ARO 7844-E User manual

Tool Products
OPERATOR’S MANUAL
INCLUDING:OPERATION,INSTALLATION& MAINTENANCE
SECTION M20
MANUAL 41
Released: W77
Revised: 1-27-95
“2200” SERIES DRILLS
Models: 7844-E, 7845-E, 7848-E-( ), 7847-E-( ),
7848-E-( ), 7849-E-( ), 7850-E, 7851-E,
7852-E, 7853-E-( ), 7854-E and 7855-E.
Form: 1166-2
READ THIS MANUAL CAREFULLY BEFORE INSTALLING,
OPERATING OR SERVICING THIS EQUIPMENT.
FAILURE TO OBSERVE THE FOLLOWING WARNINGS COULD RESULT IN INJURY.
Pneumatic tools should always be installed and used in accor-
dance with A.N.S.I. 8188.1 “Safety Code for Portable Air Tools”.
l
0
0
l
l
l
l
l
l
l
Operate this tool at 90 p.s.i.g. (6.2 bar) maximum air pressure
at the air inlet of the tool.
Disconnect air supply from tool before removing/installing bit,
socket or performing other maintenance procedures.
Keep hands, clothing and long hair away from rotating end of
tool.
Anticipate and be alert for sudden changes in motion during
start up and operation of any power tool.
Never exceed rated r.p.m. of tool.
Wear suitable eye and hearing protection while operating tool.
Tool shaft can continue to rotate briefly after throttle is re-
leased.
Donot lubricate tools with flammable orvolatile liquids such as
kerosene, diesel or jet fuel.
Do not remove any labels. Replace any damaged label.
Use only accessories recommended by ARO.
Repeated prolonged operator exposure to vibrations which may
be generated in the use of certain hand-held tools may produce
Raynaud’s phenomenon, commonly referred to as Whitefinger
disease. The phenomenon produces numbness and burning
sensations in the hand and may cause circulation and nerve dam-
age as well as tissue necrosis. Repetitive users of hand-held
tools who experience vibrations should closely monitor duration
of use and their physical condition.
l The use of other than genuine ARO replacement parts may
result in safety hazards, decreased tool performance and in-
creased maintenance and may invalidate all warranties.
l ARO is not responsible for customer modification of tools for
applications on which ARO was not consulted.
l Tool maintenance and repair should be performed by autho-
rized, trained, competent personnel. Consult your nearest
ARO authorized servicenter.
l It is the responsibility of the employer to place the information
in this manual into the hands of the operator.
Forparts and service information, contact your local ARO distributor, or the Customer Service Dept. of the Ingersoll-Rand Distribution
Center, White House, TN at PH: [phone], FAX: [phone].
ARO Tool Products
Ingersoll-Rand Company
1725 U.S. No. 1 North l PO. Box 8000 l Southern Pines, NC 28388-8000
©1995 THE ARO CORPORATION. PRINTED IN U.S.A.
Partofworldwide Ingersoll-Rand

FAILURETOOBSERVETHEFOLLOWINGWARNINGSCOULDRESULTININJURY.
Wear eye protection when
operating or performing
maintenance on this tool.
Turn off air supply and disconnect
air supply hose before installing,
,
!!
removing or adjusting any
accessory on this tool, or before
performing any maintenance on
this tool.
Do not carry the tool by the hose.
Do not overreach when operating
this tool. Keep body stance
balanced and firm.
NOTICE
PN 48178-1 LABEL PN 49883 LABEL
(NON-EU MODELS) (-EU MODELS)
This label must appear on the tool at all times. If it is
lost or damaged, a replacement label is available at
no cost.
Air powered tools can vibrate in
use. Vibration, repetitive motions
or uncomfortable positions may
be harmful to your hands and
arms. Stop using any tool if
discomfort, tingling feeling or
pain occurs. Seek medical advice
before resuming use.
Wear hearing protection when
operating this tool.
I
Do not use damaged, frayed or
deteriorated air hoses and
fittings.
WARNING = Hazards or unsafe practices which could result in severe personal injury, death or substantial
property damage.
CAUTION = Hazards or unsafe practices which could result in minor personal injury or product or property
damage.
NOTICE = Important installation, operation or maintenance information.
2

ROUTINE LUBRICATION REQUIREMENTS
M20
41
Lackof oran excessive amount of lubrication will affect the perfor-
mance and life of this tool. Use only recommended lubricants at
below time intervals:
EVERY 8 HOURS OF TOOL OPERATION - Fill lubricator reser-
voir of recommended F.R.L.with spindle oil (29665). Ifan in line or
air line lubricator is not used, apply several drops of spindle oil
(29665) in air inlet.
EVERY 40 HOURS OF TOOL OPERATION - Flush tool with a
solution of three (3) parts cleaning solvent to one (1) part spindle
oil. After flushing, apply asmall amount ofspindle oil in air inlet and
run tool for one minute to insure proper lubrication. Built-in oiler
reservoir (pistol grip models) should be filled with spindle oil
(29665).
EVERY 180 HOURS OF TOOL OPERATION - Lubricate gear-
ing. Pack bearings, coat shafts and lubricate gears with NLGI #1
“EP” grease (33153). Gearing should contain approximately 114
oz. (7 g) of grease per reduction.
AIR SUPPLY REQUIREMENTS
For maximum operatingefficiency, the following airsupply specifi-
cations should be maintained to this air tool:
l AIR PRESSURE - 90 p.s.i.g. (6.2 bar)
l AIR FILTRATION - 50 micron
. LUBRICATED AIR SUPPLY
l HOSE SIZE - 5/16” (8 mm) I.D.
An ARO@model C28231-810 air line FILTER/REGULATOR/LU-
BRICATOR (F.R.L.) is recommended to maintain the above air
supply specifications.
RECOMMENDED LUBRICANTS
After disassembly iscomplete, all parts, except sealed orshielded
bearings, should be washed with solvent. To relubricate parts, or
for routine lubrication, use the following recommended lubricants:
Where Used
AirMotor
ARO Part # Description
29665 1 qt Spindle Oil
“O” Rings & Lip Seals 36460 4 oz. Stringy Lubricant
Gears and Bearings 33153 5lb.“EP”- NLGI#1Grease
INSPECTION,MAINTENANCEANDINSTALLATION
Disconnect air supply from the tool or shut off air supply and ex-
haust (drain) line of compressed air before performing mainte-
nance or service to the tool.
It is important that the tools be serviced and inspected at regular
intervals for maintaining safe, trouble-free operation of the tool.
Be sure the tool is receiving adequate lubrication, as failure to Iu-
bricate can create hazardous operating conditions resulting from
excessive wear.
Besure that the air supply lines and connectors are of proper size
to provide a sufficient quantity of air to the tool.
Tool maintenance and repair shall be performed by authorized,
trained, competent personnel. Tools, hose and fittings shall be re-
placed if unsuitable for safe operation and responsibility should
be assigned to besure that all tools requiring guards orother safe-
ty devices shall be kept in legible condition. Maintenance and re-
pair records should be maintained on all tools. Frequency of
repair and the nature of the repairs can reveal unsafe application.
Scheduled maintenance by competent authorized personnel
should detect any mistreatment or abuse of the tool and worn
parts. Corrective action should be taken before returning the tool
for use.
Disassembly should be done on a clean work bench with a clean
cloth spread to prevent the loss of small parts. After disassembly
iscompleted, all parts should bethoroughly washed in aclean sol-
vent, blown dry with air and inspected for wear levels, abuse and
contamination. Double sealed or shielded bearings should never
be placed in solvent unless a good method of m-lubricating the
bearing is available. Open bearings may be washed but should
not be allowed to spin while being blown dry.
Upon reassembling, lubricate parts where required. Use 33153
grease, or equivalent, in bearings. Use 36460 lubricant for “O”
ring assembly. When assembling “O” rings or parts adjacent “O”
rings, care must be exercised to prevent damage to the rubber
sealing surfaces. A small amount of grease will usually hold steel
balls and other small parts in place while assembling.
When replacement parts are necessary, consult drawing contain-
ing the part for identification.
Always use clean, dry air. Dust, corrosive fumes and/or excessive
moisture can damage the motor of an air tool. An air line filter can
greatly increase the life of an air tool. The filter removes rust,
scale, moisture and other debris from the air lines. Low air pres-
sure (less than 90 p.s.i.g.) reduces the speed of the airtool. High
air pressure (more than 90 p.s.i.g.) raises performance beyond
the rated capacity ofthe tool and could cause injury. Shown below
is a typical piping arrangement.
MAIN LINES 3 TIMES
AIR TOOL INLET SIZE
SYSTEM
LUBRICATOR
REGULATOR
COMPRESSOR
DRAIN REGULARLY
3

MODEL IDENTIFICATION
MODEL
NUMBER
7850-E
7851-E
7852-E
LEVER HEAD TYPE THROTTLE
R.P.M. TOTAL MOTOR GEARING CHUCK
REDUCTION ASSEMBLY DRIVE AUXILIARY NUMBER
18,000 1:1 43139 41769 33907
4,500 4:1 43139 41771 33907
2,400 7.43: 1 43139 41770 33907
7853-E 1,100 16:1 43139 41771 40825 30016
7853-E-EU 1,100 16:1 43139 41771 40825 30016
7854-E 600 29.7:1 43139 41770 40825 30016
7855-E 325 55.2:1 43139 41770 40826 30016
1 CANCELLED MODELS MODELS WITH -EU ARE “EC” COMPLIANT MODELS
GENERAL DESCRIPTION AND OPERATION
Aro “2200” series drills are available with either a lever or pistol
grip type throttle and with 6 different speeds. The combination of
free speeds, throttle type and chuck capacities appear as models
above.
Lever throttle models feature a muffler, suspension bail, flush fit-
tings for lubrication of gearing and a 1/4” N.P.T.F.female air inlet
adapter.
Pistol grip models feature a built-in oiler, muffler, flush fittings for
lubrication of gearing and a 1/4” N.P.T.F.female air inlet adapter.
All models have a 1/2” - 20 threaded drive spindle for mounting
the chuck.
Safe and efficient operation oftour Aro drill can best be attained by
observing proper operating, inspection and maintenance proce-
dures.
Disconnect air supply from tool or shut off air supply and exhaust
(drain) line of compressed air BEFORE performing maintenance
or service to tool.
Before starting to disassemble or assemble this tool (any part or
completely), be sure to read “Inspection, Maintenance and Instal-
lation” section.
Tominimize the possibility of parts damage and for convenience,
CHUCK
CAPACITY
3/8”
3/8”
3/8”
3/8”
3/8”
3/8”
3/8”
the steps for disassembly or assembly listed on the following
pages are recommended.
The basic sections and instructions for removing them from the
tool are as follows:
GEARING SECTION
Secure the tool in a suitable holding device. Place a wrench on
spacer (33697); place chuck key in chuck and strike key a sharp
blow to loosen chuck. Remove chuck and spacer (33697). Using
a wrench on flats of ring gear and a strap wrench on motor hous-
ing, unthread and remove gearing sections. Models having both
drive and auxiliary gearing, separate using wrenches on flats of
ring gears.
MOTOR SECTION
With head oftool in a suitable holding device, remove motor hous-
ing with a strap type wrench (lever head tool only). On pistol grip
head tool, it may be necessary to tap open end of housing with a
soft face hammer to loosen motor from housing.
HEAD SECTION
Follow disassembly procedures as outlined in the preceding sec-
tions. Valve parts may be removed from head without removal of
head from tool.
4

TYPICAL CROSS SECTION OF TOOL
M20
41
HEAD SECTION
MOTOR SECTION
SPACER
35831 LOCK NUT
GEARING SECTION
AUXILIARY GEARING
5

GEARING SECTION
DRIVE GEARING
DISASSEMBLY ASSEMBLY
Remove nose housing (38379) seal (37774) and spacer NOTE: Pack bearings and lubricate gears and shafts with ARO
(33897). Grasp ring gear in one hand and tap threaded end of
spindle with a soft face hammer: spindle and components will 33153 grease, or equivalent, upon assembly. Gearing assembly
loosen from ring gear. NOTE: Further disassembly should be should contain approximately 1/4 oz. grease.
done only if it should be necessary to replace a part, as Brinelling
of the bearing races may occur, making replacement necessary. Assemble snap ring to spindle. Rotate snap ring, allowing installa-
To disassemble completely, remove bearing (33708). Turn snap tion of shafts. After both gears and shafts have been assembled to
ring on spindle so the open portion of the ring will allow the remov- spindle, rotate snap ring, locking shafts in place. Assemble bear-
al of shaft. Remove shaft, releasing gear. Repeat for removal of ing (33706) to spindle and assemble into ring gear (34490) with
opposite shaft and gear. washer (47590) and wave washer (47589). Assemble seal, nose
housing and spacer (33697) to gearing. Pack bearing (33704)
with ARO 33153 grease and assemble, with spindle, to tool.
34490 RING GEAR
41771 DRIVE GEARING ASSEMBLY (4:1)
40842 SNAP RING
* 38379 NOSE HOUSING 40835 SPINDLE 33704 BEARING
* INCLUDES 35987 GREASE FITTING 17 INTERIOR - 15 EXTERIOR TEETH)
41770 DRIVE GEARING ASSEMBLY (7.43:1)
33705 BEARING
7589 WAVE WASHER 42271 BEARING (4)
33697 SPACER
* 38379 NOSE HOUSING 33704 BEARING
* INCLUDES 35967 GREASE FITTING
34490 RING GEAR
41769 DRIVE GEARING ASSEMBLY (1:1)
33706 BEARING
35967 GREASE FiTTl 47589 WAVE WASHER 34488 SPLINED DRIVER
33697 SPACER 7590 WASHER 40841 SHAFT (2)
* 38379 NOSE H
* INCLUDES 35967 GREASE FITTING
6

GEARING SECTION
M20
41
AUXILIARY GEARING
DISASSEMBLY ASSEMBLY
Grasp ring gear in one hand and tap drive end of spindle with asoft
face hammer; spindle and components will loosen from ring gear. To assemble gears and bearings to spindle, reverse the proce-
dure of disassembly. NOTE: After assembling gears and shafts to
spindle, rotate snap ring, securing both shafts in place.
Gearing should not be disassembled further unless it is neces-
sary to replace a part, as Brinelling of the bearing races may oc-
cur, making replacement necessary.
Tofurther disassemble, remove bearing (33704) rotate snap ring
so the open portion of the ring will allow the removal of shaft. Re-
move shaft, releasing gear. Repeat for removal of opposite shaft
and gear.
Assemble spindle and components to ring gear.
Pack bearings and lubricate gears with ARO 33153 grease upon
assembly. Gearing assembly should contain approximately 1/4
oz. (7 g) of grease.
40826 AUXILIARY GEARING ASSEMBLY (7.43:1)
33708 RETAINING RING
35323 GREASE FITTING 42271 BEARING (4)
40840 SPINDLE
40841 SHAFT (2)
33704 BEARING
40843 SNAP RING
* 35270 RING GEAR
* INCLUDES 35323 GREASE FITTING 33704 BEARING
NOT INCLUDED IN GEARING ASSEMBLY 35831 LOCK NUT
40825 DRIVE GEARING ASSEMBLY (4:1)
33708 RETAINING RING 46417 GEAR (2)
\ (14 TEETH) \ 40841 SHAFT (2)
35323 GREASE FITTING 42271 BEARING (4)
40839 SPINDLE
33704 BEARING
33704 BEARIN 35831 LOCK NUT
* 35270 RING GEAR
* INCLUDES 35323 GREASE FITTING (7 INTERIOR - 15 EXTERIOR TEETH)
NOT INCLUDED IN GEARING ASSEMBLY
7

MOTOR SECTION
DISASSEMBLY
Remove motor assembly from housing. Using a spanner type
wrench, remove nut (33694) and fastener (33700). Grasp cylinder
in one hand and tap splined end of rotor with a soft face hammer;
motor will come apart.
ASSEMBLY
NOTE: Packbearings with ARO 33153 grease, or equivalent, and
coat i.d. of cylinder with ARO 29685 spindle oil upon assembly.
Assemble bearings into end plates, pressing on outer race of
bearings. NOTE: Assemble bearing (33709) into end plate with
the identification markings on the bearing facing “out”. Assemble
end plate (33710) to rotor and secure with sems fastener. NOTE:
Torque fastener to 28 in. Ibs. Assemble cylinder over rotor, align-
ing air inlet holes in cylinder with air inlet slot of end plate and as-
semble roll pin in hole of end plate. Assemble blades to rotor. As-
semble end plate (33712) to rotor and cylinder, aligning hole in
end plate with roll pin in cylinder. Assemble nut (33694) to end
plate and torque to 9 - 12ft Ibs. Insure rotor does not bind (if rotor
binds, lightly tap splined end of rotor with a soft face hammer to
loosen) and assemble to tool.
ASSEMBLING MOTOR TO TOOL
LEVER THROTTLE MODELS: Remove motor housing (37082)
from head. Place head in asuitable holding device with the “motor
end” in an upright position. Assemble motor assemble to head,
aligning roll pin in motorwith hole provided in head (.125” diameter
blind hole). Slip motor housing over motor and secure to head. As-
semble spacers (33699 and 33711) and gearing to tool.
† INCLUDED WITH 35679 CYLINDER
* NOT INCLUDED WITH MOTOR ASSEMBLY
0 TORQUE TO 26 IN. LBS
0 TORQUE TO 9 - 12 FT LBS
† Y178-20’ ROLL PIN (2)
33712 END PLATE
33709 BEARING
(FLUSH FACE -INSTALL WITH FLUSH
FACE TOWARDS END PLATE)
33710 END PLATE
33701 SPACER
3700 SEMS FASTENER
3705 BEARING 35679 CYLINDER 33694 NUT
3699 SPACER
33711 SPACER *
41522 MOTOR ASSEMBLY
43139 MOTOR ASSEMBLY
t INCLUDED WITH 38772 CYLINDER
* NOT INCLUDED WITH MOTOR ASSEMBLY
• TORQUE TO 28 IN. LBS
0 TORQUE TO 9 - 12 FT LBS
* INCLUDES 35967 GREASE FITTlNG
37082 MOTOR HOUSING * *
33699 SPACER * 35967 GREASE FITTING * q 33700 SEMS FASTENER
3711 SPACER * 33710 END PLATE
t Y178-20 ROLL PIN 33701 SPACER
33705 BEARING
33712 END PLATE
36772 CYLINDER 41521 ROTOR 33709 BEARING
(FLUSH FACE - INSTALL WITH FLUSH
41520 BLADE (5) FACE TOWARDS END PLATE)
8

HEAD SECTION
PISTOL GRIP
M20
41
DISASSEMBLY ASSEMBLY
a. Remove adapter (37073) “O” ring (Y325-13), insert assem-
bly (37981) and spring (33547).
b. Depress trigger (39764) to release valve (39286) and “O” ring
(Y325-7).
c. Toremove trigger (39764) remove locking screw (39769) and
guide pin (39768) releasing trigger and spring (32858).
d. To remove oilite casting (33190-l) insert screwdriver into
motor end of housing and unscrew.
a. Assemble spring (32858) and trigger (39764) into housing
and secure with guide pin (39768) and locking screw (39769).
b. Assemble valve (39286) with “O” ring (Y325-7), spring
(33547) and insert assembly (37981) into housing, securing
with “O” ring (Y325-13) and adapter (37073).
c. Assemble oilite casting (33190-l) into place in oil cavity, fill
cavity with oil and seal with washer (31389) and screw
(30747).
40177 PISTOL GRIP HOUSING ASSEMBLY (STANDARD MODELS)
49943 PISTOL GRIP HOUSING ASSEMBLY (-EU MODELS)
OlLlTE CASTING 33190-I WASHER 31389
OIL SCREW 30747
TRIGGER 39764
SPRING 32858
SCREW 39769
GUIDE PIN 39766
-37964 HOUSING * (STANDARD MODELS)
VALVE 39266
49944 HOUSING * (-EU MODELS)
“O” RING Y325-7
* (INCLUDES GREASE FlTTlNG 35967)
SPRING 33547
L
INSERT ASS'Y 37981
"O" RING Y325-13
ADAPTER 37013
NOTE: PARTS SHOWN,
EXCEPT
40192 MUFFLER, ARE
INCLUDED IN PISTOL GRIP HOUSING ASSEMBLY.
SCREEN 33911
1/4 P.T.F. TH’D.-AIR INLET
9

HEAD SECTION
LEVER HEAD
DISASSEMBLY
Remove nut (36776) releasing seal (36781) regulator (36775)
spring (32858) and valve stem (36777).
ASSEMBLY
Assemble “O” ring (Y325-7) to valve stem (36777) and insert into
valve opening. Assemble spring (32858) air regulator (36775)
and seal (36781) into valve opening and secure with nut (36776).
See “ASSEMBLING MOTOR TO TOOL”, page 8.
37079 LEVER HEAD ASSEMBLY
* RIVET 36992 , * MUFFLER ASS’Y. 40192
SPRING 32656
REGULATOR 36775
SEAL 36781
NUT 36776
* PARTS NOT INCLUDED IN HEAD ASSEMBLY
10

ACCESSORIES
M20
41
381021 EYE BOLT
NUT
RING ASS’Y
33906 1/4" 1-5/16" 1-3/4" 30209K
33907 3/8" 1-7/16" 1-29/32" 30510 K
30016 3/8" 1-13/16" 2-5/16" 30016 K
1-13/16" 2-5/16" 30016 K
38103 BAIL ASSEMBLY
FURNISHED FOR PISTOL GRIP MODELS, WHEN
REQUESTED, AT NO ADDITIONAL CHARGE.
AUX. HANDLE ASS)
FURNISHED ON ALL MODELS HAVING
SPEEDS OF 325 AND 600 R.P.M.
11

DIMENSIONAL DATA
,- 3/8 (10 MM) APPROX.
15/16 (24 MM) SPINDLE OFFSET 2 MM) FLATS
l-3/4 (44 MM) HEX
11/16 (17 MM)
1-11/16 (43 MM) HEX
1-7116 (37 MM) FLATS
CHUCKS LISTED IN CHART ARE FURNISHED AS STANDARD
EQUIPMENT ON MODELS AS INDICATED - FOR OTHER CHUCK
SIZES, SEE ACCESSORIES SECTION OF THIS MANUAL. 37085 AUXILIARY HANDLE IS FURNISHED ON ALL
ALL MODELS HAVE 1/2” - 20 THREADED SPINDLE. MODELS HAVlNG SPEEDS OF 325AND 600 R.P.M. -SEE
ACCESSORIES SECTION FOR PARTS BREAKDOWN.
8-1/4 (210 MM) MAX. SINGE GEARING
10-15/32 (266 MM) MAX. DOUBLE GEARING
I FLATS
5/8 (16 MM)
1-7/16 (37 MM) FLATS
1-3/4 (44 MM) HEX
38103 BAIL ASSEMBLY IS FURNISHED FOR PISTOL GRIP
MODELS, WHEN REQUESTED, AT NO ADDITIONAL CHARGE.
13/16(21 MM) HEX.
52 MM)
12
PN 49999-011