| 摘要 |
PURPOSE:To increase the torque of a motor for a VTR or the like without increasing th size by providing a magnetic material at the position for holding a coil to a rotating permanent magnet, arranging an elastic material between the magnetic material and the permanent manget, and applying previous pressure to a bearing. CONSTITUTION:A transformer base 2 is press-fitted to a shaft 1, and an upper drum 3 is engaged with the base 2. A video signal which is communicated through rotary transformers 7,8 via a magnetic head 4 is recorded and reproduced on a magnetic tape which is wound on a drum 3 and a stationary drum 9. A ball bearing 11 rotatably supports the shaft 1 to the drum 9. A rotary substrate 28 forms a magnetic circuit together with a magnet 19 and a magnet yoke 30, and a coil 27 is inserted between the substrate 28 and the magnet 29 and supported by a supporting base 26. The magnet 29 is secured to a yoke 30. A coil spring 31 is aranged between the substrate 28 and the magnet 29 to apply the prescirbed previous pressure to bearings 10, 11. |
