MTS Series 249 Swivels - Manual (Page 33)

Adjusting Models 249.41/.42/.51
Series 249 Rod Swivel Product Manual Maintenance 33
loose, the bearing is clamped too tightly and the clamping bolt can fail in
fatigue. Find and correct the source of the problem before continuing.
6. Apply hydraulic pressure and check for backlash using the methods
described in “Checking for Swivel Bearing Backlash.”
Note The increased amount of force that will be required to rotate and tilt the
swivel when it is set to an extremely tight backlash adjustment can
introduce unwanted forces into the testing system. Therefore, setting the
adjuster so that it just barely contacts the spherical washer when fully
torqued should not be considered the optimum backlash adjustment
setting. The optimum setting is determined by the performance
requirements of the testing system.
7. If unacceptable backlash is still observed, repeat Steps 1 through 6 until it is
eliminated.
Adjusting Models 249.41/.42/.51
The Model 249.41/.42/.51 Swivel assemblies use a Superbolt Torquenut as the
clamping bolt, instead of the standard bolt used in the smaller swivel assemblies.
The method used to tighten and loosen the Torquenuts is included in the
following procedure.
An ordinary torque wrench and an appropriate size hex key socket are the only
tools required to loosen or tighten the jackbolts on a Torquenut.
Superbolt Torquenuts
If backlash is observed using the methods discussed in “Checking for Swivel
Bearing Backlash,” complete the following procedure to remove the backlash.
1. Position the swivel in a secure, convenient, static position that allows access
to the swivel adjuster and clamping bolt. Ensure that hydraulic hoses and
servovalve cables are properly connected.
2. Remove hydraulic pressure from the actuator.
Jackbolts
Main thread
Top View
Side View
Jackbolt
Torquenut
Hardened washer
Spherical washers
Swivel