共查询到20条相似文献,搜索用时 203 毫秒
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针对磁悬浮飞轮转子不平衡振动问题,提出了一种在线动平衡方法。其基于磁轴承控制作用力与转子不平衡离心力之间的等效原理,通过检测磁轴承的控制作用力解算转子不平衡校正质量。设计了零位移控制器,使转子绕几何轴旋转,此时磁轴承的控制作用力与控制电流呈线性关系,通过测量控制电流来准确获得磁轴承的控制作用力。该方法消除了传统方法由动力学模型过度简化带来的误差,尤其适用于强陀螺效应的扁平型刚性磁悬浮转子系统。实验验证了该方法的有效性,对提高磁悬浮转子系统的动平衡精度具有实际意义。 相似文献
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用单面立式动平衡机在对不同尺寸、不同质量工件进行动平衡测量时,会发现存在一个与理论值不匹配的额外不平衡量,传统方法难以给出合理的解释,分析表明是其忽略了摆架系统和转子合成质心的变化,即不平衡叠加效应会影响测量的准确性。研究了转子和摆架系统质量偏心引起的质心运动方程,并通过质心位置得到振动中心位置。提出了不平衡叠加效应与额外不平衡量的概念。推导了合成系统的叠加不平衡量公式,分析了转子质量和转子安装高度对此额外不平衡量的影响,根据实验数据进行了误差对比分析,验证了该额外不平衡量与转子质量和转子安装高度的关系,阐明了此额外不平衡量的来源。 相似文献
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对浮环轴承支承的悬臂转子系统的动力学特性进行分析,建立了浮环轴承双层油膜Reynolds方程和浮环运动方程。采用4节点等参h-精细有限元网格,通过Galerkin方法求解系统Reynolds方程得到双层油膜压力。在小摄动范围内,联合悬臂转子系统的动力学方程、浮环运动方程求出浮环轴承的等效刚度和阻尼系数。应用商业有限元软件ANSYS12.1对实际微型燃气轮机用浮环轴承-悬臂转子系统进行临界转速、谐响应及不平衡响应等转子动力学仿真计算。通过与实验结果对比,验证了此物理计算模型的正确性,并证明了用此方法分析浮环轴承-悬臂转子转子动力学问题具有实际意义。 相似文献
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本文介绍一种在一个测量平台上同时测量质量、质心及偏心距的新方法,该方法利用一个三支撑点的测量平台,通过安装在各支撑点上的称重传感器,测量出各支撑点的分重量,则被试件的质量为各称重传感器分重量的和;有了三个支撑点的重量数据,它们之间的距离又可以精确测定,通过静力矩平衡的原理可以计算出被试件的质心和偏心距.该方法与传统方法相比,可以实现一次装夹完成被试件全部质量参数的测量,在测量过程中没有任何手动操作,测量效率高,劳动强度小. 相似文献
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Mathematical model of oil free claw vacuum pump is presented. The model is based on energy balance differential equations of thermodynamic system of variable mass working body. Using the equations of coordinates transformation and contact line of rotors continuity condition, equations for geometry of claw pump working chamber on condition of rotors point connection are obtained. To evaluate the leakage through the rotor mechanism channels, their existence graphs are plotted and geometric parameters of the channels depending on rotors position are determined. As a result of modeling, dependence of pressure and temperature in suction and compression‐discharge chambers on rotation angle at different rotary speeds and on different inlet pressures and relationship between pumping speed and inlet pressure are obtained. The comparison between calculated values and experimental data obtained for one‐stage claw pump with identical rotors is carried out. The maximal difference between the calculated and experimental values does not exceed 15 %. The developed mathematical model is recommended for analysis of influence of rotors geometry on the working process parameters and pumping characteristics of an oil free claw pump. 相似文献
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高精度星敏感器二轴标定转台的设计 总被引:1,自引:1,他引:0
作为航天飞行器的姿态控制重要元件星敏感器,其控制精度的检测标定显得尤为重要,本文针对星敏感器测量空间里间角距的重要指标,提出了采用高精度二轴转台的设计方案,较好地实现了对星敏感器静、动态标定的目的,并对二轴转台的设计进行了详细的介绍. 相似文献
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激光陀螺是一种以量化脉冲的形式输出角增量的数字传感器,量化误差如同白噪声一样影响着激光陀螺的测试精度。为了准确评价激光陀螺的性能,减少量化误差对激光陀螺测试数据的影响,本文应用滑动滤波技术对激光陀螺采样数据进行滤波处理,理论分析及实验结果表明,该方法有效地降低了量化噪声从而实现了对激光陀螺的准确评价。 相似文献
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对初始弯曲转子的平衡原理进行理论分析。阐述了转子带有初始弯曲与质量偏心引起的转子运动之间的差异及初始弯曲给转子平衡带来的特殊问题;推导了初始弯曲转子系统应变能与转子纯弯曲的对应关系;数值分析各平衡面的单位加重量对转子系统应变能的敏感性。最后,算例说明应变能分析在初始弯曲转子平衡中的有效性。 相似文献
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Ultrasonic density sensor for liquids 总被引:1,自引:0,他引:1
Puttmer A Hauptmann P Henning B 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2000,47(1):85-92
This paper presents an ultrasonic density sensor for liquids that unifies high accuracy with high durability and is suitable for on-line measurements in a wide range of tube diameters. The sensor consists of a transducer with a piezoceramic disk mounted between two reference rods of quartz glass. Additionally, a second transducer is used as a sound receiver. The density is obtained from the reflection coefficient of ultrasound at the interface between the quartz glass rod and the liquid and the transit time of sound between this interface and the second transducer. Parameters, such as high long-term stability and accuracy of +/-0.1% of full scale, were obtained by an internal acoustic reference measurement. The reference signal is generated using the sound radiated from the rear side of the piezoceramic disk. Design aspects such as sensor materials and signal-to-noise ratio are discussed, and experimental results are given in this paper. Applications of the sensor include concentration measurement, and ultrasonic mass flow measurement. 相似文献
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采用CMOS标准工艺,同时采用三种典型MEMS后处理关键工艺,重点通过对牺牲层释放工艺进行研究,制作实现了一种新型CMOS兼容的电容式气压传感器.在该传感器结构中,作为牺牲层的是在CMOS工艺中形成的掺硼氧化硅.通过释放使电容上电极悬空从而感应气压变化.释放过程采用氢氟酸HF、氯化铵、甘油和水的混合溶液.由于释放孔大小和释放孔间距的设计十分关键,通过实验验证优化了4μm×4μm的释放孔更适用于此传感器结构,并对此结构进行了性能分析与实验测试.结果表明,该气压传感器结构合理,工艺成功,重点解决了MEMS后处理中的牺牲层释放工艺与CMOS标准工艺的兼容问题,为利用CMOS标准工艺进行MEMS传感器的研制做出了有益的尝试. 相似文献
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Pedersen C. Jespersen S.T. Krog J.P. Christensen C. Thomsen E.V. 《IEEE sensors journal》2005,5(3):446-454
A combined differential and static silicon microelectromechanical system pressure sensor based on a double piezoresistive Wheatstone bridge structure is presented. The developed sensor has a conventional (inner) bridge on a micromachined diaphragm and a secondary (outer) bridge on the chip substrate. A novel approach is demonstrated with a combined measurement of outputs from the two bridges, which results in a combined deduction of both differential and static media pressure. Also following this new approach, a significant improvement in differential pressure sensor accuracy is achieved. Output from the two bridges depends linearly on both differential and absolute (relative to atmospheric pressure) media pressure. Furthermore, the sensor stress distributions involved are studied by three-dimensional finite-element (FE) stress analysis. Furthermore, the FE analysis evaluates current and other potential piezoresistor positions on the outer Wheatstone bridge. 相似文献