Transcript Ljudreduktion för maskiner som arbetar i flera - Liselott ericson.pptx

Ljudreduktion för maskiner som arbetar
i flera kvadranter
17/4-2012
Liselott Ericson
Introduction
The combustion engine’s
noise level has been reduced
Increased pressure levels and
reduced weight of the hydraulic
system
Makes the hydraulic system
noise level more apparent
Increases the noise level
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General Noise
Excitation
Response
Emitted noise
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Noise in Fluid Power Systems
Excitation
System Response
Hydraulic
resonance
response
Emitted noise
Pressure
pulsation
Flow pulsation
Mechanic
resonance
response
Mechanical
vibration
Noise
Force and moment
pulsation
Mechanic
resonance
response
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Noise in Fluid Power Systems
Excitation
System Response
Hydraulic
resonance
response
Emitted noise
Pressure
pulsation
Flow pulsation
Mechanic
resonance
response
Mechanical
vibration
Noise
Force and moment
pulsation
Mechanic
resonance
response
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Reduce Noise in Fluid Power Systems
Excitation
Flow pulsation
System Response
Hydraulic
resonance
response
Emitted noise
System developer
Pressure
>
pulsation
Pipes
Volumes
Orifices
Mechanic
resonance
response
Mechanical
vibration
Force and moment
pulsation
Reducing the
excitation
energy from
pump/motor
Mechanic
resonance
response
Noise
Screening
Isolation
Geometry
Material
Pipe clamping
Pump/motor designer
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Flow Pulsations
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Flow Pulsations
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Flow Pulsations
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Pump vs. Motor
Pump
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Motor
Pump vs. Motor
Pump
Motor
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Cross-angle
Cross-angle,
g
The Cross-angle varies the dead centre at
displacement changes.
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Different Driving Modes
Left port pressurised
Right port pressurised
Rotational direction
Rotational direction
Counter-clockwise
MOTOR
Counter-clockwise
PUMP
PUMP
Positive
Negative
MOTOR
Positive
Negative
Displacement
Displacement
PUMP
MOTOR
Clockwise
MOTOR
PUMP
Clockwise
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Common Noise Reduction Features

Pre-compression and
decompression angle

Very sensitive for changes
of operational conditions

Pressure relief groove

Pre-compression filter volume
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Sound Pressure at pump housing vs. Flow Ripple
Pre-compression
filter volume
Pressure
relief groove
Small volume
Large volume
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System knowledge
System knowledge
Noise reduction
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Pump/motor working space
Pump/motor working space
Noise reduction
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The choice of noise reduction feature
Constant
Variable pressure
pressure with fix displacement
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The choice of noise reduction feature
Constantpressure
Variable
pressure with
withvariable
variabledisplacement
displacement
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The choice of noise reduction feature
Variablepressure
pressure with
withvariable
variabledisplacement
displacement
Variable
fixedpressure
pressureport
port
changed
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The choice of noise reduction feature
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Tack för din
uppmärksamhet
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