Thermally conductive adhesives in electric motors

Electric motors are continuously becoming smaller and more powerful, which also increases the challenges for connection technology. Adhesive bonding has offered several advantages in the manufacture of electric motors for many years because the established connection methods such as mechanical clamping or the bandaging of magnets are increasingly reaching their limits. Nowadays, gluing is the preferred joining technique for shaft-to-collar connections. Adhesives are also being used more frequently for joining magnets with rotors or housings, as manufacturing-related tolerances can be more thoroughly compensated with an adhesive connection. This in turn allows the smallest possible air gaps between magnet and winding, which has a positive effect on the efficiency of the motor. In addition, production costs decrease, as component tolerances do not necessarily have to be small. Adhesives are therefore characterized by several general advantages in electric motor production:


  • Tension compensation through homogeneous tension distribution
  • Reduction of vibration noise (NVH)s
  • Protection of sensitive components against moisture, media or mechanical stress
  • Easy automation


Thermally conductive casting compounds increase service life

The service life of an electric motor is influenced by the resulting winding temperature in operation. Due to the design, most of the heat loss occurs in the end windings of the stator. Thermally conductive potting compounds offer an effective way of dissipating this resulting heat and thus reducing the winding temperature. Epoxy resin systems are preferably used here, on the one hand, they are formulated using fillers to achieve a good thermal conductivity, and on the other hand remain fluid enough to be able to enter the gap between the winding and the housing. The use of ceramic fillers also ensures exceptional electrical insulation. Due to the excellent thermal resistance of these systems, they are also suitable for high insulation classes.

In addition to improving thermal properties, an epoxy potting compound also protects the sensitive winding wire from mechanical loads or vibrations. Many motors, especially in the automotive sector, are also exposed to high levels of moisture or aggressive media such as gear oil. Highly crosslinked systems can permanently seal sensitive components against these media and thus guarantee a long service life.

Polytec PT offers you an adapted range of thermally conductive adhesives with high demands on the thermal properties and which are suitable for various application and curing techniques. Benefit from our wide-ranging expertise in thermally conductive bonding and potting. A contact, that conducts!