JPS643512A - Ring for rotary sensor - Google Patents

Abstract

PURPOSE:To increase the amt. of the magnetic flux passing a magnetic pole or change of the magnetic flux so that detected output is increased by rotating a magnet ring subjected to multipoilar magnetization in such a manner that at least either of the outside peripheral face or side face has parts of alternately reversed polarities. CONSTITUTION:The magnet ring 12 is subjected to the multipolar magnetization in such a manner that at least either of the outside peripheral face or the side face has the parts of the alternately reverse polarities. The inside peripheral face thereof is supported in contact with an inside ring 11 and the outside peripheral face is coated with and protected by an outside ring 14. The magnetic pole 5 is disposed to face the outside peripheral face of the magnet ring 12 via the outside ring 14. The amt. of the change of the magnetic flux passing the magnetic pole 5 on the magnetic sensor side can be increased at the time when the magnet ring 12 subjected to the multipolar magnetization rotates. The large detected output is, therefore, obtd. Since the outside peripheral face of the magnet ring 12 is protected by the outside ring 14, the ring has excellent mechanical strength and corrosion resistance.