Warner Electric Electro-Clutch EC-375, EC-475, EC-650, EC-825, EC-1000, EC-1225 - Manual (Page 6)

6 Warner Electric • 800-825-9050 819-0041 • P-210
Burnishing and Maintenance
Burnishing
Intimate metal to metal contact is essential
between the armature and the metal rings
(poles) of the magnet or rotor. Warner Electric
clutches and brakes leave the factory with the
friction material slightly undercut to assure good
initial contact.
Normally, the desired wearing-in process occurs
naturally as the surfaces slip upon engagement.
The time for wear-in, which is necessary to
obtain the ultimate torque of the unit, will vary
depending on speed, load, or cycle duty.
If maximum torque is required immediately after
installation, the unit should be burnished by
slipping the friction surfaces together at reduced
voltage. It is recommended that the burnishings
be done right on the application, if at all
pos-
sible.
Burnishing at high speed will result in a
smoother wear-in pattern and reduce the time
for burnishing. The voltage should be set at
approximately 30% or 50% of the rated value.
The unit should be cycled on and off to allow
sufficient time between slip cycles to prevent
overheating.
When a Warner Electric brake or clutch is
properly assembled and installed, no further
servicing, lubrication, or maintenance should
be required throughout the life of the unit.
Maintenance
Wear Pattern: Wear grooves appear on the arma-
ture and magnet surfaces. This is a normal wear
condition, and does not impair functioning of the
unit. Normally, the magnet and armature, as a
mating pair, will wear at the same rate. It is the
usual recommendation that both components be
replaced at the same time.
Remachining the face of a worn armature is not
recommended. If a replacement armature is to be
used with a used magnet, it is necessary to
remachine the worn magnet face. In refacing a
magnet: (1) machine only enough material to clean
up the complete face of the magnet; (2) hold the
face within .005" of parallel with the mounting
plate; and (3) undercut the molded facing material
.001" - .003" below the metal poles.
Heat: Excessive heat and high operating
temperatures are causes of rapid wear. Units,
therefore, should be ventilated as efficiently as
possible, especially if the application requires fast,
repetitive cycle operation.
Foreign Material: If units are used on machinery
where fine, abrasive dust, chips or grit are
dispelled into the atmosphere, shielding of the
brake may be necessary if maximum life is to be
obtained.
Where units are used near gear boxes or
transmissions requiring frequent lubrication,
means should be provided to protect the friction
surfaces from oil and grease to prevent serious
loss of torque.
Oil and grease accidentally reaching the
frictionsurfaces may be removed by wiping with a
rag dampened with a suitable cleaner, which
leaves no residue. In performing this operation, do
not drench the friction material.
If the friction materials have been saturated with
oil or grease, no amount of cleaning will be com-
pletely effective. Once such a unit has been
placed back in service, heat will cause the oil to
boil to the surface, resulting in further torque loss.