| 摘要 |
PURPOSE:To prevent the heat generation and unequal rotation of the motor by providing a heating means for heating the fluid of an oil dynamic pressure fluid bearing. CONSTITUTION:A bearing sleeve 14 is apertured in the upper part and a revolving shaft 11 is inserted therein. Oil which is fluid is packed therein and the bottom end of the bearing sleeve 14 is integrally fixed to a motor case 10. A heating element 15 which is the heating means is mounted to a printed circuit board 13 is mounted on the outer periphery of the bearing sleeve 14. This heating element 15 consists of a self-temp. control element, such as positive temp. coefft, thermistor. The heating element 15 is energized when a power source switch of a laser beam printer is turned on. The heating element 15 is thereby maintained at a specified temp. Namely, the bearing sleeve 14 is heated and the oil which is the fluid therein is always maintained at the low viscosity. The high-speed revolution is possible in this way and the abnormal heat generation of the motor itself and the unequal revolution thereof are prevented. |
