转速对齿轮传动混合热弹流润滑的影响

发布时间：2018-01-21 03:45

本文关键词： 粗糙齿面接触应力齿轮转速混合热弹流润滑　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：现行齿轮传动接触疲劳强度的设计依据是赫兹(Hertz)理论,但是该理论的使用条件是没有润滑油环境的光滑表面接触,这与大多数齿轮传动工作在混合热弹流润滑状态的实际工况是不相符的。齿轮转速是影响齿轮传动混合热弹流润滑的重要参数之一,所以不少学者对此影响先后做了研究。然而,现有研究往往基于光滑齿面假设或假定齿面粗糙峰谷呈余(正)弦分布,导致研究结果具有一定的局限性。因此,基于真实粗糙齿面探究转速对齿轮传动混合热弹流润滑的影响,是完全必要的。本文首先应用表面粗糙度轮廓测量仪实测了具有横向纹理的圆盘试件表面粗糙度;然后,通过对实测所得数据的傅里叶非线性变换拟合出粗糙度函数,并将其叠加至油膜厚度方程中从而建立了齿轮传动混合热弹流润滑模型。基于此模型,在保持润滑油参数和齿轮传动参数不变的基础上,针对中、重载齿轮传动,通过改变齿轮转速,进行了702组数值计算,定量分析了齿轮转速对粗糙齿面接触应力、油膜厚度的影响。分析、总结本文研究结果,可得如下结论:(1)当传递功率不变时,提高齿轮转速有利于增大油膜厚度、减小齿面压力;同时,还会减缓油膜厚度和齿面压力波动,并可降低接触区次表面应力集中现象。(2)当齿轮转速不变时,提高传递功率不仅会使齿面压力增大,同时还会加剧齿面压力与油膜厚度波动及接触区次表面的应力集中现象。(3)随着转速的不断变大,齿轮传动润滑状态由混合弹流润滑逐渐变为全膜润滑状态,这意味着轮齿载荷由原来的齿面粗糙峰与润滑油膜共同承担逐渐变为由润滑油膜全部承担。(4)在相同转速条件下,载荷(功率)变化对油膜厚度影响甚微。(5)粗糙齿面接触应力随齿轮转速的增大单调下降。在混合润滑状态下,其下降幅度较大;但在全膜润滑状态下,下降幅度比较缓慢。一般而言,工业齿轮传动大都在混合润滑状态下工作。因此,增加齿轮转速可有效降低齿面接触应力,从而提高工业齿轮传动的接触疲劳寿命。文末,运用多元回归理论,针对中、重载九种工况,分别建立了粗糙齿面接触应力与齿轮转速之间的定量关系。这些公式的建立对完善齿轮传动接触疲劳强度设计具有一定的借鉴意义。本项研究虽然使用了实测所得的真实粗糙度数据,但是为了降低数值计算难度,所建模型仍然采用了其中一个齿面是光滑齿面的假设,这与齿轮传动实际情况有较大差异。
[Abstract]:On the basis of the current design of the contact fatigue strength of gear transmission is Hertz (Hertz) theory, but the theory of the use of conditions there is no smooth surface contact lubrication environment, the actual condition of this work and most gear drive in mixed lubrication state thermal elastohydrodynamic lubrication is not consistent. The gear speed is one of the important parameters affecting the gear mixed heat the elastohydrodynamic lubrication, so many scholars has done a study effect. However, existing studies are often based on the smooth tooth surface assumption or supposition of tooth surface roughness peak valley Chengyu (positive) string distribution, cause the results have some limitations. Therefore, the real tooth surface rough inquiry speed mixed thermal elastohydrodynamic lubrication of gear transmission based on is absolutely necessary. This paper firstly applied surface roughness measuring instrument was measured with transverse texture of the specimen surface roughness; then, based on the measurement. Fourier nonlinear transform fitting data the roughness function, which added to the oil film thickness equation is established and gear mixed thermal elastohydrodynamic lubrication model. Based on this model, based on maintaining the lubrication parameters and gear parameters unchanged, in gear transmission, by changing the gear speed of the 702 groups of numerical calculations, the quantitative analysis of the gear speed on rough tooth surface contact stress and the influence of oil film thickness. The analysis, summarize the results of this study are summarized as follows: (1) when the transmission power is constant, increasing gear speed can increase the oil film thickness, reduce the tooth surface pressure; at the same time, also slow down the oil film thickness and tooth surface pressure fluctuations, and can reduce the stress of the surface contact area concentrated phenomenon. (2) when the gear speed is constant, increasing the transmission power will not only make the tooth surface pressure increases, while also increasing the tooth surface pressure With the fluctuation of film thickness and contact area on the stress concentration phenomenon. (3) as the speed increases, the lubrication state of gear transmission has gradually changed from mixed elastohydrodynamic lubrication for liquid lubrication, which means the original tooth load of tooth surface asperity and the lubricating oil film to bear gradually by the lubricating oil film all bear. (4) at the same rotational speed, load (power) has little effect on the film thickness changes. (5) the contact stress decreased with increasing rotating speed of gear tooth surface. The rough monotone in mixed lubrication state, it decreased greatly; but in the full film lubrication regime fell. The amplitude is relatively slow. In general, industrial gears are working in mixed lubrication state. Therefore, the increase of gear speed can effectively reduce the tooth surface contact stress, so as to improve the contact fatigue life of gear industry. At the end of this paper, using multiple regression theory, for Heavy, nine conditions were established, rough tooth contact quantitative relation between stress and gear speed. To establish perfect gear transmission has certain reference significance to the contact fatigue strength design formula. In this study, although the use of the measured real rough degree according to, but in order to reduce the difficulty of numerical calculation, the the model is used in which a tooth surface is smooth tooth surface with this assumption, the actual situation of gear transmission are quite different.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH132.41

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