Rexnord Industries Stearns 57,000 Series Operating instructions

Service Instructions for No. 5, 6 & 8 AC Solenoid Assembly
Series 57,000; 67,000 and 77,000 Disc Brakes
®
Brake Replacement Parts
P/N 8-078-955-05
effective 8/20/99
Important
Please read these instructions carefully
before servicing your Stearns brake.
Failure to comply with these instructions
could cause injury to personnel and/or
damage to property if the brake is
serviced or operated incorrectly. For
definition of limited warranty/liability,
contact Rexnord Industries, Inc., Stearns
Division, 5150 S. International Dr., Cudahy,
Wisconsin 53110, [phone].
Caution
1. Servicing shall be in compliance with
applicable local safety codes including
Occupational Safety and Health Act
(OSHA). All wiring and electrical
connections must comply with the
National Electric Code (NEC) and
local electric codes in effect.
2. To prevent an electrical hazard,
disconnect power source before
working on the brake. If power
disconnect point is out of sight, lock
disconnect in the
off position and tag to
prevent accidental application of power.
3. Be careful when touching the exterior
of an operating brake. Allow sufficient
time for the brake to cool before
disassembly. Surface may be hot
enough to be painful or cause injury.
4. Do not operate brake with housing
removed. All moving parts should be
guarded.
5. After usage, the brake interior will
contain burnt and degraded friction
material dust.This dust must be
removed before servicing or adjusting
the brake.
DO NOT BLOW OFF DUST using an air
hose. It is important to avoid dispersing
dust into the air or inhaling it, as this may
be dangerous to your health.
a) Wear a filtered mask or a respirator
while removing dust from the inside
of a brake.
b) Use a vacuum cleaner or a soft
brush to remove dust from the brake.
When brushing, avoid causing the
dust to become airborne. Collect the
dust in a container, such as a bag,
which can be sealed off.
6. Maintenance should be performed only
by qualified personnel familiar with the
construction and operation of the brake.
7. For proper performance and operation,
only genuine Stearns parts should be
used for repairs and replacements.
Warning! Any mechanism or load held in
position by the brake should be secured
to prevent possible injury to personnel or
damage to equipment before any
disassembly of the brake is attempted or
before the manual release knob or lever is
operated on the brake.
Instructions
1.To remove housing, follow instructions
listed under each individual brake series
in Figure 2, then continue with the
following steps.
2. Solenoid replacement can be
accomplished without removing the
support plate from brake.
3. Disconnect coil lead wires. Remove
three solenoid mounting screws (132)
and lock washers (132W) to free
solenoid frame (79).
4. Disconnect solenoid plunger (29) and
solenoid link (13) as follows:
a) On the 57,000 Series of 67,000 and
77,000 Series with No. 5 or No. 6
solenoids, remove cap screw (13C)
and nut (13N). Save for reuse later.
b) On the 67,000 and 77,000 Series
with No. 8 solenoid, remove one of
two cotter pins (13CP) and straight
pin (13P). Save pin (13P) for reuse
later.
57,000 Series
67,000 Series
77,000 Series
Remove two housing nuts (15) and
housing (7) by pulling back.
Remove four housing cap screws (15),
lock washers (15W) and housing (7)
by pulling back.
Remove four housing cap screws (15),
lock washers (15W) and housing (7)
by pulling back.
Figure 2
Item
No. Item Description Qty.
29
79
132W
132*
132
Solenoid plunger
Solenoid frame
Solenoid mounting lock washer
Solenoid mounting screw
Solenoid mounting screw
1
1
3
1
3
*For 57,000 Series only 3/8” long.

5. For metallic plunger guides (82)
remove plunger guide screw (84).
Remove both plunger guides (82) by
prying up on the flanges.
To remove non-metallic plunger guides
(82), remove screw (84) and lock
washer (84W). Insert shim stock or
other thin gauge material at top center
of coil between coil and solenoid frame.
Push to release lock tab while lifting up
on plunger guide. Repeat for other
guide.
6. Slide coil (12A) out from solenoid
frame (79) in the direction of the coil
terminals. If necessary, tap coil lightly
with a soft hammer. If solenoid coil
had burned out, be sure to remove all
foreign material from the plunger
guides.
7. Install new coil (12A) into solenoid
frame with same relative position as
old coil.
Assemble new non-metallic plunger
guides (82) by inserting into position
and pushing down until lock tab snaps
under top bar of solenoid frame. Install
plunger guide screw and lock washer.
With encapsulated coils (with
terminals) check that lock tabs allow
free movement of plunger. If movement
is restricted, file chamfer on coil at lock
tab areas.
8. a) On the 57,000 Series, or 67,000
and 77,000 Series with No. 5 and
No. 6 solenoids, install new plunger
(29) to link (13) in reverse order of
Step 4, Item a.
b) On the 67,000 and 77,000 Series
with No. 8 solenoid, install new
plunger (29) to link (13) in reverse
order of Step 4, Item b. Use new
cotter pin (not supplied).
9. Slide solenoid frame (79) over new
plunger (29). Attach to support plate
(126) with three new mounting screws
(132) and lock washers (132W). Note
that on the 57,000 brake there is a
10-24 x 3/8” long fillister head screw
required to mount the upper left
hand flange of solenoid.This screw
is provided in the assembly packet.
Before tightening mounting screws,
align the plunger and frame so
that mating surfaces are parallel.
Manually pulling the plunger (29)
down into the sealed position will help
with alignment. (If later there is a
solenoid buzz upon energization, then
a slight realignment may be
necessary).
10. Manually lift solenoid plunger to
maximum travel. Depress and allow
solenoid plunger to snap out several
times. Measure solenoid air gap
between mating surfaces of solenoid
and solenoid plunger. (On vertically
mounted brakes, it will be necessary
to push solenoid plunger into solenoid
frame to the point where spring
pressure is felt, before measuring
solenoid air gap).The correct solenoid
air gap measurements are shown
in Table.
11. Solenoid gap adjustment:
a) 57,000 Series
When gap reaches 3/4” to 7/8”
brake must be adjusted.Turn both
wear adjustment nuts (10) equal
amounts in clockwise direction
(one half turn at a time) until gap
is 1/2” to 5/8”. The screwdriver
slots in both adjustment nuts
must always be on the horizontal
centerline (Figure 4) to permit full
bearing of pressure contact points.
b) 67,000 and 77,000 Series
Insert screwdriver and turn adjusting
stud (10) counterclockwise until proper
solenoid gap is attained. (See Table
and Step 10).
12. Reconnect coil leads.
13. Replace housing and housing nuts or
bolts in reverse order of the
appropriate point in Step 1.
14. Caution! Do not run motor with brake
in manual release position. It is
intended only for emergency manual
movement of the driven load, not as a
substitute for full electrical release.
NOTE: For complete instructions, with
troubleshooting, request sheet
applicable to the series of brake that
you have.
57,000 Series
67,000 and 77,000 Series
Figure 3
Table: Solenoid Air Gap Measurement (in.)
57,000 Series
67,000 and 77,000 Series
Copyright© 1999 by Rexnord Industries, Inc.
Rexnord Industries, Inc., Stearns Division, 5150 S. International Dr., Cudahy,Wisconsin 53110 [phone] Fax [phone]
Nominal Static
Torque (lb-ft) 57,000 Series 67,000 Series 77,000 Series
6
10 1/2-5/8 1/2-5/8 — 7/16 — 7/16
15
25 1/2-5/8 —7/16 7/16 7/16 7/16
35
50 — —9/16 9/16 9/16 9/16
75
105 — —5/8 5/8 5/8 5/8