| 摘要 |
PURPOSE:To maintain the wobbling and precision of a detector ring by a simple structure, by arranging plural rolling bodies between two supporting members having tracks differing in diameter and center position in such a way that the rolling bodies are held shifted in center position and also in contact with both the tracks. CONSTITUTION:A supporting member 12 is arranged inside of a supporting member 13 together with a detector ring 11 fixed on the top surface of the member 12, and centers O and O' of tracks 18 and 19 of those supporting members 12 and 13 are displaced mutually. Rolling bodies each consist of a couple of rollers 21 and 22 arranged, for example, coaxially and are arranged between the tracks of the supporting members so that the roller 21 is in contact with the external surface track 18 of the member 12 and the roller 22 is in contact with the internal surface track 19 of the member 13. Those couples of rollers are fitted rotatably to arms 23 respectively and their position relations are fixed. Through the rotation of the rolling bodies, the detector ring 11 revolves around the circumference of a circuit having a radius equal to the distance between the centers of said tracks. |
