RATHI DISC-O-FLEX RLM Installation instructions

RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014, INDIA
Installation & Operating Manual (IOM)
DISC-O-FLEX Coupling
RLM/RLMK Series

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 1 of 15
INDEX
Page No
1. Introduction & General Guidelines 02
2. Before installation information 02
3. Installation Information 03
3.1 Hub Mounting 03
3.2 Shaft Alignment 05
3.3 Final Assembly 06
4. Disassembly/ Replacement 07
5. Safety,General Hazard & Environment 08
6. Inspection & Periodic Maintenance 09
7. Spares Management & Complaint Handling 09
8. Breakdown & Trouble-shooting 12
9. Marking Details 13
10. Declaration of Conformity 15

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 2 of 15
GO TO INDEX
1. Introduction & General Guidelines
RLM/RLMK type disc coupling are complied with ATEX (explosion protection) to transmit power
and torque between drive and driven shaft using flexible disc element blades to accommodate
misalignments between the equipments.
This manual will help you to install and maintain disc coupling before installing/disassembling of
coupling. It is advisable to read the manual carefully before starting the work. These special
designs are always provided with general assembly drawing which provides detail information of
the design and connected equipments.
Symbol description :
Caution person may get injured
Damage the product
Pay attention
Potentially explosive warning
2. Before installation information
RLM/RLMK couplings are delivered by RTPL with element blade as assembled condition which
consists components from 3 to 8 as shown in fig. 2.1, it is recommended not to disassemble it
except case of replacement for blade assembly.
Fig. 1 PART LIST
Inspect coupling assembly for visible damage, if you found contact RATHI.
Remove red marked bolts & bushes, which are provided to avoid damaging of blade during
transportation.
Sr.No
Component
Qty.
1
Coupling Bolt (DE)
06
2
Small sleeve
06
3
Driving Hub
01
4
Element Blade Assembly
02
5
Center Spacer
01
6
Cleveloc/Nylock Nut
12
7
Gagging Screw
06
8
Balancing bush
06
9
Driven Hub
01
10
Large sleeve
06
11
Coupling Bolt (NDE)
06

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 3 of 15
GO TO INDEX
3. Installation Information
Ensure the system is disconnected from electrical connection and other possible energy transmission
before starting the work.
3.1 Finish Bore Instruction (Fig. 2)
Hub finish bores machined by customer
with reference to flange outside diameter.
Finish bore strictly done within specified
limit (H7, Js9 ).
Keyway must be done between two
adjacent holes.
Provide set screw at distance L ( L = LTB /2)
3.2 Hub Mounting.
3.2.1 Clean protective coatings/lubricants from bores & keyways.
3.2.2 Remove attachment bolts (1) and separate hubs from assembly unit (fig.3).
Fig.3 coupling in disengages condition
3.2.3 Straight Bore with clearance fit ( Fig.4)
Assemble key(s) on to the shaft.
Set screws to be removed from hub, if it comes through the keyway or hub bore.
Fig. 4 HUB Mounting
Mount hubs over the shaft by maintaining DBSE as required.
Tighten the set screw with torque wrench.
Fig.2 Finish bore

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 4 of 15
GO TO INDEX
3.2.4 Straight bore with interference fit.
Check appropriate fit between shaft and hub bore.
Place the key over the shaft slotted area.
Heat the hub in oil bath up to temperature 150° C to make bore bigger than shaft.
Immediately slide expanded hub over the shaft up to desired position.(Fig. 3)
Tighten the set screw with torque wrench.
3.2.5 Taper Bore (Fig.5)
Slid the hub over the shaft without inserting key up to DBSE as required.
Mark the hub position onto the shaft, or mount the dial indicator by keeping in
contact with hub flange.
Remove the hub and insert key(s) in the shaft.
Heat the hub in oil bath up to temperature 150° C to make bore bigger than shaft.
Immediately slide expanded hub over the shaft up to marked position.
Tighten the set screw with torque wrench.
Fig. 5 Taper bore

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 5 of 15
GO TO INDEX
3.3 Shaft Alignment
In order to achieve optimum service life of the coupling, shafts must be aligned.
Initial misalignment should not be more than 25 % of maximum misalignment
(Refer Table 3).
Table 2 : Method of misalignment
Method
Parallel/Radial
Angular
1
Using dial gauge
Using dial gauge
Clamp dial gauge on driven hub
Note the reading at each quarter rotation of hub by rotating one end.
P or X is half the Total Indicated Reading (TIR) shown on dial gauge
2
Using straight edge
Using verinier calliper
If the field constraints do not permit to use dial gauge then alternatively use
straight edge & vernier calliper to measure parallel and angular alignment
respectively.

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 6 of 15
GO TO INDEX
Table 3 : Misalignment & Tightening Torque
Gap ‘G’ in above table is given when angular and axial misalignments are zero.
# SPAN = DBSE –G
For RLMK Couplings, parallel misalignment is zero.
3.4 Final Assembly
RLM/RLMK couplings are supplied with fully assembled condition with tightened
cleveloc nuts(7) at RTPL to specified tightening torque (Table 3).
Ensure hubs have been mounted as shown in fig.4,to maintain correct DBSE .
3.4.1 RLM
Support the center spacer between two hubs and ensure small holes of spacer flange
will be in line with the large holes of the hub.
Insert Allen head bolts with sleeves from hub side, first through the large holes and
then small holes by holding blade pack assembly between hubs & center spacer.
3.4.2 RLMK
The large holes of Hub-II should be in line with the small holes of Hub-I
Insert coupling bolts from driven hub side through small hole and small length sleeves
from driving side.
Insert coupling bolts with long sleeves through the large holes of driven hub
To avoid loosening of nut, apply thread locker, loctite 270 solution on threads before
tightening the bolts
Tighten the cleveoc nut with to the required tightening torques given in table 3.
Follow the same procedure from other side also for RLM.
Measure gap ‘G’ mentioned in table 2 , which should be equal throughout on both sides.
Customer must provide required safety guards, RTPL does not supply safety guards or
shields.
PERMISSIBLE MAXIMUM MISALIGNMENTS
TIGHTENING TORQUE
Coupling
Size
Angular (X)
Axial
(± mm)
Parallel
(mm/mm)
SPAN) # (P)
* GAP ‘G’
(mm)
Coupling bolt
Degree per
blade assly.
Total
Indicated
Reading
(TIR) (mm)
Size
Value
(Nm)
10
0.75°
0.5
1
0.013
6.5
M6
10
35
6.5
M6
10
95
1.5
8
M8
23
170
9.5
M10
46
220
12
M12
80
400
13
M14
129
520
2.8
2
14.4
M16
150
1000
16.2
M18
205
1300
19.5
M20
285
2000
21.5
M22
380
2500
23.5
M24
400

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 7 of 15
GO TO INDEX
4. Disassembly/ Replacement
Fig. 7
4.1 Element blade pack
4.1.1 Disassembly
Support canter spacer such that the blades should not be under stresses due to
external loads, such as spacer weight
Dismantle components by loosening coupling bolts (1) from hub.
Remove cleveloc nuts (7), bushing and blade pack (4).
4.1.2 Replacement
Replace entire blade assembly of both sides with new factory assembled one,
replacement of one blade pack is not advisable (RLM).
Tighten each cleveloc nut using incremental torque up to specified tightening
torque (Table 3) in progressive alternate pattern.

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 8 of 15
GO TO INDEX
5. Safety General Hazard & Environment
5.1 Safety General Hazard
Proper care and safety must be taken care before work started.
The relevant safety and environmental regulations must be complied during installation,
commissioning, operation, assembly, disassembly and maintenance.
Coupling must be maintained and/or repaired in the presence of skilled or qulified
persons for particular work.
During installation or maintenance ensure the drive unit is cut off from the power
supply and caution notice should be display on switch.
Immediate stop the drive unit if anything abnormalities observed on coupling (e.g.
cracks, chips, wear, noise or deformation)
Check all the bolts are tightened as per torque specified in the manual or as specified in
the GA drawing.
The supplied coupling may have to rotate at high speed, it is most important to guard the
area in compliance to ATEX and various other local applicable standards.
This coupling is certified as per ATEX requirement. Please check the suitability of
hazardous environment at the time of selection of the coupling or during installation of
the coupling.
All spare parts are to be purchased from manufacturer or authorised dealer only.
If the coupling is to be used below ground in potentially explosive areas, the
coupling, must be provided with a robust casing to avoid the risk of ignition from e.g.
friction, impact or friction sparks.
The depositing of heavy metal oxides (rust) on the coupling must be avoided by the
casing or other suitable precautions.
5.2 Environment
Our products are complying with EMS standard ISO 14001:2015, any instruction which
are impermissible according to standard are not followed.

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 9 of 15
GO TO INDEX
6. Inspection & Periodic Maintenance
The disc coupling can be monitored under running condition as well as under idle condition.
Inspect the coupling once1 in 6 months in idle condition or whenever it is taken for
periodic maintenance.
During running condition, it is recommended to check the vibration and noise of bearings on
either side of the equipments to be under specified limits.
Special attention to be given to blade assembly (flexible element) whether is there any wavy
formation of the blade (“S” or “D” type waviness), this may result in weakening of the flexible
element under continuous operation. Also check the blade assembly individual elements of any
fracture or tearing of any blades. If found then it is recommended to replace the entire blade
assembly at one short. Slight bowing or “S”/”D” like distortion/waviness is not detrimental to
the operation of the unit.
Check the flexible elements, by visual inspection, for any signs of fatigue failure or cracking to
the washer anchoring points or general signs of fretting corrosion. Note that any cracking will
begin at the outermost edge of the outside blade. This means that, this inspection is still
possible without disturbing the element bolting.
It is recommended to replace cleveloc nut after being re-tightened 4 to 5 times.
To replace blade assembly, follow procedure as per section 4.1.
7. Spare Management & Complaint Handling
7.1 Spare management
We recommend to store spare items as given below, inorder to have continuos operation
and to reduce down time due to failures.
Spare component list.(Fig.1)
Sr.No.
Part descriptions
Components/
part No.
Quantity
1
Element blade assembly
02
2 Nos
2
Coupling bolt
01 and/or 11
6 Nos
3
Hub ( I,II)
03 and/or 09
1 Nos
Don’t forget to mention hub type while giving spare order for hub and/or coupling
bolt
7.2 Complaint Handling
In case of any failure,for proper root cause, fill up Product Performance Datasheet (PPDS)
and provide us alongwith images/videos.

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 10 of 15
Product Performance datasheet(PPDS) GO TO INDEX

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 11 of 15
GO TO INDEX

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 12 of 15
GO TO INDEX
8. Breakdown & Trouble Shooting
The coupling must run with low vibration and noise during operation. any abnormal
behaviour may damage the product or drive unit.
Following are some possible causes of failure with corrective actions.
SR.
NO.
FAILURE MODE
PROBABLE CAUSES
CORRECTIVE ACTIONS
IMAGE
1
Cracking of blade
packs
Premature shaft
bearing failure
Excessive
misalignments.
Check for,
-loose base plate bolts,
-Component thermal
expansion
-Change in the assembly
gap of the coupling.
Replace the Blades
2
Fatigue of Blades
Torsional vibration
Excessive starts and
stops
conduct a torsional vibration
analysis
3
Elongation of Blade
holes
Loose coupling bolts
Change the blade assembly
on both the ends
Tighten the bolts to required
tightening torque
5
Blade Deformation
Torque Overload
Abnormal axial load
Check sizing and Service
Factor of Coupling
Review operational history
for any abnormalities.
If found unsuitable, replace
with suitable size
6
Coupling bolt
distortions
7
HUB bursting
Torsional shock
overload

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 13 of 15
GO TO INDEX
9. Marking Details
The ATEX marking for REM coupling will be given on outer surface or front side (Fig. 8).
Element blade assembly will not be marked.
Example :
Fig.8. Marking example
ATEX Punching sample
1. RATHI DISC-O-FLEX 120 RLM-95 II 45 II 2GD -30°C +135ºC
2. RATHI LM-95/140 120
3. RATHI LM-95 I 28 120
Where,
1. Manufacturing code e.g. 120 for December 2020
2. Product code e.g. LM-95/140
3. Finish bore size code e.g. 45

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 14 of 15
GO TO INDEX
10.Declaration of Conformity

Installation & Operating Manual /DISC-O-FLEX/RLM,RLMK
RATHI TRANSPOWER PVT.LTD. Gaia Apex,S No 33/2D,Viman Nagar R-II-D-03/02-09/20
Pune, 411014 Page 15 of 15
GO TO INDEX