Rotating unbalance system, (2161901) Dynamics of Machinery

1. Gandhinagar Institute
of technology
AlA Presentation
Subject:- DOM (2161901)
Topic name:- Rotating unbalance
system
Prepared by:- jani Parth
(150120119051)

2.  Contents
1.Introduction
2.Vibration due to rotating unbalance
3.Pump Balancing

3. 1. introduction
Vibration due to rotating eccentric masses is a
common
Phenomenal that one sees in everyday life such.
 All rotating machines such as
i. Centrifugal pumps
ii. Turbines
iii.Electric motor

4. 2. Vibration due to rotating unbalance

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9. 3. Pump Balancing
Pumps and pump systems are unique, engineered
products that require specialized knowledge in all phases
of repair, rebuilding and balancing.
Pump Maintenance: The Importance of Balancing
Pump users may label a problem as misalignment, bad
bearings or overheating, but the root cause is often
unbalance in a component or pump assembly. Unbalance
causes vibration and heat build-up, which result in bearing
failure.

10. …
Some dangers for unbalanced pumps include:
• Shaft deflection-a bent shaft or uncontrolled resonance can
result in deflection and damage to the entire system
• Excessive, unacceptable vibration
• Mechanical seal/mechanical packing failures
• Catastrophic bearing failures
• Seizing-In many pumps, clearances are so close that if the
impeller is not well balanced, the vibration could cause the
rotating assembly to deflect enough to seize

11. …
 To clarify the balancing process, we will describe it from the
perspective of alignment.
 Balancing involves aligning the geometric center with the mass
center. The geometric centre (manmade) is the center of the
rotating shaft and pump impeller assembly.
 The mass centre is the centre the assembly tries to rotate
around naturally.
 The pump impeller would spin around this axis if it were thrown
through the air like a Frisbee.

13. Reference
1.https://www.pumpsandsystems.com/topics/pumps/ce
ntrifugal-pumps/pump-rebuilding-and-balancing-part-
one
2.Vibration by VP singh
3.http://personal.cityu.edu.hk/~bsapplec/rotating.htm
4.https://www.google.co.in/imghp?
hl=en&tab=wi&authuser=0
5.Class work book