用一把齿条刀具或滚刀加工,且能较大幅度地提高少齿数齿轮副的承载能力.
The large contact stress of involute gear pair with small number of teeth causes a low load-carrying capacity and failure in wide application.To solve this problem,an S-shaped tooth profile was proposed that could achieve concave-convex profile meshing based on sinusoidal rack tool.A curvilinear equation of sinusoidal rack tool was introduced, a mathematical model of S-shaped tooth profile was deduced,and a geometry model of S-shaped tooth profile with small number of teeth was established.Then,the calculation method of induced normal curvature of Sshaped tooth profile was analyzed,simulation analysis on the contact stress of gear pair was conducted by FEM,and finally a comparative analysis on S-shaped tooth profile gear and involute gear with small number of teeth was made.The results show that the S-shaped tooth profile gear pair with mutual conjugate meshing shares the same equation, and one common rack tool or hob can be used to machine them,improving greatly the load-carrying capacity of the gear pair with small number of teeth
Anti-Bias Load Capacity Analysis of the Involute Arc Cylindrical Gear

刘祖奇, 宋爱平, 张益汉, 罗超
Mechanical Engineering and Technology (MET) , 2015, DOI: 10.12677/MET.2015.43023
The processing errors, installation errors and deformation often lead to Gears partial load during gear pair transmission process. The paper analyzes generating mechanism of partial load and limitations of gear modification about the spur gear pair as well as the Helical Gear Pair, proposing to use this new arc cylindrical gear to improve the carrying capacity and anti-bias load capacity of the auxiliary drive gear. The paper analyzed the principle of anti-bias arc cylindrical gear carrier based on the geometric characteristics of the arc cylindrical gear, using the finite element method to analyze the stress of straight teeth, Helical and arc tooth cylindrical gear pairs respectively, showed that the arc cylindrical gear pairs can significantly improve the stress state of tooth surface, with a clear anti-side load characteristics.
Exploring Sliding Friction Dissipation Power of Transmission Tooth Surface of Involute Gear

- , 2015,
Abstract: 基于齿轮系统的功能传递原理和摩擦耗散机理,分析了齿轮传动过程中单齿和双齿啮合的特性,求解了齿面滑动速度和齿面法向正压力分配系数,建立了齿轮系统瞬时啮合耗散功率计算的数学模型,并以某NGW型行星齿轮减速器为例计算了组成系统的各对齿轮传动的瞬时摩擦耗散功率和传动效率。结果表明:单齿啮合区齿面滑动摩擦耗散功率较小,双齿啮合区齿面滑动摩擦耗散功率较大;齿面滑动摩擦耗散功率和啮合传动效率具有周期性和时变性,并且具有很大的突变性;外啮合齿轮副齿面摩擦耗散功率大于内啮合齿轮副;各行星轮和中心轮的啮合状态之间的相位关系对瞬时摩擦耗散功率和传动效率影响很大,对行星轮系传动的平稳性有一定影响。
Based on the function transfer principle and frictional dissipation principle of a gear system, the characteristics of single tooth meshing and double tooth meshing during gear transmission are analyzed, the distribution coefficients of sliding velocity of a tooth surface and its normal positive pressure are solved and the mathematical model for computing instantaneous meshing dissipation power of the gear system is set up. Then taking the NGW type planetary gear reducer for example, we compute the instantaneous frictional dissipation power and transmission efficiency of each gear pair. The computational results show that the sliding friction dissipation power of the tooth surface is smaller in single tooth meshing areas; accordingly it is bigger in double tooth meshing areas. The sliding friction dissipation power and meshing transmission efficiency of the tooth surface have periodicity, variability and prodigious mutuality. The tooth surface friction dissipation power of external gear pair is greater than the friction dissipation power of internal gear pair. The phase relation of meshing state between each planet wheel and the central wheel has a great influence on the instantaneous frictional dissipation power and transmission efficiency and a certain influence on the transmission stability of planetary gear train
Force Characteristics of an Engaged Involute Gear Tooth  [PDF]
Nesrin Akman
Lecture Notes in Engineering and Computer Science , 2010,
The Precise Forming of Automobile Start Gear Shaft
Lingxian Meng,Zhongming Liu,Yuanguo Zhang,Zhihong Zhang
Modern Applied Science , 2009, DOI: 10.5539/mas.v3n8p72
Abstract: The start gear shaft is the key part of automobile starter, it is involute small module internal gear with addendum modification. It is step shaft with H/D>6 in the outline. Because of the concentric degree demand of the internal gear and the outline step shaft is higher, length of below shaft is large and diameter is small, So plastic forming of the shaft is very difficult. Meeting the needs of markets and improving comprehensive function of automobiles, the high efficient precision forming technology method of single-step chipless-forming for internal gear tooth surface and external step shaft is put forward based on analysis, study and repeated test. In the same time, a set of high accuracy die with simple novel structure and long service life is designed and manufactured. The advantages of the method have been verified that utilization ratio of material and production efficiency is high. For this reason, the method is profitable reference for producing the same type of complex shape gear shaft.
Gear Defect Modeling of a Multiple-Stage Gear Train  [PDF]
Andrew Sommer,Jim Meagher,Xi Wu
Modelling and Simulation in Engineering , 2011, DOI: 10.1155/2011/754257
Abstract: This study demonstrates the transient and steady state dynamic loading on teeth within a two-stage gear transmission arising from backlash and geometric manufacturing errors by utilizing a nonlinear multibody dynamics software model. Backlash between gear teeth which is essential to provide better lubrication on tooth surfaces and to eliminate interference is included as a defect and a necessary part of transmission design. Torsional vibration is shown to cause teeth separation and double-sided impacts in unloaded and lightly loaded gearing drives. Vibration and impact force distinctions between backlash and combinations of transmission errors are demonstrated under different initial velocities and load conditions. The backlash and manufacturing errors in the first stage of the gear train are distinct from those of the second stage. By analyzing the signal at a location between the two stages, the mutually affected impact forces are observed from different gear pairs, a phenomenon not observed from single pair of gears. Frequency analysis shows the appearance of side band modulations as well as harmonics of the gear mesh frequency. A joint time-frequency response analysis during startup illustrates the manner in which contact forces increase during acceleration. 1. Introduction Gear trains with different designs play very important roles in automobiles, helicopters, wind turbines, and other modern industries. Excessive loading on the gear teeth may arise due to the combination of gear backlash and teeth defects. Without vibration health monitoring to ensure proper operation performance will degrade. Dubowsky and Freudenstein [1, 2] developed a theoretical model to investigate the dynamic response of a mechanical system with clearance. Based on this research, Azar and Crossley [3] explored the dynamic behaviors of the engaged gearing systems with gear backlash, time-varying stiffness, and damping of the gear teeth. Compared with above investigations, Yang and Sun [4] developed a more realistic dynamic model for a spur gear system with backlash. By taking the involute tooth profile into consideration, they were able to account for material compliance, energy dissipation, time-varying mesh stiffness, and damping due to the contact teeth-pair alternating between one and two during the gear engagement. In order to accurately simulate the gear dynamic behavior, the gear mesh stiffness between meshing gear pairs should include at least two factors: local Hertzian deformation and tooth bending. Even though the authors only considered the Hertzian contact
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