APPLICATIONS? STEP INTO THE RING. Laser beam control Many applications therefore use rota- ry tables with a central opening that are driven by a "common" motor. Such solutions require transmission and complex mechanics, however. The resulting inevitable backlash needs to be compensated by means of elaborate measures before this type of motor can be used in high-precision applications. This complicates system integration considerably. Furthermore, numerous wear parts are involved, which leads to high maintenance requirements. Hybrid stepper motors, i.e., the combination of reluctance and stepper motor in a hol- low shaft design are likewise often the tool of choice, but have a large volu- me and are heavy when higher perfor- mance values are called for. Finding a practical solution when the applica- tion requires an opening has, thus, not necessarily been easy until now. Originally designed for optics and pho- tonics applications, the new hollow shaft direct drive also opening new possiblities in many other areas, such as wheel drives in cases where the drive shafts are guided through the motor for space reasons or in prosthetics with artificial knees or shoulders. In princi- Robotics There are many drive technologies and solutions available that are gene- rally suitable in cases where a central opening is needed. In practical use, however, each has its own disadvan- tages. With classically constructed motors, for example, the diameter of the hollow shaft is usually limited to approximately 10 to 12 mm on account of the necessary copper filling factor or magnet yoke. Due to their multi-pole design, torque motors do permit lar- ger openings, but cannot achieve high speeds due to their large moving mass. In addition, they are relatively expen- sive and often difficult to integrate. 08 0 2 . 2 0 2 0 I N N O V A T I O N Laboratory automation ple, it can be used wherever cables need to be guided through the opening or in cases where gases, fluids or light signals are to pass through the opening. Apart from the field of optics – e.g. for microscope stages, apertures, zoom lenses, laser beam controls, etc. – it can thus be used for a wide range of con- trol and positioning tasks. Typical appli- cations also include turntables, antenna mounts as well as air and gas vents.