Ring-shaped magnet unit prodn. - involves liq. plastic fed into mould-gaps to cool and harden

摘要

Annular magnetic unit has several curved permanent magnets arranged in annular groups. These are arranged on the bottom of the outer mould. Both the inner and outer surfaces have alternate N and S poles. Around the outer surface of the magnets are iron pieces. There is an space between the ends of the magnets and between the outside of the iron pieces and the outer mould. Plastic is injected to fill this space. Provides magnetic unit for use in a d.c. machine. (Provisional Basic previously advised in Week 8406).