7. Life phases
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7.3.5 The ideal configuration
With a synchro system, the positions are supposed to be
controlled during movement so that all lifting columns have
exactly the same height at all times. In practice, this is
impossible, because a controller must first detect a deviation
before it can correct it. This means for the synchro system
that a deviation from an ideal synchronous move must
always be permitted.
Particular requirements are therefore placed on the
connections between table frame and lifting column. Ideally,
the table design allows a certain freedom of movement.
The lifting columns are generally standing on heavy base plates. These guarantee the stability of
the table. The connection between base plate and lifting column does not allow linear and
rotational movements. Consequently, we can speak about a rigid connection, even if the base
plates are not interconnected. Ease of movement must therefore be created at the top
connection to the table plate.
Owing to the control deviation, it must be possible to compensate for slight height differences by
table design. We therefore recommend that the connection between the lifting column and the
table frame is supported so that slight rotation is possible or that the table plate has the required
flexibility.
Avoid countersunk screws for fastening the table frame. These are centred in the drilled holes
with solid bolts. If the drilling pattern in the table frame is not identical to that in the lifting
column, this leads to stresses or even destroys the threads. It is better if the drilled holes are
somewhat larger than the fixing bolts used. Inaccuracies in the drilling pattern can be
compensated in this way.
If the lifting columns are not exactly parallel, the top distance between the lifting columns can
change. This is why only one lifting column can be fixed (fixed bearing) and all others should have
a floating bearing in the table plane. This guarantees that stresses cannot arise during motion.
The greater the distance between the lifting columns, the better the movement behaviour. If the
lifting columns are not tightly together, then control deviations have a greater effect. The table
plate is unsteady during movement. If the distance is greater, this effect reduces.
Fixed bearing
floating
Rigid connection
