| 摘要 |
An electric motor for a magnetic tape recorder comprises an electrically insulating disk-shaped stator with a plurality of flatwise coils, a rotary shaft rotatably extending through the stator, and a first disk-shaped rotor of soft iron with a multi-pole annular magnet and a second disk-shaped rotor of soft iron rotatably extending through the shaft on both sides of the stator. A pulley is fixed on the shaft below the first rotor to drive capstans, and a reel disc or a pinion is coaxially connected to the second rotor to drive a take-up reel for forward play. In a fast forward feed mode, the first and second rotors can be mechanically interlinked. Alternatively, an electromagnetic solenoid may be used to take out a torque from the first rotor by engaging an idle roller with a roller fixed to the rotary a shaft above the pinion or to apply a pressure to the second rotor to increase the friction between the second rotor and an adjacent shoulder on the shaft.
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