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针对齿顶单圆弧过渡的齿条型刀具提出了减小刀具齿顶高 ,以提高被加工渐开线圆柱齿轮的齿根弯曲强度的方案。确定了保证齿轮工作时不发生过渡曲线干涉且不改变齿轮有效齿面前提下刀具的最小齿顶高系数 ,为外啮合渐开线圆柱齿轮传动优化设计提供依据。 相似文献
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顶隙系数、齿高系数等齿形参数是影响齿根过渡曲线形状的重要因素,而不同过渡曲线对应齿根弯曲承载能力不同。为了取得高弯曲承载能力,延长齿轮的使用寿命,从齿轮根部过渡曲线的刀具加工设计入手,分别考虑齿条型双圆弧刀顶、单圆弧刀顶,建立齿轮过渡曲线数学模型,确定齿根局部应力折截面计算模型,探究两种过渡曲线下高弯曲承载能力齿轮的齿高系数及顶隙系数最优变化范围,进而分析齿高系数、顶隙系数对齿根弯曲承载能力的影响,并用有限元对理论分析进行验证。研究表明:在特定的过渡曲线模型下选取合理的齿高系数及顶隙系数,齿根弯曲承载能力有较大提高,这为高弯曲强度齿轮设计提供理论依据。 相似文献
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《机械强度》2015,(6):1084-1091
齿根过渡曲线是影响齿轮弯曲承载能力的重要因素,它由刀具齿顶圆弧共轭形成,因此研究齿轮加工方式及刀具刀顶形状对于提高齿轮弯曲承载能力具有十分重要的意义。针对渐开线圆柱齿轮弯曲承载能力,考虑不同的齿轮加工刀具及齿高系数和变位系数等因素,建立相应的齿根过渡曲线模型,通过折截面法探究齿轮加工方式及刀具刀顶形状对齿轮弯曲承载能力的影响,并通过有限元分析对理论结果进行验证。研究表明:当齿轮基本尺寸不变时,对于不同使用要求,高变位时用齿条型单圆弧刀具加工的齿轮弯曲承载能力高于齿条型双圆弧刀具和齿轮型刀具;角变位且小齿轮变位系数为零时,用齿轮型单圆弧刀具加工的齿轮弯曲承载能力高于齿条型刀具。 相似文献
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面齿轮的弯曲强度是影响面齿轮疲劳寿命的主要因素.提出了面齿轮齿根过渡部分为光滑曲面的一新型齿面结构,给出了应用插齿刀的齿顶圆角生成面齿轮过渡曲面的方法;建立了刀具齿顶圆角的法面方程,经坐标变换,导出了被切削面齿轮光滑过渡曲面的方程;利用数字齿面的方法,分别建立了刀具齿顶尖角和圆角两种结构所生成面齿轮的有限元模型并进行了... 相似文献
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基于刀具进行齿轮参数选取的传统设计方法,对于高速重载齿轮传动很难满足振动冲击小、质量轻等性能要求。基于齿轮传动的性能要求,建立了高速重载齿轮传动的参数直接设计方法。采用动载系数、最大接触应力和滑移率描述齿轮传动的性能指标,考察齿顶高系数、压力角、螺旋角、齿数比以及变位系数对齿轮性能的影响,为进行齿轮直接设计方法和参数优化奠定了理论基础。结果表明,增大齿顶高系数和螺旋角、减小压力角可以减小动载系数使得齿轮传动中的噪声和冲击减少;增大齿顶高系数、压力角和螺旋角可以减小齿面接触应力;减小齿数比可以减小滑移率;减小齿面接触应力和滑动率并在等滑移率曲线上选取变位系数能够避免齿面胶合和传动失效。 相似文献
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笔者近几年用标准刀具在Y38滚齿机和Y54插齿机上加工了许多短齿工件,均能满足使用要求.现将加工方法简介如下:一、加工原理用标准刀具加工短齿齿轮,可看作标准齿轮与短齿齿轮啮合.由于齿顶高系数和齿根高系数不同,当加工至工件要求的齿根圆时,刀具的分度线距工件分度圆切线的距离为(h_a~ж—h_f~ж)m.(h_a~ж是刀具齿顶高 相似文献
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精度较高的硬齿磨削齿轮获得了广泛的应用,但由于设计、刀具特别是热处理变形等原因,使得磨出的渐开线齿廓与齿根圆角不能光滑卸接,往往在齿根部位产生“接刀棱”或“磨削台阶”,据了解在生产中确实存在这类问题。本文通过对典型齿形“磨削台阶”的有限元计算和光弹性试验,对齿根“台阶”部位应力分布情况进行了分析和讨论,提出了相对圆角系数和相对应力集中系数的概念,以期控制台阶所引起的应力集中程度,使这类齿轮能在一定条件下可靠工作。文中对“台阶”和“接刀棱”处的应力分布情况进行了对比,并对如何使用带“台阶”的齿轮等问题进行了讨论。 相似文献
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分别用传统的材料力学的方法计算了在齿轮设计过程中,轮齿齿根处弯曲应力和在同样的条件下,用有限元方法分析了不同齿根过渡圆角齿形的齿根剖面上各点以及过渡圆角处各节点的应力值。此结果和方法为选择正确的应力集中系数,得到适合于各种具体场合的优化齿形以及进一步进行齿根过渡圆角的优化设计提供可靠的帮助。 相似文献
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Sung-Ki Lyu Katsumi Inoue Gang Deng Masana Kato 《Journal of Mechanical Science and Technology》1998,12(2):206-214
This paper deals with effects of surface treatment on the bending fatigue strength of SCM415 carburized spur gears. The test
gears are treated by the combination of shot peening, chemical polishing and electropolishing after carburization. The fatigue
tests demonstrate that the strength is sensitive to the surface condition of tooth fillet and the removal of the nonmartensitic
layer caused by decarburization is considerably effective in enhancing the strength. In the first part of this paper, the
influence of surface treatments such as shot peening, chemical polishing and electropolishing on the strength enbancement
for carburized gears are summarized and discussed. In the second part, the crack lengths are calculated from the fatigue test
results for the carburized and surface-treated gears, and the effect of surface treatments is discussed from the view point
of fracture mechanics. 相似文献
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Thermally refined gears were tested under the effects of various modern industrial gear oils, viscosity 1SO VG 220. The wear of the gears was measured for each oil, including tooth surface roughness and the tooth fillet strain of the pinion. It is concluded that graphite additivated gear oil shows excellent wear resistance and surface roughness over sulphur-phosphorus and organic Mo compound added oils, as well as less iron oxide. 相似文献
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A study on the forging of spur gears 总被引:1,自引:0,他引:1
J.C. Choi Y. Choi K.D. Hur C.H. Kim 《International Journal of Mechanical Sciences》1996,38(12):1333-1335
In this paper, the forging of spur gears have been analysed by using the upper-bound method. The tooth profile of the gear consists of an involute curve and a circular arc shaped fillet. A kinematically admissible velocity field is newly proposed. Numerical calculations have been carried out to investigate the effects of various parameters, such as module, number of teeth, addendum modification coefficient and friction factor on the forging of spur gears. Some forging experiments were carried out with Al-2024 to show the validity of the analysis. Good agreement was found between the predicted values of the forging load and those obtained from the experimental results. 相似文献
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环面渐开线齿轮是一种对安装误差不敏感,无须修形就具有良好啮合性能,并且加工便捷的新型齿轮。根据环面渐开线齿轮的加工原理,从产形齿条的齿面方程出发,推导了凸环面渐开线齿轮和凹环面渐开线齿轮的完整齿面方程;利用MATLAB编程计算出环面渐开线齿轮齿面上点的三维坐标值,生成了精确齿面,并在Pro/E中建立了齿轮的实体模型;基于齿面数学模型,通过计算仿真对环面渐开线齿轮的根切与尖化现象进行了分析,获得了环面渐开线齿轮的根切界限曲线、尖化初始点以及不发生根切与尖化现象的最大齿宽;根据已生成的齿面进行有安装误差条件下的齿轮接触分析,证明了环面渐开线齿轮对安装误差不敏感。
相似文献
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This paper presents an algorithm for computing the form of helical or spur gear fillets on a digital computer. These types of tools are considered to generate the fillet: rack-type tool (hob, rack cutter, or grinding wheel) with or without a protruberance, shaper cutter, and shaving tool. Formulae for the coordinates of the fillet are derived and the boundary points of the fillet are determined both for non-undercut and undercut gearing. Flow diagrams for the solution of some difficult problems are given. 相似文献
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渐开线齿轮齿根过渡曲线是影响齿根弯曲应力的重要因素.为提高齿轮的弯曲强度,提出了采用椭圆曲线代替延伸渐开线的等距曲线,基于坐标转换原理,求出椭圆曲线方程.并采用30°切线法求出椭圆过渡曲线齿形系数和应力集中系数,与标准刀具加工的齿根曲线进行比较,结果表明采用椭圆过渡曲线可以使弯曲应力降低15%.根据齿形法线法,反求出获得该椭圆曲线的滚刀刀顶曲线,为滚刀刀顶设计和实际加工提供了理论依据. 相似文献
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An experimental study to evaluate the power dissipation of gears was performed.Three low-loss gear models were manufactured using standard 20° pressure angle tools. Austempered ductile iron (ADI) and 20MnCr5 carburized steel gears were tested in an FZG gear test machine using mineral, ester and polyalphaolephine (PAO)-based oils.The results compare power dissipation, the influence of different tooth flank geometries, materials and lubricants.This work concludes that conventional power-transmission gears can be replaced by these improved and more efficient low-loss models, which can be produced using common tools and that steel gears can be successfully replaced by austempered ductile iron gears. 相似文献