Technology and Application
Any vibration that affects the accuracy or noise of the entire machine
or a single product can be detected and improved using a vibrometer
(balancer).
Balance calibration purposes
Reduce the vibration
Reduce the noise
Extended product life
Improve product quality
To meet customer needs
Reasons of imbalance
Structure tolerance
ex: casting, machining, injection and assembly and
so on.
Material changes
ex: oxidation, density, and abrasive polishing and
so on.
Geometry asymmetry
ex: change the type, size changes, the airflow
caused by the deformation temperature caused by thermal expansion and
contraction.
Vibration application range:
Multi-function precision vibrometer: combined with dynamic balancing
instrument application industry, it is applied to the whole machines and
single rotating product. It can be applied to grinder whell, machine
spindle, grinder disc, computer fan, electric fan, turbine, blade,
Generators, motors, mercury pumps, armatures, etc.
How do balance correction - through the instrument ?
How do balance correction - phase change ?
How to do the balancing adjustment ?
The principle of Wheel Balancing
Wheel balance is mainly set the weights on the wheel flange, through the
auxiliary equipment can shorten the time, provide precise adjustment of
the value, and Adjusted to allow scope, Wheel of life can be extended.
Grinding wheel when in operation, the wheel in an unbalanced state, the
vibration transfer will continue to other parts of machinery, equipment,
and thus make the mechanical parts, equipment, operation of the state of
deterioration or damage.
In addition, because the vibration of the spindle and bearings will
reduce the grinding performance.
Effects on the operation of equipment
The principle of the Rotor
Machinery to contain a large number of the rotation movement of
components, such as the various drive shaft, spindle, motor and steam
turbine rotor, etc.
,These collectively known as the rotating body.
Swivel rotation and does not rotate, the pressure on the bearings is the
same, this is balanced rotary rotating body.
However, projects in a
variety of rotary, because of uneven or rough material defects,
processing and assembly errors, or even design a have non-symmetric
geometry and other factors，makes
the rotary body in rotation, each tiny particle of its surface, the
centrifugal force of inertia generated not cancel each other out, the
role of the machinery, causing a vibration, noise, and accelerated
bearing wear，
reduced mechanical life, can
cause severe destructive accident.
Cause of the vibration
Not perfectly homogeneous materials, precision manufacturing
constraints, after use, wear and other factors, caused by the operation
of the object vibration.
Measurements on rotating machinery to the
vibration waveform is a vibration of many parts.
Vibration damage
Fatigue failure of the general rotating machinery in the 600 ~ 120,000
the CPM, with frequency proportional to the speed measurement unit.
Low frequency (typically below 600 the CPM) for
displacement damage, "displacement" as the unit of measure.
High frequency (usually in the destruction of the
force above the CPM 120,000), the "acceleration" is a measurement unit.
Vibration of elements
Method of vibration diagnosis
Absolute judgment:
In some absolute benchmark for judgment in
accordance with the ISO, VDI API.
Relative judgment:
Determination of the equipment on a regular basis
the same location, to determine whether this value is normal, and
usually use the initial value.
Spectrum
analysis:
From the measured vibration, the use of Fourier
transform (Fast Fourier transform) broken down into different parts of
the vibration waveform can be judge by the frequency distribution of the
source of the vibration; such as the shaft or bearings.
Phase analysis:
From the measured vibration, broken down into
different parts of the vibration waveform, the phase difference on
frequency vibration mode; such as shaft deformation or shaft is bad on
the heart.
Spectrogram
Vibration according to physics, rotating objects, showing the sine wave.
Measurements on rotating machinery to the vibration waveform is a
vibration of many parts. The
use of mathematical methods can be synthesized vibration, the use of
mathematical methods (Fourier transform) broken down into different
parts of the sine wave vibration.
Shown in (a) The grounds of mechanical
measurements of the total vibration can be decomposed into the frequency
of vibration of different speed. (B)
the graph of the sine wave, observed by the right direction, and its
side view and (c), the so-called spectrogram.
The horizontal axis represents the frequency of
the speed of the frequency spectrum, the longitudinal axis of the table
vibration. If
the peak frequency of the mechanical spindle speed graphics, large
amount of vibration in said shaft. In multiples of spindle speed peak
and its multiples impeller number on behalf of the impeller of the
vibration source. Peak in the high frequency region, are generally
bearing a problem.
Vibration spectrum
Vibration spectrum
Vibration sensor
Sensor is a physical device that can detect, feel the outside of the
signal, and the discovery of the information to other devices.
sensor
Can feel the vibration of the amount of mechanical movement (such as the
vibration velocity, frequency, acceleration, etc.) and converted into
usable output signal.
The forefront of the test system is the sensor,
it is the soul of the entire test system, is the world as a cutting-edge
technology.