共查询到18条相似文献,搜索用时 156 毫秒
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可倾瓦径向滑动轴承支承的转子系统瞬态响应计算 总被引:3,自引:0,他引:3
研究了可倾瓦径向滑动轴承支承的转子系统瞬态响应的计算方法,提出了可倾瓦径向滑动轴承非线性滑膜力计算的数据库方法,将可倾瓦与轴颈的结构和运动参数归结到三个参数中,建立了起可倾瓦的非线性油膜力数据库,通过精确插值到每一运动参数组合下轴承提代的油力和轴瓦上所受的油膜力矩。 相似文献
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圆形瓦推力轴承动特性研究 总被引:3,自引:2,他引:1
建立了圆形可倾瓦推力轴承动特性计算的数学模型,考虑瓦变形对轴承性能的影响,对中心支承条件下的圆瓦推力轴承的动特性数学模型进行了有限元求解,得出了圆瓦推力轴承的动特性系数值,同时讨论了弹簧支承时的弹簧刚度选取依据,所得结果可用于指导圆形瓦推力轴承的设计和应用。 相似文献
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弹性箔片动压径向气体轴承动特性的实验研究 总被引:2,自引:1,他引:2
建立了新型弹性箔片动压气体轴承性能测试实验台,在静载60N、转速9000r/min条件下进行轴承性能测试试验,通过中心插值法获得轴承中心的扰动速度和加速度,采用时域最小二乘法计算不同激振频率下的8个轴承动态线性刚度和阻尼系数,考察了激振频率对轴承动特性系数的影响.结果表明:轴颈中心扰动轨迹为椭圆形且振幅随动态激振频率增加而增大;刚度和阻尼系数的直接项随动态激振频率增加而减小;交叉刚度和阻尼相对激振频率的变化较小,且其值小于直接项;当激振频率与轴颈转动频率相同时,工频成分的影响较大,轴心扰动幅值明显增大,刚度和阻尼的直接项小于其它频率时的值. 相似文献
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本文中建立了水润滑可倾瓦推力轴承启停过程瞬态模型,采用Hertz接触模型,以自定义可倾瓦推力轴承起动过程发生初始倾斜时刻转速—初始倾斜转速Uft为对象,分析了支点接触与磨损变形量、载荷大小对水润滑可倾瓦推力轴承起动过程影响.初始倾斜转速Uft随着支点变形量增大而增大,随着载荷增大而增大.在给定可倾瓦推力轴承可接受初始倾斜转速最大值Uftc情况下,几何尺寸确定可倾瓦推力轴承载荷及支点变形均存在最大值.采用水润滑可倾瓦推力轴承性能试验台进行模型验证,结果表明:Uft测量值与数值分析结果吻合度较高,误差小于10%;采用加速度传感器及扭矩传感器联合方法可以比较准确地判断出轴承推力瓦发生倾斜时刻,从而确定可倾瓦推力轴承的Uft值. 相似文献
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为了精确计算可倾瓦推力轴承的静特性,本文建立了推力轴承静特性的计算模型,推导了推力轴承动力润滑的基本Reynolds方程,考虑了润滑油温粘效应、素流的影响、瓦块的温度变形及压力弹性变形。本文还以广州蓄能水电厂一期工程四号机组的推力轴承为例,计算了几种不同初始参数条件下的计算结果,以期对机组推力轴承的特性有一个较全面的认识和了解。 相似文献
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为了精确计算可倾瓦推力轴承的静特性,本文建立了推力轴承静特性的计算模型,推导了推力轴承动力润滑的基本Reynolds方程,考虑了润滑油温粘效应、素流的影响、瓦块的温度变形及压力弹性变形.本文还以广州蓄能水电厂一期工程四号机组的推力轴承为例,计算了几种不同初始参数条件下的计算结果,以期对机组推力轴承的特性有一个较全面的认识和了解. 相似文献
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基于可倾瓦径向滑动轴承瓦块的扰动特性,提出了计算轴承完整动力系数的数学解析模型。在由单块瓦和轴颈构成的子系统上建立局部动坐标参考系,全局广义位移向量可以通过简练的步骤转换为局部动坐标系下轴颈的位移向量,利用求解固定瓦轴承动力特性的方法求得的局部动坐标系下的油膜力又可以精确地转换为全局坐标系下的表达形式,全局坐标系下的油膜力向量关于广义位移和广义速度的Jocabian矩阵形成轴承的完整动力特性系数;利用Newton-Raphson方法同时求解瓦块和轴颈在给定的静态载荷下的平衡位置,其中所需用到的系数矩阵恰好为轴承油膜力关于广义位移的Jocabian矩阵的负值,在得到平衡位置的同时可以获得轴承完整的刚度和阻尼矩阵。数值算例证明了此方法的有效性。 相似文献
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推力主动磁轴承的动特性参数辨识 总被引:1,自引:0,他引:1
针对五自由度刚性非对称磁轴承 -转子系统 ,建立了系统动力学模型 ,在此基础上推导出系统动特性参数辨识公式 ,并用多频电流激励法辨识出参数 .与理论计算结果相比表明 :系统所建模型符合实际 ,辨识方法有效 ;径向轴承在 x和 y方向上的力 -刚度和力 -电流系数相同 ,与推力轴承对应系数相比稍大 ;推力轴承对转子横向振动产生的耦合效应明显影响系统的稳定性 ,在设计系统时必须加以考虑 相似文献
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随动耦合变阶梯径向滑动轴承动力特征及稳定性的研究 总被引:4,自引:1,他引:3
用有限差分法循环迭代求解了随动耦合变阶梯结构径向滑动轴承油膜压力的雷诺方程和两阶段油膜耦合变阶梯结构的流量控制方程。在分析轴承油膜压力形成机量及静力特性的基础上,采用对位移和速度的小扰动法计算了轴承的动力特性系数,考察了运转参数对这种轴承承载特性、动力特性系数、等效刚度、界限涡动比以界限失稳转速的影响,结果发现合理地选择设计参数可以使这种轴承具有较好的静力特性、动力特性和稳定性。 相似文献
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D.R. Oliver 《ournal of non Newtonian Fluid Mechanics》1988,30(2-3)
A model bearing is described which is 20.0 mm in diameter and 2.5 mm in length; a short bearing of diameter to length ratio eight. The clearance is large (500 μm) and the rotor may be run true or eccentric on its own shaft; in each case the mean load and frictional (tangential) force is measured as the centreline eccentricity is varied.Comparison is made between the lubricating performance of Newtonian and highly elastic liquids; the latter give load enhancement ratios of up to 300 and reductions in coefficient of friction by factors of the order 30. These effects are greatly in excess of those obtained when dealing with bearing of diameter to length ratio close to unity; possible reasons for this are discussed.A Newtonian oil and a polymer-thickened oil are tested in the same way, the latter oil is found to give load enhancement ratios of 1.4 (true rotor) and 3.5 (eccentric rotor) with corresponding reductions of coefficients of friction by factors of 1.5 (true rotor) and 3.0 (eccentric rotor). Such effects had not previously been observed when using oils in the internal cylinder geometry (journal bearing type) although somewhat similar effects have been found in the external cylinder and squeeze film geometries.The rheological properties of the polymer-thickened solutions are measured and the relevance of the results to friction and load bearing discussed. 相似文献
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The aim of this paper is to compare a new vertical vibro-compaction machine, carried by a tracked vehicle of total weight 10.9 kN, with compactors using centrifugal, vertical and horizontal oscillators at the exciting force of 9.8 kN and at a frequency of 16 Hz. These were tested experimentally on a thick lift of decomposed weathered granite sandy soil. It was observed that the final amount of sinkage of the terrain surface using the vertical vibro-tracked vehicle was the greatest. The final distribution of dry density was almost uniform in depth and the values were the largest of all other maximum dry densities for centrifugal and horizontal vibro-tracked vehicles. As a result, the vertical vibro-tracked vehicle was verified theoretically from the analysis of the stress and the acceleration propagation to be an excellent and impressive new compaction machine for compacting thick lifts of soil stratum. 相似文献
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Chaos in the unbalance response of journal bearings 总被引:5,自引:0,他引:5
The behaviour of non-linear systems often yield unexpected phenomena which are extremely sensitive to initial conditions. The hydrodynamic journal bearing is a common machine element which is strongly nonlinear for large excursions within the clearance space. A simple model of a rigid journal, supported hydrodynamically using a short bearing theory is shown to behave chaotically when the rotating unbalance force exceeds the gravitational load. At these values of the force ratio the time history of the response is very sensitive to initial conditions and a spectral analysis demonstrates a significant broadening from the expected peak at the rotational frequency. A once per revolution sampling of the time history (Poincaré plot) revealed an apparent aperiodic pattern. An estimate of the fractal dimension using the Grasberger-Procaccia algorithm resulted in a lower bound of 2.15, a typical result for low dimensional systems with significant dissipative action. The required levels of unbalance are only an order of magnitude greater than acceptable levels for rotating machinery and thus could be achieved with in-service erosion or minor damage. The subsequent non-synchronous response could result in fatigue and potential shaft failure. 相似文献
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研究了可倾瓦推力轴承在名义转速分别为2000r/min和4000r/min下,当载荷突然变化时推力轴在油膜温度和油膜厚度的瞬态变化规律。实验结果表明:当载荷突然增大时,油膜温度以及进油边温度上升,油膜厚度减小;随着载荷变化幅度的增大,温度上升幅度也增大,油膜厚度进一步减小;在载荷变化相同的情况下,相同时间间隔内转速高时油膜温度增大幅度比转速低时要大,而油膜厚度减小幅度比低转速下小。 相似文献