Fisher 657 - Manual (Page 13)

Instruction Manual
D100307X012
657 Size 80 and 100 Actuators
December 2010
13
6. Loosen the two set screws (key 41), and unscrew the two worm retainers (keys 48 and 49). The ball bearings (key
50) will come out with the retainers. Remove the worm shaft (key 45).
Assembly
1. Pack the ball bearings (key 50) with lithium grease lubricant, and insert one ball bearing in the back worm retainer
(key 49) as shown in figure 7 (section C‐C).
2. Thread the back worm retainer and ball bearing (keys 49 and 50) into the gear case. Align the slot in the worm
retainer with the set screw hole in the gear case, insert the set screw (key 41), and tighten it.
3. Coat the worm shaft (key 45) threads with anti‐seize lubricant (key 244), and slide the shaft into the gear case so
that the end of the shaft fits snugly in the back worm retainer.
4. Insert the bearing in the front worm retainer
(key 48), and thread the retainer and ball bearing into the gear case. Align the slot in the retainer with the set screw
hole in the gear case, insert the set screw (key 41), and tighten it.
5. Put the spring and ball (keys 56 and 55) in the handwheel (key 51). Slide the handwheel onto the worm shaft (key
45). Thread the handwheel cap (key 54) onto the worm shaft.
6. Pack the two thrust bearings (key 67) with lithium grease lubricant. Install one thrust bearing; then, install the
worm gear (key 44) followed by the second thrust bearing and the bearing and gear retainer (key 66).
7. The lower sleeve (key 46) has two screw holes in one end. Coat the sleeve threads with lithium grease lubricant,
slide the end of the lower sleeve with the holes into the thrust bearing (key 67), turn the handwheel, and feed the
sleeve through the worm gear. Continue turning the handwheel until the lower sleeve protrudes from the gear
case. Fasten the travel stop indicator (key 58) to the sleeve with the two machine screws (key 28).
8. Install the key (key 47) on the adjusting flange (key 36). Coat the adjusting flange threads with anti‐seize lubricant
(key 244). Install the adjusting flange so that the key engages the slot in the lower sleeve. Secure adjusting flange
with cap screws (key 64).
9. Adjust set screws (key 40) to eliminate free play in the bearings.
Note
Over‐tightening the set screws will make handwheel operation difficult.
10. Install the adjusting screw and thrust bearings (keys 12 and 35). Pack bearings with lithium grease lubricant (key
241), and install as shown in figure 7.
11. Slide the spring case (key 29) into position, and secure with cap screws (key 62).
12. Complete steps 3 through 8 of the size 80 actuator assembly section.
Size 80 Hydraulic Snubber
The size 80 657 is available with a hydraulic snubber, as shown in figure 7, to dampen vertical instability of actuator
stem movement. The snubber is adjusted by rotating the adjusting screws (key 83, figure 7) counterclockwise out of
the reservoir (key 79, figure 7) to increase damping action and clockwise to decrease damping action. The adjusting
screw on the right (the lower of the two adjusting screws in section B‐B of figure 7) regulates downward damping
action, and the screw on the left regulates upward damping action.
Size 80 Top‐Mounted Handwheel (Adjustable Up Travel Stop)
CAUTION
If repeated or daily manual operation is expected, and the actuator is equipped with a casing‐mounted travel stop or
top‐mounted handwheel, the diaphragm could be subject to excessive wear.