Rotating grinding and diamond dressing tools operate under demanding conditions. High speeds, fluctuating loads and confined installation spaces are part of everyday operation in many grinding machines. This makes it all the more important to have a drive system that controls the spindles consistently and reliably, even under dynamic conditions. The drive controllers from SIEB & MEYER’s SD4x series are specifically designed for high rotating-field frequencies and are also characterised by high speed stability. They not only control the spindle but also serve as an interface to the machine control system, supplying it with all relevant process data.

Constant spindle temperatures as a decisive factor

A key aspect of grinding is the thermal stability of the process. If the temperature rises, the overall length of the spindle changes and the tool shifts. Even minor deviations can affect the machining result. The SD4x controllers minimise motor heating and thus help to maintain a constant spindle temperature.

At the same time, the drives must be able to respond to changing load conditions. During grinding, and particularly during dressing, a stable speed is just as important as a high available torque. This is precisely where the importance of control technology becomes apparent. Of particular relevance here is sensorless vector control (SVC), which SIEB & MEYER also offers for asynchronous motors. The speed is determined and controlled using current and voltage values, without the need for an additional sensor. This enables encoder-less dressing spindles to be operated with high dynamics.

For machine manufacturers, this offers the advantage of reduced design complexity, as the spindles can be constructed more compactly and the limited installation space within the machine can be utilised optimally.

Customised solutions through parameterisation

As numerous different spindle types and motor variants are in use, the parameterisation of the drive controllers plays a central role. The adaptation of the control system to the respective spindle characteristic curve is therefore carried out in close technical collaboration between the customer and SIEB & MEYER. This results in bespoke drive concepts that are precisely tailored to the specific requirements of dressing: stable speeds, low thermal load and compact integration into the machine.