VIBRATORY FEEDER
7
With unit operating at full voltage and tray empty,
observe where the fine gray lines on the displacement
sticker meet. This point will be higher or lower as the
displacement changes. Opposite the point where they
meet, read amount of displacement.
The following general rules, which apply only to the
feeder operating ideally on the “normal” side of its
“tuning curve,” should be borne in mind when making
tuning adjustments to increase or decrease the
displacement:
1. To DECREASE the tray displacement, INCREASE
the stiffness of the tuning springs.
2. To INCREASE the tray displacement, DECREASE
the stiffness of the tuning springs.
If decreasing or increasing the tuning spring stiffness
has an opposite effect, it means that the spring
stiffness is not great enough, and that the unit is
operating on the “opposite” side of its tuning curve.
The spring stiffness should be increased until the
behavior is in accordance with rules 1 and 2. The
unit can then be properly tuned to the desired
displacement.
As a guide to the stiffness of individual tuning springs,
each spring is marked with a code number- example,
5-27. The first number (5) is the number of fiberglass
plies in the spring. The following number (27) indicates
the relative stiffness of the spring; the higher this
number the stiffer the spring.
The total stiffness of the tuning spring stack is the
sum of the relative stiffness numbers. By various
combinations of different ply springs having different
relative stiffnesses, practically any desired total
stiffness can be obtained.
Operation & Maintenance
(cont.)
Tuning For Non-Standard Trays
(Note: See “Special Trays and Attachments”)
If it is necessary to tune the unit to an off-size or
non-standard tray, follow this procedure:
1. Attach the tray, making sure that all lockwashers
are in place and the fasteners tight.
2. Energize the unit at the nameplate voltage
and frequency.
3. (a) During tuning, if a hammering or striking
noise appears during warm-ups or if such a noise
occurs when the unit is turned off and on quickly,
the displacement is well in excess of normal.
Whether striking or not, if the displacement
exceeds the normal range for that particular size
of tray (see Tuning Guide-General Information),
it must be reduced by substituting a tuning spring
of greater stiffness, or by changing one or more
springs, until approximately normal displacement
is attained at full voltage. Then use the controller
for fine or variable control of displacement and
feed rate.
(b) If the displacement at full voltage after
warmup is below the nominal range for that
particular size tray, and greater displacement
is desired, decrease the tuning spring stiffness
by substituting leaves of lesser stiffness or by
subtracting more leaves.
Tuning For Different Conditions
of Tray Loading
Units with Eriez-built trays are factory tuned for normal
displacement (approximately .055" to .060" [1.4 mm
to 1.5 mm]) with light loading (light head load, light
materials, limited depth of flow of heavier materials).
Ordinarily this tuning will not need to be changed. In
no case should the unit be permitted to deflect more
than .060" (1.5 mm) without load.
CAUTION: A small amount of striking during
tuning is permissible, but must not be allowed
during regular operation since damage to the
feeder can result.
