Dual-role motor slides as it turns

Siemens has developed a printing press motor that combines rotary and linear movements in a single housing, and can replace existing systems that need complex assemblies of motors and gears. The combination motor (shown below) uses a linear motor to move the rotor of a permanent-field synchronous motor in an axial direction.

The combined movements are needed to distribute ink evenly over the plate inking rollers of offset presses. Siemens says that the technology could have other applications where rotary motion needs to be combined with short linear movements.

The combination drive will allow printers to adjust the rotational speed of the rollers, as well as lifting heights and speeds, while presses are running. The technology is said to reduced wear, boost efficiency, and enhance print quality.

To control the motor`s movements precisely, the rotating axis is fitted with a pulse encoder and the linear axis with a linear encoder. The combination drive is controlled by a Sinamics S120 servo converter, and is controlled in the same way as the linear drives of shaftless printing machines.

Last year, SKF announced a similar dual-role drive for printing presses.