Unwind Drive Cooling Fan Beat Frequency ©Bill Kilbey 2009.
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Unwind Drive Cooling Fan Beat Frequency ©Bill Kilbey 2009
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Transcript of Unwind Drive Cooling Fan Beat Frequency ©Bill Kilbey 2009.
Unwind Drive Cooling FanBeat Frequency
©Bill Kilbey 2009
High 1x Cooling Motor/Fan
• Constant Speed Motor/fan sit on top of large variable speed motor, fan mounted directly on motor shaft
• The fan is subject to buildup of dirt/product• 1x TS dominant with amplitudes increasing• Attempt to balance was not successful
– Varying amplitude 1mil pk-pk to 7mils pk-pk– Unstable phase ±100⁰
High 1x TSS1 - WINDER UNWIND DR COOLING FAN
2PM UDCF -BH MTR. INBOARD BRG. HORIZ.
Route Spectrum 16-Oct-09 09:21:49
OVERALL= .7546 V-DG PK = .7514 LOAD = 100.0 RPM = 1770. (29.50 Hz)
0 20000 40000 60000 80000
0
0.2
0.4
0.6
0.8
1.0
Frequency in CPM
PK
Vel
oci
ty in
In/S
ec
Freq: Ordr: Spec:
1822.5 1.030 .699
High Resolution SpectrumS1 - WINDER UNWIND DR COOLING FAN
2PM UDCF -AH MTR. OUTBOARD BRG. HORIZ.
Analyze Spectrum 16-Oct-09 09:15:17
PK = .6680 LOAD = 100.0 RPM = 1770. (29.50 Hz)
0 3000 6000 9000 12000
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Frequency in CPM
PK
Vel
oci
ty in
In/S
ec
Freq: Ordr: Spec:
1773.7 1.002 .638
High Resolution Spectrum ZoomS1 - WINDER UNWIND DR COOLING FAN
2PM UDCF -AH MTR. OUTBOARD BRG. HORIZ.
Analyze Spectrum 16-Oct-09 09:17:00
P-P = 8.38 LOAD = 100.0 RPM = 1770. (29.50 Hz)
1740 1760 1780 1800 1820
0
3
6
9
12
Frequency in CPM
P-P
Dis
pla
cem
ent
in M
ils
1773
.0
1768
.8
Freq: Ordr: Spec:
1769.1 .999 1.624
Spectrum from other cooling fanS1 - WINDER UNWIND DR COOLING FAN
3PM UDCF -AH MOTOR OUTBOARD BRG HORZ.
Analyze Spectrum 16-Oct-09 09:27:06
PK = .3501 LOAD = 100.0 FPM = 3540. (1770. RPM)
1750 1760 1770 1780 1790 1800 1810
0
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Frequency in CPM
PK
Vel
oci
ty in
In/S
ec
1769
.3
1773
.1
Freq: Ordr: Spec:
1772.8 1.002 .204
Calculations
• 1773.1 – 1769.3 = 3.8 RPM Delta (.063 Hz)• The inverse of Diff. F1-F2 = T beat• T beat = 15.8 secs. approx.
Time waveform beat on #2S1 - WINDER UNWIND DR COOLING FAN
2PM UDCF -AH MTR. OUTBOARD BRG. HORIZ.
Analyze Waveform 16-Oct-09 09:15:17
RMS = .2380 LOAD = 100.0 RPM = 1770. (29.50 Hz)
PK(+) = .5407 PK(-) = .6437 CRESTF= 2.70
0 4 8 12 16 20 24 28 32
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
Time in Seconds
Acc
eler
atio
n in
G-s
Time waveform beat on #3S1 - WINDER UNWIND DR COOLING FAN
3PM UDCF -AH MOTOR OUTBOARD BRG HORZ.
Analyze Waveform 16-Oct-09 09:27:06
RMS = .1311 LOAD = 100.0 FPM = 3540. (1770. RPM)
PK(+) = .2954 PK(-) = .3219 CRESTF= 2.46
0 10 20 30 40 50 60 70
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
Time in Seconds
Acc
eler
atio
n in
G-s
Time: Ampl: Dtim: Freq:
37.73 .201 15.63 3.838
approx. 15 sec beat
#2 PM Fan
#3 PM Fan
