| 摘要 |
PURPOSE:To obtain a rotary driving gear of high precision, by a method wherein a rotary driving force of a motor is transmitted by a set of permanent magnet units in non-contact manner. CONSTITUTION:A rotary driving gear is to rotationally drive a turn table 1 for a record disc player, and the turn table 1 is machined to be formed in a ring shape with the outer circumferential section and the central section left as they are. A rotary shaft 3 supported pivotally by a bearing 2 for the frame is fitted on a slot bored through the center of the table 1, and is held horizontally to be freely rotated. For the inner circumferential face of the turn table 1, a plurality of ferrite magnets are provided, and a ring-formed permanent magnet unit 4 on the driven side is formed. A ring-formed permanent magnet unit 5 on the driving side is pivotally provided for a rotary shaft 8 for a motor 7, via circular cylindrical aluminum bearing substance 6. Then, by driving the motor 7 rotationally, with the mutual suction between the permanent magnet units 4, 5, said turn table 1 on the driven side can be rotated in the direction of (b). |
