风电机组主轴承的设计与技术要求

介绍了风电机组主轴承中滚子尺寸、保持架结构确定的原则及套圈、保持架材料的性能要求,运用有限元分析软件对该轴承的结构及保持架的强度、刚性进行了校核计算;运用转盘轴承计算软件对轴承寿命进行了校核计算,并在此基础上完善了轴承的结构设计,消除了由于轴承结构和保持架的刚性不足造成轴承早期失效的因素。     

小孔节流静压止推气体轴承静特性的数值分析

介绍了计算流体力学软件 FLUENT 及其在气体轴承研究中的应用.针对环形小孔节流静压止推气体轴承,基于 FLUENT 软件进行了简化假设并建立了计算模型,利用 FLUENT 软件对止推气体轴承模型进行了数值分析,求解了环形小孔节流静压止推气体轴承的压力场分布、耗气量和承载能力等轴承静特性,并成功捕捉到了大气膜间隙下供气孔周围的压力突降区.对计算结果进行了分析,并与文献计算值以及试验值进行了对比,验证了数值分析的可靠性.     

动静压混合轴承性能计算分析

本文对不同类型的动静压轴承进行概述分析,概括了不同型式轴承的特点,总结了静压升举轴承的基本型式和动静压性能计算,并对某型发电机轴承的动静压性能进行计算和校核。     

考虑游隙及挠度的十字轴万向节轴承寿命修正

采用MATLAB编程和ANSYS数值分析的方法,对某解放牌载货车用十字轴万向节轴承进行了考虑游隙及挠度的载荷分布计算,并将载荷分布计算结果作为应力分析的输入条件,对受载最大滚针进行了接触应力分析,根据所得应力极值建立了十字轴万向节轴承寿命修正模型。分析计算结果表明,相比于传统寿命计算方法,修正后的轴承寿命计算方法考虑到了游隙与挠度对十字轴万向节轴承寿命的影响,对轴承寿命的预测精度显著提高,试验验证结果与分析结论具有良好的一致性。     

流量泵电机轴承磨损试验及寿命分析

对流量泵电机轴承进行磨损试验后将电动机分解,对轴承进行外观检查及性能测试。通过测试结果与出厂记录的对比,分析了轴承产生磨损的原因,计算了轴承的磨损寿命,并根据计算结果对轴承的剩余寿命进行了预测。     

双螺杆压缩机圆锥滚子轴承的受力分析

针对面对面安装的圆锥滚子轴承进行受力分析,分别计算轴承预紧力、预紧前后的轴承载荷。通过分析,有效地解决了轴承预紧力的计算问题,为后续进行轴承寿命计算提供理论依据,可有效提高螺杆压缩机的可靠性。同时,根据载荷分布特点,对圆锥滚子轴承的选型给出合理化建议。     

主动控制节流气体润滑轴承静动态特性研究

将表面节流与主动控制节流相结合,提出了一种新型的主动控制节流气体润滑轴承,采用工程简化计算与有限元分析相结合,对轴承进行了理论分析,建立了该轴承的理论分析模型,较好地解决了数值计算中多重迭代与快速收敛问题,理论分析和试验研究结果表明,该轴承通过主动控制节流器对轴承压力的反馈控制,轴承静动态性能显著提高。     

电磁轴承磁场计算的磁路法优化

介绍电磁轴承磁场计算和转子受力特性分析的磁路法和有限元法。基于上述两种方法,详细地计算了考虑铁磁材料磁阻及其非线性因数的电磁轴承磁场,讨论了两种方法计算结果的差异。参考有限元法的计算结果,对计算电磁轴承磁场的磁路法进行了优化。优化后的电磁轴承磁路法简单、准确,具有工程应用价值。     

大型离心水泵轴承改造及计算分析

对景电提灌工程离心泵采用的滚动轴承进行故障分析和理论计算，发现离心泵在不利工况下运行会造成轴承使用寿命缩短。针对此问题对景电提灌工程离心泵进行改造，通过解析法和有限元分析法对轴承进行建模分析，计算其轴承压力分布，分析了正交刚度与阻尼、轴承温升、轴承偏心率等参数随转速的变化规律，同时对改造后轴承的稳定性进行分析。结果表明：经过改造后的滑动轴承力学特性表现良好，在不利工况下可显著提升轴承的承载力；通过与滚动轴承计算对比分析，改进后的滑动轴承轴系稳定性表现更优。     

用CFD方法研究具有通用膜厚方程径向轴承的动压特性

应用CFD软件FLUENT和COMSOL Multiphysics对具有通用径向方程的径向轴承建立有限元模型,并进行了三维数值仿真模拟,得到了动压径向滑动轴承内部的压力场分布,通过编程计算出雷诺边界条件下的承载力及相关参数。比较FLUENT和COMSOL Multiphysics的计算结果与数值分析的计算结果可知,对于具有通用型线方程的非圆弧轴承和圆轴承,FLUENT和COMSOL Multiphysics与数值分析计算的径向轴承动压特性一致,即非圆型线轴承的承载力大于圆弧型轴承的承载力,验证了通用膜厚方程理论的正确性。     

A FEM approach to simulation of tilting-pad thrust bearing assemblies

Finite-element method (FEM) modelling is applied to analysis of the performance of hydrodynamic tilting-pad thrust bearing assemblies. A 3D model of the bearing assembly that includes the bearing pad and shaft is used to assess the influence of operating conditions on bearing parameters such as temperature and oil film distributions across the pads. The model is first applied to the investigation of a spherically pivoted-pad. Through comparison with results from experiments carried out on just such a bearing, good correlation between the model and experimental results is found for maximum oil film temperature, pressure distribution and thickness. The model is then applied to the examination of a bearing having spring-supported babbitt pads. The effect of different oil types on a spring-supported thrust bearing is analysed. Further application of the model to investigate the same spring-supported pad, this time with a resilient surface coating, is discussed.     

Influence of pad–pivot friction on tilting pad journal bearing

Some experimental studies reported that the performance of tilting pad journal bearing is related with the pad–pivot friction. Only a few researches, however, consider the friction as a factor even though many ones have theoretically analyzed the performance of bearing. Also, there is no mathematical model for the friction to explain the effect of friction on the performance of bearing. Therefore, this study proposes a mathematical model for the pad–pivot friction and analyzes the effect of friction on the tilting pad journal bearing.The results of this analysis show that the friction has a large influence on the attitude angle of the journal. It is found that the eccentricity direction of the journal does not coincide with the load direction when the friction is not zero. According to working conditions, the attitude angle can be up to 25° when friction coefficient is equal to 0.5. It is also found that the tilt angle of the pad is not determined as a fixed value in case of the bearing with non-zero friction, even though working conditions is given for the static analysis. This study represents four different tilt angles under same working conditions.     

基于多体动力学的齿轮箱圆锥滚子轴承温度场分析

为研究齿轮箱圆锥滚子轴承在不同实际运行工况下的温度分布,对圆锥滚子轴承进行热分析并建立其有限元模型;采用ADAMS对圆锥滚子进行动力学分析,得到滚子在不同转速下的接触正压力和摩擦力,将结果导入ANSYS进行静力学分析后得到滚子的平均接触应力,在此基础上求得摩擦热流量,进而获得轴承的稳态温度场,并通过试验验证了模型的正确性。结果表明,随着转速的增加,轴承温度不断升高;轴承滚动体与内圈接触时的温度高于与外圈接触时的温度,最大值出现在滚子与轴承内圈的接触处。     

基于旋滚比的电主轴轴承预紧力优化研究

为研究不同工况下轴承预紧力对电主轴轴承动力学的影响规律,基于外轨道控制理论,建立了一种以旋滚比可优化的轴承预紧力动力学模型。通过分析高速状态下滚动体载荷和特征参数动态变化过程,构建综合考虑滚动体滚动、自旋转、陀螺运动和离心力的轴承动力学分析模型,在此基础上,计算旋滚比动态变化结果;研究Jones发现的阈值与旋滚比之间的动态定量映射关系;以轴承滚动体打滑状态为优化目标,使用MATLAB仿真分析不同工况下轴承最佳预紧力。建模分析表明,轴承旋滚比大小可以反映轴承预紧效果,也可实现轴承预紧力动态定量优化。     

考虑不同加速工况的滑动轴承的启停性能分析*

滑动轴承的摩擦磨损主要发生在启停阶段。为了研究启停工况下的滑动轴承的摩擦学性能,建立一种面向径向滑动轴承的混合润滑数值分析模型。采用质量守恒边界条件的雷诺方程求解流体压力,采用Greenwood和Tripp接触模型预测固体表面接触,而通过Johnson载荷分配概念将润滑模型和接触模型联系起来,从而实现对滑动轴承在启停工况下从混合润滑过渡到动压润滑的摩擦学行为分析。利用该模型,研究轴承系统在启停阶段从边界润滑、混合润滑到动压润滑演化过程中的摩擦学性能;以径向滑动轴承系统为例,结合不同的轴承转速变化函数,分析轴承加速对轴承启停性能的影响;同时研究工作工况、润滑油温度、轴承的结构参数对轴承启停性能的影响。结果表明：轴承启动加速度在合理范围内越大越好,能使轴承更快进入动压润滑;较高的转速、较低的润滑油温度和较大的径向轴承间隙能使轴承拥有更好的启停性能。     

低速重载工况下连杆小头轴承变形与润滑耦合分析

连杆小头轴承是内燃机中的关键摩擦副,在低速重载工况下容易发生变形和咬合失效,是影响重型卡车发动机可靠性的重要原因。为揭示低速重载工况下连杆小头轴承的性能,以某6缸柴油机连杆小头轴承为分析对象,考虑连杆小头轴承和活塞销孔轴承对活塞销的摩擦转矩,建立柴油机活塞-连杆-曲轴摩擦动力学模型,在此基础上耦合连杆小头轴承的瞬时弹性变形,对比分析轴承变形对连杆小头轴承润滑性能的影响。研究结果表明：在低速重载工况下,忽略轴承变形可能会使预测的活塞销旋转方向相反;连杆小头轴承在吸气冲程受拉会产生严重变形,并且导致轴承与活塞销间润滑性能下降。     

轿车轮毂轴承耐久性试验载荷谱的研究

为了制定轿车轮毂轴承耐久性试验的载荷谱,在建立轿车动力学模型的基础上,分析了轿车轮毂轴承受载的情况。根据实际轿车的一般行驶状态,制定出了轿车行驶的循环周期,基于我国路况特点,确定出了在每个循环周期内每种行驶状态所占的比例。针对一个周期内不同行驶状态轮胎所受的力不同,从而制定了轮毂轴承的试验载荷谱,分析结果表明,该方法对轮毂轴承加载方式的研究具有指导意义。     

Theoretical Prediction of Journal Bearing Stability Characteristics Based on the Extent of the Slip Region on the Bearing Surface

Journal bearing performance depends on the boundary conditions at the interfaces between the fluid and the solid surfaces. In the derivation of the Reynolds equation used to predict the bearing performance, the no-slip boundary conditions of the fluid and the solid interfaces are used. Recent research has shown that a slip can occur on specially made surfaces, the conventional no-slip boundary conditions are not valid, and the Reynolds equation is no longer applicable. If the slip is allowed to occur in certain regions, the fluid flow in the bearing can be altered, and the bearing stability characteristics can be improved. In this article, the numerical stability analysis of a journal bearing based on the extent of the slip region on the bearing surface is analyzed. An extended Reynolds equation is derived based on the slip length model, using a no-slip boundary condition against the journal surface and the slip against the bearing surface. A linearized perturbation method is used to determine the stability limit of a rigid rotor supported on two symmetrical journal bearings. Using the linear stability analysis, the linearized stiffness and damping coefficients, the threshold speed, and the critical whirl ratio are evaluated. The effects of the slip parameter on the bearing stability performance are discussed. The results show that with a critical shear stress of zero, an increase in the stability threshold can be achieved with a higher value of the nondimensional slip length and a smaller extent of the slip region on the bearing surface.     

Computational Mixed TEHL Model and Stribeck Curve of a Journal Bearing

The aim of this article is to propose a model capable of estimating the friction along a heavily loaded journal bearing under mixed and hydrodynamic lubrication. The finite element analysis–computational fluid dynamics (FEA-CFD) model takes into consideration the effect of solid deformations, the asperity contact phenomena, and the influence of metal–metal contact in the Reynolds equation. The Stribeck curve for a plain journal bearing under different operational conditions is calculated and compared to experimental results. The major contribution of the article is the novelty of including mixed lubrication, high-load conditions, and thermal effects in a single computational steady-state model. This comprehensive model, not limited to a specific range of operational conditions, can help during design and for health condition monitoring.     

高速高性能电主轴热态性能分析

基于高速电主轴的能量流模型,应用摩擦学和电磁学理论分别计算轴承的生热率和内置电机的电磁损耗;应用传热学理论,确定电主轴的热边界条件.在此基础上建立电主轴有限元分析模型,并对其仿真分析和求解.结果表明,前端轴承、主轴前端和定子是电主轴温升最严重的部位,且在主轴运行初始阶段,温升最快.因此要改善电主轴的热态性能,不仅要在温...