BISOPE series
91- Vibration Problem of Rolling Bearing - 4 - Cause of Defect Frequency----------------------------------------------------
Rolling bearings have their own defect
frequency calculation formula. This defect frequency always occurs even if it
is small, but it is not exactly a natural frequency because the frequency is
constant and unique, so it is not called a ‘defect’ frequency
but a ‘natural’ frequency of the bearing.
This is because the natural frequency actually exists somewhere else.
Therefore, it seems a better expression to change the name of this defect
frequency to the ‘rotational characteristic frequency’ of the rolling bearing.
However, there are times when I get questions about this rolling bearing defect
frequency not matching the formula. After a long period of operation and
disassembly, the bearing defect is correct, but the frequency is close to it,
but it is not accurate. Therefore, it is only a correct formula if the outer
ring is defective (scratched) and assembled and turned right away. Since the
characteristics change slightly due to thermal expansion and tapping when
assembling the bearing, there is bound to be a slight error. Moreover, as time
passes, the tolerance of the bearing increases and becomes looser, and the
frequency also fluctuates. So how do you check for bearing
defects?
Fault frequency mechanism of cloud bearings
Bearing
defects are checked by the frequency or time waveform pattern. If the pattern
(harmonic, sidebands) is checked, and the bearing information is not accurate
and there is an error of less than 10Hz,
Keywords:
Bearing vibration, rolling bearing, bearing defect, spectrum, BPFI, BPFO, inner
ring defect, outer ring defect, bearing defect frequency, bearing natural
frequencyMeasurement Location
Shaft vibration- Vibration in which the shaft shakes directly- Housing surface vibration(casing) and its counterpart- The amount of vibration that can be directly measured (relative displacement, non-contact) using a displacement sensor (proximity probe) installed on the bearing housing of the rotating machine's shaft is called shaft vibration, and it is a vibration measurement method currently being monitored in most high-speed, large-scale rotating machines (generators, turbines, turbo compressors, large pumps, etc.) supported by sleeve bearingsKey! #Shaft vibration, bearing vibration, casing vibration, 6-axis vibration#vibration education, #frequency analysis, #resonance measurement#vibration measuring instrument, #frequency setting, #Fmax, #maximum frequency, #sampling frequency, #sampling rate, #FFT, #3-axis vibration sensor, #acceleration sensor, #vibration education, #building vibration, #vibration measurement, #resonance analysis, #resonance measurement, #vibration monitoring, #vibration noise consulting www.kCBM.kr, https://blog.naver.com/vs72 , https://contents.premium.naver.com/bisope/visope
It
is said that the horizontal vibration on the NDE side is high. Where should I
look?
Looking at the components of a rotating
machine, they can first be divided into the
driving part (driving part) side, the driven part (driven part) side, and the coupling (direct coupling, buffer type, belt,
etc.) that connects them. Another connection element may be a gearbox that requires an additional separate coupling.
Since each component is a machine that is all connected and rotates together,
the speed may be different, but vibration is transmitted between each other,
and if any connecting part is incorrect or misaligned, the entire machine
(equipment) is affected by vibration. Therefore, determining what the vibration
is like at a certain location is a very important appointment. Among these, DE and NDE are words that you must know and understand.
DE, NDE and Outboard, Inboard
Naming the location of the
facility is an issue that has already been------
Compressors can be categorized by type into centrifugal,
reciprocating, diaphragm, and screw types. Among them, the most noisy and
structurally problematic type due to vibration is the reciprocating type.
However, even though the structure is small, the type that produces too much noise to
be operated without a soundproofing enclosure and has frequent vibration
problems regardless of high or low frequencies is the screw compressor. A screw-type
compressor appears to be a square box covered with an enclosure and connected
to pipes, but inside it is a type of compressor that is complex and vibrates,
consisting of many gears, bearings, and pipes. Let's summarize what causes
vibration that may occur in this screw compressor.
The sound of bands and orchestras resounding in the
concert hall entertains our brains. Unfortunately, we also analyze the sound. A
string instrument that produces sound by plucking the string and its harmonics,
a wind instrument that blows wind and produces a beautiful sound with the
pipe's unique frequency, and a drum of its own size by beating a drum A
percussion instrument that makes a percussive sound, and a keyboard instrument,
a person's vocal cords vibrate, and a person's vocal cords vibrate in the throat...
This is just music, but it is also called 'structure borne noise, air
borne noise' in engineering. What does that mean? is it a guitar? is it a
flute? is it a piano? Is it the sound of drums? Why are the pictures of
railroad rails and wheels below?
The difference between 'structure borne
noise, air borne noise'
1. What is the difference between the sound coming out
of a speaker or mouth and 2. the sound made when hitting a xylophone or drum?
