Exlar Curtiss-Wright Tritex II Series, Installation And Service Manual

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Curtiss-Wright | TRITEX II AC 75 Rev. K PN61928 7/12/2022 67
Grease Renewal
The angular contact thrust bearings located in the front of the actuator,
the roller screw cylinder, and the roller screw assembly are the
components that require grease. They require a coating of grease. They
do not need to be packed with grease. Excess grease requires more
torque from the motor when returned to operation, and does not improve
the lubrication of the unit.
1. Use a brush to work approximately 0.5 in
3
of grease for every
3 inches of stroke length into the roller screw cylinder. Be sure to
cover all of the threaded areas of the cylinder.
2. Use a brush to work grease in to the roller screw assembly. Be
sure to cover all the threaded surfaces of the screw assembly. This
can be accomplished by applying grease to a few places on the
roller screw assembly and rotating the components repeatedly in
both directions to work the grease into the assembly.
Reassembly
1. Rethread the roller screw into the internally threaded cylinder
(ITC). It is a multiple start screw, and this is not always easy. DO
NOT FORCE THE ROLLER SCREW INTO THE CYLINDER. It is
best to have the actuator vertical with the open end of the roller
screw cylinder facing up. Position the roller screw above the
cylinder so that it is aligned axially with the ITC. Slowly turn the
roller screw 1/4 to 1/2 a turn counterclockwise with it in contact
with the ITC. This will help to align the threads on the roller screw
with the threads in the ITC. Rotate the roller screw clockwise and it
should begin to thread into the cylinder. If it does not turn freely,
remove it and begin again. When threading the screw into the
cylinder, it will roll freely into the actuator. When it reaches the
portion of the cylinder that contains the motor magnets, the roller
screw will be more difficult to turn because of the magnetic field of
the magnets. THIS IS NORMAL. Continue to thread the roller
screw into the cylinder. When it reaches the bottom, it will become
difficult to turn and the motor and bearings will begin to rotate with
it. The roller screw is now fully inserted into the cylinder.
2. Place a small amount of seal lubricant on the inside surface of the
seal/bushing assembly.
3. Carefully slide the bushing/seal assembly over the actuator rod
end. The seal is a tight fit on the rod end.
Take care not to damage the seal on the threads of the extending
rod. Standard T2M Series rods have a chamfer to provide a lead in
for replacement of the seal and bushing. The mounting screws
should have a low or medium strength thread locker added, such
as Loctite 222MS. The mounting screws torque values are as
follows.