The development of the new motor, a result of a collaboration between GKN and RWTH University of Aachen, demonstrates that the use of Soft Magnetic Composite (SMC) materials can allow for the design of motors featuring smaller dimensions, lower weight and reduced noise.
In its basic version the motor consists of a stator element, a copper winding and a rotor with permanent magnet. The stators are made of Soft Magnetic Composite (SMC) material consisting of pure iron particles with diameters of less than 0.2 mm coated with an insulation layer. Being pressed to the desired shape, the material is cured at temperatures between 600–700°C, much lower than the 1000°C commonly used in sintering, in order to not cause damage to the insulation layer. The insulation layer allows three-dimensional magnetic properties which are absolutely essential for the motor design and effect a significant reduction of eddy current losses.
Another benefit provided is the reduction of the copper content, resulting in less weight and lower cost compared to traditional radial flux motors. The copper winding along with two identical stator poles in combination with a permanent magnet in the rotor generate a greater toque density. In order to produce a motor with an output of one kilowatt, three phase elements have to be assembled in line with a displacement of 120 degrees each. Higher performance can be achieved with a modular design of several motors assembled in line. Their frequencies range from 500 Hz up to 30 kHz.
GKN Sinter Metals offers three versions of SMC material. The special properties of the powder and the insulation layer allow specific control of permeability and losses. The three-dimensional stator design approach is free, particularly in axial direction.
Another advantage of the transversal flux motor compared to the radial flux motor is its compact design, offering as much as 30% size reduction. With only small masses rotating in the rotor supported by axial magnetic forces, the result is a low-noise motor.
The development of the transversal flux motor, stated GKN, coincides with the growing demand for high-performance electric motors of compact design and low weight.
In addition to the Transversal Flux Motor, GKN Sinter Metals will display other products from its portfolio, including sleeve bearings made of sintered metals. GKN Sinter Metals will be in hall 1.2, stand 1307.