For decades, our client has been manufacturing blower motors, employing rotors made from injection-molded, plastic-bondet hard ferrite.
The company approached us with a specific inquiry: How could we modify the design of the existing rotors to increase their power output?
It was clear to all that achieving a higher output from the blower would require a stonger magnetic material. So far so good. However, for cost reasons, it was imperative to continue using the existing base material of hard ferrite, which did not simplify matters.
Plastic-bonded, injection-molded hard ferrite reaches a maximum remanence (Br) of apporximately 290mT. To tackle the challenge presented to us, we opted for the next higher class in the hard-ferrite spectrum: dry-pressed, axially oriented, sintered hard ferrite magnets, which allowed us to achieve a remanence of up to 370mT.
The rotor's magnetization was defined as a 4-pole or 6-pole. The magnets are ground on the outer diameter and height, where they exhibit very small tolerances. This precision enables the motor shaft to be secured by overmolding with plastic.
With this rotor, we have accomplished two crucial objectives:
- Utilization of the same magnetic base material while simultaneously enhancing power output through the revised manufacturing process.
- Identical integration into existing blower systems with an increase in performance as well.