Rotary transfer machines - use
for medium to large quantities
The rotary transfer machines, sometimes also named revolving
or indexing machines, belong to the field of manufacturing technology. They are
mainly used for the "material separating" manufacturing process. In
special cases, "material forming" manufacturing processes can also be
used with rotary transfer machines. The possible
combinations of the processes in rotary transfer machines is therefore very
extensive and can also lead to a certain complexity.
A rotary transfer machine is usually a
CNC-controlled machine tool that is able to carry out several processing steps
one after the other. The order of the processes is defined from step to step.
There is no provision for deviating from the sequence of the machining steps.
There is no reverse. As the name suggests, the indexing stations of the rotary transfer
machine are arranged in a circle.
For example, the following processes are possible
from the material-separating process: sawing, drilling, thread cutting,
milling, turning, slotting, punching, reaming and grinding. Rotary transfer
machines with forming functions can, for example, beading, flanging, thread
forming, rolling, marking or embossing. It is not uncommon to find combinations
of cutting and forming processes in a rotary transfer machine.
Using rotary transfer machines, time-saving and
economical complete machining of a workpiece is possible if the number of
workpieces is medium to high. All processing steps are programmed and run
automatically in the specified cycle.
Construction
of rotary transfer machines
Rotary transfer machines are very individualized
machines which, depending on the requirements of the workpieces, are designed
in a horizontal or vertical design. The workpiece is picked up and clamped
centrally on a rotary table (indexing table). Clamping is ideally carried out
in such a way that all tools in the processing stations have free access to the
workpiece and that re-clamping is not necessary. This also increases the
tolerances to be achieved. At the end of a work process, that means with each cycle
(switching) of the table, a finished workpiece is ejected.
The rotary transfer machines are available in a
wide variety of sizes and capacities for machining large and small workpieces.
The size is defined by the diameter of the shifting table and the number of
clamping and processing stations.
The flexibility of a rotary transfer machine can be
expanded by using tool crown turrets as the processing station. In the next
step, a linking of rotary transfer machines with handling units connected in
between is also conceivable. There are hardly any limits to automated
production.
The blank can be introduced into a rotary transfer
machine in an aligned manner via a handling unit or material is fed in via an
automatic bar machine. In this case the first processing station is a sawing
device.
The rotary indexing table and the machining units
have gone through a great deal of development over time. The first rotary
transfer machines were controlled by gears. The indexing table had a star
indexing gear and the feed of the machining units was realized mechanically by
cam gears. In the course of time and with the increase in the performance of
the drives with a compact design, more and more movements and positioning were
implemented by electric motors or servomotors.
The CNC control for the rotary transfer machines
was only a matter of time. CNC rotary transfer machines are more flexible than
the older mechanical designs. A cam-controlled rotary transfer machine still
has the advantage of speed (short cycle times), but the very high expenditure
of time when changing over to another workpiece stands in the way of this.
Advantages
and disadvantages of rotary transfer machines
The greatest advantage of rotary indexing machines
is the economically efficient production of complex series parts in as large a
number as possible. The individual assembly options and the large number of
different processing stations are further advantages.
The disadvantages are the long set-up times, even
with CNC-controlled machines, and the low flexibility in terms of manufacturing
options.
The rotary
transfer machine and its areas of application
The rotary transfer machines are only used sensibly
for machining workpieces in large numbers. Part families can also represent a
decision-making feature when deciding on a rotary transfer machine. In the case
of part families, only one processing station may have to be converted or readjusted
and a variant of the workpiece can be produced.
There are many classic areas of application for
rotary transfer machines. However, these rarely occur in small workshops.
The typical industry in which rotary transfer
machines are used is the metalworking industry. Standard parts, e.g. for the
metal and furniture industry, are manufactured there in large numbers.
Fastening elements, connecting pieces, tools, ferruls
and fittings are typical examples for production on rotary transfer machines.
The rotary
transfer machine and the associated category
At tramao, we decided to classify the rotary
transfer machine in the machining centers category in the field of metalworking
machines. Of course, the processing of plastic or other materials on rotary
transfer machines is also conceivable.
With us you
will find a large selection of used rotary transfer machines
tramao offers you a large selection of used rotary
transfer machines. You will also find the right service companies for repairs
and spare parts procurement on tramao.de.
On tramao you will also find a wide range of
machine accessories for rotary transfer machines such as spindles, tool
holders, clamping devices, coolant and lubricant systems, servo drives, axes
and much more.
Not to be forgotten is our range of tools.
If you decide to buy a used rotary transfer
machine, you will find a large selection of well-known manufacturers such as
Pfiffner, Winema, Porta, Gehring or Eubama on tramao.