水轮机静压自调式主轴端面密封设计

静压自调式端面密封是一种目前国内大中型机组中应用较广泛的水轮机主轴密封,这种密封性能良好、密封稳定可靠。本文结合功果桥水轮机设计较系统介绍了静压式主轴端面密封的结构特点及工作原理,并对其计算数学模型及计算结果进行了简要说明。     

新型磁驱动增大检测电容的高精度MEMS惯性传感器研究

增大传感器振子的质量和静态测试电容可以减小电容式MEMS惯性传感系统的噪声,而深度粒子反应刻蚀工艺由于复杂的工艺原因,当深宽比较大时,不能刻蚀出大质量和大初始电容的传感器.据此,本文研究了一种磁驱动增大检测电容的MEMS惯性传感器,通过电磁驱动器,传感器的静态测试电容可以大幅增加,在梳齿电容上刻蚀阻尼槽后,其机械噪声达到0.61μg每根号赫兹,仿真其共振频率为598Hz,静态位移灵敏度为0.7μm每重力加速度,基于硅 玻璃键合工艺,制作了栅形条电容式惯性传感器,并用电磁驱动的方式测试其品质因子达到715,从而验证了制作工艺的可行性和电磁驱动器改变传感器初始静态测试电容的可行性.     

一个新型的大检测电容结构的MEMS惯性传感器研究

A novel MEMS inertial sensor with enhanced sensing capacitors is developed. The designed fabricated process of the sensor is a deep RIE process, which can increase the mass of the seismic to reduce the mechanical noise, and the designed capacitance sensing method is changing the capacitance area, which can reduce the air damping between the sensing capacitor plates and reduce the requirement for the DRIE process precision, and reduce the electronic noise by increasing the sensing voltage to improve the resolution. The design and simulation are also verified by using the FEM tool ANSYS. The simulated results show that the transverse sensitivity of the sensor is approximately equal to zero. Finally, the fabricated process based on silicon-glass bonding and the preliminary test results of the device for testing grid capacitors and the novel inertial sensor are presented. The testing quality factor of the testing device based on the slide-film damping effect is 514, which shows that the enhanced capacitors can reduce mechanical noise. The preliminary testing result of the sensitivity is 0.492pf/g.     

低真空封装的新型变电容面积MEMS惯性传感器阶跃响应特性分析

一种新型变电容面积MEMS惯性传感器与传统的梳齿电容传感器相比,具有对梳齿电容不平行敏感度低,可加测试电压高等优点.通过对该传感器在低真空封装条件下的惯性阶跃响应特性分析,着重研究了不同梳齿电容倾斜角度对该传感器的阶跃惯性信号响应的影响,以及不同倾斜角度梳齿的位移响应和测试电压、空气真空度的关系,并把该结果和梳齿结构的情况进行比较.结果表明,工艺因素对变电容面积MEMS惯性传感器在低真空封装下的阶跃惯性响应影响很小;另外,该结构上可加的测试电压可以是梳齿电容结构上可加测试电压的近10倍,这有利于减小接口电路的噪声.以上分析论证了该新型传感器有利于降低器件的工艺要求和提高传感器的分辨率.     

一种新型的基于滑膜阻尼的电容式双向MEMS惯性传感器

设计了一个新型的结构完全对称的双向MEMS电容式惯性传感器.该传感器主要由可动质量块、栅形条、支撑梁、连接梁、阻尼调整梳齿组成.设计的结构采用变电容面积的检测方式,在降低空气阻尼的同时也降低了对DRIE工艺的要求,并通过加大测试信号电压来降低电路噪声,从而提高传感器的分辨率.用有限元工具ANSYS详细讨论了传感器的参数和性能,并模拟验证了设计的双向传感器的交叉效应近似为零.制作了滑膜阻尼测试器件,在大气压下,测得的品质因子可达514,验证了该结构设计可以提高传感器的分辨率和该工艺设计的可行性.     

水轮机主轴密封的研究与实践

结合东芝水电针对不同型式主轴密封的研究与实践,较系统地介绍了水轮机主轴密封装置的基本原理、结构型式及特点,供水轮机主轴密封设计时参考。     

一种新型的带栅形条电容和可变间距电容的惯性信号检测结构

The comb capacitances fabricated by deep reactive ion etching （RIE） process have high aspect ratio which is usually smaller than 30 ： 1 for the complicated process factors, and the combs are usually not parallel due to the well-known micro-loading effect and other process factors, which restricts the increase of the seismic mass by increasing the thickness of comb to reduce the thermal mechanical noise and the decrease of the gap of the comb capacitances for increasing the sensitive capacitance to reduce the electrical noise. Aiming at the disadvantage of the deep RIE, a novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances is developed. One part of sensing of inertial signal of the micro-accelerometer is by the grid strip capacitances whose overlapping area is variable and which do not have the non-parallel plate＇s effect caused by the deep RIE process. Another part is by the sensing gap alterable capacitances whose gap between combs can be reduced by the actuators. The designed initial gap of the alterable comb capacitances is relatively large to depress the effect of the maximum aspect ratio （30 ： 1） of deep RIE process. The initial gap of the capacitance of the actuator is smaller than the one of the comb capacitances. The difference between the two gaps is the initial gap of the sensitive capacitor. The designed structure depresses greatly the requirement of deep RIE process. The effects of non-parallel combs on the accelerometer are also analyzed. The characteristics of the micro-accelerometer are discussed by field emission microscopy （FEM） tool ANSYS. The tested devices based on slide-film damping effect are fabricated, and the tested quality factor is 514, which shows that grid strip capacitance design can partly improve the resolution and also prove the feasibility of the designed silicon-glass anodically bonding process.     

新型双向电容式MEMS加速度计特性分析

文章研究了一新型的栅形条电容MEMS加速度计,通过新型结构设计降低了传感器的机械噪声和电子噪声。用软件ANSOFT-Maxwell对栅形条电容的宽度、厚度及叠加宽度对检测电容的影响进行了分析。用深度离子刻蚀工艺和硅-玻璃键合工艺制作了传感器,初步测试结果表明其在X和Y方向的灵敏度分别为0.53pF/g 、0.49pF/g。制作的栅形条谐振子在大气下的品质因子达到514,说明栅形条结构可大大降低机械噪声。     

倾斜梳齿的MEMS电容式传感器惯性脉冲响应特性研究

 DRIE(Deep Reactive Ion Etching)工艺加工的高深宽比梳齿电容不能保证绝对平行.本文在考虑低真空空气阻尼力的同时,研究了梳齿电容倾斜的MEMS传感器对脉冲惯性信号的响应,并分析了DRIE工艺因素对器件性能的影响.研究结果表明,当传感器为没有静电力反馈的双边电容结构时,梳齿电容的不平行对传感器的响应位移、惯性脉冲响应线性度范围影响明显,且随着封装真空度增加而加重.若传感器有静电力反馈,惯性脉冲响应的灵敏度降低,但DRIE工艺因素的影响程度降低.为了抑制DRIE工艺导致的梳齿电容不平行因素的影响,文中还设计了一个新型的变电容面积的MEMS惯性传感器,并用ANSYS初步分析了其性能,设计了其详细的制作工艺流程.     

低真空封装的新型变电容面积MEMS惯性传感器阶跃响应特性分析

一种新型变电容面积MEMS惯性传感器与传统的梳齿电容传感器相比,具有对梳齿电容不平行敏感度低,可加测试电压高等优点。通过对该传感器在低真空封装条件下的惯性阶跃响应特性分析,着重研究了不同梳齿电容倾斜角度对该传感器的阶跃惯性信号响应的影响,以及不同倾斜角度梳齿的位移响应和测试电压、空气真空度的关系,并把该结果和梳齿结构的情况进行比较。结果表明,工艺因素对变电容面积MEMS惯性传感器在低真空封装下的阶跃惯性响应影响很小;另外,该结构上可加的测试电压可以是梳齿电容结构上可加测试电压的近10倍,这有利于减小接口电路的噪声。以上分析论证了该新型传感器有利于降低器件的工艺要求和提高传感器的分辨率。