Nexen MTL2055 976889 - Manual (Page 4)

FORM NO. L-21219-D-0610 4
INTRODUCTION
Carefully read and complete the following installation, operation and maintenance procedures for the Nexen me-
chanical torque limiters. Failure to follow these procedures may result in poor performance and/or the failure of the
torque limiter.
WARNING
Installation and Operating Instructions for Nexen Mechanical Torque Limiters
WARNING
Installation of these torque limiters should only be preformed by a qualified technician.
Nexen mechanical torque limiters are ball detent style
overload clutches. They protect drive and driven mechanical
components from damage associated with torque overloads.
Backlash free torque transmission is accomplished by a
series of steel balls (4) nested in hardened detents (5).
Disc springs (2) push against an actuation ring (3) keeping
the balls nested. The disengagement torque is adjustable
by means of an adjustable ring (1). In the event of an
overload, the actuation ring moves axially allowing the
balls to come out of the detents separating the drive and
driven elements. The movement of the actuation ring can
be sensed by a proximity sensor (6) triggering the drive to
shut down.
General Functioning
In a torque overload, for the single-position design (standard) and multi-position design, the spring disengages
to allow the balls to come out of their detents separating the drive and driven elements. Very low residual spring
pressure remains so that the MTL will re-engage once the torque is reduced below the overload setting.
Single-Position / Multi- Position
Actuation Path (S)
Disengaged Engaged
Figure 1
CAUTION
Re-engagement may only be effected at low speed.
With this design, when a torque overload is detected, the
disc spring completely flips over and places no residual
spring pressure on the actuation ring. The drive and driven
elements are completely separated.
Full Disengage, Free- Wheeling
CAUTION
Re-engagment should only be performed when the MTL is
still and not rotating!
Press-in force
Recess on the
adjustment nut
Lever
(Screwdriver)
Axial Pressure
engaged disengaged
Actuation
Ring
The Nexen full-disengage MTL can be re-engaged in six
different positions or every 60 degrees with low “press-in”
force. Marks on the actuation ring and body (13) of the MTL
must line up and indicate the re-engagement points. Apply
axial pressure on the actuation ring to re-engage.
NOTE
Re-engagment of the MTL is not automatic and must be
performed manually.
Re-engagment of the Full Disengage Design
Figure 2