共查询到17条相似文献,搜索用时 296 毫秒
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针对柔性气膜密封技术在航空发动机中的应用需求,使用CFD数值分析技术分析柔性支承柱面气膜的密封性能。首先在Proe中建立柱面气膜的密封参数化模型,并分析了气膜密封原理;然后基于有限元分析的Linear Soid划分方法,使用ANSA网格划分软件来划分网格,得到柔性支承柱面的静压、速度和剪应力分布等数据,并分析柱面结构参数与操作参数对柔性支承柱面气膜密封性能的影响。实验结果表明,粘度、压差和转速等操作参数能明显影响柔性支承柱面气膜的密封性能。 相似文献
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针对某些飞行器舵机控制系统需要旋转型超声电机具有中空结构、转子与负载结构融合以及具备一定的保持力矩等特定工程技术需求,该文提出了一种圆筒型转子与舵翼结构一体设计(外圈输出)的中空型超声电机,开展了该型电机的结构及预压力施加方案的设计和试验研究。建立了电机定子的有限元模型,分析了不同结构尺寸对定子模态的影响,进行了结构尺寸的灵敏度分析,优化了定子的结构,计算出其共振频率、振动幅值。最后试制出了原理样机。实验表明,在激励电压为450 V,激励频率为40.2 kHz时,样机的空载转速可达208 r/min,堵转力矩可达0.35 N·m。 相似文献
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多自由度超声电机是将两种以上的超声振动模式按照一定的方式组合,通过在定子表面的椭圆运动实现转子的多自由度转动.该文对纵弯复合模式圆柱形多自由度超声电机的振动特性进行了研究,该电机的定子由两组夹心式振子组成:一组夹心式压电片在电压激励时能在纵向产生较大的振动位移;另一组夹心式压电片由2个纵向振动的压电片和4个铜电极组成,用于产生两个方向的弯曲振动.为了研究电机的工作特性,参照换能器频率的计算方法,通过纵弯振动的波动方程推导了电机纵弯振动频率方程,考虑多自由度工作时,电机定子纵弯振动的相互影响,对纵弯振动频率方程进行了修正,并将理论计算结果、数值仿真结果及实验测试结果进行了比较,证明了理论计算的正确性. 相似文献
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对音箱的无益振动和现有的处理技术作了分析,并对"单元悬浮技术"和在音箱里采用"穿孔板吸声结构"的新技术途径进行初步探讨。"单元悬浮技术"可以达到目前最好的振动隔离,而"穿孔板吸声结构"在音箱里的应用,不但解决了音箱内的低频声波未能得到有效吸收的问题,而且还有降低箱体的驻波、提高隔声量等附加作用。 相似文献
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超声电机是一种全新概念的新型电机,它利用压电材料的逆压电效应,使定子表面产生一定轨迹的微米量级的振动,进而通过摩擦耦合将振动动能转换成转子或滑块的宏观运动(转动或平动)动能,文章探究了在不同予应力的作用下电机的频率、相位对转速的影响。该研究为超声电机转速的控制提供了理论依据。 相似文献
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Performances of bearingless and sensorless induction motor drive based on mutual inductances and rotor displacements estimation 总被引:3,自引:0,他引:3
Tera T. Yamauchi Y. Chiba A. Fukao T. Rahman M.A. 《Industrial Electronics, IEEE Transactions on》2006,53(1):187-194
A self-sensing bearingless motor is considered as an effective solution to reduce cost and shorten a shaft length. In this paper, a novel estimation method of a rotor displacement is proposed. The method is based on the detection of currents induced by mutual inductances, which vary as a function of the rotor displacements. A high-frequency carrier voltage is superimposed on a motor main terminal voltage. The induced carrier-frequency current component is distinguished from the suspension-winding current. The carrier signal is selected high enough to suspension-current components. However, the carrier current is disturbed in transient conditions. The disturbed current results in a vibration of the estimated rotor displacements. A suspension-current estimator is proposed to reduce this vibration and to obtain the difference between the detected current and the estimated current. As a result, the disturbance vibration is significantly reduced. It is shown that a successful magnetic suspension is realized with the proposed method. 相似文献
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无轴承无刷直流电机集成了直流和交流电机的优点,具有重要的实际应用价值,针对传统悬浮力控制方法存在工作复杂、逆变器通断频繁等缺陷,为了提高磁悬浮力的控制效果,提出了基于有限元分析的无轴承无刷直流电机悬浮力控制策略。首先对无轴承无刷直流电机的结构以及悬浮力产生的原理进行了分析,然后采用有限元分析法对电机转矩和悬浮力进行计算,从而实现无轴承无刷直流电机控制,最后采用Matlab/Simulink工具对其性能进行测试与验证。结果表明,本文策略可以提高转子悬浮的稳定性,能够保证无轴承无刷直流电机的正常运行。 相似文献
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基于扭纵复合型超声电机动力学模型的模拟计算 总被引:4,自引:0,他引:4
基于动力学原理,利用一种新的扭纵复合型超声电动机的动力学模型,模拟计算了扭纵复合型超声电动机的转速、转矩、效率和响应时间等特性。计算结果揭示了预压力、定子两路振动振幅等输入参数对负载特性的影响。此外,转子运转的响应时间与负载力矩间的关系也可由模拟计算导出。利用该模型对所研制的复合型超声电机实验样机进行的计算结果与实际测量结果基本相符,验证了该模型及相应数值计算方法的可靠性。利用该模型首次计算出定,转子接触与分离点的不对称特性。 相似文献
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《Mechatronics》2006,16(1):1-12
This paper first presents an equivalent circuit model of a new disc-type ultrasonic motor and discusses its applications in evaluation of the stator’s frequency characteristics. The equivalent circuit analysis is based on the principle of ultrasonic motor operations and is conducted from the viewpoint of the mechanic vibration of the piezoelectric ceramic disk. Furthermore, because drift of the piezostator characteristics will cause variation of the motor speed, a controller is thus necessary in order to produce a constant output speed. In this research, the speed control scheme is implemented by using current modulation, so the revolutional speed will be kept constant. Meanwhile, the frequency behaviour of the proposed motor and its consequences on speed control scheme are discussed. Finally, a 3-D mechanical element with an extra electrical degree of freedom is employed to simulate the dynamic vibration modes of the linear piezoelectric, mechanical and piezoelectro-mechanic behaviours of a metal disc structure embedded with a piezoelectric actuator. In piezoelectric finite element formulation, a discretized equation of motion is developed and solved by using the integration scheme to explain why an adaptive boundary condition, a simple support condition with three non-equal-triangular (120°–90°–150°) fixed points near the edge for the mechanical design of a new disc-type piezoelectric ultrasonic stator, is defined so that a lateral elliptical motion of the contact point between stator and rotor can be realized for driving the rotor. 相似文献