Magnetising systems

Becoming a pole positioner - with magnetising systems from ITK

Becoming a pole positioner - with magnetising systems from ITK

The demand for magnets is increasing, especially due to the transition to electromobility and renewable energies. Magnets are needed for sensors, such as encoders, as well as for electric motors. Magnetic encoder systems for precision applications depend heavily on the quality of the magnetic scale. Measuring standards such as pole rings or linear scales are an essential component of magnetic measuring systems and determine the achievable precision in positioning systems. With ITK's magnetising systems, sensor manufacturers can rely on the quality but also on the desired productivity when magnetising scales for linear and rotary applications.

ITK's magnetising systems are customised and managed as the PolePositioner family. They "write" suitable carrier material with a wide variety of pole patterns in the highest quality for linear and rotary applications. The systems are flexibly designed so that they can be used for series production with the requirement for cost optimisation or for samples and small quantities..

Linear Magnetiser LMP

Linear magnetising machines of the LMP type are intended for processing linear scales made of hard magnetic, elastomer and plastic-bonded materials. The material to be magnetised is mechanically fixed and the recording head is guided in a translatory direction over the material to be magnetised, into which it imprints magnetic fields.

Essential for the quality of the scale are

  • Precise positioning of the print head along the direction of writing
  • Exact distance to the magnetic material
  • Exact magnetising parameters and magnetising currents

Alternatively, the print head can be permanently installed and the scale moved. In principle, scales of any length can be produced. However, the exact positioning of the scale relative to the print head is more complex. Especially with very long scales, thermal effects and possible slippage when moving the material play a role.

LMP systems can be used flexibly. In principle, scale lengths from 50 mm up to 2000 mm can be written in the standard variant; other lengths up to 10,000 mm are possible on request. Those who want to produce scales with different magnetic and geometric properties can take advantage of the interchangeability of the write and read heads. It offers almost unlimited possibilities.

LMP systems are preferably equipped with positioning axes in linear motor technology and ITK's own measuring systems. Spindles for movement are dispensed with. This offers additional convincing advantages:

  • Inaccuracies due to backlash are eliminated.
  • Scales can be produced with very high precision and at a high cycle rate

The use of a laser interferometer reference measuring system as a standard ensures that the "poles" are stamped into the scale material with a high degree of accuracy. Scales with high accuracy can be produced reproducibly and avoid a high reject rate - the best prerequisites for opening up new fields of application. The scale material is written on with a write head using the pulse writing method or analogue.

Rotary magnetising unit type RMP

For rotative scales, the circular magnetising unit type RMP is used. The material to be magnetised is fixed on a rotary axis of corresponding diameter and guided past the recording head over the material to be magnetised in the direction of rotary movement. In the process, the magnetic fields are impressed. As with the LMP family, materials made of hard magnetic, elastomer and plastic-bonded materials can also be written on with the circular magnetising units. The poles can be arranged both radially and axially. With the RMP system, scales with different diameters can be generated - and in a wide range. The clamping systems can be exchanged without any problems. Diameters between 3.5 mm and 500 mm can be realised in no time at all. By using a high-precision encoder system as a dimensional standard, the poles can be stamped into the scale material with a high degree of accuracy and a high degree of reproducibility can be guaranteed. Once the writing process is complete, each individual scale can be clearly marked. Barcodes can be applied directly to the scale for this purpose. The advantages:

  • There is no risk of confusion
  • Traceability is guaranteed - even after many years

A magnetising system is only as good as its components. That's why only high-quality, tried-and-tested products are used. ITK offers 40 years of know-how in the development and manufacture of complex positioning systems and MR measuring technology. The machines are designed for continuous industrial use (24/7). On request, ITK provides the customer with a turnkey solution according to individual specifications. The scope of delivery of the systems includes

  • CE conformity
  • Customer software
  • Commissioning
  • Calibration
  • Training
  • Service/maintenance

LMP and RMP in use