| 摘要 |
PURPOSE: To prevent a bearing from contamination and prolong its lifetime by installing a brush to capture a pulverized/granular substance between a bearing member and the pulverized/granular substance, and installing a propelling means to push the pulverized/granular substance away from the bearing member. CONSTITUTION: A shaft 64 extends outward from the ends of a sleeve 60 and is supported at the ends by bearings 66 rotatably. A brush 68 is fixed by one end to the shaft 64, and the other end extends in the radial direction to contact with an inner threaded region 70 on the wall surface of a chamber 56 in a housing 54. When a pulverized/granular developer moves in the axial direction toward the bearing 66, the developer contacts with the brush 68 to be captured in it. The brush 68 rotates together with the shaft 64, and all pelverized/granular substance having intruded in such a way as approaching the bearing through the threads is swept continuously and pushed away from the bearing. Thus the bearing member is prevented from being contaminated with the pelverized/ granular substance, and the lifetime of the bearing member can be prolonged. |
