英语翻译3.Experimental set-upThe test-rig employed for this expe

英语翻译
3.Experimental set-up
The test-rig employed for this experimental work consisted of two identical oil-bath lubricated gearboxes,
connected in a back-to-back arrangement,see Fig.1.The gear set employed was made of 045M15 steel
(without any heat treatment),which had a measured hardness of 137 Hv30.The gears (49 and 65 teeth) had a
module of 3 mm,a pressure angle of 201,and a surface roughness (Ra) of between 2 and 3 mm.A simple
mechanism that permitted a pair of coupling flanges to be rotated relative to each other,and locked in
position,was employed to apply torque to the gears.
The AE sensors used for this experiment were broadband type with relatively flat response in the region
between 100 kHz to 1MHz.One sensor was placed on the pinion with 49 teeth.And the second AE sensor was
located on the bearing casing.The cable connecting the sensor placed on the pinion with the pre-amplifier was
fed into the shaft and connected to a slip ring (‘IDM’ PH-12).This arrangement allowed the AE sensor to be
placed as close as possible to the gear teeth.The sensor was held in place with strong adhesive superglue.The
output signal from the AE sensors was pre-amplified at 20 dB.The signal output from the pre-amplifier was
connected (i.e.via BNC/coaxial cable) directly to a commercial data acquisition card.
An accelerometer was fitted onto the bearing casing to record vibration data,see Fig.1.The accelerometer
used for vibration measurement in this experiment was a resonant type sensor with a frequency response
between 10 and 8000 Hz.The accelerometer was mounted on the base of the bearing casing connecting to the
ARTICLE IN PRESS
Fig.1.Back-to-back gearbox arrangement with AE sensors and accelerometer.
210 C.K.Tan et al./ Mechanical Systems and Signal Processing 21 (2007) 208–233
pinion shaft.The accelerometer was connected to a charge amplifier,and the signal output from the preamplifier
was fed to a commercial data acquisition card.
In normal gearbox operation,an anti-wear lubricant is usually employed to prevent or slow down wear on
the gear teeth.In order to initiate surface pitting in a relatively short time frame,lubricant oil without antiwear
properties was employed for the accelerated gear fatigue tests; SAE 20W-50.Also,to accelerate the
pitting process the face width of the pinion employed was half that of the wheel.