旋转叶片整阶次振动双参数分析与仿真

介绍了1种利用非接触式测量技术分析旋转叶片整阶次振动分析的新方法。利用单自由度振动系统,对该方法进行了仿真验证,获得了满意的结果。该方法可用于旋转叶片频率测量。     

高精度接触式测头测量力影响分析与建模

针对高精度非球面检测过程中,测量力对接触式传感器测头测量不确定度的影响问题,本文在建立接触式测头简化结构模型的基础上,分析建立了测杆倾斜、滑动以及弯曲变形对测量精度的影响模型.并通过仿真分析得出了高精度非球面测量过程中接触式测头受非球面相对口径等的影响规律,即,其中测杆的弯曲变形是测量力影响的主要分量.为进一步提高接触式测量的精度奠定了基础.     

接触式干涉仪技术改造

介绍了一种接触式干涉仪数字化改造的方法。改造后的接触式干涉仪采用高精度电感式位移传感器采集数据，由计算机直接输出测量报告；减少了人为的读数误差和对线误差，具有测量精度高、测量速度快、操作简单易掌握等优点。     

高速电主轴负载扭矩软测量技术研究

在分析高速电主轴功率与负载转矩关系的基础上,提出了一种负载扭矩软测量的方法.采用电主轴定子电压、定子电流、空载电流和主轴转速作为辅助变量,建立了基于BP神经网络的负载扭矩软测量模型.以航空发动机离合器轴承试验台扭矩检测为例,对软测量模型进行了仿真研究.仿真结果表明,该方法能够满足一定精度要求,为解决高速电主轴拖动系统扭矩传感器昂贵和不易安装等问题,提供了一种解决方法.     

非接触式转子叶片振动测试技术应用研究

介绍了旋转叶片整数阶次与非整数阶次的振动理论分析,并利用非接触式叶片振动测量系统进行了模拟试验器和台架压气机试验验证.理论分析和试验结果吻合,表明由非接触式叶片振动测量系统测试振幅的变化特征,可确定整阶次共振与非整阶次叶片振动.      

市场

Mountz公司设计了一种使用5伏直流电的扭矩分析仪。它具有与无刷旋转传感器连接的功能。这个仪器记录并分析从强烈振动脉冲器中得出的扭矩及角度读数。有五种工作模式可供选择:轨迹、峰值、初峰、仪器功率、角度。另外,操作者可以选择三种不同的低频过滤器来测试工具和确定任何高灵敏度传感器的适用范围,以减少传感器界面接     

旋转系下的实时压力测量方法研究

航空发动机旋转盘表面的压力测量需要压力传感器与旋转盘一同旋转,因此压力传感器在感受测点压力的同时,其感压膜片还将受到旋转离心力的影响。为了能使压力传感器能反应真实被测点的压力值,在旋转设备上的压力传感器的实时标定技术成为解决这一问题的关键。本文利用空气柱在离心力场中的理论压差给出了旋转状态下的标准压力,进而对传感器进行了实时标定。      

SiC/SiC复合材料氧化退化研究进展

针对高速推进系统温度测量传感器的设计方法、测量误差等核心问题,综述了现阶段高速推进系统接触式和非接触式温度测量的方法。其中,重点综述了辐射与红外测量、可调谐二极管激光吸收光谱(TDLAS)、相干反斯托克斯拉曼散射(CARS)及温度敏感涂料(TSP)等非接触温度测量技术在高速推进系统应用的研究进展和发展趋势,并分析了上述温度测量技术存在的问题。     

声表面波扭矩传感及其在航空发动机领域的潜在应用

分析了声表面波传感器谐振频率随扭矩变化的传感机理,实际制作了差动型声表面波传感器,并通过网络分析仪测试了传感器的线性度和灵敏度。在此基础上搭建了阅读器收发链路,通过阅读器实现了转轴扭矩的无线无源检测。与现有航空发动机测量扭矩时常用的滑环、变压器、电池等能量供给和信号传输方式相比较,该研究方案和搭建的测试系统在一定程度上可以有效地解决可靠供电和信号传输的困难。     

激光位移传感器在铁路轮对测量中的应用

激光位移传感器是一种实用的、高精度、高可靠性的位移传感器，是激光技术和光电检测技术高度发展的必然结果。它的出现，使位移测量的精度、可靠性得到极大的提高，也为非接触位移测量提供了有效的测量方法。使用接触式位移传感器无法完成的测量工作，现在使用激光位移传感器可以很容易的实现。文中介绍了利用激光位移传感器实现对铁路轮对外形尺寸的精确测量的方法。     

飞机高升力系统扭力管旋转角度测试方法

在飞机地面模拟试验环境下需要测试高升力系统襟翼扭力管旋转角度.由于扭力管属于系统试验件,在不改变试验环境构型的情况下不可截断或更换安装用于测试扭力管旋转角度的旋转编码器.本文利用同步轮法实现了在不破坏扭力管前提下安装旋转编码器测试扭力管旋转角度,方法简单、可靠,且容易实现,很好的满足了试验大纲要求.     

旋转超声钻削碳纤维复合材料钻削力和扭矩的研究

针对碳纤维增强树脂基复合材料(CFRP)加工过程中的问题,对金刚石套料钻旋转超声钻削CFRP-T700型复合材料展开了研究。研究发现,钻削力随主轴转速的增加具有减小的趋势,而扭矩则随着主轴转速的增加,呈现增大的趋势;与传统加工相比,旋转超声振动钻削可降低切削力及扭矩达56.6%和39.1%,有效抑制加工缺陷的产生。初步建立了切削力和扭矩之间的数学模型,并通过试验对切削力和扭矩之间的比例常数k加以验证。研究结果表明,旋转超声钻削CFRP在降低切削力和扭矩方面有较大优势。     

基于二次调节原理的力矩负载模拟器中压力波动的补偿

 基于静液二次调节原理的力矩负载模拟器具有能够连续高速旋转和无多余力矩的特点。在恒压网络中,二次元件的力矩输出与其斜盘倾角成正比,即：如果系统压力出现波动,也将导致输出力矩的波动。导致系统压力变化的原因可能是油源压力脉动,但更主要是负载的变化。为了研究压力波动的影响及补偿,建立了基于静液二次调节原理的力矩负载模拟器,给出了仿真参数,并在此基础之上进行了仿真研究。为了提高力矩跟踪精度,提出利用斜盘倾角传感器和系统压力传感器来进行压力补偿,可有效地将系统压力波动对于力矩输出的影响抑制到20%左右。仿真和试验验证了此补偿方法的有效性。     

基于螺旋机构的旋转作动器研究

 研究出一种翼面驱动用旋转作动器。利用逆滚动螺旋机构将油缸的直线运动直接转换为旋转运动。研究表明,这种新作动器与现有作动器比较,具有输出力矩大,直径小,重量轻,标准化通用化的优点。     

基于六霍尔的无刷直流电机换相转矩脉动补偿

针对永磁无刷直流电动机换相过程进行理论分析,提出了一种采用六路霍尔的无刷直流电机换相方法,补偿由于换相引起的转矩脉动。仿真结果表明,与常规三路霍尔的换相方式相比,采用六路霍尔的换相方式使脉动幅值减小了17%。结果证明,六霍尔换相方法可以有效补偿无刷直流电机换相转矩脉动。     

基于交互正交试验的空间用谐波减速器传动性能影响因素研究

 针对空间用谐波减速器的传动性能受多种因素影响且这些因素又相互作用的实际情况,选用XB1-60-150型谐波减速器,采用交互正交试验方法,进行了谐波减速器传动性能热真空试验,考察了转速、环境温度、负载扭矩和润滑方式等因素及其耦合作用对谐波减速器传动效率的影响.通过极差分析和方差分析研究了各因素及其耦合作用对传动效率的影响敏感性,两种分析方法得到的试验结果一致.结果表明,在置信度p=99%时,转速和环境温度对谐波减速器传动性能有显著影响,且负载扭矩与润滑方式之间的交互作用高度显著;交互作用分析获得了谐波减速器最佳的空间使用条件,在该条件下谐波减速器的传动性能最优.     

Reliability estimation of rotary lip seal in aircraft utility system based on time-varying dependence degradation model and its experimental validation

With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach based on time-varying dependence analysis. The dependence between the two performance indicators of rotary lip seals, namely leakage rate and friction torque, is modeled by time-varying copula function with polynomial to denote the time-varying parameters, and an efficient copula selection approach is utilized to select the optimal copula function. Parameter estimation is carried out based on a Bayesian method and the reliability during the whole lifetime is calculated based on a Monte Carlo method. Degradation test for rotary lip seal is conducted and the proposed model is validated by test data. The optimal copula function and optimal order of polynomial are determined based on test data. Results show that this model is effective in estimating the reliability of rotary lip seals and can achieve a better goodness of fit.     

A Numerical Model of the SEIS Leveling System Transfer Matrix and Resonances: Application to SEIS Rotational Seismology and Dynamic Ground Interaction

Both sensors of the SEIS instrument (VBBs and SPs) are mounted on the mechanical leveling system (LVL), which has to ensure a level placement on the Martian ground under currently unknown local conditions, and provide the mechanical coupling of the seismometers to the ground. We developed a simplified analytical model of the LVL structure in order to reproduce its mechanical behavior by predicting its resonances and transfer function. This model is implemented numerically and allows to estimate the effects of the LVL on the data recorded by the VBBs and SPs on Mars. The model is validated through comparison with the horizontal resonances (between 35 and 50 Hz) observed in laboratory measurements. These modes prove to be highly dependent of the ground horizontal stiffness and torque. For this reason, an inversion study is performed and the results are compared with some experimental measurements of the LVL feet’s penetration in a martian regolith analog. This comparison shows that the analytical model can be used to estimate the elastic ground properties of the InSight landing site. Another application consists in modeling the 6 sensors on the LVL at their real positions, also considering their sensitivity axes, to study the performances of the global SEIS instrument in translation and rotation. It is found that the high frequency ground rotation can be measured by SEIS and, when compared to the ground acceleration, can provide ways to estimate the phase velocity of the seismic surface waves at shallow depths. Finally, synthetic data from the active seismic experiment made during the HP³ penetration and SEIS rotation noise are compared and used for an inversion of the Rayleigh phase velocity. This confirms the perspectives for rotational seismology with SEIS which will be developed with the SEIS data acquired during the commissioning phase after landing.     

Tilt-Table Alignment for Inertial-Platform Maintenance without a Surveyed Site

A method for aligning the rotary tilt table for an inertial-platform maintenance facility without surveying the site is analyzed and evaluated. The method utilizes multiple measurements of the tilt-table azimuth alignment error with different inertial platforms to determine a best estimate of the alignment error. Error analysis indicates that useful facility performance can be obtained with only a small number of measurements. The tilt-tablealignment accuracy can be improved as more measurements of the alignment error are made during normal facility operation.     

A novel in-plane mode rotary ultrasonic motor

Ultrasonic motors have the merits of high ratio of torque to volume, high positioning precision, intrinsic holding torque, etc., compared to the conventional electromagnetic motors. There have been several potential applications for this type of motor in aerospace exploration, but bearings and bonding mechanism of the piezoelectric ring in the motors limit the performance of them in the space operation conditions. It is known that the Langevin type transducer has excel- lent energy efficiency and reliability. Hence using the Langevin type transducer in ultrasonic motors may improve the reliability of piezoelectric motors for space applications. In this study, a novel in-plane mode rotary ultrasonic motor is designed, fabricated, and characterized. The proposed motor operates in in-plane vibration mode which is excited by four Langevin-type bending vibra- tors separately placed around a ring-shaped stator. Two tapered rotors are assembled to the inner ring of the stator and clamped together by a screw nut. In order to make the motor more stable and convenient to fix, a thin cylindrical support is placed under the stator ring. Due to its no-bearing structure and Langevin transducer excitation, the prototype ultrasonic motor may operate well in aeronautic and astronautic environments.