Manual E
0904e
EDITION 2010
Pneumatic Actuators
MANUAL
Modifications reserved. Date 06.2011.
No guarantee for accuracy.
Older data sheets are invalid.
C.
End caps disassembly (Part N° 30), fi gure 03:
•
End caps disassembly for spring return actuators (disassemble one end cap at a time).
Unscrew the end cap bolts (13) in the sequence shown in fi gure 03, until the end-caps are free from springs force (for AT045U and AT051U
20-23 turns of the screws, for AT101U to AT801U 4-5 turns of the screws).
Then completely unscrew the screws and remove the end-cap and the springs.
If there is still force on the end-caps after unscrewing as indicated above, this may indicate that
spring cartridge is damaged or that the pistons are not completely closed, so any further disassem-
bly should be discontinued.
Further disassembly of the end caps may result in injury.
•
End caps disassembly for double acting actuators (disassemble one end cap at a time)
Unscrew the end cap bolts (13) in the sequence shown in fi gure 03, until the screws are completely
unscrewed and the end caps are free.
•
Remove the o-rings (14) using a screwdriver. Discard soft parts if replacing.
•
Only for actuators with adjustment 50% or 100%, remove the nut 04R, the washers 03R and o-rings 11R and discard soft parts if replacing.
D.
Pistons disassembly (Part N° 40), fi gure 04:
•
Holding the body (50) in a vice or similar device, rotate the drive shaft (60) until the
pistons (40) are released.
Caution: air pressure should not be used to remove the pistons from the body.
•
Remove o-rings (16) using a screwdriver. Remove the piston back (05) and piston
head (15) bearings.
•
Discard bearings when replacing all soft components.
E.
Drive shaft disassembly
(Part N° 60), fi gure 05:
•
If necessary, remove the graduated ring (19.0) with a screwdriver, remove the spring clip (18) using snap-ring
pliers or screwdriver for spiral rings, remove the thrust washer (10) and the external thrust bearing (08).
A.
Removal of position indicator and graduated ring (Part N° 19,19.0,19.1), fi gure 01:
•
Remove cap screw (39) if fi tted.
•
Lift position indicator (19 or 19.1) off shaft, it may be necessary to pry gently with a screwdriver.
•
Lift, if necessary, the graduated ring (19.0) off the body, it may be necessary to pry gently with a screwdriver.
B.
Removal of stop cap screws (Part N° 02), fi gure 02:
•
Remove both stop cap screws together with nut (04) and washer (03).
•
Remove stop screw o-rings (11) and discard if replacing all soft parts.
Apply downward force to top of drive shaft (60), until it is partially out of the bottom of the body when it is possible to remove the internal thrust bearing (08)
and the octi-cam (01), then push the pinion (60) completely out of the body. If pinion is not easily removed, gently tap the top of the shaft with a plastic
hammer.
•
Remove top (06) and bottom (07) pinion bearings and top (20) and bottom (21) pinion o-rings.
•
Discard bearings (06) and (07), internal and external thrust washer (08) and o-rings (20) and (21) if replacing the soft components.
All the components disassembled and not replaced will have to be cleaned and inspected for wear and before reassembly, if necessary, also replace
the plugs (09).
6.3 ASSEMBLY:
Prior to assembly, ensure that:
•
all the components are perfectly clean and in good condition.
•
the spare parts and the lubricant used are suitable for the operating temperature of the actuator (see Air Torque technical data
sheets).
•
Note: The lubricants suitable for the various operating temperatures (Standard, HT and LLT actuators) are available in Air Torque.
Only for “standard” actuators, for temperature from -40°C (-40°F) to +80°C (+176°F), it is possible to use lubricant Dow Corning type
Molykote® G-2003.
A.
Drive shaft assembly (Part N° 60), fi gures 06, 07 and 07A:
•
Install top (06) and bottom (07) bearings, grease and insert the bottom (20) and top (21) pinion o-rings onto the
shaft.
•
Grease the outside surface of the drive shaft as shown in fi gure 06.
•
Insert partially the drive shaft (60) in the body (50), install octi-cam (01) in the correct position (for standard
assembly or for lock-out) as shown in fi gures 07 and 07A, related to the bottom and top of the drive shaft and
the rotation of the actuator when energised. Install the internal thrust bearing (08). Insert completely the drive
shaft in the body.
•
Fit external thrust bearing (08), thrust washer (10) and then external spring clip (18) using snap ring pliers or
screwdriver for spiral rings.
B.
Pistons assembly (Part N° 40), fi gures 08, 09, 10 and 11:
•
Grease and install o-rings (16), piston back (05) and piston head (15) bearings.
•
Grease the internal surface of the body (50) and the piston (40) rack teeth.
•
Insert the female connection of the drive shaft (60) in a properly fi xed coupling.
•
Ensure that the octi-cam is in the right position as shown in fi gure 09.
•
For standard rotation assembly type “ST” (clockwise to close), rotate the body (50) about 40-45° clockwise
from top view, as shown in fi gure 10.
•
Insert and press the two pistons (40) simultaneously inside the body (50) until the pistons are engaged,
then rotate the body anticlockwise from top view until the stroke is completed.
•
Ensure that with pistons completely closed, the rotation obtained referred to the axis of the body is about
over 0° for models AT051U - AT801U (0,5° over 0° for AT045U) and that the dimension “A” on both sides is
the same as shown in fi gure 11.
