2. required tools, 3. general procedures, 4. disassembly – Duff-Norton SK6405-100 User Manual

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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).


Voltage Supply

Avoid using a low voltage supply for the 115 Volt AC


Avoid using a voltage supply lower than 11 volts D.C.


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.





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

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