HYDRAULIC DRILL HYDRAULIC DRILL JUMBOSJUMBOS
A COMPREHENSIVEA COMPREHENSIVE
PRESENTATIONPRESENTATION
Pinaki RoyPinaki RoyM. S. RaoM. S. Rao
BackgroundBackground
In order to create an opening in a In order to create an opening in a rock mass DRILLING is the basic rock mass DRILLING is the basic requirement.requirement.
Range & Selection of Drill Range & Selection of Drill JumbosJumbos
……………….for every Tunnel .for every Tunnel sectionsection
Single Boom JumbosSingle Boom Jumbos
Two Boom Jumbos (8 - 45 Two Boom Jumbos (8 - 45 sq.m.)sq.m.)
Two Boom with basket (8 - 90 Two Boom with basket (8 - 90 sq.m.)sq.m.)
Three Boom/Three Boom with Three Boom/Three Boom with Basket Boom Basket Boom
(upto 168 sq.m.)(upto 168 sq.m.)
Probing aheadProbing ahead
Drill Jumbo - Long HolesDrill Jumbo - Long Holes
Optional equipmentOptional equipment
Basic Basic requirement requirement
for rock drillingfor rock drilling
Rock Drilling - Rock Drilling - PrinciplePrinciple
Basic requirement :
Rock drill Rock drill mechanismmechanism
Impact Impact The piston transmits the The piston transmits the impact energy through the impact energy through the drill steel to the hole drill steel to the hole bottom. A valve directs the bottom. A valve directs the compressed air / hydraulic compressed air / hydraulic oil from one side to the oil from one side to the other of the piston so that other of the piston so that it moves up and down.it moves up and down.
Impact
RotationRotation The drill steel is turned lightly with The drill steel is turned lightly with
each blow. each blow. IN PNUEMATIC ROCK DRILLS :IN PNUEMATIC ROCK DRILLS :The rotation is normally anti-clock The rotation is normally anti-clock
wise and normally made on the wise and normally made on the return stroke of the piston. return stroke of the piston.
The theoretical angle of rotation per The theoretical angle of rotation per stroke is 36 degree. In practice it is stroke is 36 degree. In practice it is 30 degree. The difference is due to 30 degree. The difference is due to mating part.mating part.
IN HYDRAULIC ROCK DRILLS :IN HYDRAULIC ROCK DRILLS :Hydraulic motor is normally used for Hydraulic motor is normally used for
rotation. The rpm of the drill bit is rotation. The rpm of the drill bit is adjusted as per drill bit diameter. adjusted as per drill bit diameter.
Rock drill Rock drill mechanismmechanism
Rock drill mechanismRock drill mechanism
Feed forceFeed force
The feed force is created by hand The feed force is created by hand in case of hand held drills , in case of hand held drills , Pusher leg or hydraulic cylinder.Pusher leg or hydraulic cylinder.
Proper feed force will give the Proper feed force will give the best penetration rate.best penetration rate.
Improper feed force will cause:Improper feed force will cause: Loosening / damaging of Loosening / damaging of
thread.thread. Overheating / low life of drill Overheating / low life of drill
string.string. Diverted hole / poor pull in Diverted hole / poor pull in
blasting.blasting.
Rock drill Rock drill mechanismmechanism
FlushingFlushing
Flushing is done Flushing is done normally by air or normally by air or water on all the water on all the rock drills used in rock drills used in underground, underground, water is used as water is used as flushing media. flushing media. Optimum flushing Optimum flushing will provide better will provide better penetration rate.penetration rate.
Factors which influence drilling Factors which influence drilling raterate
Type of rockType of rock Air pressure/Hydraulic PressureAir pressure/Hydraulic Pressure Bit sizeBit size Bit conditionBit condition FlushingFlushing Feed forceFeed force Wear of front of rotation chuck Wear of front of rotation chuck
bushing bushing
Drifter - Heart of Drifter - Heart of Drilling JumboDrilling Jumbo
New Generation Rock Drill
Components of Hydraulic Components of Hydraulic DrifterDrifter
Shank AdapterShank Adapter Flushing HeadFlushing Head Damping PistonDamping Piston Stroke SelectorStroke Selector PistonPiston Rotation GearsRotation Gears CylinderCylinder AccumulatorsAccumulators Hyd. Rotation MotorHyd. Rotation Motor
DriverDriver
Transmit rotation from Hyd. Transmit rotation from Hyd. Motor to Shank AdapterMotor to Shank Adapter
Triangular in shapedTriangular in shaped Housed in rotation chuckHoused in rotation chuck Has internal splinesHas internal splines Made of bronze/SteelMade of bronze/Steel Splines wear limit is half it Splines wear limit is half it
original width.original width.
Stop RingStop Ring
Serves as retainer for Shank Serves as retainer for Shank AdapterAdapter
Stop Ring is extremely hard Stop Ring is extremely hard and wear resistantand wear resistant
It is subject to impact It is subject to impact energyenergy
Wear limit is 1 mm to the Wear limit is 1 mm to the front end of the splinesfront end of the splines
Damping PistonDamping Piston
Damping Piston protects the Damping Piston protects the Rock Drill from shock Rock Drill from shock waves (thru hydraulic waves (thru hydraulic pressure)pressure)
Subject to powerful axial Subject to powerful axial shock waves.shock waves.
It helps in absorbing reflex It helps in absorbing reflex shocks upto 20 tonnes. shocks upto 20 tonnes.
Since it is pressed against Since it is pressed against rot.chuck/shank adapter, it rot.chuck/shank adapter, it tends to partially rotate.tends to partially rotate.
Side BoltsSide Bolts
Two long side bolts hold Two long side bolts hold together the external parts together the external parts of the Rock Drill (front of the Rock Drill (front head, cover, gear housing, head, cover, gear housing, interm. part and cylinder interm. part and cylinder
Third long side bolts Third long side bolts connect all above parts connect all above parts except front head.except front head.
Two long side bolts have Two long side bolts have have integral eccentric have integral eccentric lugs(for tightening)lugs(for tightening)
Side BoltsSide Bolts
Tension of the side bolts Tension of the side bolts must be checked must be checked regularly.regularly.
Rear dome nuts are Rear dome nuts are tightened as per the tightened as per the recommended torquerecommended torque
Recommended to Recommended to change both the bolts change both the bolts together.together.
Piston GuidesPiston Guides
Front and Rear piston Front and Rear piston guides located on either end guides located on either end of the cylinder guides the of the cylinder guides the lateral movement of the lateral movement of the piston.piston.
It prevents the piston lands It prevents the piston lands from touching the cylinderfrom touching the cylinder
Its has wear resistant quality Its has wear resistant quality and also gives lowest and also gives lowest possible friction.possible friction.
Impact Piston Impact Piston
The piston strikes the shank The piston strikes the shank adapter between 3000 – adapter between 3000 – 3600 stokes per minute3600 stokes per minute
Piston is supported by Piston is supported by piston guides.piston guides.
Slim piston design transfer Slim piston design transfer optimum energy to the drill optimum energy to the drill stringstring
Slim piston design also has Slim piston design also has low stress on Rock Toolslow stress on Rock Tools
Rotation Chuck Sleeve Rotation Chuck Sleeve
Rotation Chuck sleeve Rotation Chuck sleeve is a press fitted into the is a press fitted into the rear of the Rotation rear of the Rotation ChuckChuck
It is made of high It is made of high quality bronze with high quality bronze with high resistance to wear and resistance to wear and frictionfriction
Rotation Chuck Bushing Rotation Chuck Bushing
The smaller front face of the The smaller front face of the Rotation Chuck bushing Rotation Chuck bushing acts on the shank adapter.acts on the shank adapter.
Larger rear face is subject to Larger rear face is subject to the thrust from the damping the thrust from the damping piston.piston.
Front face of the rotation Front face of the rotation chuck bushing is subject to chuck bushing is subject to steady wear.steady wear.
Max. permissible wear on Max. permissible wear on the front face of the rotation the front face of the rotation chuck bushing is 1 mm.chuck bushing is 1 mm.
Flushing Head Flushing Head
Rock Drill - ReflexRock Drill - Reflex
Hydraulic Rock Drills normally work at Hydraulic Rock Drills normally work at 200 Bar Impact Pressure200 Bar Impact Pressure
Every Impact of the Rock Drill Every Impact of the Rock Drill Generates 20 Ton Reaction / Reflex from Generates 20 Ton Reaction / Reflex from
RockRock
Reflex 20 Ton Drifter Impact
Drifter without Reflex Drifter without Reflex DampenerDampener
Reflex kills the Drifter & Reflex kills the Drifter & MountingMounting
Most effective Reflex Most effective Reflex DampenerDampener
CARE & MAINTENANCECARE & MAINTENANCE
ofof
HYDRAULIC DRIFTERSHYDRAULIC DRIFTERS
SAFETY REGULATIONSSAFETY REGULATIONS Special attention must be paid to safety information Special attention must be paid to safety information
and especially to the warning symbol (triangle).and especially to the warning symbol (triangle). Never attempt maintenance of Rock Drill when the Never attempt maintenance of Rock Drill when the
hydraulic system is pressurisedhydraulic system is pressurised Always use correct specification hoses, specially the Always use correct specification hoses, specially the
impact hose of rating SAE 100 R9R/4SH/4SP (4 layers, impact hose of rating SAE 100 R9R/4SH/4SP (4 layers, spirally wound steel wire braided).spirally wound steel wire braided).
Use protective plugs when dismantling the Rock DrillUse protective plugs when dismantling the Rock Drill Always overhaul a Rock Drill in a Container or a clean Always overhaul a Rock Drill in a Container or a clean
workshopworkshop
Start UpStart Up
Before starting up a new or a newly overhauled Rock Before starting up a new or a newly overhauled Rock Drill:Drill: Connect up all hydraulic hosesConnect up all hydraulic hoses Charge the Accumulators with Nitrogen gas to the Charge the Accumulators with Nitrogen gas to the
correct pressurecorrect pressure Fill correct hydraulic and lubricating oilFill correct hydraulic and lubricating oil Adjust correct lubricating systemAdjust correct lubricating system
Tighten all threaded joints after first shift of operationTighten all threaded joints after first shift of operation
Every ShiftEvery Shift
CheckCheck that Air & Lubricating oil come out that Air & Lubricating oil come out between the shank adapter and front guidebetween the shank adapter and front guide
Check S/Adapter threads are not damagedCheck S/Adapter threads are not damaged Keep an eye on the hydraulic hose vibration. Keep an eye on the hydraulic hose vibration.
If they vibrate too much check the If they vibrate too much check the Accumulators.Accumulators.
Check there is no leakage from the Rock Check there is no leakage from the Rock Drill. If flushing water leaks from the hole Drill. If flushing water leaks from the hole in the front head, change the seals.in the front head, change the seals.
Every 40 Percussion HourEvery 40 Percussion Hour
Grease the Gear HousingGrease the Gear Housing Tighten all threaded joints as per Tighten all threaded joints as per
specified torque.specified torque. Check for external leakage on the Rock Check for external leakage on the Rock
Drill. Replace the seals if leakingDrill. Replace the seals if leaking Check condition of hydraulic hoses, Check condition of hydraulic hoses,
replace damaged/defective hoses.replace damaged/defective hoses.
Every 400 Percussion HourEvery 400 Percussion Hour
Recommended for complete Recommended for complete overhaul.overhaul.
Overhauling to be done in a clean Overhauling to be done in a clean and suitable workshop. Always use and suitable workshop. Always use Hydraulic Drifter Repair Tools.Hydraulic Drifter Repair Tools.
AccumulatorsAccumulators
Accumulators are fitted with Accumulators are fitted with safety labelssafety labels
They should be charged with They should be charged with Nitrogen gas only (other gas can Nitrogen gas only (other gas can cause explosion)cause explosion)
All new accumulators are not All new accumulators are not chargedcharged
Charging the AccumulatorsCharging the Accumulators
Remove the protective plugsRemove the protective plugs Open the valve nut and connect the charging hoseOpen the valve nut and connect the charging hose Open the gas valve on the cylinderOpen the gas valve on the cylinder Charge the Accumulator to the collaring pressure Charge the Accumulator to the collaring pressure
minus 30 bar. However the maximum pressure minus 30 bar. However the maximum pressure should not exceed 110 barshould not exceed 110 bar
Tighten the valve nut and also close the cylinder Tighten the valve nut and also close the cylinder valve.valve.
Remove the charging hose and fit back the Remove the charging hose and fit back the protective cap on the accumulator valveprotective cap on the accumulator valve
AccumulatorsAccumulatorsIntake :
30 bar belowcollaring pressure
Max - 110 bar
Damping : 20-25 bar
Return : Not to be charged
MAIN COMPONENTS OF DRILL JUMBOS
• CARRIER
• BOOM
• FEED
• ROCK DRILL
• POWER PACK
Carrier
Power train
Carrier SystemCARE & MAINTENANCE
Engine – Air Filter
1.Clean every week2.Change interval
normally depends on environment
Engine – Oil & Filter
Change interval depends on different factors:
a. Quality of oilb. Working tempc. Environment
Engine – Fuel Filter
Change interval normally depends on quality of fuel
Carrier GreasingGrease every week.Check once in every month whether grease is passing through every point
Drive line : greasing
Grease every point once in a week.
Only two stroke of grease is sufficient.
Use good quality grease.
Check bolt torque weekly
Coolant Level
Check Coolant
level daily
Transmission Oil & Filter
Change interval depends on different factors:
a. Quality of oilb. Working tempc. Environment
Transmission oil change
A - FillingB - Drain C - Filter
Drain the oil when it is hot through drain plug “B”. Fill the oil through port “A” up to “LOW” mark on dipstick. Change the filter.Run the engine at low idle to fill up the
converter and fill oil up to low mark.Run the engine to heat up the oil at 80 deg. C
fill up to high level.
Differential
Check level every week
Change every 500
hours
Planetary hub
Check level every week
Change every 500
hours
Release Park brake
Loosen lock nut “A”Screw in stud “B” to the bottom.
To reset the park brake screw out the stud “B” to 47 mm.Tighten the lock nut.
Service brake adjustmentPlace the rig on jacks. Open the lock nut “A” & lock plate “B”.Unscrew the adjusting screw “C” anticlockwise to take up any play. Continue to turn until a torque of 40 Nm is attained.
Now screw the adjusting screw “C” clockwise 3 turns.Refit lock plate “B” & lock nut “A”.
Hydraulic Booms
A
B
C
Cross cut drilling
Hydraulic Booms
Rotation unit
Boom Hydrauli
cSystem
Cylinder movement - Vertical
Cylinder movement - Horizontal
Maintenanc
e
Adjustment - Feed cradle
Cradle clearance adjustment
Replacement of guide rail
In Conclusion….
Drilling is the backbone of all mining & tunneling applications & thus the role of Electro Hydraulic Drill Jumbos assumes critical proportions.While these equipment are quite simple to operate with built in ling term reliability, optimization of drilling functions and high levels of availability is only possible if correct maintenance and operational directions are followed.
The presenters of this paper thankfully acknowledge the assistance from M/s Atlas Copco & M/s Sandvik for their inputs during preparation.