Rexnord Thomas Tpack 52 Series Instruction Manual

Rexnord® Thomas®Disc Couplings •Installation and Maintenance
Series 52 • Sizes 225-750 (Tpack) (Page 1 of 4)
Rexnord Industries, LLC, 5555 S. Moorland Rd., New Berlin, WI 53151-7953 538-212
Telephone: [phone] Fax: [phone] November 2008
e-mail: [e-mail] web: www.rexnord.com Supersedes CP-Series 52-T, 8-06
4. Hub Mounting
A. General. Clean the hub bores and shafts. Remove
any nicks or burrs. If the bore is tapered, check
for a good contact pattern. If the bore is straight,
measure the bore and shaft diameters to assure
proper fit. The key(s) should have a snug side-to-
side fit with a small clearance over the top, and the
corners must be chamfered.
B. Straight Bore — Install the key(s) in the shaft. If the
hub is an interference fit, heat the hub in oil bath
or oven until the bore is sufficiently larger than the
shaft. 350ºF is usually sufficient. An open flame is
not recommended. However, if flame heating is
necessary, use a very large rose bud tip to give
even heat distribution. A thermal heat stick will help
determine hub temperature. DO NOT SPOT HEAT
THE HUB OR DISTORTION MAY OCCUR. With the
hub expanded, slide it quickly up the shaft to the
desired axial position. A pre-set axial stop device
can be helpful.
C. Straight Bore Slip Fit — Install the key(s) in the
shaft. Install the set screw(s) in the hub making sure
they do not protrude into the keyway or the bore.
Now slide the hub up the shaft to the desired axial
position. The set screw(s) which hold the hub in
place are tightened, using a torque wrench, to the
values shown in Table 1A.
NOTE: Never use two set screws one on top of the
other.
D. Taper Bore — Put the hub on the shaft without the
key(s) in place. Lightly tap the hub on the shaft with
a soft hammer. This will assure a metal-to-metal fit
between shaft and hub. This is the starting point
for the axial draw. Record the position between
shaft end and hub face with a depth micrometer.
Mount a dial indicator to read axial hub movement.
ATEX: In order for this coupling to meet
the ATEX requirements, it is mandatory to
precisely follow these installation instructions
along with the included supplement form
0005-08-49-01. This supplement outlines the
ATEX requirements. If the operator does not
adhere to these instructions, conformity is immediately
invalidated.
WARNING: Because of the possible danger to person(s)
or property from accidents which may result from improper
use or installations of products, it is extremely important to
follow the proper selection, installation, maintenance and
operational procedures.
All rotating power transmission products are potentially
dangerous and can cause serious injury. They must be
properly guarded in compliance with OSHA, ANSI, and
any other local standards for the speeds and applications
in which they are used. It is the responsibility of the user to
provide proper guarding.
For ATEX requirements the guard must have a minimum of
½ inch (12.7 mm) radial clearance to the coupling major
diameter ”A” (See Figure 1) and allow for good ventilation.
1. Purpose — These instructions are intended to help you
to install, align, and maintain your THOMAS coupling.
2. Scope — Covered here will be general information, hub
mounting, alignment, assembly, locknut torque, disc
pack replacement, and part numbers.
3. General Information — The coupling, as received,
may or may not be assembled. If assembled, the
locknuts are not fully tightened. Examine the parts to
assure there is no visible damage. If the coupling is
assembled, remove the bolts, locknuts, and washers
that attach the hubs to the disc packs. Remove both
hubs. Leave the disc packs attached to the center
member assembly.
A
HUB
C
N
N
LOCKNUT
WASHER
CENTER MEMBER
TPACK DISC PACK
BOLT
HUB
SINGLE HEADED BUSHING
CLEARANCE HOLE
BOLT HOLE
Figure 1

Installation and Maintenance •Rexnord®Thomas®Disc Couplings
(Page 2 of 4) Series 52 • Sizes 225-750 (Tpack)
538-212 Rexnord Industries, LLC, 5555 S. Moorland Rd., New Berlin, WI 53151-7953
November 2008 Telephone: [phone] Fax: [phone]
Supersedes CP-Series 52-T, 8-06 e-mail: [e-mail] web: www.rexnord.com
Set the indicator to “0”. Remove the hub and
install the key(s). Heat the hub in an oil bath or
oven until the bore is sufficiently larger than the
shaft. 350°F is usually sufficient. An open flame
is not recommended. However, if flame heating is
necessary, use a very large rose bud tip to give
even heat distribution. A thermal heat stick will help
determine the hub temperature. DO NOT SPOT
HEAT THE HUB OR DISTORTION MAY OCCUR.
With the hub expanded, slide it quickly up the shaft
to the “0” set point. Continue to advance the hub
up the taper to the desired axial position. Use the
indicator as a guide only. A preset axial stop device
can be helpful. Check the final results with a depth
micrometer. Install the hub retention device to hold
the hub in place.
5. Shaft Alignment — Move equipment into place.
A. Soft Foot — The equipment must sit flat on its base.
Any soft foot must now be corrected.
B. Axial Spacing — The axial spacing of the shafts
should be positioned so that the disc packs (flexing
elements) are not distorted when the equipment
is running under normal operating conditions. This
means there is a minimal amount of waviness in the
disc pack when viewed from the side. This will result
in a flexing element that is centered and parallel
to its mating flange faces. Move the connected
equipment to accomplish the above. Refer to the
assembly drawing and the connected equipment
installation procedures for specific axial spacing
requirements.
NOTE: The disc pack is designed to an optimal
thickness and is not to be used for axial adjustments
by removing or adding individual discs.
As a guide, maximum and minimum values for
dimension “N” are given. These dimensions are
suggested for initial installation. Additional capacity
is available to compensate for thermal and structural
movement. Maximum axial capacity values for these
couplings are also given. See Table 1 and Figure 1.
NOTE: C=2N+Center Member Length.
C. Laser Alignment is an Option — If not available,
proceed with dial indicator method.
D. Angular Alignment — Rigidly mount a dial
indicator on one hub or shaft, reading the face of
the other hub flange, as shown in Figure 2. Rotate
both shafts together making sure the shaft axial
spacing remains constant. Adjust the equipment
by shimming and/or moving so that the indicator
reading is within the values shown in Table 1.
E. Parallel Offset — Rigidly mount a dial indicator
on one hub or shaft, reading the other hub flange
outside diameter, as shown in Figure 3. Compensate
for indicator set-up sag. Rotate both shafts together.
Adjust the equipment by shimming and/or moving so
that the indicator reading is within .001 inch per inch
of the axial length between flex elements.
NOTE: If the driver or driven equipment
alignment tolerances are more stringent than our
recommendations, the driver or driven equipment
tolerances should be used. Also, be sure to
compensate for thermal movement in the equipment.
The coupling is capable of approximately four times
above shaft alignment tolerances. However, close
alignment at installation will provide longer service
with smoother operation.
6. Final Assembly — With the coupling in good alignment,
the bolts should easily fit through the holes in the
flanges and the disc packs.
NOTE: All bolt threads should be lubricated. A clean
motor oil is recommended. Also, see Footnote below
Table 1.
A. If the coupling arrived assembled, the disc packs
are still attached to the center member assembly.
Remove the disc packs from the center member.
B. With the hubs mounted and the span length “C”
set, proceed to put the center member into place
between the two hubs. Care should be taken when
handling the center member as the tube can be
damaged. Support the center member at both ends
on wood blocks, with nylon straps from a hoist, or
some other convenient way. It may help to support
the end not being worked on with bolts through the
spool flange bolt holes. This will hold the parts in line
at that end.
C. Now install the disc pack. Rotate the hub or center
member so that the hub bolt holes line up with
the center member flange clearance holes. If the
coupling was assembly balanced, also align the
match marks. Start a bolt through a loose washer.
The radius side of the washer must always be
against the disc pack. Hold the disc pack in one
hand and slip it down between the two flanges so that
the bushing heads in the pack line up with the bolt
holes in the flanges as shown n Figure 1. Slide the
bolt and washer through the clearance hole in one
flange, into the bushing, and through the bolt hole of
the opposite flange. Make sure all parts pilot on the
body ground area of the bolt. Install a locknut onto
the bolt, but do not tighten it at this time.
Now pivot the pack around until it lines up the
bushing heads with the rest of the bolt holes. Place
a loose washer on each remaining bolt and install
the bolts through the clearance holes, into the
bushings, and through the bolt holes. The last bolt
may be tight and require some light tapping on the
head of the bolt to work it through the disc pack.
Install a locknut on each bolt. The locknuts can be
slightly tightened at this time. The disc pack, when
installed, should look centered and parallel with the
mating flanges.
FIGURE 2 FIGURE 3

Rexnord® Thomas®Disc Couplings •Installation and Maintenance
Series 52 • Sizes 225-750 (Tpack) (Page 3 of 4)
Rexnord Industries, LLC, 5555 S. Moorland Rd., New Berlin, WI 53151-7953 538-212
Telephone: [phone] Fax: [phone] November 2008
e-mail: [e-mail] web: www.rexnord.com Supersedes CP-Series 52-T, 8-06
TABLE 1A — Set Screw Tightening Torque
Setscrew
Thread Size
Torque
in-lb
Torque
ft-lb
Torque
Nm
1/4-20 66 6 7
1/4-28 76 6 9
5/16-18 132 11 15
5/16-24 144 12 16
3/8-16 240 20 27
3/8-24 276 23 31
1/2-13 600 50 68
1/2-20 660 55 75
TABLE 1 — Locknut Tightening Torques, Dimension “N” Limits and
Suggested Maximum Alignment Values
COUPLING
SIZE
“A”
Diameter
Inch
Dimension “N”
Inch Axial
Capacity
Inch
Locknut Alignment Total
Indicator Reading
Thread
Size
Torque
Min Max Ft-Lb
(In-Lb) Nm (Angular)
Inch
Parallel
Inch
225 5.69 .37 .38 ± .036 5/16 - 24 25 34 .006
.001 inch per inch of axial
length between flex elements
262 6.63 .48 .49 ± .043 3/8 - 24 34 46 .007
312 7.81 .51 .52 ± .051 7/16 - 20 60 81 .008
350 8.69 .54 .55 ± .056 1/2 - 20 95 129 .009
375 9.69 .60 .61 ± .062 9/16 - 18 130 176 .010
425 10.50 .63 .64 ± .067 5/8 - 18 175 237 .011
450 11.31 .73 .75 ± .072 11/16 –16 150203.012
500 12.88 .79 .81 ± .082 3/4 –16 190258.012
550 14.44 .92 .94 ± .092 7/8 –14 255346.014
600 16.00 .99 1.01 ± .102 1-14 335454.016
700 18.25 1.20 1.23 ± .115 1-1/8-12 425576.018
750 19.81 1.26 1.29 ± .125 1-1/4-12 560759.020
NOTE:
1. These torque values are approximate for steel bolts with lubricated threads. The locknuts are prevailing torque type
and some resistance will be felt. If galling is suspected, immediately stop and contact Rexnord. Modification will be
necessary for stainless steel. For stainless steel, the tightened torque must be reduced to 60% of the values shown.
Stainless steel bolt and locknut threads must also be liberally coasted with molybdenum disulfide grease.
2. Bolts should be held from rotating while the locknuts are tightened to the values shown.
These locknuts are cadmium plated. Do not use any lubricants other than clean oil noted in Section 6. Consult
Rexnord if unsure.
D. Now proceed to the other end of the coupling.
Remove the support bolts, if used, and support
the center member in one of the other ways. Using
paragraph “6. C” above install the second disc
pack.
E. Make the final coupling alignment check at this time.
F. Fully tighten the locknuts evenly and in an
incremental and alternating fashion. See Table 1 for
torque values.
NOTE: With the coupling in good alignment, the
bolts should easily fit through the holes in the
flanges and the disc pack.
It is recommended that all locknuts be retightened
after several hours of initial operation whenever
possible.
G. For further help with the installation or alignment
consult Rexnord.
7. Disc Pack Replacement — If it becomes necessary to
replace the disc pack, it can be done as follows:
NOTE: Sizes 225 through 750 use the Tpack unitized
disc pack. The Tpackdisc pack will replace the
original Thomas round, non-unitized disc pack without
modification to the coupling. Be sure to use the washers
that are supplied with the Tpack replacement kit.
A. At one end of the coupling remove all locknuts
Support the center member at this end. Back out
and remove the bolts and loose washers. It may
be necessary to tap ends of the bolts with a soft
hammer to start them out. Slide the pack out while
supporting the center member at this end.
B. Now disassemble the other end per “7. A” above,
being sure to support the center member when
taking out the last bolt. Remove the center member.

Installation and Maintenance •Rexnord®Thomas®Disc Couplings
(Page 4 of 4) Series 52 • Sizes 225-750 (Tpack)
538-212 Rexnord Industries, LLC, 5555 S. Moorland Rd., New Berlin, WI 53151-7953
November 2008 Telephone: [phone] Fax: [phone]
Supersedes CP-Series 52-T, 8-06 e-mail: [e-mail] web: www.rexnord.com
C. Replace parts as necessary. If an original Thomas
round, non-unitized disc pack is being replaced,
discard the washers that were removed with the
bolts in Section 7.A on previous page. Recheck
alignment per Section 5. Reassemble per Section 6.
8. For Replacement Parts —See Table 2.
TABLE 2 — Part Numbers and Quantity Required
CPLG
SIZE
Hub
(Rough
Bore)
Qty = 2
Center Member
Qty = 1
TpackDisc Pack
Two per Coupling TpackDisc Pack Joint Hardware
Tomaloy Stainless Bolts Locknuts Washers
Part No. Part No. Dim.
“C” Part No. Part No. Part No. Qty Part No. Qty Part No. Qty
225 434408 587513 5 586056 586070 116088 16 316505 16 712610 16
587514 7
262 634409 587515 5 586058 586071 564586 16 56421416 311399 16
587516 7
312 834410 587517 5-1/2 585913 586072 564588 16 56421516 011674 16
587519 7
350 034411 587520 6 586059 586076 716091 16 516508 16 911767 16
587521 7
375 234412 587522 7 586060 586077 916092 16 916509 16 311677 16
425 434413 587535 7 586062 586078 116093 16 316510 16 711850 16
450 634414 587538 7 586063 586080 316094 16 71651116 516100 16
587541 8
500 834415 587544 9 586065 586081 516095 16 11651216 711460 16
550 034416 587548 10 586066 586082 716096 16 03912516 311750 16
600 234417 587551 10 586067 586083 916097 16 02025316 612127 16
700 434418 587554 11 586068 586084 116098 16 02025416 511413 16
750 663126 587557 11 586069 586085 316099 16 02025516 111803 16
These locknuts are cadmium plated.