The Main Spindle Drive for Machine Tools

Frequency Converter FC72 – The Main Spindle Drive for Machine Tools

The SIEB & MEYER frequency converter FC72 is used for the vector-controlled drive of asynchronous and synchronous motors. Speeds up to 150,000 rpm are reached. The vector control provides full torque at low speeds and allows back-magnetization of synchronous motors. Thus, also field-weakened motors can be accelerated up to their maximum speed.
In the machine tool the frequency converters reach positioning accuracies of 0.007°. Beside precise orientation during tool change this also allows interpolated working with feed axes, for example in threading applications.

The Vector-Controlled Drive for High Demands

FC72 with the performance ranges from 8 to 20 kVA is available as a compact device with integrated power supply. Frequency converters with power ranges of 30 kVA and higher are supplied by the separate power supply PS10. Alternatively, the devices with power ranges from 30 kVA and higher can be supplied by the intermediate circuit of an existing voltage supply. The FC72 devices are available up to performance ranges of 173 kVA, whereas water cooling is applied for devices with performance ranges of 100 kVA and higher. The frequency converter is connected to the machine controller via Profibus or analog and digital control signals. FC72 allows a definition of up to 4 motor data sets. This way, different spindles can be operated in one machine or a star-wye switch-over can be realized.