powder productıon and nano materıals - 6th International Powder ...

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6. ULUSLARARASI TOZ METALURJİSİ KONFERANSI ve SERGİSİ
th INTERNATIONAL POWDER METALLURGY CONFERENCE & EXHIBITION
As a leading manufacturer of axial powder pressing technology, DORST Technologies is always striving for new
approaches and solutions to optimize the production step of shaping. The mentioned drive technologies are fully
developed nowadays.
For pressing forces of up to 1600kN there is now an alternative drive technology, which incorporates the various
advantages of both existing systems:
2. THE ELECTRICAL SERVO DRIVE SYSTEM
2.1. Fundamental Principles Of The Electrical Servo Drive
With the new EP press series the movements of the punches are generated by means of servo-motors and a
backlash-free spindle drive. They provide for dynamic movements with accurate positioning and, as a result, for
high stroke rates and precise compacts.
In order to use all the positive characteristics of servo-motors to their full extent for the powder pressing technology,
DORST Technologies did not integrate the new drive type into an existing press type but has developed a new press
series for this purpose.
The motors are of compact design and do not require any intermediate elements such as a transmission or coupling,
but activate the spindles directly. That is why this drive technology has an extremely high rigidity.
Each drive motor is equipped with its own measuring system – the closed-loop control is carried out individually
and directly on the active axis. Thus, inaccuracies resulting from indirect measuring are eliminated. In addition, the
press is equipped with length measuring systems. Joint processing of both signals leads to a very high positioning
and repeat accuracy of the axes.
As a result there is a significant increase of speed, since the normal time-consuming adjustments, e.g. through
hydraulic lines and hydraulic valves, are eliminated and the correction is carried out directly on the axis!
All axes for compaction on a standard press, which are the upper punch, the die and the core rod, are driven by their
own servo-motor. All movements can be carried out independently of each other.
The maximum torque and thus the force are at disposal at any rotational speed and in any position. Thanks to this,
movements can be carried out at the highest speeds up to the pressing position.
2.2. Implementation Of The Technology In The Machine
The EP press type is equipped with a pre-stressed frame with four columns. The frame is of high rigidity and at the
same time ensures easy access to the press area, respectively the tool, from all sides.
The new press series comprises pressing forces from 150kN up to 1600kN and operates according to the die
withdrawal process. It is designed for the application of quick-action clamping systems as well as for the installation
of die sets. Thanks to the resulting flexibility, tools from existing presses can easily be integrated into the new
machines.
The new development is based on the modular design of DORST Technologies: Besides the new frame, DORST
Technologies uses parts and complete subassemblies, which have been successfully used in production on other
press types for years and have proven their reliability.
For instance: Guidance of the axes is carried out in backlash-free linear guides, which provide a favorable length
to supporting difference ratio within the frame. These guides have been successfully used in powder presses of the
type TPA-HS for more than 10 years.
The EP press series is designed in compliance with well-proven and reliable technology, which fulfills all requirements
for the operation in daily production.
The compact design of the drive motors allows for space-saving installation compared to conventional plants. The
floor space of an EP50 press requires for instance only about 70% of the floor space of a comparable mechanical
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