Apparatus & Procedures（实验与采集装置）
As shown in Figure 1 above, the test stand consists of a 2 hp motor (left), a
torque transducer/encoder (center), a dynamometer (right), and control
electronics (not shown). The test bearings support the motor shaft. Single
point faults were introduced to the test bearings using electro-discharge
machining with fault diameters of 7 mils, 14 mils, 21 mils, 28 mils, and 40
mils (1 mil=0.001 inches). See FAULT SPECIFICATIONS for fault depths. SKF
bearings were used for the 7, 14 and 21 mils diameter faults, and NTN
equivalent bearings were used for the 28 mil and 40 mil faults. Drive end and
fan end bearing specifications, including bearing geometry and defect
frequencies are listed in the BEARING SPECIFICATIONS.
（如图所示，实验平台包括一个 2 马力的电机（左侧）（1hp=746W），一个转矩传感器
（中间），一个功率计（右侧）和电子控制设备（没有显示）。被测试轴承支承电机轴。
使用电火花加工技术在轴承上布置了单点故障，故障直径分别为 0.007、0.014、0.021、
0.028、0.040 英寸（1 英寸=2.54 厘米）。其中前三种故障直径的轴承使用的是 SKF 轴承，
后两种故障直径的轴承使用的是与之等效的 NTN 轴承。
Vibration data was collected using accelerometers, which were attached to
the housing with magnetic bases. Accelerometers were placed at the 12
o?clock position at both the drive end and fan end of the motor housing.
During some experiments, an accelerometer was attached to the motor
supporting base plate as well. Vibration signals were collected using a 16
channel DAT recorder, and were post processed in a Matlab environment. All
data files are in Matlab (*.mat) format. Digital data was collected at 12,000
samples per second, and data was also collected at 48,000 samples per
second for drive end bearing faults. Speed and horsepower data were
collected using the torque transducer/encoder and were recorded by hand.
（实验中使用加速度传感器采集振动信号，通过使用磁性底座将传感器安放在电机壳体上。
加速度传感器分别安装在电机壳体的驱动端和风扇端 12 点钟的位置。在有些实验中，传
感器也被安放在电机支承底盘上。振动信号是通过 16 通道的 DAT 记录器采集的，并且后
期在 MATLAB 环境中处理。数字信号的采样频率为 12000S/s，驱动端轴承故障数据同
时也以 48000S/s 的采样速率采集。
Outer raceway faults are stationary faults, therefore placement of the fault
relative to the load zone of the bearing has a direct impact on the vibration
response of the motor/bearing system. In order to quantify this effect,
experiments were conducted for both fan and drive end bearings with outer
raceway faults located at 3 o?clock (directly in the load zone), at 6 o?clock
(orthogonal to the load zone), and at 12 o?clock
