Vibration of Hydraulic Problems Mechanical Vibrations-Universitas Gadjah Mada

1. Vibration of Hydraulic Problems
Arranged by:
1. Handoko Prasetyo (15/379049/TK/42991)
2. Haqqi Muhammad Hafizh (15/379050/TK/42992)
3. Haryo Bagus Budiawan (15/379051/TK/42993)
4. Iqradatul Hasbi (15/379053/TK/42995)

2. Methodology of Discussion
Start
What is Vibration?
Vibration of
Hydraulic Problems
Types Vibration of
Hydraulic Problems
Characteristics
Vibration of
Hydraulic Problems
Example from
Causes Vibration of
Hydraulic Problems
Spectrum Vibration
of Hyraulic
Problems
Finish

3. What is Vibration?
1. Vibration is a reciprocating or periodic motion of an elastic body, rigid body, or
virtually any medium forced from a state of equilibrium.
2. Machinery vibration problems resulting from the interaction between an exciting
force (hydraulic or mechanical) and the associated structural and / or hydraulic
resonance frequencies.
• Example vibration in the hydraulic pump.
Klik this video

4. Vibration of Hydraulic Problems
1. Cavitation induced vibration and noise:
Cavitation is the local internal vaporization of the pumped liquid within the impeller
inlet due to high velocities that drop the local static pressure below the liquid vapor
pressure. Vibration and damage from cavitation can happen when these vapor bubbles
collapse (implode) as they reach higher pressures within the impeller.
2. Hydraulic impact
When the speed is high and the load inertia is large, sudden opening and closing valve
or reversing can make the liquid inside the system produce hydraulic impact. When the
pressure peak is too large it causes not only the great vibration and noise but so the
hydraulic system damage

5. Vibration of Hydraulic Problems
Figure 1. Hydraulic pump because Cavitation

6. Vibration of Hydraulic Problems
3. Turbulent flow and vortex
Due to high flow velocity, the liquid flow will be in the turbulent state and
generates a local eddy. When there is turbulent flow and vortex, fluid particle
motion mutual impact and interaction with the oil pump, cylinder, particle,
pipeline, valve body wall or other interactions will produce vibration and noise.
4. Hydraulic valve vibration and noise
When passes through the orifice or other valve port the oil fluid becomes
high-speed jet,then partial pressure decreased sharply which leads to vibration
and noise.

7. Types Vibration of Hydraulic Problems
• The vibration model for the two degrees of freedom of a hydraulic plunger pump was
developed based on the data and conditions regarding the structural features,
parameters, variables, constraints, operational states, and flow pulsation. The model
is shown in Figure 2.
Figure 2. Vibration model for the two degrees of freedom of a hydraulic plunger pump.

8. Types Vibration of Hydraulic Problems
1. One of the most influential factors in the vibration model of hydraulic plunger pump is
the value of input vibration excitation, because flow pulsation is the source of pressure
pulsation, flow pulsation has to be analysed to study pressure pulsation.
2. Flow pulsation refers to the instantaneous flow variation when a hydraulic pump is
running. When a hydraulic pump keeps operating continuously, the ever-changing
sealing volume is expected to be generated in a majority of hydraulic pumps.
3. The model of vibration of hydraulic problems can be horizontal vibration or vertical
vibration based on the direction of the axis.

9. Characteristic Vibration of Hydraulic Problem
The characteristics of the vibration problem in the hydraulic pump are as
follows:
1. With the increase of the excitation frequency,
2. vibration displacement, acceleration
3. stress and strain will generate the peak at the corresponding resonant
frequency

10. Characteristic Vibration of Hydraulic Problem
Figure 3. Vibration displacement frequency Figure 4. Acceleration frequency
Figure 5. Stress frequency Figure 6. Strain frequency

11. Example Causes Vibration of Hydraulic Problems
• There are 5 example causes vibration of hydraulic problems:
1. Occurs in the hydraulic pump station
2. Occurs in the hydraulic hoses Fail
3. Occurs in the hydraulic Tubing Systems
4. Occurs in motorcycle components especially in motor shock
5. 0ccurs in hydraulic pump shaft due to cavitation

12. Example Causes Vibration of Hydraulic Problems
Figure 7. Hydraulic pump shaft due to cavitation Figure 8. Hydraulic hoses Fail

13. Spectrum Vibration of Hydraulic Problems
1. Spectrum analysis here is an attempt to find the problem and its cause by studying the pattern
of comparison of the magnitude of the vibration amplitude at all possible frequencies.
Spectrum analysis is the most useful way compared with orbit analysis and phase analysis.
2. It has also been demonstrated that 85% of mechanical problems in rotating machinery can be
identified by looking at the results of vs. vibration amplitude measurements this frequency. The
success of the analysis using this method is sometimes to be further supported by doing both
other means of analysis.
3. By using vibration spectrum analysis at the hydraulic pump can be determined its natural
frequency. This natural frequency will be a reference as whether or not the state of the
hydraulic pump part. If the resulting vibration exceeds the vibration spectrum or exceeds its
natural frequency then the pert is in a bad state and needs to be replaced.

14. THANK YOU