Magnetic sensing system without bearings for large shaft diameters

HDmag is the name of the new Baumer hollow shaft encoder family utilizing the magnetic sensing principle. With a 17 bit singleturn resolution the series also comprises absolute encoders that can endure the tough ambient conditions of drive engineering or wind turbines. This top-grade precision and utmost ruggedness is possible by the signal evaluation electronics being integrated in the sensing head – fully encapsulated and thus protected against dirt, shocks and vibrations. The ultra-high accuracy and resolution of HDmag are realized by FPGA signal processing and integrated offset, amplitude and phase control generating square pulses of max. 524,288 periods per revolution. Also the unique sine/cosine interpolation to max. 32,768 periods per revolution sets new benchmarks. By virtue of their compact axial design conceived for big hollow shaft diameters the new magnetic encoders are predestined for attachment to even the largest shafts.

Magnetic, no bearings and ultra-precise

The magnetic hollow-shaft absolute encoders are conceived for drive shafts with maximum 740 mm diameter, even larger diameters are technically feasible. They consist of an encoder wheel, which is mounted directly on the drive shaft, and a separate sensor head. A magnetic scale fitted on the outside of the encoder wheel is sensed tangentially. It is covered with a bandage to provide additional protection. The absolute sensing system offers a maximum resolution of 17 bit, the signal processing integrated in the sensor head enables optional generation of sine/cosine signals or square-wave signals (HTL or TTL).