Nexen MTL2055 976889 - Manual (Page 5)

5 FORM NO. L-21219-D-0610
SAFETY ALERT
Rotating torque limiters can be very dangerous. Proper guarding should be in place at all times and is the respon-
sibility of the machine builder, user or operator. Do not approach or touch a torque limiter while it is rotating. Make
sure that the machine is “Locked Out” and cannot be accidentally started during installation or maintenance of the
torque limiter.
MOUNTING
All mounting surfaces including shafts, bores, keys and key ways must be clean and free of burrs, nicks or dents.
Inspect shaft diameters; MTL bore diameters, key and key-way dimensions and tolerances. All Nexen torque limiter
bores are machined to ISO tolerance H7. Clearances between shaft and hub bores are maintained to 0.01 and 0.05
mm. A light coating of oil is recommended to ease the mounting process and will not affect the clamping force of
the hub.
Mounting Preparation
CAUTION
Do not use sliding grease or oils and grease with molybdenum disulfide or other high pressure additives.
Mounting Drive Elements to Mechanical Torque Limiter (MTL)
Center the drive element (i.e. timing belt pulley or gear) onto the connecting flange of the MTL and fasten with
screws. If the center of the radial load falls over the middle of the MTL an additional support bearing is not required.
(Figure 3). Please observe the maximum allowable radial load for each MTL sized as indicated in Table 3. Excess
radial load will affect the performance of the MTL.
Series
Belt Pre-tensioning
Force Max.
N [lbs]
Distance
From - to
mm [in]
Fastening
Screws
Tightening
Torque
Nm [ft-lbs]
A B Clamping Hub
15 1400 [315] 7-14 [.28 - .55] M4 4 [3]
20/30 1800 [405] 8-18 [.31 - .71] M5 4 [3]
40/60 2300 [517] 8-18 [.31 - .71] M5 7 [5]
80/150 3000 [674] 12-20 [.47 - .79] M6 12 [9]
200 3500 [787] 12-22 [.47 - .87] M6 14 [10]
300 4500 [1012] 12-23 [.47 - .91] M8 18 [13]
500 5600 [1259] 12-25 [.47 - .98] M8 25 [18]
800 8000 [1798] 14-34 [.55 - 1.34] M10 36 [27]
1500 12000 [2698] 20-42 [.79 - 1.65] M12 70 [52]
F max (A)
Distance from - to (B)
Figure 3
Table 1
Mounting and Dismounting: Model MTL
Mounting:
Slide the MTL on the shaft to the proper axial position. Using a torque
wrench, uniformly tighten the clamping screws using a cross-wise tight-
ening pattern until all the clamping screws are evenly tightened to the
correct tightening torque as given in Table 1. While tightening, the MTL
may move slightly towards the tapered bushing.
Keyed bore models do not include integral set screws. Use a lock collar
to secure the unit axially along the shaft.
Dismounting:
Loosen the clamping screw. Insert
the three jack screws into the tapered
holes on the tapered segment. Apply
even pressure to remove the tapered
segment. Remove the MTL.
CAUTION
Further tightening of the clamping screws may destroy the
tapered bushing connection.
NOTE
Prior to reassembly make sure that the jack-
screws are raised to their original position.