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公开(公告)号：US5001378A
公开(公告)日：1991-03-19
申请号：US402070
申请日：1989-09-01
CPC分类号： H02K19/20
摘要： A homopolar, transverse pole rotor (14) having a central cylindrical body (24) with a set of circumferentially spaced, axially extending salient poles (28) at each end thereof, is constructed to reduce windage losses. Integral shrouds (29, 31) are placed on either side of each set of salient poles, and a relief is machined into the outer surface of each shroud to form an accentuated pole tip (64) which ensures magnetic centering of the rotor. To further minimize windage losses, the diameter of the central cylindrical body (24) can be reduced, and non-magnetic material can be secured within interpole recesses. Mechanical fasteners (66), dove tails (72) or tensioned circumferential banding (82) can be used to secure the non-magnetic interpole pieces to the rotor.
摘要翻译： 具有中心圆柱体（24）的单极横极转子（14）在其每个端部处具有一组周向间隔开的轴向延伸的凸极（28），以减少风阻损失。 整体护罩（29,31）放置在每组凸极的任一侧上，并且将浮雕加工到每个护罩的外表面中以形成加强的极尖（64），其确保转子的磁中心。 为了进一步减少风阻损失，可以减小中心圆柱体（24）的直径，并且可以在极间凹槽内固定非磁性材料。 可以使用机械紧固件（66），鸠尾（72）或张紧的周向条带（82）来将非磁性间极件固定到转子。
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公开(公告)号：US4975855A
公开(公告)日：1990-12-04
申请号：US323313
申请日：1989-03-14
申请人： William H. Miller , Warren R. Brook
发明人： William H. Miller , Warren R. Brook
CPC分类号： G01H1/003 , G01N29/12 , G01N2291/2696
摘要： The presence, size and location of a crack in a shaft is determined by comparing actual measured natural frequencies of the shaft with the results of an analytical model. From a multistation analytical model of an uncracked shaft, natural frequencies and associated mode shapes are derived. A suspected axial location of a crack is defined and a natural frequency of interest is selected which has an associated mode shape exhibiting maximum deflection at the supected axial location of the crack and at a site of excitation. The analytical model is modified to include a representation of an asymmetric crack, at the suspected crack location, and the predicted split and downward shift of the natural frequency of interest as a function of crack depth is calculated from the modified model. The actual shaft is subjected to a radial excitation force, and vibrational response measurements are taken with an accelerometer along multiple radial directions. A fast Fourier transform analyzer derives a frequency response function from the measurements for each radial direction. The frequency response functions indicate the actual natural frequencies of the shaft. A comparison of these actual natural frequencies with those predicted by the modified model is employed to determine the presence and severity of a crack in the shaft.
摘要翻译： 通过将轴的实际测量固有频率与分析模型的结果进行比较来确定轴中裂纹的存在，尺寸和位置。 从未破裂的轴的多分析分析模型，推导出固有频率和相关模式形状。 定义了裂纹的可疑的轴向位置，并且选择了感兴趣的固有频率，其具有在裂纹的超声轴向位置和激发位置处显示最大偏转的相关模式形状。 修改了分析模型，以便在可疑的裂缝位置处包含非对称裂纹的表示，并根据修改后的模型计算了裂缝深度函数的感兴趣固有频率的预测分裂和向下移动。 实际的轴受到径向的激励力，振动响应测量采用加速度计沿着多个径向进行。 快速傅里叶变换分析仪从每个径向方向的测量中导出频率响应函数。 频率响应函数表示轴的实际固有频率。 将这些实际固有频率与通过改进模型预测的固有频率的比较用于确定轴中裂纹的存在和严重性。
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公开(公告)号：US5159563A
公开(公告)日：1992-10-27
申请号：US585884
申请日：1990-09-19
申请人： William H. Miller , Warren R. Brook
发明人： William H. Miller , Warren R. Brook
CPC分类号： G01H13/00 , G01N29/12 , G01N2291/2693
摘要： The presence, size and location of a crack in a shaft is determined by comparing actual measured natural frequencies of the operating shaft system with the results of an analytical model. From a multi-station analytical model of an uncracked operating shaft system, natural frequencies and associated mode shapes are derived. A suspected axial location of a crack is defined, and a natural frequency of interest is selected which has an associated mode shape exhibiting significant localized bending at the suspected axial location of the crack and at a site of response measurement. The analytical model is modified to include a representation of an asymmetric crack at the suspected crack location. A predicted split and downward shift of a lateral natural frequency of interest as a function of crack depth and/or a predicted downward shift of a torsional natural frequency of interest as a function of crack depth is calculated from the modified model. The actual shaft system is subjected to an operating force excitation, and vibrational response measurements are taken with strain gages and then output through a short range telemetry system. A fast Fourier transform analyzer derives frequency response spectra from the measurements which indicate the actual natural frequencies of the shaft system. A comparison of actual natural frequency(s) in the region near the natural frequency of interest with frequency values predicted by the modified model is employed to determine the presence and severity of a crack in the shaft.
摘要翻译： 通过将操作轴系统的实际测量固有频率与分析模型的结果进行比较来确定轴中裂纹的存在，尺寸和位置。 从一个未裂缝的操作轴系统的多工位分析模型，推导出固有频率和相关模式形状。 确定裂纹的可疑轴向位置，并且选择感兴趣的固有频率，其具有在裂纹的可疑轴向位置处和在响应测量位置处显示出显着的局部弯曲的相关模式形状。 分析模型被修改为包括在可疑裂缝位置处的不对称裂纹的表示。 根据修改的模型计算作为裂纹深度的函数的感兴趣的侧向固有频率和/或作为裂纹深度的函数的感兴趣的扭转固有频率的预测的向下偏移的预测的分裂和向下移位。 实际轴系受到操作力激励，应变计采用振动响应测量，然后通过短距离遥测系统输出。 快速傅立叶变换分析仪从测量中得出频率响应谱，表明轴系的实际固有频率。 采用在修正模型预测的频率值附近的感兴趣自然频率附近的实际固有频率的比较来确定轴中裂纹的存在和严重程度。
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公开(公告)号：US5520061A
公开(公告)日：1996-05-28
申请号：US107326
申请日：1993-08-16
CPC分类号： G01H13/00 , G01H1/003 , G01H1/10 , G01N29/12 , G01N29/223 , G01N29/225 , G10K11/004 , G01N2291/105
摘要： An improved apparatus and method for determining the existence and severity of a crack in a shaft system is provided. The apparatus includes means for mounting multiple vibration responsive output transducers around an outer circumference of the shaft system, allowing simultaneous measurements of vibrational response of the shaft system when multiple vibration responsive output transducers are mounted to the mounting means. In a first approach, the mounting means comprises a collar having two connected arcuate members, with drilled milled and tapped apertures for mounting radial input and output transducers. Torsional input and output transducers may also be mounted tangentially on the collar in drilled milled and tapped heads of bolts used to connect the two arcuate members. In a second approach, the mounting means comprises a plurality of support blocks disposed substantially symmetrically around and protruding outward from the outer collar circumference with each of the blocks orienting at least one transducer in a radial direction and at least one transducer in a tangential direction. Each block may further orient another transducer in an axial direction.
摘要翻译： 提供了一种用于确定轴系中的裂纹的存在和严重性的改进的装置和方法。 该装置包括用于在轴系的外周安装多个响应振动的输出换能器的装置，当多个响应振动的输出换能器安装到安装装置时，允许同时测量轴系的振动响应。 在第一种方法中，安装装置包括具有两个连接的弓形构件的套环，其具有用于安装径向输入和输出换能器的钻孔和螺纹孔。 扭转输入和输出传感器也可以切向地安装在用于连接两个弓形构件的钻孔的研磨和螺纹螺栓头部的套环上。 在第二种方法中，安装装置包括多个支撑块，这些支撑块基本上对称地设置在外围环周围并且从外环周向外突出，其中每个块沿径向定向至少一个换能器，并且沿切线方向定向至少一个换能器。 每个块可以进一步沿轴向方向定向另一个换能器。
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公开(公告)号：US5068800A
公开(公告)日：1991-11-26
申请号：US584893
申请日：1990-09-19
申请人： Warren R. Brook , William H. Miller
发明人： Warren R. Brook , William H. Miller
CPC分类号： G01N29/12 , G01H13/00 , G01N2291/2693
摘要： The presence, size and location of a crack in a shaft is determined by comparing actual measured natural frequencies of the shaft system with the results of an analytical model. From a multi-station analytical model of an uncracked shaft system, natural frequencies and associated mode shapes are derived. A suspected axial location of a crack is defined, and a natural frequency of interest is selected which has an associated mode shape exhibiting significant localized bending at the suspected axial location of the crack and at a site of response measurement. The analytical model is modified to include a representation of an asymmetric crack at the suspected crack location, and a predicted split and downward shift of a lateral natural frequency of interest and/or a predicted downward shift of a torsional natural frequency of interest as a function of crack depth is calculated from the modified model. The actual shaft system is subjected to an excitation force, and vibrational response measurements are taken. A fast Fourier transform analyzer derives a frequency response function from the measurements which indicates the actual natural frequencies of the shaft system. A comparison of actual natural frequency(s) in the region near the natural frequency of interest with frequency values predicted by the modified model is employed to determine the presence and severity of a crack in the shaft.
摘要翻译： 通过将轴系的实际测量固有频率与分析模型的结果进行比较来确定轴中裂纹的存在，尺寸和位置。 从一个未裂缝轴系的多工位分析模型可得出固有频率和相关模式形状。 确定裂纹的可疑轴向位置，并且选择感兴趣的固有频率，其具有在裂纹的可疑轴向位置处和在响应测量位置处显示出显着的局部弯曲的相关模式形状。 分析模型被修改为包括在可疑裂缝位置处的不对称裂纹的表示，以及感兴趣的侧向固有频率的预测的分裂和向下移位和/或感兴趣的扭转固有频率的预测向下移动作为函数 裂纹深度由修正模型计算。 实际轴系受到激励力，并进行振动响应测量。 快速傅里叶变换分析仪从测量结果中得出频率响应函数，表明轴系的实际固有频率。 采用在修正模型预测的频率值附近的感兴趣自然频率附近的实际固有频率的比较来确定轴中裂纹的存在和严重程度。
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