强化研磨加工轴承滚道疲劳寿命研究

发布时间：2018-06-07 16:48

本文选题：强化研磨 + 轴承滚道　；参考：《广州大学》2017年硕士论文

【摘要】：轴承广泛地应用于各行各业,其性能的好坏直接关系到整个装备的使用寿命的长短。随着现代工业和科学技术的发展,对于轴承的高可靠性、高精度、承载能力、动态性能、高速高温和轻量化、小型化、组合化等提出了愈来愈高的要求。滚动轴承结构虽然简单,但其设计和制造过程却十分复杂,掌握轴承的设计原理与制造工艺,才能生产出满足人们需求的轴承以及相关装备。本文基于一种金属材料强化研磨高性能加工技术,用这种技术方法处理轴承滚道表面,使之产生残余应力,研究残余应力的产生与分布,并通过寿命试验来说明这种加工方法对于轴承寿命的影响。本文首先通过理论分析,结合Hertz理论给出了残余应力的预测模型,对6组不同强化研磨加工时间下的试样进行金相分析,推导出了强化研磨时间与强化层厚度的关系。通过SEM分析,对强化层进行了分区,解释了强化研磨产生残余应力的实质原因。通过有限元方法,求解出了在某一载荷之下轴承位移、等效应变、等效应力和接触压力的数值,分析了残余应力对接触应力及裂纹的影响,不同径向载荷下轴承的疲劳寿命,并与赫兹解进行了比较,结果表明:赫兹理论解比仿真解大,随着径向载荷的增大,轴承的外圈与内圈的接触应力也相应地增大,外圈的接触应力总是比内圈的接触应力要小,外圈的寿命始终要大于内圈寿命,残余应力对轴承的接触应力基本无影响,残余压应力对裂纹的生长有抑制作用。然后对强化研磨残余应力场进行检测,并对对应力释放造成的影响通过弹性理论的计算加以修正,得到残余应力在深度方向的分布关系。分布关系表明强化研磨工艺喷射比较均匀,随着测量深度地增加,残余应力值随之增加。在30μm深度以上,残余压应力衰减很快,在120μm深度左右,基本上没有残余应力,在150μm~180μm之间,残余应力会由压应力转变为拉应力。由于测量值与修正值相差始终小于0.15%,说明应力释放造成影响可以忽略。最后进行了轴承的寿命试验,分析了试验过程轴承温度,径向游隙,振动的变化情况。
[Abstract]:Bearing is widely used in all walks of life. Its performance is directly related to the length of the service life of the whole equipment. With the development of modern industry and science and technology, the high reliability, high precision, bearing capacity, dynamic performance, high speed and high temperature and light quantization, miniaturization and combination of bearing are more and more demanding. Although the bearing structure is simple, its design and manufacturing process is very complicated. In order to produce bearings and related equipment to meet the needs of the people, the bearings and related equipment can be produced by mastering the design principle and manufacturing process of the bearing. The residual stress is produced and distributed, and the effect of this processing method on the bearing life is explained by the life test. First, the prediction model of residual stress is given by theoretical analysis and Hertz theory, and the metallographic analysis is carried out on 6 groups of specimens with different intensification grinding time, and the strengthening research is derived. The relationship between the grinding time and the thickness of the reinforced layer is made. Through the SEM analysis, the strengthening layer is divided and the substantial reasons for the reinforcement of the residual stress are explained. Through the finite element method, the value of the bearing displacement, equivalent strain, equivalent stress and contact pressure under a certain load is solved, and the residual stress is analyzed for contact stress and crack. The fatigue life of the bearing under different radial loads is compared with the Hertz solution. The results show that the Hertz theoretical solution is larger than the simulation solution. With the increase of the radial load, the contact stress between the outer ring and the inner ring of the bearing increases correspondingly, and the contact stress of the outer ring is always smaller than that of the inner ring, and the life of the outer ring is always larger. In the inner ring life, the residual stress has no effect on the contact stress of the bearing, and the residual compressive stress has a restraining effect on the growth of the crack. Then the residual stress field of the reinforced lapping is detected, and the effect of the corresponding force release is corrected by the calculation of the elastic theory, and the distribution of the residual stress in the depth direction is obtained. The relationship shows that the intensified grinding process is more uniform, and the residual stress value increases with the depth of measurement. At the depth of 30 mu m, the residual stress attenuation is very fast, at the depth of 120 mu m, the residual stress is basically no residual stress, and the residual stress will change from pressure stress to tensile stress at 150 u m~180 mu m. The difference of value is always less than 0.15%, which indicates that the effect of stress release can be ignored. Finally, the life test of bearing is carried out, and the change of bearing temperature, radial clearance and vibration in the test process is analyzed.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH133.3;TG580.68

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