| 摘要 |
PROBLEM TO BE SOLVED: To reliably seal in fine powder inside a rotary body at lower costs. SOLUTION: A seal member 10 is of a bushing type used for sealing a rotary shaft 12 of a developing roller 11 to prevent toners from escaping toward the bearing thereof. The seal member 10 comprises alternate laminations of urethane layers 20, 22, 24 and 26 and sponge layers 21, 23 and 25, and is bulged at the sandwiched sponge layers 21, 23 and 25 radially inward and outward by the axial inward compression from both ends. The inner peripheries of the urethane layers 20, 22, 24 and 26 closely contact with the outer periphery of the rotary shaft 12 at their crest line to check the passage of toners with their sharp edging effect, and passed toners are absorbed in pores on the surface of the sponge layers 21, 23 and 25, which enables reliably checking the passage of fine toners by the seal member 10 totally. |
