共查询到18条相似文献,搜索用时 765 毫秒
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以半球螺旋槽动静压气体轴承为研究对象,建立球面动静压混合气体轴承的非线性动态润滑计算分析数学模型,采用偏导数法推导出扰动压力控制方程;在广义坐标系下,采用有限差分法对扰动压力控制方程离散化,推导出扰动压力的差分表达式;推导出半球螺旋槽动静压气体轴承刚度和阻尼系数与扰动压力之间的关系表达式;采用VC++6.0编制程序,数值计算出三维微气膜的瞬态扰动压力分布、非线性气膜力及动态刚度系数和动态阻尼系数。研究转速、偏心率及供气压力对气膜动态特性系数的影响规律,结果表明:随着转速、偏心率及供气压力的增大,气膜刚度和阻尼系数均有不同程度的变化。 相似文献
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针对高速动静压气体轴承气膜的复杂非线性动力学行为,以球面螺旋槽动静压气体轴承为研究对象,建立润滑分析数学模型;采用有限差分法与导数积分法进行求解,得到动态扰动压力分布及动态特性系数,并研究切向供气条件下螺旋槽参数、径向偏心率、供气压力、转速对气膜刚度阻尼系数的影响规律;建立线性稳定性计算模型,预测气膜涡动失稳转速,分析运行参数对失稳转速的影响。结果表明:气膜阻尼是一种抑制涡动的因素,气膜的稳定性取决于气膜刚度与阻尼的协同作用;气膜刚度阻尼随着槽宽比、槽深比、螺旋角的增大,整体上呈先增大后减小的趋势;刚度随转速的升高而增大,阻尼则随转速的升高而减小;径向偏心率和供气压力越大,气膜刚度和阻尼越大;在一定范围内,提高供气压力、增大径向偏心率能够提高系统失稳转速;合理地选取轴承结构参数和运行参数,能够优化轴承动态特性,保证气体轴承较高的运行稳定性。 相似文献
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以流体润滑为基础,考虑热效应对油膜黏度的影响,研究涡轮增压器浮环轴承的动态特性,利用DyRoBesBeperf软件建立涡轮增压器浮环轴承的参数化模型,在环速比一定时分析浮环轴承内外油膜压力的分布,以及偏心率、油膜的刚度、阻尼随转速的变化规律。研究表明:在浮环轴承结构参数及载荷一定的情况下,随转子转速的增加,其偏心率下降,Sommerfeld数和功耗均增大,且内油膜的Sommerfeld数、功耗大于外油膜的Sommerfeld数及功耗,因此内油膜承载力大于外油膜承载力;因偏心率随转速的增大而减小,因此油膜等效刚度和等效阻尼下降。 相似文献
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提出一种新型结构的动静压轴承——径向推力联合浮环动静压轴承,将径向浮环和推力浮环做成一体。给出该轴承径向部分的内、外油膜Reynolds方程和边界条件,进行了静、动特性计算和稳定性分析。与同等工况下高速旋转机械中广泛使用的五瓦可倾瓦轴承进行比较,该联合浮环动静压轴承具有摩擦功耗低和较高的旋转稳定性等特点。计算结果表明,这种轴承摩擦功耗降低约20%,失稳转速为125685r/min,可以取代五瓦可倾瓦轴承。 相似文献
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给出了动静压径向推力联合浮环轴承推力部分内、外层油膜Reynolds方程和边界条件,通过有限元计算得到了不同间隙和转速下内、外层油膜的压力分布和静、动态特性参数。采用深腔作为节流腔,分析计算了该内置扁毛细管节流的相当节流比。该推力浮环轴承与透平膨胀机组原来使用的五瓦可倾瓦轴承相比,稳定工作时摩擦功耗降低约26%。 相似文献
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Results of the analysis of hybrid (aerostatic and aerodynamic) taperedland ournal bearings are presented. For a known bearing geometry, the Reynolds equation is reduced to a set of partial differential equations by using a first-order perturbation method. These differential equations are solved by a finite-difference numerical technique. The effects of various design and operational parameters on the load-carrying capacity and the attitude angle of the bearing were studied. The results are expressed in terms of non-dimensional parameters to enable their direct use for design purposes. 相似文献
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This paper compares the performance of a six-pocket capillary compensated hydrostatic/hybrid flexible journal bearing to that of a simi ar four-pocket journal bearing. The comparison is based on theoretically computed results. The finite-element method has been used to obtain simultaneous solutions of the three-dimensional elasticity equations and the Reynolds equation. It is observed that the six-pocket journal bearing may be more efficient from a stability point of view as compared to a similar four-pocket journal system. 相似文献
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针对动静压混合滑动轴承,分析了主动节流轴承的可控性,并提出以可控性系数来加以衡量。通过有限差分法迭代求解Reynolds方程,根据油腔内的流量平衡关系修正油腔压力,继而得到轴承间隙内的油膜压力分布和油膜合力;采用小扰动法求解得到轴承的8个动力特性系数和可控性系数。结果表明:增大油腔面积,将能有效提高轴承的可控性;油腔轴向宽度对轴承可控性系数的影响较大,而周向包角的影响相对较小;轴承的同心节流比对轴承的可控性有较大影响,提高节流比将能得到较好的可控性;油腔轴向宽度和轴承的同心节流比对轴承流量影响甚大,需要综合考虑轴承可控性和流量的关系,以达到最优性能。 相似文献
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Every high speed machine, demanding high level of perfection, can operate successfully through a precise design of bearings. Such a design can be formulated after carefully studying both static and dynamic characteristics of the journal bearing. The present paper described the study of static and dynamic performance of a hole‐entry hybrid journal bearing system compensated with constant flow valve restrictor by considering the combined influence of thermal effects and non‐Newtonian behaviour of the lubricant. The variation of the viscosity due to the non‐Newtonian behaviour of the lubricant and temperature rise has been considered in the study. The numerical solution of the generalized Reynolds equation governing the flow of the lubricant, having variable viscosity along with the energy and heat conduction equations, was obtained using finite element method. The non‐Newtonian lubricant has been assumed to follow the cubic shear stress law. The study included the performance of a double row symmetric hole‐entry hybrid journal bearing configuration containing 12 holes per row. The results presented in this paper indicate that change in viscosity of lubricant affects the performance of the hole‐entry hybrid journal bearing system quite significantly. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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Rama Subba Reddy Gorla 《Wear》1981,67(3):351-359
A study of the behavior of an externally pressurized circular porous thrust bearing using a non-newtonian fluid lubricant was made. The governing Navier-Stokes equations were reduced to a set of ordinary differential equations and were solved numerically with the cross-flow Reynolds number and the Prandtl number as parameters. The pressure distribution and the lift force were evaluated. The effects of cross-viscosity coefficients on the flow and heat transfer characteristics of the bearing were determined. 相似文献
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Satish C. Sharma Nathi Ram 《Tribology International》2011,44(12):1852-1863
A theoretical study concerning the slot-entry hybrid journal bearing lubricated with micropolar lubricants is presented. The modified Reynolds equation for micropolar lubricant is solved using finite element method along with equation of lubricant flow through slot-entry restrictors as a constraint together with appropriate boundary conditions. It has been observed that a slot-entry hybrid journal bearing operating with micropolar lubricant shows an increase in the value of minimum fluid film thickness and a reduction in the value of coefficient of friction as compared to a corresponding similar slot-entry hybrid journal bearing operating with Newtonian lubricant. 相似文献