5.0 REOVIB – Terms
Through the course of time, various terms that sometimes seems different but is really the same, relating to
equipment, functions and characteristics, have evolved. These have been compiled, below, together with
explanations. In instances where there are several terms relating to a theme, the most widely used expres-
sion is underlined.
Bowl feeder
Feed equipment fitted with a round bowl that has a spiral track inside;
components move upwards and outwards along the track and tooling is
fitted sort the components so that they leave the feeder correctly orientated.
Linear feeder
Track feeder/ In-Line
feeder
Feed equipment for conveying orientated components in a straight line
Pre-feeder
Bunker / Feeder
hopper
Large vibratory feeders (bulk storage), feed conveyors or slatted belt ele-
vators; used for topping-up bowl feeders, over a long period, without the
need for manual intervention.
Component
Product, Material
The material or work-piece that is fed by the vibratory feeder
Vibrating frequency
The
mechanical
frequency at which the feeder vibrates.
In the case of thyristor or triac controllers this is completely dependent on
the mains supply frequency. When both half waves of the mains cycle are
used this gives a frequency that is twice that of the mains supply. When a
half-wave only is used this provides a frequency the same as that of the
mains supply.
A frequency inverter can provide a frequency that is independent of the
mains supply frequency.
Vibrating speed
Refers to the derivative of deflection against time
Amplitude
Deflection
Deflection of the feeder [mm] relative to the static air-gap between the coil
and armature; normally expressed as the entire backward/forward (±)
movement.
Resonant frequency
A particular frequency at which a feeder vibrates with the minimum power
requirement. In theory resonance is defined as the frequency that gives in-
finite amplitude.
Off-resonance condi-
tion
A difference between the operating frequency and the resonant frequency
of a vibratory feeder
Over-critical opera-
tion
Running a feeder at a frequency that is higher than resonant frequency; the
amplitude becomes smaller as loading or damping increases.
Under-critical damp-
ing
Running a feeder at a frequency that is lower than resonant frequency; the
amplitude is not affected by product loading.
Air-gap
Static air gap
The space between the coil and armature when a feeder is at rest
Feeder power
Feeder speed /
Feeder throughput
A measurement of the amount of components fed over a time period
Full-wave control
6000 vibs / min
100 Hz operation
Both mains, sine wave, half-cycles are controlled. The vibrating frequency
is twice the mains frequency.
6000 vibrations / min at 50Hz mains frequency
7200 vibrations / min at 60 Hz mains frequency
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