Duff-Norton SK6405-100 - Manual (Page 5)

3-1. A.C. Motor
This motor is an intermittent duty type motor having a
five minute rating. Since the motor draws almost the
same amperage at no load as at full rated load, it only
takes 5 minutes of continuous running, regardless of how
light the load may be, before the thermal overload relay
cuts out. It then takes about 10 minutes before the
motor cools sufficiently for the thermal relay to close.
Make sure that the duty cycle to which the actuator is
subjected is not too severe for the motor. The rear end
bell of the motor has a rubber grommet, which when
removed, exposes a hole threaded for 1/2” NPT (SPB).
3-2. Voltage Supply
Avoid using a low voltage supply for the 115 Volt AC
motor.
Avoid using a voltage supply lower than 11 volts D.C.
3-3. Clevis Pins
The axes of the clevis pins should be parallel so that the
actuator can pivot without binding. A few drops of oil
should be used on the clevis pins.
SECTION III
OPERATIONAL PRECAUTIONS
SECTION IV
MAINTENANCE
4-1. Lubrication
Duff-Norton recommends the use of the following lubri-
cant in conjunction with proper maintenance procedures
of this unit: Exxon Ronnex Exra Duty #1.
4-2. Required Tools
A bearing puller and press, soft jaw table clamp and
common hand tools are required for proper disassembly
and assembly.
4-3. General Procedures
Duff-Norton recommends following these procedures
during disassembly and assembly:
1. Tag critical parts to facilitate reassembly.
2. Mark mating surfaces to ensure proper meshing.
3. Clean and lubricate parts as required.
4. All seals must be replaced at time of rebuild.
5. All screws, washers and other small common parts
must be replaced if mutilated in any way.
4-4. Disassembly
Disassemble the 6405 Series Mini-Pac™ actuator as fol-
lows while referring to Figure 5.1. Read instructions thor-
oughly before disassembling.
1. Clamp housing (13) in vice - use soft jaws.
2. A. D.C. Unit
I. Loosen screws (1) (back end of motor (3)
from motor adaptor (9) (do not remove
screws from motor).
II. Remove motor (3) from motor adaptor (9) (use
screw driver to separate motor end
from adaptor), Taking care that motor end
bells do not separate from motor shell.
B. A.C. Unit
I. Remove socket head cap screws (1) and
lock washers (2) from motor (3) and remove
motor (3) from motor adaptor (9).
3. D.C. Unit - Remove brake springs (7) from motor adap-
tor (9) and brake cam (6) from pinion (12).
4. Remove screws (8) from housing (13) and remove
motor adaptor (9).
5. Remove pinion (12) and bearing (11) from housing.
6. Remove retaining ring (10) from pinion (12) and remove
(11) from pinion (12).
7. Clamp housing (13) clevis end in vice (use soft jaws),
remove set screw (17) from housing (13).
8. Unscrew outer tube (22) from housing (13) and remove
translating tube (32), screw (25), gear (19) and outer tube
(22) from housing (13).
9. Remove translating tube (32) from outer tube (22) by
slipping outer tube (22) over translating tube (32) towards
clevis end (35).
10. Remove seal (24) from outer tube (22) and press
guide bushings (23) from outer tube (22) and press guide
bushing (23) from outer tube (22) (seal guide bushing
need not be removed unless damaged).
11. Support screw (25) end taking care not to damage
gear (19) teeth. With a 3/16 diameter punch, drive pin
(18) from screw (25), remove gear (19) bearing (20) and
washer (21) from screw (25).
12. Thread screw (25) part way out of nut (27) and check
screw (25) and nut (27) for wear (there should not be
excessive lay between screw and nut thread). If screw or
nut are not excessively worn, the disassembly of screw
(25), nut (27) and translating tube (32) will not be neces-
sary unless clutch must be replaced.
13. Pins (31) should be approximately 3/32 above trans-
lating tube (32) OD. Grind pins (31) flush with OD of
6405-100 10/10/06 11:50 AM Page 5