STUDY ON DOUBLE CIRCULAR ARC PROFILE SPIRAL BEVEL GEAR TRANSMISSION

A stepped double arc spiral bevel gear tooth profile is examined. The development ofconjugate tooth surfaee of double are profile spiral bevel gears is described. The design and man-ufacture of the cutter is also discussed. Experimental results show that these gears have high loadcarrying capacity and that they are suitable for heavily loaded transmission. It is asserted thatsuch gears have higher power-to-weight ratios, are longer-lived, and provide more reliable per-formance than ordinary spiral bevel gears.

Tooth surface geometry optimization of spiral bevel and hypoid gears generated by duplex helical method with circular profile blade

In order to effectively improve meshing performance of spiral bevel and hypoid gears generated by the duplex helical method, the effects of straight lined and circular cutting edges profile on meshing and contact of spiral bevel and hypoid gears were investigated analytically. Firstly, a mathematical model of spiral bevel and hypoid gears with circular blade profile was established according to the cutting characteristics of the duplex helical method. Based on a hypoid gear drive, the tooth bearings and the functions of transmission errors of four design cases were analyzed respectively by the use of the tooth contact analysis(TCA), and the contact stresses of the four design cases were analyzed and compared using simulation software. Finally, the curvature radius of the circular profile blade was optimized. The results show that the contact stresses are availably reduced, and the areas of edge contact and severe contact stresses can be avoided by selecting appropriate circular blade profile. In addition, the convex and concave sides are separately modified by the use of different curvature radii of inside and outside blades, which can increase the flexibility of the duplex helical method.

Mathematic model and tooth contact analysis of a new spiral non-circular bevel gear

A novel spiral non-circular bevel gear that could be applied to variable-speed driving in intersecting axes was proposed by combining the design principles of non-circular bevel gears and the manufacturing principles of face-milling spiral bevel gears.Unlike straight non-circular bevel gears,spiral non-circular bevel gears have numerous advantages,such as a high contact ratio,high intensity,good dynamic performance,and an adjustable contact region.In addition,while manufacturing straight non-circular bevel gears is difficult,spiral non-circular bevel gears can be efficiently and precisely fabricated with a 6-axis bevel gear cutting machine.First,the generating principles of spiral non-circular bevel gears were introduced.Next,a mathematical model,including a generating tooth profile,tooth spiral,pressure angle,and generated tooth profile for this gear type was established.Then the precision of the model was verified by a tooth contact analysis using FEA,and the contact patterns and stress distributions of the spiral non-circular bevel gears were investigated.

EFFECT OF GEAR WIDTH AND HELIX ANGLE ON FACTOR OF DYNAMIC LOAD OF DOUBLE CIRCULAR ARC HELICAL GEARING

Based on theory of mechanical dynamics, meshing characteristic as well as thedynamic model of double circular arc helical gearing, an analysis approach and a computer programhave been developed for studying the state of dynamic load and factor of dynamic load of thegearing, the changing situation of dynamic load and dynamic load factor vs some affecting factorssuch as gear width, helix angle and accuracy grade etc are investigated. A series of conclusions areobtained: ①With the increasing in the values of gear width, the dynamic load factor appears slowdecreasing tendency in most region of gear width. ②When the accuracy grades of the gearing areimproved, the values of dynamic load factor decrease. ③The value of dynamic load factor appears adecreasing tendency with the increasing of value of helix angle at the same ratio of criticalrotational speed.

Experimental Investigation of the Deformation of Helical Gears with Double－Circular－Arc Tooth Profile Using Linear Variable Differential Transformer

A small hole of 0.9mm in diameter is drilled at the theoretical contact point of the convex tooth flank of the measured gear, and the hole leads throughout to the non-working flank. A stylus glued to the core of transformer is put into the hole, and the stylus can freely contact with the meshed concave tooth flank. The transformer is installed on the body of gear to be measured. Rotate the positioning worm slowly after loading, and locate the contact point at the hole of convex tooth flank, the displacement value measured is considered as the deformation of convex tooth. The deformations at the middle and the two ends of tooth breadth for the helical gears with double-circular-cra tooth profile whose modules are 3mm and 4mm respectively are measured in the paper.

安装误差对双圆弧齿轮啮合特性影响分析

为深入研究安装误差对双圆弧齿轮副啮合特性的影响,基于有限元法建立齿轮加载分析模型,研究啮合过程中单齿凸、凹齿廓的接触性能,对比分析安装误差对接触性能以及传动误差的影响规律。结果表明:啮合周期内,双圆弧齿轮的凹齿廓先接触且承担较大的法向接触力,但凸齿廓的啮入端接触应力最大,凸、凹齿面接触压力差与转矩成正比;安装误差对齿面接触性能影响较大,其中中心距误差容易引起齿轮分阶处应力集中,轴线平面的安装误差会引起齿面接触偏载,且对安装误差影响最大。

双圆弧齿廓椭圆齿轮建模与运动学仿真

为了满足齿轮变传动比运动、提高轮齿承载能力,结合齿轮啮合理论和双圆弧齿廓曲线结构参数特征,提出了一种新型双圆弧齿廓椭圆齿轮。阐述了其节曲线的设计方法,利用SolidWorks软件建立了双圆弧齿廓椭圆齿轮三维模型;使用Adams软件对双圆弧齿廓椭圆齿轮副模型进行了运动学仿真,分析了不同偏心率对双圆弧椭圆齿轮副传动比变化规律的影响,并对比理论传动比曲线,分析了仿真传动比曲线存在波动误差的影响因素;为了减小齿轮副振动脉冲,给出了偏心率适当的取值范围。本文的设计方法和分析结果对双圆弧齿廓非圆齿轮的参数化设计有理论参考价值,可为双圆弧齿廓椭圆齿轮副数控加工制造及应用提供依据。

双圆弧内齿轮车齿切削仿真及试验研究

针对目前双圆弧内齿轮加工难、精度差、效率低的问题,提出了一种采用车齿工艺加工双圆弧内齿轮的方法。根据车齿加工原理,梳理了刀具与工件的相对位置,建立了双圆弧内齿轮车齿加工数学模型;运用Vericut进行双圆弧齿形的成型仿真,验证了车齿加工内齿轮的可行性与准确性;利用Abaqus对车齿过程中的切削力进行仿真计算,获得了加工参数对切削力的影响规律;使用六轴数控机床完成了双圆弧内齿轮的车齿加工,螺旋线精度检测结果符合设计要求。上述研究结果拓展了双圆弧齿轮的加工工艺,提升了内齿轮加工精度和效率,为后期双圆弧内啮合及行星传动奠定了基础。

双圆弧齿轮泵不同工况下流量特性分析

为分析不同工况下的双圆弧齿轮泵流量特性,使用AMESim软件对双圆弧齿轮泵进行精确建模,设定不同转速、负载压力和气体质量分数并分析其瞬时出口流量和出口流量脉动率。结果表明:转速与瞬时出口流量呈正相关,转速为3000 r/min时的平均出口流量是转速为1500 r/min时平均出口流量的2.17倍;负载压力与瞬时出口流量呈负相关,负载压力为6 MPa时的平均出口流量较负载压力为2 MPa时平均出口流量减小0.621 L/min;在转速为3000 r/min、负载压力为2 MPa时,出口流量脉动率最小;出口流量脉动率与转速呈负相关,与负载压力呈正相关。油液的气体质量分数增大会加剧双圆弧齿轮泵空化现象,对流量特性造成不利影响。

新型无困油齿轮泵齿轮副型线优化与工作过程模拟

齿轮泵齿轮副的型线对齿轮泵性能影响极大。传统的渐开线型齿轮泵齿轮存在困油现象,产生局部高压,对其运行产生极大的危害。通过型线设计,来解决齿轮泵困油现象。基于曲线啮合理论,采用圆弧和高次曲线,构建一种新型双圆弧-高次曲线齿轮副,消除了齿轮泵的困油现象。进而,建立其几何模型并推导出型线方程,通过数值模拟,分析新型无困油齿轮泵的流场变化规律,并与现有齿轮泵进行对比。结果表明:新型齿轮泵消除了困油现象,型线组成简单,便于优化设计;此外,新型齿轮泵的工作性能更佳,流场更均匀。

双圆弧弧齿锥齿轮章动传动啮合齿轮本体温度的相关影响因素分析

啮合温度影响双圆弧弧齿锥齿轮章动传动过程中的疲劳、振动、噪声等行为,在双圆弧弧齿锥齿轮的寿命预测和力学响应时不可忽视。为了揭示双圆弧弧齿锥齿轮章动传动本体温度场分布规律,对双圆弧弧齿锥齿轮进行齿面接触分析,得到啮合区间;结合摩擦学和传热学得到齿轮的热载荷,建立了双圆弧弧齿锥齿轮温度有限元数值模型;采用控制变量法,分析了相关影响因素对锥齿轮温度的影响规律及原因。结果表明,齿轮温度随模数的增大而降低,随螺旋角的增大而升高,随章动角的增大先降低再升高;润滑油温度对本体温度的影响呈线性关系。研究为降低齿轮高温失效风险提供了参考。

非圆行星齿轮马达设计与排量分析

非圆行星齿轮马达具有容积效率高、密封性良好、传递扭矩大等优势,可应用于井下机械和食品机械等领域。根据几何关系推导圆弧-圆弧型(双圆弧型)节曲线参数所需满足的弧长条件、传动条件与约束条件,建立并求解内齿圈与太阳轮节曲线非线性规划模型。在分析非圆行星齿轮马达进排液规律的基础上,确定不同太阳轮旋转角度下各容腔进排液的周期变化规律。通过面积拟合法与图解法求解马达最大与最小容腔面积,确定马达理论排量。非圆行星齿轮马达试验测试结果表明,试验法与理论计算法确定的马达实际流量随转速变化的趋势基本一致,最大误差仅为9.57%,验证了双圆弧型节曲线马达理论排量模型的正确性,可为进一步探索非圆行星齿轮马达优化设计提供参考。

Mathematical modeling and characteristics analysis for the nutation gear drive based on error parameters

We focused on the mathematical modeling and characteristics analysis for the nutation drive based on error parameters. The crown gear tooth profile equation was introduced according to the national standard double circular arc tooth profile and based on the equal tooth strength principle. The nutation drive meshing coordinate system was set up by introducing the cone vertex error, tilt error, nutation angle error and spiral angle error. The tooth profile equations of the double circular arc external and internal spiral bevel gears were further obtained based on the crown gear tooth profile equation concerning above mentioned error parameters. The influences of the nutation gear reducer tooth contact conditions were analyzed with the gear tilt error and axial misalignment error. Finally, the correctness of the theoretical analysis was verified by the contact spot test.

小模数弧齿锥齿轮半滚切切齿加工方法研究

为了大幅度提高齿轮传动性,解决传统机械结构弧齿锥齿轮滚切双面法铣齿加工(即双重双面法)齿面啮合质量难以控制的问题。这里提出了小模数弧齿锥齿轮半滚切加工方法,详细地介绍了加工的相关理论计算和机床的刚性改造,分析了机床带有对刀装置的结构能保证均匀的齿切加工余量。通过生产实践,结果表明:该加工方法将有助于提高小模数弧齿锥齿轮加工效率,提高齿面啮合质量,降低生产能耗,对小模数弧齿锥齿轮的加工有一定的借鉴作用。

高速高压双圆弧斜齿齿轮泵空化抑制措施研究

双圆弧斜齿齿轮泵在高速高压工况下其内部流场空化现象严重,对齿轮泵的性能产生不利影响。为抑制齿轮泵的空化,建立了双圆弧斜齿齿轮泵吸油腔近啮合区域压力数学模型,以该区域压力值最大为目标函数,利用遗传算法对其各个影响因素求最优解,重新建立齿轮泵三维模型并设定模拟工况,利用动网格技术,通过PUMPLINX对齿轮泵内部流场的空化现象进行数值模拟,并分析了抑制空化后对齿轮泵的影响。结果表明:抑制空化后齿轮泵内部流场空化现象明显减小,齿轮泵的空化现象得到了有效的抑制,验证了吸油腔近啮合区域压力数学模型的正确性;相对于抑制空化前,抑制空化后的齿轮泵流量脉动和流量脉动率明显减小,泵出口流量脉动率减小了25.63%,泵出口平均流量提高了4.4 L/min,泵容积效率提高了10.04%,显著提高了双圆弧斜齿齿轮泵的性能。

双圆弧斜齿轮泵高速高压化流量脉动研究

为提高双圆弧斜齿轮泵在高速高压工况下的流量品质,减小流量脉动对振动、噪声等问题的影响,文中通过理论推导流量脉动系数公式,得到齿轮各参数与流量脉动之间的关系,进而对齿形参数进行优化设计,使得流量脉动系数理论为零。采用流体动力学(CFD)仿真,对双圆弧斜齿轮泵内部流场进行数值模拟,与试验结果进行对比验证。结果表明:螺旋角为31.3°时,脉动系数为零,实现了新型双圆弧斜齿轮泵理论上无流量脉动;转速为5 000~12 000 r/min,出油口流量脉动基本为零,验证了理论设计的正确性及满足了齿轮泵高速化后的性能要求;负载压力为5~25 MPa,出油口流量脉动基本为零,满足了齿轮泵高压化后的性能要求;试验结果与仿真结果流量误差在3%左右,说明了仿真结果的正确性及双圆弧斜齿轮泵泄漏量少,容积效率高。

双圆弧齿轮泵流量特性影响因素数值模拟

目的:分析新型双圆弧齿轮泵内部流场脉动特性的影响因素,采用合理参数以提高齿轮泵输出效率。方法:建立齿轮泵的二维流场仿真模型,采用计算流体力学软件Fluent进行仿真分析,研究不同齿顶间隙、不同齿轮偏心距、负载及转速对齿轮泵出油口瞬时流量、流量脉动、流场特性的影响。结果:随着齿顶间隙增大,齿轮泵出口流量逐渐减小,当齿顶间隙为0.09 mm时,出口流量脉动系数最小为0.135,为该结构参数下齿轮泵最佳齿顶间隙;受负载压力和转速的影响,齿轮泵中心轴线产生偏差,随着齿轮泵转子中心轴线偏心距增加,齿轮泵出口流量逐渐增大,当偏心距为0.05 mm时,齿轮泵出口流量比无中心偏差时增加了5.09%,提高了流量输出。结论:齿轮泵流量特性主要影响因素为转子转速和齿顶间隙,中心偏差的影响较小。

温度对双圆弧斜齿齿轮泵性能的数值模拟研究

双圆弧斜齿齿轮泵在高速工况下,其内部流场温度升高现象明显,对齿轮泵的性能产生不利影响。为了探究温度对齿轮泵性能的影响,建立了双圆弧斜齿齿轮泵容积效率与温度的数学模型。利用动网格技术,通过PumpLinx设定不同入口温度,模拟不同工况下齿轮泵内部流场的变化情况。结果表明:入口油液的温度不同,其内部流场温度变化明显,入口温度越高,其温升现象越明显;温升严重区域为存在压差区域,且压差越大温升越明显;温度升高,内部流场空化现象明显减弱;相对于常温油液情况下,入口油液温度为60℃时,齿轮泵流量脉动和流量脉动率明显增大,泵的出口脉动率增加了4.74%,泵出口平均流量降低了1.52 L/min,泵的容积效率降低了3.04%,温度的升高对齿轮泵性能产生了不利影响,验证了温度与容积效率数学模型的正确性。

章动式双圆弧螺旋锥齿轮齿面曲率与运动特性研究

为了准确评估章动式双圆弧锥齿轮副两处啮合区域之间的啮合特点和差异,对表征齿轮传动质量好坏的曲率和相对运动参数进行了理论计算研究。首先,基于齿轮空间啮合原理,推导了双圆弧内、外锥齿轮的齿面参数方程;接着,在此基础上建立了章动传动啮合坐标系,采用齿面接触分析(TCA)方法,得到了无装配误差情况下接触点的运动轨迹;然后,根据微分几何理论推导出了接触点处各类曲率和速度的数学表达式,并根据赫兹(Hertz)弹性接触理论确定了齿面接触区形态;最后,采用算例分析了接触点的主曲率、诱导法曲率、卷吸速度、相对滑动速度和滑滚比等变化趋势及其反映的特性。研究结果表明:椭圆长轴方向诱导法曲率接近0,短轴方向诱导法曲率绝对值较小,由齿面公法矢量方向可知,两啮合区域在传动过程中不发生曲率干涉现象,且具有良好的接触强度;相对滑动速度远小于卷吸速度,这有利于减小磨损;两区域的滑滚比均趋近0,表明传动接近纯滚动;瞬时接触点和齿面接触区均位于啮合齿面中部并沿整个齿宽方向分布,有限元结果与理论计算结果一致。该研究结果可为章动式双圆弧锥齿轮的弹流润滑和磨损分析提供理论基础。

双圆弧谐波齿轮齿形参数化设计仿真与验证

谐波减速器的应用领域对产品性能的要求日益提高,尤其是机器人行业,要求谐波减速器具备高寿命、高精度、高转矩容量等。传统的渐开线齿形由于同时啮合齿对数较少,传动能力有限,难以达到使用要求。而双圆弧谐波齿形能满足上述要求。但目前国产谐波减速器主要还是以渐开线齿形为主,对双圆弧谐波齿形的设计原理基本没有掌握。首先介绍了谐波减速器的研究概况,然后讲述了双圆弧谐波减速器齿轮传动的基本原理和双圆弧齿形计算机辅助设计软件的开发,提出了几种齿形设计中如何提高啮合精度的方法和基于复杂柔轮有限元变形分析的中性曲线的三次样条模型。通过理论计算模型开发出了双圆弧谐波齿轮计算机辅助设计软件,极大地提升了设计开发效率,降低了开发成本。通过有限元分析模拟了柔轮的真实变形,有限元模拟出的柔轮变形齿廓能与刚轮齿廓精确啮合,与理论计算出的刚柔轮齿廓能精确啮合达成一致,证明理论模型计算出的双圆弧齿廓是准确无误的。