Developer containing device and image forming apparatus

An image forming apparatus comprising a developer containing device for containing a developer, wherein said developer containing device includes:

• a partition located between an outer space and an inner space for containing said developer;
• a bearing arranged on said partition;
• a rotation shaft carried by said bearing and extending from said outer space into said inner space;
• a sealing member arranged on an inner space side of said partition for isolating said bearing from said inner space by fixing one end side of said sealing member to said partition and keeping the other end side of said sealing member in contact with a surface of said rotation shaft, said sealing member being spaced apart from said bearing so that said sealing member forms a closed space between said bearing and said sealing member;
• a communication groove arranged at the surface of said rotation shaft for connecting said outer space to said closed space;
• a communication passage arranged in said partition for connecting said outer space to said closed space;
• and
• wherein said communication groove and said communication passage form a path configured to circulate air between said outer space and said closed space so that air flows through said communication groove and said communication passage in opposite directions.

A device for housing developer comprising:

• a partition positioned between an exterior space and an interior space configured to house the developer;
• a rotatable shaft extending through the partition between the exterior space and the interior space;
• a bearing surrounding a portion of the rotatable shaft extending through the partition and configured to rotatably support the rotatable shaft;
• a sealing member fixed to a surface of the partition facing the interior space and sealingly engaged with a portion of the rotatable shaft inside the inner space, the sealing member being configured to shield the bearing from developer housed in the interior space, wherein a portion of the sealing member is spaced apart from the rotatable shaft and the partition to form a cooling gap between the partition, the rotatable shaft and the sealing member;
• a through hole extending through the partition and providing a path for air to flow between the exterior space and the cooling gap;
• a groove formed in the portion of the rotatable shaft surrounded by the bearing, the groove being configured to circulate air between the exterior space and the cooling gap during rotation of the rotatable shaft so that air flows through the groove and the through hole in opposite directions.