The Grismir® motor in the TREZIUM® System is a 2-pole, three-phase slotless permanent magnet synchronous motor. Provided with adequate cooling, the motor is designed to produce 2kw output at the rated speed of 30,000rpm. Iron-neodymium-boron magnets are used to form the 2-pole rotor. The system can use standard world voltages (115 to 240 volts, 50/60Hz).

The Grismir® motor is an AC, synchronous, sine wave, permanent magnet motor that is also brushless, slotless and sensorless. It provides the benefits of variable speed, forward/reverse, high power-to-weight ratio, and unparalleled efficiency. The motor is classified as a brushless AC motor and shares the positive characteristics of a brushless DC (“BLDC”) motors without having some of the disadvantages.

Using standard world voltages (100 to 267 volts, 50/60Hz), the system can generate up to 400 volts.

For example, the TREZIUM® controller does not “cog,” which happens with BLDC and Switched Reluctance (“SR”) motors when they run at lower speed RPMs.Three fully pitched coils electrically connected in a star configuration form the stator field. These coils are wound using several parallel strands to minimize copper losses. The slotless back-iron assembly is composed of very thin non-oriented silicon steel laminations which minimize core losses.

An aluminum extrusion is heat shrunk onto the back-iron assembly to provide cooling. A single PTC thermistor is embedded into the windings to provide motor over-temperature feedback to the drive electronics.

The Thor Power Grismir® motor, part of the TREZIUM® Electric Motor System