PDF Maintenance & Operation Manual Cat Bucyrus 7820 Dragline - 1 MB
Master the operation and maintenance of your Cat Bucyrus 7820 Dragline with this official manual.
It covers everything from daily safety checks to detailed periodic maintenance procedures, ensuring your massive machine operates safely and efficiently.
The operational section provides critical guidance for operators to maximize productivity while adhering to best practices.
By following the instructions in this guide, you can significantly reduce downtime and extend the service life of your equipment.
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BI006278
© Bucyrus
All Rights Reserved
BUCYRUS R
Technical Manual
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BI006278
MAINTENANCE T1PS
-
Just as the operator acquires a "feel" for the machine, the entire crew should try to sensa
failure before it strikes. Take that extra step to examine anything that appears out of place.
How about a bubble or discolored crack in the paint? It is an early warning for metal stress
or breakage. Could that slight hiss indicate a growing air leak? Aher all, it i.s easier to
tighten a packing nut than shut down for packing repairs. An alert crew will:
Check operating air pressure.
Wipe away excess lube around bearings and gears.
Maintain correct supply lubricants.
Lube regularly.
Never lubricate parts in motion, that is gears, etc.
Look for and secure any loose bolts or locking devices.
-
Check all wire ropes for early signs of wear or failure.
Promptly replace ail guards, inspection plates, access covers or other safety devices aher
inspection/repair.
USE EXTREME CAUTION around ANY electrical lines and equipment. This pertains to
low as well as high voltage.
Never attempt electrical repairs, unless qualified.
Assure power source is properly grounded.
Check limit switches for proper operation.
Check overloads and thermal breakers.
./
1-4
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BI006278
The swing pedals, centered on floor in front of seat, control the machine rotation. Pressing
right pedal, machine swings right. Left pedal causes a left swing or rotation. The swing
motion is stopped also by plugging the controls, that is, depressing opposite swing pedal to
Right Swing
r
Left Swing
slow or stop motions. The pedals are linked together so that only one pedal can be pressed.
When no pressure is applied, the pedals will self-neutralize in the neutral position.
NOTE: This machine is equipped with a special "Limitrol System". In addition to the
standard functions of tightline detection and hoist and drag limits, this system has special
functions of bucket depth indication, hoist and drag load indication, presettable bucket
depth signals, and loaded bucket indication. Operator controls are located in a control box
attached to the left hand control stand. A rope limit display box is located in the left front
corner of the operators' cab. Refer to the Limitrol System operation manual for details.
COMMENT ABOUT PRIMARY CONTROLS - The hoist and drag controller is a SPEED
REGULATOR. Practically full torque or line pull is obtained with the slightest handle
movement Move lever only far enough to obtain desired speed. Do not move lever(s) too
far, then back off. Use smooth movements, lever jockeying is not required and only results
in overheating the motors.
The swing pedals are a TORQUE REGULATOR. The swing torque applied to machine in-
creases as the pedal is pushed farther down and thus the acceleration rate is increased. This
means full swing speed is obtainable at any pedal position.
PLUGGING THE MOTION means reversing the generator field to act as a braking force and
stop motion.
--
2-4
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BI006278
Start TYPICAL DIGGING CYCLE with bucket on ground, in pit, under boom (point). If
machine tends to drift (rotate) apply enough pressure on opposite swing pedal to hold
machine.
Start dragging in bucket by pulling toward you the drag control lever \at left hand). The
further the lever is moved, the faster the bucket is pulled toward the machine. Hold tension
on hoist ropes by depressing the thumblatch on drag controller. If more power is needed
-
coordinate movement of hoist and drag controls. Pull bucket in until it is full.
Then by proper movement of hoist and drag control levers, power on hoist is increased
(pulled back) and power on the drag is decreased (moved forward).
NOTE: Only enough tension is kept on the drag ropes to keep the bucket from dumping.
Too much tension will cause bucket to carry near boom, add strain to boom and slow down
hoist speed.
2-14
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BI006278
LUBRICATION SPECIFICATIONS
SPECIFICATION - GREASES
CODE OR ASTM MPG RGL OGL
SYMBOL NO. or TEST TYPE B TYPE H
Penetration Worked SOX
Summer, N LGI 0-217 2 semi- 1
Winter, N LGI 1 fluid 0
Penetration Worked
5000X, Max. Change 0-217 10%
Dropping Point, Min. of. 0-566 350 325
Base Oil Viscosity
@ 210°F., Min. 0-446 75 SUS 140 SUS 200 SUF 200 SUF
Oxidation Stability
Max. psi Drop - 100 hrs. 0-942 10
Water Resistance
Max. Loss @ 100° F. 0-1264 20% 10% 10%
"-"
Texture Visual Buttery Adhesive Tacky
EP Timken, Min. OK 351bs. 351bs. 351bs.
SPECIFICATION - OILS
CODe OR ASTM MO OILS
SYMBOL NO. or TEST . PO..
---_. _.
Pour Point of. Max. . Summer 0-97 5 15
Winter a 15
Flash Point of. Min. - Summer 0-92 450 410
Winter 420 410
Viscosity @ 100°F. SUS 0-446 150
Min. "~'
3-4
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BI006278
NO.OF LUB. METHOD &
~-~
NAME OF PART TYPE POINTS LOCATION SYM. FREQUENCY
Fan Motors EMG 500-600 hrs.
Filter Ducts Motor EMG 500-600 hrs.
Floating Sheaves Bushing 5 End of Pins MPG Auto, 15 min.
on House
Boom Raising As required
Sheave
LUBRICATION OF DRAGLINE BUCKET
Dump Block 2 End of Shaft MPG Hand, 8 hrs.
Sheave and Pin
Dump Block 2 End of Pin MPG Hand, 8 hrs.
Anchor
-
3-14
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-
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The main propel drive shaft connects the left hand and right hand second intermediate shaft
assemblies. The drive shah is mounted on the deck of the rotating frame.
Pinions on the left hand and right hand third intermediate shafts mesh with the main propel
drive gears to turn the propel cranks. The cranks extend through the walls of the machinery
house to connect with the walking arms which raise and lower the walking shoes.
The PROPEL LINKAGE on each side of the house consists of the walking arm, the stabi-
lizer arm and the walking shoe. The upper end of the walking arm is connected to the
stabilizer arm. The lower end of the walking arm is connected to the walking shoe by a ball
and socket joint which allows the shoe to tilt in any direction to compensate for uneven
ground. A lateral shaft through the ball joint allows side movement of the shoe.
CAUTION IS THE BY-WORD
4-6
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~ .r W-M
BI006278
Gear
Gear Case
rr
I I
Pinion
\
Retainer
Lube
Lube Fitting
Fitting
Searing -
SHAFT - FIRST INTERMEDIATE PROPEL
4-16
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f'f
BI006278
Working inside the tub, the bearings and spacers can now be installed on the lower end of
the main rotating shaft. Then jack the pinion up into position on the shaft splines and in-
stall the retainer plate. Secure the retainer pt~te cap screws with lock wire. Make sure that
-
the main rotating shaft bearing is properly lubricated.
Lower the intermediate gear onto the shaft and measure the distance between the top of the
shah and top of the gear hub. This distance should be five-eighths Inch. If it is not, replace
or grind the spacer to obtain the correct measurement. Install the gear retainer plate.
Remove the temporary holddown bolts securing the gear case center section to the lower
section. Lower the gear case cover into position and install all of the holddown bolts to
secure it in position.
Assemble the cylindrical bearings on the motor extension shaft and install the shaft in the
motor coupling housing. Lower the motor coupling housing into position on the gear case
and install the holddown bolts. Add shims under housing as required to align extension
shaft pinion with intermediate gear.
Install the lower coupling half on the motor extension shaft, tighten the jam nut on the
shaft, and tighten the cap screws to secure the jam nut in position. Finally, lower the motor
onto the coupling housing, install the motor holddown bolts, and the coupling halves. Then
install the access cover plates on the housing.
Call an electrician to make the electrical connections. Connect the brake air line and, after
-
double checking the drain valves to make sure they are closed, fill the gear cases with lubri·
cant.
ROTAT1NG BRAKE - The rotating brake is located on the top of each of the four rotating
electric motors. The brake is an e:< ternaI shoe type brake that acts on a friction housing,
keyed to the rotating motor armature shaft. The brake is spring set and air released.
The rotating brake is a holding brake. Do not apply the brake to slow down or stop the
swing motion except in case of emergency. Stop the swing by "plugging" the swing motor.
The brake is set by moving the two operating links together totward the toggle position.
Adjust the position of the toggle by turning the adjusting bolt between the end castings of
the inside link. Loosen the lock nuts" A" and turn the hex on the adjusting bolt "8" until
the centerlines of the links are 5/8" apart, measured at point "C".
Adjust the set spring by turning the spring retainer sleeve at the rod end of the cylinder.
Loosen the set screw "0" and turn the sleeve clockwise to increase the spring tension. Do _.
4-26
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The hoist and drag brakes are not intended to stop or slow the rotation of the motor arma-
ture shaft. The brakes are designed as holding brakes to be used when the motor is de-
energized. Each brake consists of two shoes that act on a brake wheel that is keyed to the
motor armature shaft. The brake is set by a compression spring and released by an air
cylinder. If power to the machine is lost, for any reason, the brakes will set.
To adjust the brake on the rear drag motor, see the propel section of this manual for adjust-
ment instructions.
To adjust the brake on the front drag motor or either hoist motor, turn the manual over-
ride switch on the magnet valve to the Ilrelease" position. Air pressure will push the brake
cylinder piston out and release the brake.
c Lever
-- -- - ----- ---- - - - - --- -- -----------
HOIST·DRAG BRAKE ASSEMBLY
Adjust brake in the released position. Loosen set screws A" and liB" and turn nuts IIC" on
II
adjusting bolt "0" until clearance is 1/8 inch between brake shoes and brake wheel. Equal-
ize clearance by adjusting set screws liN'. Position brake shoes by turning set screw 118" so
that heel of shoe does not drag on housing when brake is released.
With the brake in SET position, adjust nuts liE" so that spring initial length is 19 inches
for either hoist or drag brake.
4-36
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11
BI006278
At six month intervals, a damper should be removed for examination of the inside strands.
If the first one is found in bad condition, remove the others and inspect The fabric liner
should be statu rated with light lubricant if dry.
-
The GANTRY is a welded structure and pin connected to lugs on the front girder of rota-
ting frame. Two wide spread back legs support the top of gantry.
Boom Support Boom Raising Sheave
Rope Connections
Hoist
Deflecting
Sheave
Upper
-
Fairlead
Sheave
1 - - - - Gantry Tower
GANTRY-FAIR LEAD TOWER ASSEMBLY
4-46
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BI006278
••••••••••••••••••••••••••••••
WARNING
DUE TO THE DANGERS INHERENT IN THE OPERATION OF ANY HIGH VOLTAGE
ELECTRICAL EQUIPMENT, A SAFE GROUNDING SYSTEM SHOULD INCLUDE
GROUND CONDUCTORS IN THE CABLE, A NEUTRAL GROUNDING RESISTOR
AND RELATED RELAYS AND SWITCHGEAR. A GROUND CONTINUITY CHECK
SYSTEM IS ALSO RECOMMENDED.
••••••••••••••••••••••••••••••
Marion provides (under separate cover) a separate book/manual from the electrical manu- _""
facturer in addition to the information supplied in this section.
FEEDER CABLE must contain a provision for a ground connection. Especially where 2300
volts and above are used. The power line end must attach (see paragraph on ground circuits)
to a suitable permanent ground. The machine end must securely attach thru a bolted con-
nection to ground machine frame. This provides a constant ground for the machine and
electrical equipment. Failure to provide this adequate ground endangers works and equip-
ment.
POWER LINE GROUNDING CIRCUIT ADEQUATE FOR THE MACHINE CANNOT BE
OVER EMPHASIZED. Without a good grounding system, high voltage exists between the
machine and ground. The portable cable and power lines supplying the machine must have
a ground wire ample in capacity running parallel to the main wires over the entire distance
from transformer to machine. A suitable grounding system must be used at the transformer.
Consult your local electric supplier for details.
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BI006278
Rectifiers normally fail by shorting, but the effect depends upon the circuit. With rectifiers
used to convert A.C. to D.C., shorting provides A.C. in output; detected by a multimeter on
the output circuit. Shorted, blocked rectifiers allow current flow when the wrong polarity
of voltage is detected.
Rectifier failure detection using the ohmmeter works, but the low voltage batteries in the
meter do not always give a good test. Best results show up using the high resistance scale,
but even this may not be conclusive.
The best test for rectifiers uses D.C. voltage at least 1/4th its rating. Connect a resistor in
series with rectifier to limit current to a safe value. Connect resistor and rectifier across D.C.
voltage, then read voltage across resistor. Reverse rectifier and measure resistor voltage. A
good rectifier gives voltage across resistor with only one polarity.
Many other failures occur and often good intuition and ingenuity is needed to find them.
The trouble discussed thus far usually results in complete and permanent malfunction.
Perhaps more common and more difficult to find are intermittent failures resulting in only
partial power loss. These trouble types distinguish a good troubleshooter from an average
one.
Start as before, interviewing operator, oiler and witnesses. Try in questioning to determine
the exact nature of trouble. When complaint indicates partial power loss, find the effect
-
under various load conditions and determine the cause of this effect.
Often a cause for weakening may be determined in a similar manner as locating complete
failure. Select a starting point and compare measurements taken against recorded data.
Compare honestly. A slight difference shows due to aging, temperature or an inaccurate
instrument along with failure. Tests under one condition might not give a true problem
indication. For example, tests at stall do not indicate no-load voltage is incorrect. Likewise,
test for proper motor field voltage ON LY with controller (master switch) in proper position.
In addition, check that stall current or no-load voltage varies properly with master switch
position, since trouble could be failure of master switch.
In locating trouble of the weakening kind, one needs to know the various devices functions
used to augment or increase power under certain conditions. Master switch contacts fall in
this device class. Motor field contactors increase field strength under certain conditions.
Conversely, current or voltage feedback circuits limit certain quantities to acceptable values.
Failures resulting in decreased or increased outputs generally come from failure in these
supplementary circuits.
Help here comes from knowing the effects certain changes have on performance. Naturally,
5-10
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filling; NEVER REFILL THRU WICK CAP. Use methyl alcohol only. (Permanent anti-
freeze types do not evaporate fast enough for good protection). --
MAGNET VALVES need little or no maintenance. Dirt
and scale cause a leaky valve sometimes. Try opening
and closing it several times quickly by turning the small
screw on top. Cleaning this way often avoids disassem-
bly. If not, DISMANTLE, CLEAN, and REPLACE worn
or damaged parts. Lube with a small amount of MPG.
These el ectrically operated (on and off) valves are nor-
mally closed when de-energized. A spring loaded plunger
shuts OFF air from supply to cylinder while the exhaust
port from the cylinder to atmosphere is OPEN. Ener-
gizing the coil moves the plunger down, CLOSI NG the
exhaust port and OPEN ING the port from supply to the
brake release cylinder.
'---~0---~
'. _ _ .-Y
:-==1
PRESSURE REGULATORS consist of a spring loaded
diaphragm that moves a cone shaped seat which opens and
closes, allowing air to pass thru the valve. A spring under
this seat keeps it against the diaphragm. A T-handle on
top screws in and out to adjust diaphragm spring tension.
Right (clockwise) increases and left (counterclockwise)
decreases the tension; and the air pressure. When used in
connection with clutches, the setting is at tank pressure
low end to soften action and protect the clutch or parts.
NEVER USE MORE pressure than needed to handle a
fully loaded bucket. When used elsewhere, a pressure
gauge reading shows needed operating setting.
AIR CYLINDER VALVES actuate the brakes and are spring set; air released. A sleeve re-
tains the spring and threads into the open cylinder end. A set screw locks this sleeve. To re-
pack cylinder, unlock set screw and turn out sleeve to release return spring tension. Discon-
6-2
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RUNNING CLEARANCE FOR BRONZE BUSHINGS
Shaft Running Shaft Running
Nom. Clear- Nom. Clear-
Oiam. 0.0. ance Oiam. 0.0. ance
1.000 .006 5 5.000 .011
.999 .010 4.998 .020
1-1/4 1.250 .005 5-1/4 5.250 .011
1.249 .010 5.248 .020
1-1/2 1.500 .008 5-1/2 5.500 .012
1.499 .013 5.498 .020
1-3/4 1. 750 .008 5-3/4 5.750 .012
1.749 .013 5.748 .021
2 2.000 .007 6 6.000 .012
1.999 .012 5.998 .021
2-1/4 2.250 .006 6-1/4 6.250 .012
2.248 .013 6.248 .021
2-1/2 2.500 .006 6-1/2 6.500 .012
2.498 .013 6.498 .021
2·3/4 2.750 .008 6·3/4 6.750 .013 .~
2.748 .015 6.748 .022
3 3.000 .008 7 7.000 .013
2.998 .015 6.998 .022
3·1/4 3.250 .008 7-1/4 7.250 .013
3.248 .015 7.248 .022
3-1/2 3.500 .008 7-1/2 7.500 .014
3.498 .015 7.498 .022
3-3/4 3.750 .011 7·3/4 7.750 .016
3.748 .019 7.748 .024
4 4.000 .011 8 8.000 .015
3.998 .019 7.998 .024
4-1/4 4.250 .010 8-1/4 8.250 .015
4.248 .019 8.248 .024
4-1/2 4.500 .010 8-1/2 8.500 .016
4.498 .019 8.498 .025
4-3/4 4.750 .014 8-3/4 8.750 .016
4.748 .022 8.748 .025
7-2
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BI006278
D. To check the temperature of the component, use a Fahrenheit or Celsius thermcr
meter by placing putty over the bulb and holding it against the hub. Heat com-
ponent a few degrees above the desired temperature before removing it from the
oven.
9. After the component has been removed from the oven, wait a few minutes until the
bore has cooled to the temperature required, remove the thermometer and quickly
mount as described.
10. After making sure the bore is clean, quickly locate the component in the same angular
position on the shaft as when cold. When nearly engaged with the taper fit, but not
actually in contact, snap it forcibly into place with a quick push. It is important that
the hot component be instantly snapped into position before it has cooled appreciably.
Otherwise, it will immediately freeze to the shaft and cannot be adjusted further.
1t Check the hot shrunk-on position of the component on the shaft using the micrometer
depth gauge as before.
A. The actual advance is the difference between the depth gauge reading at the hot
and cold positions. To control the stresses in the component the advance must be
within the limits specified in the table.
If the advance is not within the limits given, the component should be pulled and
remounted.
-
12. After the component has been properly shrunk on the shaft, assemble the lock washer
and nut or other means of locking.
13. When shou Ider nuts are used, make certain the shoulder does not bottom before the
main body of the nut tightens on the locking plate. In case the shoulder on the nut
bottoms before tightening on the locking plate, the nut should be removed and the
shoulder ground or machined off so clearance is available.
14. After it is certain that the nut is securely tight, turn up the locking plate on at least
two faces of the nut
A. It shou Id be kept in mi nd that the component fit on the shaft and the fit on the
key are the important points in doing a good job of holding the component on the
shaft. The locking plate simply serves to hold the nut on the shaft. With the cor-
rect fit between the tapered bore and shaft there is no load on the nut and locking
plate.
7-12
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BI006278
GEAR INSPECTION PROCEDURES
METHOD OF CHECKING RIM FACE RUNOUT OF GEAR. If gear can be rotated without
end float., place dial indicator squarely against the rim face stamped (000), at station stamp-
ed (1) and set to zero.
Revolve gear slowly. Record reading at each station. After one complete revolution, indica-
tor should read within (plus or minus) .002". If not, recheck. Allowable rim face runout is
shown in table 1. Total rim face runout is the algebraic difference between maximum plus
and maximum minus readings.
EXAMPLE: Readings for a 16 foot diameter gear are listed in a chart below.
Total tim runout is .020" is obtained between station 3 with a maximum plus reading of
.005" and station 9 with a maximum minus reading of .015", This is within allowable
.022" shown in table 1.
TA8L~';"·
( Out1.de Allowable
11 Dlomete, ~im Face
A
of Geo' ~unout Station No.
(feet) (,"chell
Indicator Reading
~
6 006
7
8
007
008 ~-.0~51-.:101
m/
1
9
10
11
009
010
012
11 1
1-.0~41 -.0~5 I-.o~~ I _.0101_.0051 .O~O I
2
12 014 7
14 018
16
18
022
026
III
20 032
~.
22 038 14
24 044 ::;::,
CHECKING RADIAL RUNOUT OF GEAR: Mount a dial indicator so it can be set against
one of four machined surfaces. See sketch. Place indicator square with the machined sur-
faces at one of the stations stamped on the gear rim face. Revolve gear slowly and record
readings at each station under the corresponding station number. After one complete revolu-
tion, indicator should read within (plus or minus) ,002" of initial reading at starting station.
ALLOWABLE RADIAL RUNOUT is shown in table 2. The total radial runout is the alge-
braic difference between maximum plus and maximum minus readings. If radial runout ex-
7-22
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BI006278
Broken wires.
Corroded wi res.
Marks indicating mechanical abuse, distortion or crushing.
Inspect rope sheaves often. Check sheaves and drums for proper alignment. Use no reeving
that requires reverse bends unless provided with sufficient space between the bends for ade-
quate rope recovery.
Do not allow wear at rope sheave groove. An old rope wears a groove to a reduced radius.
This groove crushes or deforms a newly installed rope.
Avoid sheave groove or drum lagging from assuming rope lay shape. Alternate right and left
hand lays, if needed" Keep sheaves and drum free of rough spots, nicks or burrs. Never use
cracked or ch ipped sheave.
Maximum rope life and the best service evolves from extreme care in handling and installa-
tion. This is important. Working a new rope at reduced loads gives the rope lay time to ac-
quire a permanent set. Slow acceleration and deceleration of load and eliminating sudden
actions are good habits to develop. Never overstress a rope by jerking or catching a heavy,
falling load.
Lubrication remains the most important item in rope care. All rope is lubed when manufac-
tured. Generally thin and filmy, this lube eases the manufacture rather than preserves the
rope. This film drys rapidly or dissipates thru surrounding conditions.
Lubricate every rope at installation and keep coated thru continued service. Lubricant
serves to reduce internal friction wear and the outer wire wear against sheave or drum. Lube
protects rope from weather and corrosive air, too.
Marion recommends a light, penetrating type lubricant (WR L) containing anti-rust or cor-
rosion agents and anti-wear additives. This lube saturates rope interior thus reducing inter-
nal friction while providing a protective outer coating.
The rope lubricant selected may be an asphaltic type containing volatile solvent or diluent
which allows strand and core penetration. This lube type works well for operations in high-
ly abrasive material or water submersion.
One method of rope lubrication utilizes an automatic system that provides a drip fixture
above sheaves on boom point, gantry, and fairlead. This system is generally timer controlled
with manual override for severe conditions.
7-32
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BI006278
On beam flange where
center rib exists
REINFORCING REQUIRES EXTREME CAUTION in