Rigidity and a High Level of Dynamism for Processing Machines for Large Workpieces
HEYLIGENSTAEDT has just implemented a new machine to process and manufacture large-format tools and moulds for a German automobile manufacturer. In particular this machine offers extraordinary properties due to its DualDRIVE rack drive system by REDEX-ANDANTEX. This linear drive offers very high stiffness and has a unique system to eliminate play. So this allows short processing times while simultaneously guaranteeing high precision.
HEYLIGENSTAEDT is a German company founded in 1867 and is one of the most renowned tool manufacturers worldwide, particularly in the areas of rotating and milling. It has 200 employees and particularly distinguishes itself through contact with its customers, the company offering an entire range of specific products at excellent prices. HEYLIGENSTAEDT also commissioned another processing machine of the HEYNUMILL type for formatting large-size mechanical components for a German automobile manufacturer. These parts had to be manufactured with great precision in the shortest possible cycle time.
In order to guarantee rigidity, precision and a high level of dynamism, the HEYLIGENSTAEDT company has decided to use the DualDRIVE by REDEX-ANDANTEX: "We had to boost performance", explains Ulrich KRAUSE, sales manager of HEYLIGENSTAEDT. "Now we are able to achieve tolerances in magnitudes of just hundredths with perfect dynamism".
The line installed for a German automobile manufacturer is part of the vertical milling machine line with the HEYNUMILL portal construction. The machines of this line have work tables up to 4 m wide, of any design (palette tables, double tables, integrated round tables). Their drive capacity can reach up to 100 kW and the maximum spindle speed is of 6000 rpm. The entire HEYNUMILL product range is equipped with DualDRIVE gears.
Heynumill has two DualDRIVE systems for the drives of the X and Y axis. Another REDEX product is used to actuate the main spindles - a two-step gearbox of the RAMmsd type which has set itself apart through its high power density. The drive capacity can reach up to 100 kW and the maximum spindle speed is 6000 rpm.
"We really had to appreciate the quality of the technical consultation of REDEX ANDANTEX. The company met our expectations. From the financial point of view, this offer is certainly competitive", adds Ulrich KRAUSE.
DualDRIVE Rack Drive System
DualDrive is a rack drive system with a unique concept and is appealing due to two major characteristics.
First DualDRIVE is extremely stiff due to the particularly optimised form of its reinforced drive bearings and its shaft drive pinions (with a high precision factor manufactured in the drive shaft itself). As a result, in addition to having one of the best torsion rigidity levels offered on the market, the DualDRIVE gears also provide the highest rigidity in all other relevant axis directions and therefore allow double the accelerations and loads achievable with other solutions. The design of DualDRIVE makes it possible to achieve a considerable decrease in radial flexion, which is responsible for 60% of the entire deformation. Technically speaking this is achieved specifically by optimising the diameter of the drive pinion so that the transferred torque has the best ratio to rigidity on the toothed rack. The bearing force primarily consists of two pre-tensioned and well-distanced taper roller bearings. It is built in such a way that the pinions can be carried as close as possible to the active load and is only separated by the width of the tensioning unit from the drive bearing. As a whole, the DualDRIVE gear is unusually stiff, which allows higher resonance frequencies with machine axes with high dynamic requirements. For moving masses of the magnitude of 15 tons, for example, it was possible to achieve slight boosts in performance of up to 25% compared to comparable systems.
Zero backlash solution...
The second major property of the DualDRIVE drive gear is the elimination of play between both driving pinions by creating an electrical or mechanical pretension; this achieves the highest possible precision. The pinion steering rack of the DualDRIVE type thus consists of 2 servo-planetary gears with parallel installation and twisted together either electrically or mechanically. In the case of HEYLIGENSTAGT, electrical preload was selected. This solution offers the advantage of variable wiring. Electrical wiring offers means controlling each gear with a separate servomotor and simultaneously creating an opposing force between the two drive pinions (eliminating the play) and a resulting force which guarantees actuation of the system. The setting for HEYLIGENSTAEDT turned out to be very simple. It is also possible to create a mechanical pretension with which the pinions are twisted together. In this case, a single motor is sufficient to control both gears. An angular gear is integrated into each step-down gear and the patented pretension is mechanically set with a torsionally stiff coupling.
"The next HEYNUMILL line, consisting of 6 machines, is in the works for an automobile manufacturer. The translation motions occur in the X-Y-Z direction, the milling capacity will be 67 kW and the speed 6000 RPM. "We would like to use the DualDRIVE system by REDEX-ANDANTEX also for other machine lines", concludes Ulrich KRAUSE.
ANDANTEX USA Inc.
1705 Valley Road
Wanamassa, NJ 07712
USA
Phone: +1 (800) 713 6170 / Fax: +1 (732) 493 2949
Patty Drescher - pat@andantex.com
REDEX ANDANTEX
ZI - BP 79 F-45210 Ferrières
Phone: +33 2 38 94 42 00 / Fax: +33 2 38 94 42 99
France: Claude FOURTUNE ( cfourtune@redex.fr )
