Direct Drive Technology and Mechatronic Solutions for Machine Tools

Direct Drive Technology and Mechatronic Solutions for Machine Tools INA ¨C Drives & Mechatronics GmbH & Co. oHG (IDAM) will present innovative direct drive technology and mechatronic solutions for machine tools at EMO 2007 in Hanover. New developments for torque motors ensure optimized latching force and load pulsation. The new L2U linear motor series reaches peak forces of up to 13,000 N and is now suitable for use in large machining centers. In the further development of torque motors, IDAM especially focuses on the optimization of latching force behavior and load pulsation. Latching forces are magnetic reaction forces (reluctance changes) that can be measured even at the deenergized motor and can only partially be compensated for by high performance controls. Load or moment pulsation has the effect that even with constant-moment current the released moment fluctuates about an average value. This cannot be compensated for with the help of commonly available controls. These characteristics often result in vibration problems. Yet they can also lead to short-wave surface defects of the machined workpieces. A mechanical excitation of the system and significant acoustic vibration can for example be the consequence in gearwheels manufactured for transmissions. The optimization of the internal structure makes it possible to diminish this effect for all IDAM motors or even reduce it down to a nondetectable level. Further focal points in development include higher efficiency, speed increases and the reduction of heat power loss. With its L2U linear synchronous symmetrical motor series, IDAM offers a fundamentally refined series that reaches peak forces of up to 13,000 N with a deadweight of 45 kg. Thus it is now possible to equip large machining centers with these motors. The main advantage of this motor technology is the compensation of magnetic forces of attraction between motor and magnet. The resulting unloading of the guidance system results in clearly longer service life. In addition, accuracies are maintained for a longer period and heat generation due to friction is reduced. This is achieved with an iron-core linear AC synchronous motor with two symmetrically opposed secondary parts. The reduced iron content in the movable primary part additionally helps reduce the mass in this three-phase motor. The lower deadweight of the L2U motors relative to the payload has a positive effect for highly dynamic tasks with relatively low payloads (up to ten times the mass of the primary part).