共查询到19条相似文献,搜索用时 78 毫秒
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超声波电机摩擦和磨损特性探究 总被引:2,自引:0,他引:2
超声波电机是以摩擦力作为驱动源的新型电机。阐述了其摩擦磨损机制,从力学的角度分析了超声波电机产生非线性的原因:一是定子与转子之间基于摩擦的非线性接触,使得超声波电机系统具有跳跃、滞后等特性;二是温度、磨损等导致电机材料特性和电机输出特性的变化。指出只有提高超声波电机的线性度和稳定性,才能提高它的输出功率,延长其使用寿命。 相似文献
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针对现有直线超声电机特性测试系统存在的测试精度低、功能单一和自动化程度低的问题,笔者设计了一种直线超声电机特性测试系统,主要由电机驱动模块、数据采集模块和测试控制及数据处理模块3部分组成。电机驱动模块以STM32F429微控制器为核心,可方便实现对驱动信号的电压、相位以及频率等参数调节;数据采集模块主要由位移传感器、拉压力传感器和高速数据采集卡组成;测试控制数据处理模块主要由PC机实现。利用该系统对一种蝶形直线超声电机的机械特性和瞬态特性进行了测试,结果表明:该系统可很好地实现对直线超声电机的特性测试,而且操作简便,易于扩展。 相似文献
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轮毂电机驱动电动汽车技术的关键点在于轮毂电机设计与驱动电动汽车的悬架设计,本文主要从轮毂电机驱动电动汽车的液压制动系统与轮毂电机电制动瞬态、稳态特性方面切入分析了其电制动特性内容,同时验证轮毂电机驱动电动汽车的电制动控制技术性与可行性. 相似文献
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以自行研制的包被机伺服进给系统为研究对象,设计了基于虚拟仪器的电机在线监测系统.该监测系统可在线诊断超声波电机堵转状态、实时显示步进电机温度变化、振动幅值及能量. 相似文献
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针对当前超声电机电参量的测试方法无法表征其启动瞬态电参量变化规律的问题,提出一种用于超声电机启动瞬态电参量测试的方法。基于加窗的短时傅里叶变换,对超声电机的驱动电压和驱动电流信号进行时频分析处理,得到超声电机启动瞬态下电流电压信号对应的频谱。利用单峰谱线插值法对信号的频谱进行插值修正,得到信号精确的幅值、频率和相位信息,并进一步计算得到阻抗、阻抗角等电参量信息。通过对仿真信号进行处理分析,验证该方法在启动瞬时电参量计算方面的准确性。搭建超声电机瞬态测试平台并对PMR-60/E型超声电机进行测试。结果表明,该方法能够揭示超声电机启动瞬态电参量在电机启动过程中的变化规律,可用于评估超声电机的振动响应特性,同时为超声电机等效电路模型的建立及驱动电路的设计提供重要信息。 相似文献
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Jeong Sam Han 《Journal of Mechanical Science and Technology》2013,27(9):2789-2800
Nowadays, transient dynamic responses of a large-size finite element (FE) model can be solved within a reasonable computation time owing to rapid improvement in both numerical schemes and computing resources. However, increasing demands for accurate simulation and complicated modeling have led to larger and more complex finite element models, which consequently result in considerably high computational cost. In addition, when structural optimizations include transient responses such as displacement, velocity, and acceleration, the optimizations often do not end within a reasonable process time because the large-size simulation must be repeated many times. In order to reduce the computational cost in this respect, model order reduction (MOR) for the original full-order model (FOM) can be used for the transient response simulation. In this paper, a transient dynamic response analysis using Krylov subspace-based MOR and its design sensitivity analysis with respect to sizing design variables is suggested as an approach to the handling of large-size finite element models. Large-size finite element models can incur the problem of a long computation time in gradient-based optimization iterations because of the need for repeated simulation of transient responses. In the suggested method, the reduced order models (ROMs) generated from the original FOMs using implicit moment-matching via the Arnoldi process are used to calculate the transient response and its design sensitivity. As a result, the speed of numerical computation for the transient response and its design sensitivity is maximized. Newmark’s time integration method is employed to calculate transient responses and their design sensitivities. In the case of the transient sensitivity analysis, we apply a temporal discretization scheme to the design sensitivity equation derived by directly differentiating the governing equation with respect to design variables. This methodology has been programmed on the MATLAB with the FE information extracted from the FE package ANSYS. Two application examples are provided to demonstrate the numerical accuracy and efficiency of the suggested approach. The relative errors of transient response and design sensitivity between the FOMs and ROMs are also compared according to the orders of the reduced model. Calculation of transient dynamic responses and their sensitivities using Krylov subspacebased MOR shows a sizeable reduction in computation time and a good agreement with those provided by the FOM. 相似文献
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用一维绝热模型研究了滑动推力轴承在阶跃载荷冲击下的热瞬态行为.通过对轴承油膜压力、温度和推力盘的动力学参数进行建模,应用有限差分以及Runge-Kutta法等对模型求解,获得了大载荷阶跃冲击条件下推力轴承热瞬态过程中性能参数的非线性响应曲线,给出了瞬态过程中轴承最高温度、最小膜厚等参数的变化规律.结论认为如果轴承设计和运行不当,轴承有可能因为瞬态过程中温升过高或膜厚的突然减小而失效. 相似文献
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联立求解广义雷诺方程、油膜瞬态三维能量方程、轴瓦瞬态三维固体热传导方程及轴颈的运动方程,并考虑粘度和密度随温度及压力的变化,在油膜与轴瓦界面使用热流连续性边界条件,得到了在载荷突然变化时汽轮机组椭圆轴承的瞬态响应。介绍了一种有效的用于求解轴承瞬态性能的改进Newton-Raphson算法。结果表明,载荷突然变化后,各性能参数经振荡衰减后均能稳定在一新的恒定值,只是最小油膜厚度和最高油膜压力的变化量很大。 相似文献
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本文改进了R iccati传递矩阵法并将其扩展应用于分析强非线性转子——轴承系统的动力响应。提出了一种新型的传递向量{fT┇.e.T,1}={fT┇..e*T}T和新的变换{f}=[S*].{.e*},简化了Riccati传递矩阵法,并提高了R iccati传递矩阵法的数值稳定性。文中就一强非线性转子-轴承系统,分别用本文的方法和Runge-Kutta法做了计算。通过理论分析和两算法结果的比较,验证了本文方法的有效性和数值稳定性等多种优点。本法特别适合于分析强非线性大型复杂转子-轴承系统的瞬态响应。 相似文献
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Modern electronics found in various measuring equipment is sensitive to the effect of transient over-voltages. This paper treats the measurement procedure for the estimation of Finite Impulse Response (FIR) models of voltage instrument transformers, dedicated for the study of fast electromagnetic transients, with the special concern to its influence on the equipment connected to the secondary. A black-box approach is applied, and the model identification is based solely on a single measurement with the impulse excitation. The paper proposes two different procedures for the estimation of the analytical expression of the excitation, based on the parameters of the impulse generator or its estimation using a least-squares procedure. The frequency response of the transformer is used for the design of an initial FIR model, which was further reduced using corrected Akaike information criterion. This way the duration of the transient response calculation is further decreased, and the computation complexity reduced. Once determined, the FIR model allows, through the digital filtering operation (closely related to the concept of recursive convolution), a very easy time-domain calculation of the system’s response at any excitation. 相似文献
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