Magnets for DC motors depend a lot of the application. It is always a balace between technology and price
The steps needed to select properly the type and the shape of magnets that will go into the dc motor can be the following:
Type of the magnet:
- Magnetic density and resistance to demagnetization.
The magnets should often supply the highest magnetic strenght to the motor in order to maximize the torque that will be produced.
- A strong flux
Finally, the shape of the magnet has to be optimized in order to have the highest magnetic flux going between the rotor and the permanent magnets. A cylinder shape or sector shape is wildely used in this kind of application.
One can easily understand the importance of the quality of the permanent magnet in the speakers. It must be able to provide a strong field while having reduced dimensions and a relatively low cost.
We at Ugimag are working every day with OEM of automotive starter motors to supply them with millions of ferrite sectors permanent magnets for their starter motor applications.
We are always innovating with them, developping new materials and design to improve the starter DC motors and generally speaking all applications with highly optimized permanent magnets.
Please contact us and we will be happy to study your application with you.