Thrust magnetic bearing for rotary optical deflector

Abstract

Abstract PURPOSE:To float and support a polygon mirror with simple, easy-to-assemble constitution and to rotates it at a high speed by putting the external peripheral surface of a rotor which is an annular magnetic body and the inner peripheral surface of a stator composed of a permanent magnet and a magnetic plate opposite each other across a fine gap. CONSTITUTION:The cylindrical rotating shaft 6 which has the polygon mirror 67 mounted at the upper part rotates around a fixed shaft 4 and is floated and supported by a thrust magnetic bearing 22. The bearing 22 consists of the rotor 20 which is the annular magnetic body and the stator 21 composed of annular magnetic plates 24 and 25 clamps the annular permanent magnet 23 from above and below. The inner peripheral surface of the stator 21 and the outer peripheral surface of the rotor 21 face each other across the fine gap, so lines of magnetic force flowing from the N pole of the magnet 23 to the S pole are converged on end parts 24a, 25a, 20b, and 20c to float the rotor 20 strongly, so that the lower end surface 61 of the rotating shaft does not contact a base surface 1a. Thus, the polygon mirror is rotated at a high speed with the simple, easy-to-assemble constitution.

Inventors

• 👤 Takaharu Sugishita
• 👤 杉下　敬治
• 👤 Hiroyuki Kaji
• 👤 加治　裕之

Bibliographic Details