串行轴承组均载性能及承载能力分析

针对潜油螺杆泵采油系统中,限径轴承轴向力过大导致系统整体寿命受限这一关键技术难题,基于"串联结构,并行均载"的设计理念,设计了串行轴承组结构,使轴承组轴承单元平均承担轴向载荷,以提高系统的整体寿命。以串行轴承组形式取代了原有单一轴承结构,建立了轴承组的等效力学模型,应用机械阻抗分析法得到了等效力学模型的等效机械网络,并对串行轴承组的均载理论进行了分析;采用数值模拟的手段,对多级轴承组和原结构的等效应力、应变进行了对比,分析了多级轴承组的均载性能和承载能力。研究结果表明:在轴向载荷一定时,二级、三级、四级、五级轴承组对原结构等效应力的减少比例分别为40.75%、60.36%、67.77%、71.19%,并且均载率在82%以上,均载效果良好,有效提高了轴承组承载能力;串行轴承组为研究潜油螺杆泵采油系统轴向承载能力提供了一种可行方法,也为极端工况下需提高限径轴承承载能力和可靠性的其他装置提供了借鉴。     

轴承串对轴向力的均压作用仿真分析

针对潜油螺杆泵采油系统中轴承部分做优化设计,采用ANSYS有限元软件,对单个推力球轴承、二级推力球轴承串、三级推力球轴承串、四级推力球轴承串在相同外界条件下进行仿真分析,对比轴承串所受等效应力、等效弹性形变,验证轴承串结构的受载情况及轴承串结构的均压作用,估算出轴承串结构与原有结构相比的优化效果。     

螺杆泵斜-平面固定瓦推力轴承润滑特性分析

为了提升润滑油系统可靠性,避免轴承磨损,采用CFD分析螺杆泵斜-平面固定瓦推力轴承的润滑特性。计算该螺杆泵螺杆轴向力,得到油膜承载力数值范围;采用有限差分法得到油膜压力分布与厚度分布,采用有限体积法仿真分析不同油膜厚度、不同进油温度时轴承的压力场。仿真结果表明：温度通过影响润滑油黏度对轴承压载产生影响,当油膜厚度固定时,进油温度越低,润滑油黏度越大,轴承所受压载越大;当进油温度一定时,油膜厚度降低,则承载能力增加。因此,在低温启动滑油泵时,油膜由薄变厚平衡螺杆轴向力的过程中,轴承压载可能会超过许用压载,从而导致轴承磨损。     

潜油螺杆泵采油系统数字化设计平台的开发研究

阐述了数字化设计技术的内涵和重要性,分析了潜油螺杆泵采油系统研发中存在的问题,应用数字化设计技术建立了具有设计、分析和数据管理功能的潜油螺杆泵采油系统数字化设计开发平台.介绍了潜油螺杆泵采油系统数字化设计开发平台的基本构成和特点.     

基于FLUENT的涡轮增压器推力轴承特性分析

轴向推力轴承,又称为止推轴承,被广泛应用于涡轮增压器中,增压器转子系统中产生的轴向力都是由轴向推力轴承承受。本文对涡轮增压器滑动轴承模型进行基于FLUENT的全三维数值仿真分析,得到轴向推力轴承三维油膜压力、流场、温度分布。通过分析,得到了稳态下轴向推力轴承油膜压力场、温度场、流场在不同转速下的分布特点:随着转速的上升,推力轴承内部流场的峰值压力随之上升,推力轴承承载能力与滑油流量也随之上升,并且峰值压力、轴向推力以及滑油流量和转速的关系是呈等比例上升;同时对比分析了转子转速、楔形深度、最小油膜厚度等一些关键参数对轴向推力轴承性能的影响。     

非对称并行结构螺杆泵采油系统参数配置方法研究

非对称并行结构螺杆泵采油系统,可以从根本解决推力球轴承限径、承载能力过小以及寿命短的问题。但是,目前非对称反旋向并行结构螺杆泵采油系统只有概念模型结构,尚未有人对双泵的参数配置方法进行研究。为此,提出了一种新型井下非对称反旋向并行结构电机驱动螺杆泵采油系统。首先,基于“等寿命”理念开展了双螺杆泵的参数配置方法研究,给出了双泵匹配需要满足的约束条件,建立了易失效部件的受力分析模型,根据力平衡原理给出了部件之间的受力关系,分析了单螺杆泵转子所受轴向力和工作扭矩;然后,依据等寿命准则(推力球轴承与万向联轴器的疲劳使用寿命趋于相等),确定了推力球轴承所受轴向压力与联轴器所受拉力之间的比值关系,给出了上下两螺杆泵之间所受轴向力之比;最后,确定了定子橡胶寿命为一年及泵端压差12 MPa条件下,双泵参数匹配方案,对所选方案进行了寿命和排量对比分析,分析了不同泵端压差对下螺旋杆泵极限排量的影响。研究结果表明：针对特定推力球轴承和十字联轴节,下螺杆泵与上螺杆泵之间所受轴向力之比为1.41∶1;螺杆泵定子橡胶寿命一定,双泵的排量相比于单螺杆泵有了很大的提升,平均增长率在50%左右。     

涡轮增压器推力轴承轴向载荷变化规律研探究

在发动机运行工况变化过程中,涡轮增压器推力轴承轴向载荷也随之发生连续变化.本文通过实际发动机台架试验测试,采用理论数值计算分析涡轮增压器推力轴承轴向载荷随发动机工况的变化规律,以探究实际发动机运行过程推力轴承因轴向载荷过大导致推力轴承异常磨损的风险工况.     

联合载荷作用下交叉圆柱滚子转盘轴承的承载能力分析

建立了在径向、轴向和倾覆力矩联合载荷作用下交叉圆柱滚子转盘轴承的力学模型,该模型考虑了转盘轴承的游隙参数。采用Newton-Raphson法对力学模型进行了数值求解。计算了转盘轴承的安全系数和疲劳寿命两个承载能力指标,分析了转盘轴承游隙变化对转盘轴承内部载荷分布、安全系数和疲劳寿命的影响规律。结果表明:转盘轴承游隙的变化对转盘轴承内部的载荷分布和承载能力有着显著的影响。随着转盘轴承轴向游隙的增大,转盘轴承内部承担外部载荷的滚子数量逐渐减少,受载最大的滚子载荷也随之逐渐增大。在转盘轴承的轴向游隙从0 mm增大到0.24 mm的过程中,转盘轴承的承载能力安全系数下降了16%,疲劳寿命减小了26%。     

基于热流固耦合的离心压缩机推力轴承温度场预测

针对离心压缩机推力轴承的温度场预测,采用热-流-固多场耦合分析方法,利用专业轴承计算软件THRUST开展有限元仿真分析,在考虑推力盘和瓦块的受力、受热形变的前提下,首先计算得出了推力瓦块的温度分布云图,在此基础上,以转速、轴承载荷、进油温度为主要指标,计算得出不同参数对推力轴承最高瓦温的影响规律。结果表明:提高转速或增加进油温度,轴瓦最高温度会升高,加大轴向载荷最高瓦温同样升高,但趋势变缓。研究结果可为离心压缩机推力轴承的设计、选型、故障诊断提供理论依据。     

2Z-V型电动潜油螺杆泵采油系统用行星减速器优化设计

电动潜油螺杆泵采油系统(ESPCPS)的设计关键是要解决螺杆泵低转速、高扭矩的动力输入要求,研究实验结果发现机械减速器是整个机组系统的难点所在。根据胜利油田某油井工况对电动潜油螺杆泵采油系统用减速器的设计要求,采用2Z-V型少齿差行星齿轮传动进行优化设计。根据所建立的数学模型,选用可靠性高、搜索速度较快的分层网络法进行寻优,性能参数良好、优化效果明显。首次提出了潜油螺杆泵减速器综合性能系数R,解决了不同机组、不同工况下、不同结构潜油螺杆泵减速器的性能比较问题。     

附加轴向力法计算向心推力滚动轴承轴向力

向心推力滚动轴承本身所受轴向力通常采用判断“压紧”端和“放松”端的方法来求解,现有的判别方法既不完备,又容易出错。为了完善现有的判别方法,通过轴系结构的分析,引入轴承安装方式这一新增判别条件。为了简化计算过程,通过力学推导,提出了一种不需要利用判别方法,直接得到向心推力滚动轴承本身所受轴向力的新方法,称为附加轴向力法,即向心推力滚动轴承本身所受轴向力等于其本身派生轴向力与其本身所受附加轴向力之和,并通过与原先方法的结果对比验证了新方法的正确性。     

Theoretical and Experimental Study on the Axial Oil Film Stiffness of Tilting Pad Thrust Bearings

Tilting pad thrust bearings are a key component of marine propulsion shaft systems. The dynamic performance of thrust bearings has a significant influence on the propeller vibration. To investigate the axial oil film stiffness of tilting pad thrust bearings, a two-dimensional thermohydrodynamic model incorporating the vibration frequency is developed. The test apparatus and experimental identification model are also constructed. The axial oil film stiffness is experimentally identified at different speeds, loads, and temperature employing the hammer impulse excitation. The axial oil film stiffness between theoretical and experimental results is compared. The discrepancies are not more than 7% for 30 kN operation cases but increase with axial static load. This is partially because the influence of the pivot stiffness becomes obvious with the axial static load increase and cannot be ignored. The results indicate that axial oil film stiffness is at a magnitude of 10⁹ N·m^?1. Compared to foundation stiffness of the thrust bearing system, the influence of axial oil film stiffness needs to be considered for bearing–rotor system design of marine propulsion systems in engineering practice.     

Thrust bearing groove race defect measurement by wavelet decomposition of pre-processed vibration signal

Nature of vibration signal from a ball bearing system reveals location of fault and its severity. A proper signal processing technique is required to extract relevant information from a vibration signal. In this work measurement of groove race defect width in thrust bearing is presented by processing vibration signal using wavelet based technique. In the first step, pre-processing of vibration signal is done by multiplying the signal amplitude with its own absolute values. It helps to overcome the problem of detection of weak burst in normal vibration signal retaining sign of the original signal. In the second step, Symlet5 wavelet based decomposition is applied to the pre-processed signal to measure the size of seeded defect in outer groove race of thrust bearing. The decomposition based on Symlet wavelet is preferred because it reduces the ambiguity in detecting the entry point and exit point of the defect as it is having linear phase in nature. Measurement has been done for the groove defect width over the range of 0.4399–1.4854 mm. Measurement of defect has been also verified using image examination. Maximum deviation in result has been found in the cases which have minimum axial load (48 N) for every size of defect. With increase in axial load to 73 N and further to 98 N the bearing system gets properly stressed, which increases the accuracy of measurement. With further increase in axial load to 126 N and above, it has been observed that the burst disappears due to prevailing over-stressed condition of the loading disk and additional stiffness and damping of the flexible shaft at increased load.     

推力球轴承接触问题有限元分析

推力球轴承是被广泛应用的支承机械,用于承受转速较低的轴向载荷.它是由上下座圈、保持架和球体组成的可分离结构,分为单向推力球轴承和双向推力球轴承两种.着重分析了不同尺寸、形状的球形滚动体和橄榄球形滚动体对接触情况下的应力和变形量的影响.使用Pro/E建立实体模型,导入ANSYS进行数值模拟和计算.通过对获得的数值模拟结果和赫兹理论解进行对比,结果表明有限元分析是比较准确而且可靠的.最大接触应力和弹性趋近量取决于滚动体与滚道接触处的主曲率和、主曲率差,与滚动体形状、体积没有直接联系.     

The Performance of Externally Pressurized Bearings Using Simple Orifice Restrictors

The load capacity and vibration characteristics of externally pressurized thrust and journal bearings have been investigated. The bearings used orifices sufficiently recessed back from the bearing surface to ensure that the area of the orifice is the minimum presented to the gas flow. The journal bearings consist of plain cylinders with one or two rows of eight orifices, and the thrust plates of plain discs with six orifices drilled in equispaced circumferential grooves.

The load capacity of the thrust plates agrees with that calculated but the vibrations are greater than predicted. The load capacity of journal bearings is about half that calculated assuming axial flow conditions in the bearing, but circumferential flow can account for the difference. Synchronous and half-speed vibrations of a shaft rotating within these bearings have been measured and found to agree with those calculated on the assumption that the gas films behave as linear springs.     

Study of the Tribological Behavior of a Thrust Washer Bearing

This study addresses the mechanisms that distress a flat-faced thrust washer bearing system. This washer bearing system separates a helical gear and its carrier within a gearset. It was found that the bearing can experience distress by the combination of rotational speed, axial load, and the sequence and rate of their application. Distress is defined as a sudden rise in the real-time frictional torque and temperature.

The various tests suggest the presence of hydrodynamic effects at certain rotational speeds and axial load combinations marked by decreases in the calculated effective coefficient of friction with decreases in velocity. In the tested cases, a distinct increase in the coefficient of friction occurs at the instant of distress.     

大型地平式望远镜的方位轴系支撑结构

设计了用于2m口径望远镜的方位轴系支撑结构.通过对比大型地平式望远镜方位轴系的典型支撑结构,拟定了由向心球轴承和大接触角推力球轴承集成的一体化轴系支撑方案以及相应的轴承结构参数.依据Hertz接触理论并采用AYSYS有限元软件对60～85°不同原始接触角下的静载荷特性参数进行了理论计算和非线性仿真分析验证,结合加工工艺设计了85°接触角的推力球轴承结构.研制成功了直径为1 500 mm轴承样机,其轴向跳动为0.009 mm,径向跳动为0.006 mm,最大空载启动摩擦力矩为30 N·m,承载能力优于30 t.该项设计为大型望远镜高精度方位轴系的研制提供了可靠的设计依据和技术途径.     

Analysis of a hydrodynamic thrust bearing with elastic deformation using a recurrent neural network

A theoretical analysis on the general behaviour of a thrust bearing is presented in this paper. The model programme using a method adaptation of finite differences was developed to solve the Reynolds equation for lubrication. The model in the theoretical analysis uses a single one-dimensional grid. The altering of total lubrication load obtained in the result of under-cutting in the thrust bearing have been determined together with the parameters such as oil film thickness and pressure. Parameters such as the pressure and thickness of the oil film were determined. The hydrodynamic behaviour of thrust bearing was analysed by considering of different dimensionless system pressure, speed and geometry of the bearing. The effect of the elastic load due to elastic deflection is taken into account as on the load-bearing characteristics is included. Also, a proposed neural network predictor is utilised to analyse of the general behaviour of thrust bearing. The results of the proposed neural network predictor gives superior performance for analysing of the behaviour of a thrust bearing undergoing in elastic deformation.     

轴向推力轴承性能仿真及试验研究

推力轴承是离心压缩机的关键部件,其性能对压缩机的可靠性有决定性的影响。本文首先利用THRUST软件建立了可倾瓦止推轴承的三维模型,并考虑轴承瓦块、推力盘和油膜之间的流场-温度场-弹性变形的耦合,获得转子转速1500 r/min,2000r/min,2500 r/min,3000r/min 和3500r/min下可倾瓦推力轴承的油膜厚度、转子轴向位移及轴瓦温度。同时,建立试验装置并进行试验研究,最大轴承载荷为30000N。最后将试验结果与软件仿真结果相对比,发现模拟得出的瓦块温度和轴位移值与试验相吻合,从而证明THRUST软件的算法适用于本文研究的工况范围内的推力轴承的模拟,可为推力轴承的性能预测、优化设计及改造提供指导。