Developing device and image forming apparatus including same

A developing device comprising:

• a developing container for storing developer containing toner;
• a developer carrier for carrying the toner in the developing container;
• a bearing fixed by being inserted in a through hole provided to the developing container;
• a stirring transport member including a rotation shaft supported by the bearing in a rotatable manner, and a stirring blade formed on an outer periphery surface of the rotation shaft, so as to stir and transport the developer in the developing container;
• and
• a seal member disposed between the bearing and the rotation shaft, wherein
• the developing container has an upper housing and a lower housing connected to the upper housing,
• the through hole is divided into an upper housing side and a lower housing side,
• the bearing has a bearing side engaging part formed on an outer periphery surface of the bearing, the bearing side engaging part having an outer diameter different from that of other part in the axial direction of the bearing, a first outer periphery part positioned inside the bearing side engaging part in the axial direction, and a second outer periphery part positioned outside the same in the axial direction, and
• the through hole has an inner periphery surface on which a container side engaging part engaging with the bearing side engaging part is formed at the same position in the axial direction as the bearing side engaging part, the container side engaging part having an inner diameter different from that of other part in the axial direction of the through hole.