高造斜井眼轨迹控制工具主轴力学行为研究与优化设计

依据高造斜井眼轨迹控制工具的基本结构,建立实际工况下的主轴力学模型.分析了钻压、偏置机构的偏距对主轴力学行为的影响规律,分析得出,外壳与主轴存在较强的相互作用;增加钻压会降低钻头偏转角、偏置机构作用力和主轴最大截面弯矩;钻头偏转角、偏置机构作用力和主轴最大截面弯矩随着偏置机构偏距的增加而线性增加.通过分析偏置机构安装位置、主轴刚度对主轴力学行为的影响规律得出,降低主轴刚度能有效减小偏置机构作用力和主轴最大截面弯矩,且不影响钻头的偏转角.该分析能有效指导高造斜井眼轨迹控制工具的设计与现场应用.     

流体动压轴承主轴系统的动态特性实验研究

选用螺旋槽轴承代替球轴承 ,建立了螺旋槽轴承主轴系统模拟试验台 ,研究了螺旋槽轴承主轴系统的动态特性 ,并考察了载荷、速度、轴承间隙以及润滑剂等对其动态特性的影响 .结果表明 :随着转速提高 ,螺旋槽轴承主轴系统的径向和轴向不可重复误差 ( N RRO)均减小 ;载荷对主轴的径向动态特性影响很小 ,但对其轴向动态特性影响较大 ,随着载荷增大 ,轴向 N RRO逐渐减小 ;主轴的径向和轴向 N RRO均随轴向间隙减小而减小 ;随着润滑剂粘度增大 ,主轴径向 NRRO逐渐减小 ,而轴向 NRRO受润滑剂的影响不明显 ;润滑剂粘度越大 ,主轴所消耗的功率越大     

井眼轨迹控制工具主轴载荷与造斜能力关系研究

井眼轨迹控制工具是随钻实时完成导向功能的一种导向式钻井工具.在复杂工况下,主轴承受钻压、扭矩和偏置机构作用力等,十分复杂.在课题组前期研究的基础上,对样机主轴的力学行为开展了进一步的研究,在建立主轴静力学模型的基础上,分析了工具外壳刚度、偏置机构安装位置等因素对主轴力学行为与造斜能力的影响规律.研究发现,主轴下端偏转角、偏心机构作用力和最大截面弯矩会随着偏心位移增加呈线性增加;随着外壳刚度的增加和偏置机构安装的位置与上支撑轴承之间距离的增加,工具造斜能力也会增强;通过分析偏置机构安装位置和外壳刚度对主轴力学行为的影响规律发现,随着外壳刚度的增大和偏置机构安装位置与上支撑轴承之间距离的增大,主轴最大截面弯矩也会增大.最后,给出了最佳的外壳刚度与偏置机构安装位置建议.     

从主轴表示到抽象表示

本文提供一个系统的方法,将主轴法的结果转换为不依赖于主标架的抽象表示,从而把主轴法结果的进一步应用向前推进了一大步。      

6140机床主轴力学特性有限元分析

建立了6140机床主轴的力学简化模型,计算了在计算转速下的受力参数,从而建立起有限元分析模型,采用四面体单元划分网格,分析了机床主轴在加工过程中的变形和应力,依据有限元分析结果,提出了减小机床加工误差的方法．     

旋转构件变形的完备性论证与分析

问题处于重力场中的工程机械主机上安装的旋转部件如图1所示:四根质量均为m、长度均为L的杆件以铰接构成菱形,竖直固定主轴与其一条对角线重合,菱形最上方的点被锁定而最下方的点是一个可在主轴上自由滑动的轴套且此两点间连接有一根刚度系数为k、自然长度为2L的螺绕弹簧(密布缠绕在主轴上)。电动机驱动菱形结构绕主轴旋转,杆件与主轴夹角60°时体系达额定工作状态。     

考虑动力学特性的航空发动机主轴球轴承热弹流分析

本文中以476728航空发动机主轴球轴承高速重载典型工况为算例,提出一种将轴承动力学分析和热弹流润滑分析相集成的数值算法,打破传统分析中二者在各自领域独立进行的局限性,提高了轴承数值计算的精确度.对比了传统拟动力学分析、集成分析和实验实测的最小膜厚,结果表明:集成分析结果与试验获得数据更为一致,证明本文的算法可行,能够更为准确地判断航空发动机主轴球轴承的润滑状态.探讨了航空发动机主轴球轴承结构参数曲率系数、初始接触角和滚动体数目对轴承接触应力、相对滑动速度、弹流润滑膜压力、膜厚和温度性能的影响,为航空发动机主轴球轴承的结构设计及优化提供重要理论依据.     

指向式导向工具主轴偏置力与造斜性能研究

为研究钻压传递机构安装位置对指向式导向工具主轴偏置力与造斜性能的影响规律，基于横向弯曲梁和纵横弯曲梁力学模型建立了考虑轴向载荷的主轴力学模型，运用微分方程通解对管柱力学进行求解的管柱单元组合方法，推导出主轴的几何方程和力学方程，分析了钻压传递机构安装位置对导向工具偏置力、钻头侧向力与钻头倾角等造斜性能参数的影响。结果表明，钻压传递机构安装位置距离钻头越远，工具主轴造斜所需的偏置力越小，而钻头侧向力与钻头倾角越大。     

CA6140机床主轴有限元分析

建立了6140机床主轴的力学简化模型,计算了在计算转速下的受力参数,从而建 立起有限元分析模型,采用四面体单元划分网格,分析了机床主轴在加工过程中 的变形和应力，依据有限元分析结果，提出了减小机床加工误差的方法.     

关于正多边形截面的形心主轴

<正> 在材料力学教学中,对于矩形、工字形、T 形和 L形等截面,它们的形心主轴一般都是唯一的一对相互垂直的坐标轴;而对于圆形、正多边形截面等,凡是通过截面形心的任意一对相互垂直的坐标轴,都是形心主轴,即形心主轴不是唯一的.圆形截面的这一几何特性,在各种版本的《材料力学》教材中都极易证得.现将正多边形截面的形心主轴并非唯一的这一几何特性,作如下论述.     

大学物理《力学》中的自由度分析

对《力学》中的物体自由度进行多方面分析,以深化教学、提高学生正 确分析物理问题的能力.使用实际教学分析的研究方法,在《力学》范围内讨论自由度与坐标、 自由与约束的关系并得以下结论: (1) 同一物体的自由度随其所在的``空间'不同而不同, 不因坐标系的选取不同而 异, 在同类参考系中不因参考系的动静而有别;(2)自由度遵循叠加原理. 讨论了质点系的总自由度及相关计算问题,并指出研究《力学》中自由度的意义.     

Development and design of new methods of measurement of state of strain of structures

The present paper deals with development and design of new methods utilizing Wiedemann's effect for determination of state of strain in building structures. Wiedemann's effect and some features of torsional strain of magnetic field are the basis of new experimental method. Especially the point electromagnetic strain gages using the effect of pure torsion of electromagnetic field to enable universal examination. For strain-gage measurements, almost all physical quantities are used which can be related to the variation in length of the structures. From the electric strain measurements, the most commonly used methods are the measurements by resonance-wire strain gages or by electric-resistance strain gages. In this paper, electromagnetic strain gages are discussed using the Wiedemann effect, and the author describes some new measuring equipment and his own suggestions and methods based on an application of this effect.     

Calculation of aerodynamic characteristics of arrays of profiles of arbitrary shape

It is well known that the problem on nonseparating potential flow of an incompressible fluid about an array of profiles reduces to an integral equation for a certain real function, determined on the contours of the profiles of the array. As such a function one can take, as was done, for instance, in [1–5], the relative velocity of the fluid on the profiles of the array. For arrays of profiles of arbitrary shape it is necessary to solve the corresponding integral equation numerically. In the particular examples of the calculation of aerodynamic arrays that are available [1–3] the numerical methods used were based on the approximate evaluation of contour integrals by rectangle formulas. As investigations showed, sizeable errors arose thereby in the approximate solution obtained, these being especially significant in the case of curved profiles of relatively small bulk. In the present paper a method for the numerical solution of the integral equation obtained in [5] is proposed. The method is based on the replacement of a profile of the array with an inscribed N polygon, the length of whose sides is of the order N^–1 and whose internal angles are close to . Convergence with increasing N of the numerical solution to an exact solution of the integral equations at the reference points is demonstrated. Examples of the calculation are given.Novosibirsk. Translated from Izvestiya Akademii Nauk SSSR. Mekhanika Zhidkosti i Gaza, No. 2, pp. 105–112, March–April, 1972.     

Method of constructing estimates of the solution of equations of filtration of an aerated liquid

The exact solutions of the nonlinear equations of filtration of an aerated liquid have been obtained in [1–3]. In [4] the system of equations of an aerated liquid have been reduced to the heat-conduction equation under certain assumptions. An approximate method of computing the nonsteady flow of an aerated liquid is given in [5], where the real flow pattern is replaced by a computational scheme of successive change of stationary states. In [6] the same problem is solved by the method of averaging. In the present article estimates of the solution of the equations for nonstationary filtration of an aerated liquid in one-dimensional layer are constructed under certain conditions imposed on the desired functions. These estimates can be used as approximate solutions with known error or for the verification of the accuracy of different approximate methods. We note that the use of comparison theorem for the estimate of solutions of equations of nonlinear filtration is discussed in [7–9]. The methods of constructing estimates of solutions of various problems of heat conduction are given in [10, 11]