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© 2022 S. Himmelstein and Company—all rights reserved. www.himmelstein.com
A. Mechanical Installation
A.1 Applicability
This discussion is applicable to all MCRT
®
48200V torqueme-
ters, i.e, MCRT
®
48201V, MCRT
®
48202V, etc.
A.2 Coupling Selection
Your torquemeter installation method dictates the type of
coupling needed. There are two installation methods, i.e., a
floating shaft and a base (or foot) mount.
In floating shaft installations, a single flex coupling is installed
at each shaft end. It takes out angular misalignment, and the
torquemeter “tilts” to take out parallel misalignment. Use a flex-
ible strap to prevent housing rotation and to strain relieve the
torquemeter electrical cable. Caution:
when conduit is required
for electrical connections, the conduit must be flexible. If rigid
conduit must be used, then use a foot mounted installation as
described below.
Install a foot mounted Torquemeter between double flex
couplings as shown. The double flex couplings accommodate
both parallel and angular misalignments.
For either installation method
, choose couplings that will handle the:
• Expected shaft end float
• Parallel and angular misalignments
• Maximum expected shaft speed
• Maximum expected shaft torque
• Expected extraneous loading
A.3 Coupling Installation
Use a slight interference fit (0.0005 inches per inch of shaft
diameter) and follow the coupling manufacturers’ instructions.
Before installation, lightly coat the torquemeter shaft with an
anti-seizing compound suitable for use at 400 deg. F.
Next, heat the coupling hub, not the torquemeter, to
approximately 400 deg. F. Then, install the coupling.
The heated coupling hub should “slip” on the
torquemeter shaft without significant resistance.
That is, coupling installation force shouldn’t
exceed a few pounds of axial force. Next, allow the
assembly to cool to room temperature. Then, repeat
the process for the second coupling.
If desired, use forced air to accelerate cooling.
Air cooling avoids contaminating the torque-
meter with anti-seizing compound. If cooling is
speeded with water dampened rags,
orient the
torquemeter to prevent entry of water mixed
with anti-seizing compound. Otherwise, internal
damage can occur.
After coupling installation, verify that:
• Clearance exists between the coupling and
the torquemeter stator, and
• The shaft-to-coupling fit is snug enough to
prevent vibration induced coupling motion.
To Avoid Damage Or Injury
• Use fixturing to support the hot shaft.
• Use insulated gloves when handling hot parts.
• Stop the hub installation if the pressing force
exceeds a few pounds. Remove the coupling.
Cool all parts, and then inspect for burrs on
the coupling bore, shaft, keys and keyways. If
the parts are burr free, check the bore size and
verify the coupling keyway squareness.
• Don’t allow fluids to enter the torquemeter.
A.4 End-to-End Orientation
MCRT
®
torquemeters are bi-directional. Their output
signal polarity reverses when the direction of
transmitted torque reverses. Himmelstein uses the
following convention for defining torque direction.
CW Torque:
the shaft turns CW,
when viewed
from the driven end
CCW Torque:
the shaft turns CCW,
when viewed
from the driven end
Reversing a torquemeter end-for-end doesn’t
change the torque direction or magnitude. There-
fore, it will have no effect on the torquemeter output
signal. When in doubt about shaft torque direction,
observe the output signals during normal machine
operation. A positive signal output indicates CW
torque per the above definition. A negative output
signal signifies a CCW torque.
Load
Driver
Torquemeter
Single-Flex Coupling
Single-Flex Coupling
Flexible Strap
Figure 1. Floating Shaft Installation.
Load
Driver
Torquemeter
Double-Flex Coupling
Double-Flex Coupling
Figure 2. Foot Mounted Installation.
