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高速滾動軸承的混合潤滑性能及疲勞壽命研究

發(fā)布時間:2018-12-27 12:11
【摘要】:航空科學(xué)技術(shù)的進(jìn)步和發(fā)展要求未來航空發(fā)動機(jī)主軸軸承能夠在高溫、高速和重載工況下可靠運(yùn)轉(zhuǎn),因而滾動軸承的設(shè)計及制造技術(shù)面臨著嚴(yán)峻的挑戰(zhàn)。在上述工況下,滾動體與滾道處于更加苛刻的混合潤滑狀態(tài),潤滑油的非牛頓效應(yīng)和表面形貌效應(yīng)將對混合潤滑性能和滾動接觸疲勞壽命產(chǎn)生重要影響;而軸承在高速運(yùn)轉(zhuǎn)時滾動體的滑動速度、自旋速度以及離心力也將對熱彈流潤滑性能產(chǎn)生影響,進(jìn)而改變軸承的溫升、功率損失和疲勞壽命。然而目前這些方面都缺乏系統(tǒng)的理論研究。 本文針對航空發(fā)動機(jī)主軸軸承的工況條件,在考慮非牛頓和表面形貌效應(yīng)的混合潤滑研究基礎(chǔ)上,提出了高速滾動軸承的疲勞壽命預(yù)測方法,對混合陶瓷軸承和全鋼軸承的溫升特性、功率損失和疲勞壽命進(jìn)行了系統(tǒng)研究。主要內(nèi)容如下: 研究了潤滑油非牛頓特性、接觸副材料、表面形貌和橢圓率等對混合潤滑性能的影響。結(jié)果表明:潤滑油的特征剪應(yīng)力增大會引起膜厚增大但同時會導(dǎo)致壓力波動加;具有橫向紋理特征的粗糙表面對混合潤滑性能更為有利;粗糙度參數(shù)偏態(tài)和峰度對膜厚的影響作用較小,但是對最大壓力的影響較為明顯;橢圓率增大會導(dǎo)致膜厚和最大壓力的減小。 在考慮非牛頓和表面形貌效應(yīng)的混合潤滑研究基礎(chǔ)上,提出了三維次表面應(yīng)力和疲勞壽命預(yù)測方法,研究了潤滑油的非牛頓特性、接觸副材料和幾何參數(shù)、表面形貌等因素對次表面應(yīng)力和疲勞壽命的影響。結(jié)果表明:潤滑油的特征剪應(yīng)力增大會引起摩擦系數(shù)和次表面應(yīng)力的增大,最終導(dǎo)致疲勞壽命的減小,而潤滑油黏度對疲勞壽命的影響作用與潤滑狀態(tài)有密切關(guān)系;在混合潤滑狀態(tài)下,隨著粗糙表面由縱向紋理特征轉(zhuǎn)變?yōu)闄M向紋理特征,次表面應(yīng)力減小而疲勞壽命增加;粗糙度參數(shù)偏態(tài)值的增大會導(dǎo)致疲勞壽命單調(diào)減小,而疲勞壽命隨著峰度的增大呈現(xiàn)明顯的波動變化;峰度值增大,偏態(tài)變化對疲勞壽命的影響作用更明顯,反之亦然。橢圓率的增大有利于次表面應(yīng)力的減小和疲勞壽命的增加。 建立了考慮自旋和潤滑油非牛頓效應(yīng)的點(diǎn)接觸熱彈流潤滑模型,發(fā)展了高效的數(shù)值求解方法,研究了卷吸速度、滑滾比和自旋速度對溫升特性、功率損失及疲勞壽命的影響。結(jié)果表明:卷吸速度對疲勞壽命的影響與橢圓率有密切關(guān)系;滑滾比增大會導(dǎo)致溫度顯著升高和疲勞壽命的減小,并且滑滾比的影響與卷吸速度有密切關(guān)系;滾動體的自旋速度增大會導(dǎo)致油膜溫度升高和功率損失增大,雖然自旋會引起摩擦系數(shù)的減小,但是自旋的存在會降低疲勞壽命。 將點(diǎn)接觸熱彈流潤滑模型與滾動軸承擬靜力學(xué)模型相結(jié)合,,研究了混合陶瓷球軸承和全鋼軸承的溫升特性、功率損失和疲勞壽命。結(jié)果表明:軸承滾道曲率比增大會引起總功率損失的顯著減小;與全鋼軸承相比,在低速時,混合陶瓷球軸承的最大接觸壓力和油膜溫度更高而疲勞壽命更短;在高速時,混合陶瓷軸承具有更低的油膜溫度和更長的疲勞壽命。 通過實(shí)驗(yàn)研究了陶瓷球和鋼球在不同潤滑狀態(tài)下的摩擦學(xué)性能。結(jié)果表明:在混合潤滑狀態(tài)下,陶瓷球的摩擦系數(shù)要大于鋼球的摩擦系數(shù);在全膜潤滑或近似全膜潤滑狀態(tài)下,陶瓷球和鋼球的摩擦系數(shù)幾乎沒有差別;在考慮離心力引起的差異后,陶瓷球的摩擦系數(shù)要小于鋼球的摩擦系數(shù)。
[Abstract]:The progress and development of aviation science and technology require that the main shaft bearing of aeroengine can operate reliably under high temperature, high speed and heavy load, so the design and manufacturing technology of rolling bearing face serious challenge. under the working condition, the rolling body and the rolling track are in a more severe mixed lubrication state, the non-Newtonian effect and the surface appearance effect of the lubricating oil can have an important influence on the mixed lubricating property and the rolling contact fatigue life, and the sliding speed of the rolling body when the bearing is at high speed, The spin speed and the centrifugal force will also have an effect on the lubrication performance of the thermal elastic flow, thus changing the temperature rise, the power loss and the fatigue life of the bearing. However, there is a lack of systematic theoretical research in these aspects. In this paper, the fatigue life prediction method of high-speed rolling bearing is put forward based on the mixed lubrication study of the non-Newtonian and surface morphology effects, and the temperature rise of the mixed ceramic bearing and the full steel bearing is put forward. System research on the performance, power loss and fatigue life of the system The main content is, for example, The non-Newtonian behavior of the lubricating oil, the contact sub-material, the surface morphology and the ellipticity of the lubricating oil were studied. The results show that the increase of the characteristic shear stress of the lubricating oil can cause the increase of the thickness of the film, but at the same time, the pressure fluctuation is increased; the rough surface with the transverse texture feature can be more favorable to the mixed lubricating property, and the influence of the roughness parameter deviation state and the kurtosis on the film thickness It is small, but the effect on the maximum pressure is more pronounced; the increase in the ellipticity results in film thickness and maximum pressure Based on the study of mixed lubrication with non-Newtonian and surface morphology effects, the three-dimensional surface stress and fatigue life prediction method are put forward, the non-Newtonian characteristics of the lubricating oil and the contact sub-materials are studied. and other factors such as geometric parameters, surface morphology and the like, The results show that the increase of the characteristic shear stress of the lubricating oil can cause the increase of the friction coefficient and the secondary surface stress, which can lead to the decrease of the fatigue life, and the effect of the viscosity of the lubricating oil on the fatigue life is closely related to the lubrication state. Under the condition of lubrication, as the rough surface is changed from the longitudinal texture feature to the lateral texture feature, the secondary surface stress is reduced and the fatigue life is increased; the increase of the partial state value of the roughness parameter can lead to the monotonicity of the fatigue life, and the fatigue life is obviously changed with the increase of the kurtosis; The peak-to-peak value is increased, and the effect of the change of the partial state on the fatigue life is more obvious and vice versa. The increase of the ellipticity is beneficial to the reduction and fatigue of the secondary surface stress In this paper, a point-contact thermal elastic flow lubrication model considering the non-Newtonian effect of the spin and the lubricating oil is established, and a high-efficiency numerical solution method is developed to study the temperature rise characteristics, power loss and the spin speed of the rolling speed, the slip ratio and the spin speed. The results show that the effect of the rolling speed on the fatigue life is closely related to the ellipticity. The increase of the sliding ratio can lead to a significant increase of the temperature and the decrease of the fatigue life, and the effect of the slip ratio and the roll-out ratio The speed is closely related; the increase in the spin speed of the rolling element results in an increase in the temperature of the oil film and an increase in the power loss, although the spin may cause a decrease in the coefficient of friction, but the presence of the spin The temperature rise characteristics of the mixed ceramic ball bearing and the full steel bearing are studied by the combination of the point contact thermal elastic flow lubrication model and the rolling bearing quasi-static model. Power loss and fatigue life. The results show that the increase of the curvature ratio of the bearing raceway can cause a significant reduction in total power loss. Compared with the full steel bearing, the maximum contact pressure and the oil film temperature of the mixed ceramic ball bearing are higher than that of the full steel bearing. shorter life; at high speeds, the hybrid ceramic bearings have a lower oil film temperature The fatigue life of the ceramic ball and the steel ball is studied by the experiment. The results show that the friction coefficient of the ceramic ball is greater than that of the steel ball under the condition of mixed lubrication, and the friction coefficient of the ceramic ball and the steel ball is almost no difference under the condition of full-film lubrication or approximate full-film lubrication. the friction system of the ceramic ball after considering the difference caused by the centrifugal force
【學(xué)位授予單位】:北京理工大學(xué)
【學(xué)位級別】:博士
【學(xué)位授予年份】:2014
【分類號】:TH133.33

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