- November 13, 2019
- POSITAL - Fraba Inc.
November 13, 2019 - POSITAL-FRABA’s introduced Hollow Shaft Kit encoders have been selected as a complementary product in Rockwell Automation’s PartnerNetwork Encompass program.
POSITAL’s Hollow Shaft Kit encoders feature an integrated rotation counter that records each revolution the instrument experiences, even if these occur when no external power is available. Power for the counter circuitry is supplied by POSITAL’s Wiegand energy harvesting system. There is no need for troublesome backup batteries or complex mechanical solutions.
The Hollow Shaft Kit encoders are especially well suited to robots and cobots. Weighing in at just 110 g, with an outer diameter of 80 mm, they can be integrated directly into the joints of the robot arms. Their open-center form factor leaves room for designers to route mechanical components, cables or pneumatic/hydraulic lines through the center of the joint. Their design (17.8 mm deep) and large central opening (30 or 50 mm) make them suitable for space-critical applications, including servomotors and drives. Installation and commissioning are straightforward: a few simple steps and the measuring system is ready for use, without complicated calibration procedures.
At the heart of the self-powered multi-turn system is POSITAL’s Wiegand energy harvesting technology. To accommodate the open-center layout, a new arrangement for the magnets (on the rotor) and Wiegand wire assembly had to be developed. Through experimentation and extensive magnetic field simulation, a solution was developed that included four diametrical-oriented magnets placed evenly around the rotor. These four magnets provide a stable magnetic field that triggers polarity reversals in the Wiegand sensor installed in the stator. With each 360-degree rotation of the rotor, the Wiegand assembly generates a current pulse that energizes the counting electronics