PR 3 Alber
Maaf para pembaca, lama tidak update ehehe. Sebenarnya udah ada niat mau mengomentari pesta demokrasi kemarein, tapi gak ada waktu eh. Yaudah, malah dapat PR lagi. Mending saya posting saja, siapa tahu ada yang mau mengomentari karena ini belum tentu bener juga lho.
Nih soalnya:
1.
Sketsa dan 2 kondisi pembebanan kritis
a.
Sketsa:
b.
Kondisi pembebanan kritis
2.
Daftar kegiatan preventive/ predictive maintenance pada excavator:
Daily Strategy Based On Predictive
Maintenance:
a. Hydraulic Pump
·
Inspection of pump electrical energy consumption
·
Monitor fluid cleanliness
·
Inspection of pump operating temperature
·
Pressure consistency checks daily
b. Hydraulic Cylinder
·
Inspect condition of unit
c. Check Valve
·
Monitoring of pressure data
·
System Operator
d. Cylinder Control Valve
·
Monitoring of pressure data
e. Pressure Line
·
Inspection for leaks
f.
Return
Line
·
Inspection of leaks
g. Pilot Circuit
·
Inspection of leaks
h. Control Lever
·
Inspection of working data
i.
Pressure
relief valve
·
Monitoring of pressure
j.
Accumulator
·
Inspection for preliminary signs of loose
connections and/or fittings (screws, nuts and bolts)
·
Inspection for preliminary signs of
erosion/corrosion
Overhaul Strategy Based on Preventive
Maintenance:
a. Hydraulic Pump
·
Inspect pump impeller
·
Inspect Shaft
·
Inspect screws
b. Hydraulic Cylinder
·
Inspect Condition of unit
c. Check Valve
·
Inspect valve
d. Cylinder Control Valve
·
Inspect valve
e. Pressure Line
·
-(run to failure)
f.
Return
Line
·
-(run to failure)
g. Pilot Circuit
·
Check wiring
·
Check connection
·
Test circuit
h. Accumulator
·
6 monthly inspections of the physical unit,
'real time' sensors which measure the levels of gas in the accumulator
i.
Piston
·
Inspect piston rings and general condition of
piston
Tabel Kerusakan Yang Mungkin Terjadi Pada
Beberapa Komponen Beserta Penanggulangannya
a.
Hydraulic
Oil Tank:
|
Function
|
Storage container for hydraulic oil
|
Storage container for hydraulic oil
|
Storage container for hydraulic oil
|
|
Functional
Failure
|
Tank holds
less oil than required |
Tank holds
no oil |
Oil is unable to flow from tank |
|
Failure Mode
|
Tank not
made big enough |
Tanks
structure was compromised |
Tank entry and exit paths blocked |
|
Consequence
|
Possible Pump failure
|
Possible
pump failure |
Possible pump failure |
|
Severity
|
Due to production losses >8hrs
|
Due to
production losses > 8hrs |
Failure generates safety hazard |
|
Frequency
|
Once in the life time
|
Occur up
to once/ year |
Occur up to once/ month |
|
Method
of Control
|
Compensation by increasing in working
hours
|
Regular inspection |
Regular Inspection |
|
Detect
ability
|
Very high
|
High |
High |
|
Recommended
Action
|
Redesign
|
Repair or replace where necessary |
Remove obstruction |
|
Responsibility
|
Designer
|
Maintenance supervisors |
Maintenance supervisors |
b. Hydraulic Pump
|
Function
|
The device that pumps hydraulic oil
|
The device that pumps hydraulic oil
|
The device that pumps hydraulic oil
|
|
Functional
Failure
|
Pump fails to pump oil |
Pump isn’t powerful enough |
Pump can’t pump oil fast enough |
|
Failure Mode
|
Mechanics of pump fail |
Pump isn’t powerful enough |
Mechanics of Pump Fail |
|
Consequence
|
Device does not work |
Device does not work |
Device does not work |
|
Severity
|
production losses between 2 & 8 hrs |
production losses > 8 hours |
production losses between 2 & 8 hrs |
|
Frequency
|
Occur more than once a year |
Once in a lifetime |
Occur more than once a year |
|
Method of
Control
|
Monthly recalibration and testing |
Increase of working hours |
Monthly recalibration and testing |
|
Detect
ability
|
High |
High |
Can be detected using a verification process |
|
Recommended
Action
|
Repair/ replace |
Pump capable of capacity required |
Repair/replace |
|
Responsibility
|
Operator/ Maintenance supervisors |
Operator/ Maintenance supervisors/ hydraulic system designers |
Operator/ Maintenance supervisors/ hydraulic system designers |
c. Boom Control Lever
|
Function
|
Control levers control flow of hydraulic oil which in turn controls the
pitch of the boom |
Control levers control flow of hydraulic oil which in turn controls
the pitch of the boom
|
Control levers control flow of hydraulic oil which in turn controls
the pitch of the boom
|
|
Functional
Failure
|
Lever fails to control flow |
Lever fails to send enough fluid to the boom |
Lever sends too much fluid to boom |
|
Failure Mode
|
Structural integrity of the lever fails |
Mechanically the levers aren’t suitable |
Mechanically the levers aren’t suitable |
|
Consequence
|
Device fails to operate, operates in an unsafe of less efficient manner |
Device fails to operate, operates in an unsafe of less efficient manner |
Device fails to operate, operates in an unsafe of less efficient manner |
|
Severity
|
production losses and downtime between 2-8hrs |
production losses and downtime between 2-8hrs |
production losses and downtime between 2-8hrs |
|
Frequency
|
more than once a year |
more than once a year |
more than once a year |
|
Method of
Control
|
Frequent inspection |
Frequent inspection |
Frequent inspection |
|
Detect
ability
|
very high |
very high |
very high |
|
Recommended
Action
|
Repair/replace |
Repair/replace |
Repair/replace |
|
Responsibility
|
Mechanical maintenance supervisors |
Mechanical maintenance supervisors |
Mechanical maintenance supervisors |
d. Boom
|
Function
|
Used to manipulate the bucket up and down |
Used to manipulate the bucket up and down
|
Used to manipulate the bucket up and down
|
|
Functional
Failure
|
Boom isn’t strong enough to lift bucket with materials |
Boom isn’t strong enough to lift bucket with materials |
Boom isn’t strong enough to lift bucket with materials |
|
Failure Mode
|
Boom fails structurally |
Not enough pressure is being provided to the boom |
The boom isn’t properly designed |
|
Consequence
|
Device is unable to be used productively |
Device is unable to be used productively |
Device is unable to be used productively |
|
Severity
|
production losses and downtime between 2-8 hrs |
losses of up to 1 hour, safety hazard |
production losses and downtime >8hrs |
|
Frequency
|
up to once per year |
more than once per year |
once in the lifetime |
|
Method of
Control
|
Frequent inspection (and testing where applicable) |
Frequent inspection (and testing where applicable) |
Frequent inspection (and testing where applicable) |
|
Detect
ability
|
Very high |
2ery high |
Certainty |
|
Recommended
Action
|
Repair/replace |
Repair/replace |
Repair/replace |
|
Responsibility
|
Mechanical maintenance supervisors |
Mechanical maintenance supervisors |
Mechanical maintenance supervisors |
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