ROSTA
2.21
These “natural frequency” feeding system generally shows the
same constructive design like the “brute-force” shaker, but is
disposed with additional spring accumulator sets installed be-
tween trough structure and ground frame in order to reduce the
hard hits by the change in direction of the crank shaft drive.
Furthermore, due to the high dynamic stiffness of the spring
accumulator sets, the course of motions of the trough becomes
harmonic, energy-saving and gentle avoiding material stress
and early fatigue cracks on the structure. This system runs very
silent due to the permanent, bidirectional spring action support
at the stroke ends. The max. acceleration of this one mass sys-
tem should not exceed 2.2 g-forces. The quantity and size of
the required spring accumulators depends on the trough weight
and the relevant rpm’s of the crank shaft drive.
This system is the “fast-runner” among the crank shaft driven
shaker conveyors offering a very high material throughput. The
lower counter-mass frame, directly connected with the feeding
trough by means of ROSTA double rocker arms, fully compen-
sates the resulting inertia forces of the mass 1 (trough) provided
that its overall weight is identical with the trough weight. The up-
per shaker trough and also the counter-mass frame (or trough)
offer a
procedural
field of applications. Both are feeding bulk
material in the same direction; e.g. adding a sieve fraction in the
upper trough bottom the small particles are sorted out and drop
on the lower counter-mass or counter-trough being also shaken to
the discharge-end of the machine.
For the most part, these two mass high-speed shaker conveyors
are designed as smooth running “natural frequency” systems.
Adding a quantitatively sufficient number of double rocker arms
between trough, machine frame and counter-mass, the resulting
One mass shaker conveyor systems equipped with spring accumulators
Two mass shaker conveyor systems with direct reaction force-compensation
Design
Characteristics
ROSTA elements
“natural frequency” system offering smooth course
acceleration:
1.1 to 2.2 g-forces
conveying speed:
6 to 22 m/min
trough lengths:
up to 20 meters
oscillating mountings:
AU, AS-P, AS-C, AR
drive heads:
ST
spring accumulators:
DO-A elements
Design
Characteristics
ROSTA elements
“fast-runner” system offering high capacities
acceleration:
1.5 to 5.0 g-forces
conveying speed:
10 to 45 m/min
trough lengths:
up to 25 meters
oscillating mountings:
AD-P, AD-C, AR
drive heads:
ST
spring accumulators:
additional DO-A elements
high dynamic stiffness of the elastic suspensions keeps the shaker
machine running close to the natural frequency of the rocker
arms. Otherwise, also by installing some additional DO-A spring
accumulators between machine frame and trough or between
machine frame and counter-mass a natural frequency acting of
the system can be attained.
Oscillating Mountings