THE brushless motor design is facing a revolution phase as traditional “needle wound” or “field coil” motors reached along the years their maximum efficiency (mainly limited by the fill factor).
Today several motor manufactures in various markets as Automotive Hybrids, Automotive actuators, Industrial Automation, Household appliances, Commodities are taking into consideration to produce brushless motor’s stators using the “open poles” motor winding concept.
By the means of this innovative motor winding production concept is possible to increase the motor performances up to 20-25%, and to obtain a considerable material cost reduction.
As a consequence, in the same space, it is possible to apply more wire turns obtaining an higher motor torque, or to use a larger wire size, allowing an higher motor current.
The inner side of the lamination stack design in traditional close stator is conditioned by the air-gap required to allow the needle passage between the pole-shoes. Reducing the air gap between the pole-shoes the magnetic field increases reducing the cogging effect and is possible to add more wire turns.
These superior performances in the motor winding process can effect two advantages:
Higher power density allows to create a more powerful motor with equivalent size as a traditional one.
Keeping the same power output is possible to reduce size and weight (and in consequence material cost too).