ENERGY AND VIBRATION
Does vibration consume energy?
General conditions:
• Motor GE, 1/3 hp, single-phase, 3450 rpm, 115 Volts bolted to the working table of a drill press.
• In order to increase the resolution the voltage was decreased to about 40 Volts.
• No attempt was made to balance the motor, but initially the vibration was reasonably low.
• The unbalance was created by adding weight (23 grams) to the pulley on diameter 1.5”.
• Following are data from the initial run:
MIH-LO
VOLTAGE-LO
CURRENT-LO
COMMENTS:• The overall vibration in horizontal direction was about 0.085 in/sec
mainly due to 1x.
• The vertical vibration was similar.
• Note the speed of 3553 rpm.
• The voltage is almost pure sine-wave (very low distortion – see the spectrum).
• The current is distorted more. But this distortion is nothing out of ordinary.
• The watts calculated from voltage and current: 47.38 W.
• Weight of 23 grams was added to the pulley at 1.5” radius.
• Every effort was made to keep the voltage constant
• Following slides are from the high vibration run:
MIH-HI
VOLTAGE-HI
CURRENT-HI
COMMENTS:
• The overall vibration increased to 1.5 in/sec (similarly in vertical direction.
• Note the speed of 3539 rpm.
• No change in voltage, the current increased from 1.66 Amp to 1.94 Amps.
• The calculated watts: 61.95 W
CONCLUSIONS:
• The increased vibration caused drop in speed from 3553 RPM to 3539 RPM.
• The required watts have increased from 47.38 W to 61.95 W.