Drives and Controls Magazine
Servodrives tackle vibrations and ripple
Published:  22 December, 2014

At the recent SPS IPC Drives show in Germany, Yaskawa unveiled a new generation of servomotors and drives with improved performance, a wider speed loop bandwidth (3.1kHz), and enhanced vibration suppression and force ripple compensation compared to their predecessors. The Sigma-7 motors are 20% shorter than the previous Sigma-5 models – which they can replace directly – and provide 16 times better resolution, thanks to the inclusion of 24-bit encoders.

The matching servodrives, which can be used with either linear or rotary motors, can suppress high-frequency vibrations occurring at two ends of a mechanism, at the same time. The automatic force ripple compensation allows precise positioning.

Yaskawa has improved the Sigma-7 drives’ auto-tuning function which ensures reliable operation without having to adjust the gain. It says that the drive can handle loads up to 30 times larger than the moment of inertia, without vibrating. This performance is not affected by dynamic load variations.

The drives support EtherCat and Mechatrolink communications (with Profinet on the way) and have several built in safety functions. They can be daisy-chained or mounted side-by-side.

Yaskawa's new generation of servomotors and controls promise enhanced performance

The IP67-protected motors, which cover the power range 50W–15kW, are said to produce much less heat than their predecessors. They have the same flange dimensions as the earlier Sigma-5 range.