Rhein-Nadel Automation GmbH
13
VT-MA-SRC 160-800-EN_2019 / 20.03.2019 SJ
When you loosen the spring fastening screw you can observe a change in feeder speed.
The following graph shows the resonance curve of a vibratory feeder.
Notice
The resonance frequency of the vibratory feeder must not be equal to the mains frequency, it should be
lower than the driving frequency of the current.
If the feeder speed decreases after you loosen the spring fastening screw, proceed as described in
section 5.1
.
If, on the contrary, the feeder speed increases, proceed as described in
section 5.2
.
Notice
Tuning is facilitated by the use of an electronic frequency controller that is part of our standard product
range.
The vibratory feeder should be tuned so that the desired feeder speed is obtained with a controller setting of approx.
80%. This is to ensure sufficient magnetic saturation.
5.1.
Feeder speed decreases?
Install additional springs. Start by adding one spring (including spacers) to
one
spring pack. If the feeder speed con-
tinues to decrease after you loosen a fastening screw anew, install additional springs one by one progressively in an-
other spring pack until the desired speed is obtained with the controller set at 70 - 80%.
5.2.
Feeder speed increases?
Remove springs. Start by removing one spring (including spacers) from
one
spring pack. If the feeder speed continues
to increase after you loosen a fastening screw anew, remove springs one by one progressively from another spring
pack until reaching a range where the feeder speed decreases when you loosen the spring fastening screws. In this
range the resonance frequency of the system is lower than the driving frequency of the current. Now proceed with the
actual tuning procedure as described in Section 5.1.
Notice
As the tuning procedure is done with the enclosure removed, be sure to add one more spring after finding
the optimum setting. This compensates the influence of the sheet metal enclosure on the frequency.
With type SRC-N 800 feeders, install 6 additional springs (one each in every 2nd spring pack).
Objective of the tuning procedure:
To set a stable feed rate matching the requisite amount of product.
When the desired feeder speed is obtained at a controller setting of 80 %, the feeder speed must always decrease
when the spring fastening screw is loosened.
Notice
Make sure that the number of springs per spring pack will not deviate by more than 2
– 3 springs. Other-
wise the feeder speed at the circumference of the bowl is no longer constant.
A
Feed rate
B
Desired feeder speed
C
Resonance frequency of the system
D
Resonance curve
E
Spring force (number of springs) increasing