Drives and Controls Magazine
New-generation servos are smaller, lighter and faster
Published:  04 March, 2016

Panasonic has announced a new generation of servodrives with a velocity response of 3.2kHz, resulting in faster reaction times. There is also a news series of matching servomotors, with built-in 23-bit encoders, which are claimed to be 30% shorter and 10% lighter than their predecessors.

The new Minas A6 series drives support a 100Mb/s full-duplex communication system called Rtex (real-time express) which cuts communication periods to 0.0625ms (a 25% improvement on the 0.083ms of the previous A5 generation). The maximum pulse frequency has been increased from 400Mp/s to 4Gp/s.

The Rtex system allows the servodrives to communicate with host controllers via Cat5e cables up to 100m long, thus simplifying connections. It also allows the drives to be located closer to their motors. The ring topology supports up to 32 slave drives.

The drives incorporate functions for cancelling load disturbances and reducing resonance. Variations in torque have been reduced and Panasonic says that the drives will maintain stability even if the load changes. The 3.2kHz velocity response is 40% faster than the 2.3kHz of the A5 series. A position comparison function provides a precise pulse output that avoids the need for a pulse counter.

Micro-vibrations are said to have been reduced considerably, thanks to improved current regulation and linearity. Vibration suppression during standstill under a static load has also been improved.

Panasonic's Minas A6 servo drives and motors are faster, smaller and more precise than the previous-generation A5 models

The new A6 motors have a split core structure and new housings. A 200W high-inertia version is 67.5mm long and weighs 760g – 20% less than the previous version. For models up to 400W, the maximum speed is now 6,500 rpm (30% faster than before) and for versions up to 1kW, the maximum torque is 350% (a 16% improvement).

The motors’ compact 23-bit absolute encoders represent an eight-fold improvement in resolution compared to the 20-bit encoders used in the previous generation. They result in more precise position control and disturbances being reduced by about 20%. The infinitely rotatable encoders (which can also be used in an incremental mode) allow maximum values to be set freely. Triple-lip oil seals offer improved protection against movement of dust and oil.

The new motors use the same cables, connectors and flanges as the A5 series, allowing direct replacements.