Drives and Controls Magazine

Cogging torque is slashed to cut the vibes

01 September, 2004

Cogging torque is slashed to cut the vibes

A new range of AC servo drives and motors launched by Hitachi is claimed to cut cogging torque by 65%, compared to conventional motors. The AD series servos incorporate a patented "advanced motor technology" which makes them suitable for applications where accurate positioning without vibration is essential - such as precision positioning tables and smart conveyors.

The servo motors, available in the UK from Silverteam, are matched to 32-bit processor drives with on-board digital signal processing (shown above). The drives deliver a speed cut-off frequency of 500Hz and, used with a 17-bit serial encoder, allow precise positioning and stable rotation at low speeds. An auto-tuning function allows the drive to set the most suitable control gains automatically.

Windows software is available to set the drives` parameters and to monitor speed, position and torque graphically.

Options available include embedded PLC cards, and communications interfaces such as DeviceNet, Sercos and Ethernet.