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B-LOC
® Shrink Discs provide a high capacity, zero-backlash shaft/hub or
coupling connection by means of a mechanical interference fit. Please follow
these INSTALLATION AND REMOVAL INSTRUCTIONS carefully to ensure
proper performance of this
B-LOC
® unit.
WARNING
When installing or removing
B-LOC
® products, always adhere to the following
safety standards:
1. Be sure that the system is de-energized using proper lockout tagout
procedures.
2. Wear proper personal protective equipment.
Figure 1
Figure 2
INSTALLATION
(Refer to Figure 1)
B-LOC®
Shrink Discs are supplied ready for installation. However, prior to
tightening of locking screws it is necessary to remove wooden spacers that may
have been used during shipping.
Important:
Never tighten locking screws before shaft installation, as inner ring
of Shrink Disc and/or hub can be permanently contracted even at
relatively low tightening torques.
1. Clean hub O.D. and Shrink Disc bore. Lightly lubricate hub O.D. using an
ordinary machine oil before assembling Shrink Disc on hub.
2. Carefully clean shaft and hub bore of any lubricant using a non-
petroleum based solvent prior to mounting hub onto shaft.
This
step is critical, as any lubricant on the shaft/hub bore interface
will greatly reduce the torque transmitting capacity of a
B-LOC® Shrink Disc connection.
3. After confirming correct position of hub and Shrink Disc, hand-tighten three
(3) or four (4) equally spaced locking screws and make sure that outer collars
of Shrink Disc are parallel. Hand-tighten remaining locking screws.
4. Use torque wrench and set it approximately 5% higher than specified
tightening torque (Ma). Tighten locking screws in either a clockwise or
counterclockwise sequence, using approx. 1/4 (i.e., 90°) turns (even if initially
some locking screws require a very low tightening torque to achieve 1/4 turns)
for several passes until 1/4 turns can no longer be achieved.
5. Continue to apply overtorque for 1 to 2 more passes. This is required to
compensate for a system-related relaxation of locking screws since tightening
of a given screw will always relax adjacent screws. Without over torquing,
an infinite number of passes would be needed to reach specified tightening
torque.
6. Reset torque wrench to specified torque (Ma) and check all locking screws.
No screw should turn at this point, otherwise repeat Steps 5 and 6.
REMOVAL
(Refer to Figure 2)
Prior to initiating the following removal procedure, check to ensure
that no torque or thrust loads are acting on the Shrink Disc, shaft or
any mounted components.
1. Loosen all locking screws in several stages by using approx. 1/2 (i.e., 180°)
turns, following either a clockwise or counterclockwise sequence, until Shrink
Disc can be moved on hub. The Shrink Disc, hub and shaft will return to
their original clearance fits.
WARNING
DO NOT
completely remove locking screws before outer collars are disengaged
from inner ring. A sudden release of the outer collars involves high separating
forces and could result in permanent injury or death. Be certain that outer collars
are disengaged from inner ring before completely removing locking screws.
REINSTALLATION OF SHRINK DISCS
In relatively clean operating conditions, Shrink Discs can be re-used without
prior cleaning. Shrink Discs used under severe conditions, however, require
thorough cleaning and re-lubrication with Dow Corning® Molykote® G-Rapid
Plus Paste or equivalent.
RIGHT
WRONG
©2010 Fenner Drives B-PR-020 09/01/2012
INSTALLATION AND REMOVAL INSTRUCTIONS
FOR B-LOC
®
SHRINK DISCS
SD
LOCKING SCREW SIZES AND SPECIFIED TIGHTENING TORQUE M
a
Screw Size M5
M6
M8 M10 M12 M16 M20 M24 M27
Tightening Torque
Ma (ft lb)
3.6
8.7
22
44
74 185 362 620 922
Wrench Size
Across Flats (mm)
8
10
13
17
19
24
30
36
41
