| 摘要 |
<p>PURPOSE:To improve workability of sealing oil in an oil chamber by forming the oil chamber in a cover and providing an oil supply hole to be opened to the oil chamber in the cover while a plug unit being able to be mounted to and removed from this oil supply hole further a ventilating hole in this plug unit. CONSTITUTION:When oil is sealed in an oil chamber 21, a plug unit 42 is removed from an oil supply hole 40. Here because the supply hole 40 is drilled in the center of rotation of a cover 20, the oil can be sealed in a horizontal position despite a stop position of rotation of the cover 20. While, when a pulley 15 is in rotation, the oil in the oil chamber 21 also rotates, causing heat to be generated by friction or the like, and a pressure in the oil chamber 21 rises. When the pressure in the oil chamber 21 exceeds a fixed value, a ventilating hole 41 opens its slit 41a, relieving the internal pressure. When the slit 41a opens, because the oil is positioned in the peripheral edge of the oil chamber 21, the oil is prevented from passing through the ventilating hole 41 and leaking to the outside. While dust or the like is prevented from mixing because the slit 41a is always closed.</p> |
