| 摘要 |
PURPOSE:To make uniform the weight balance of rotor yokes installed on the rotary shaft of a drum motor designed to issue two or more kind of rpm detecting signals by reducing the number of parts and assembly man-hour for the drum motor, thereby thinning the motor in the direction of rotation shaft. CONSTITUTION:A ring-shaped magnet 361 installed on a rotor 36 has 12 magnetized main poles 362. Magnetized commutating poles 363 are provided on part of the periphery of a pair of the adjoining main poles 362. A ring-shaped magnet 361a (for FG signals) consisting of only magnetized main pole 362 on the internal periphery the magnet 361 faces patterns for FG that generates FG signals. The entire ring-shaped magnet 361 faces the patterns for PG that generates FG & PG signals. |
