Development apparatus and image forming apparatus having the same

1. A development apparatus, comprising:

a stir member that stirs a developer in a development container;

a stir gear that rotates the stir member;

a stir rotation shaft that connects the stir member and the stir gear to each other;

a development member that supplies the developer onto a surface of an image carrier;

a development gear that collaborates with the stir gear to form a series of gears and rotates the development member;

a development rotation shaft that connects the development member and the development gear to each other;

a housing box that houses the stir gear and the development gear, supports rotatably the stir rotation shaft and the development rotation shaft, and is provided with an air take-in opening for taking in air and an air discharge opening for discharging the taken-in air; and

a wind sending member that takes in the air from the air take-in opening into the housing box and makes the taken-in air pass through the housing box to discharge the air from the air discharge opening; wherein

the air take-in, opening and the air discharge opening are disposed such that the air flows in a direction perpendicular to the stir rotation shaft,

the air discharge opening is disposed at a position higher than the air take-in opening,

the stir gear is disposed to oppose the air take-in opening; and

air flowing into the housing box from the air take-in opening flows from the stir gear to the development gear.

2. The development apparatus according to claim 1 , wherein the wind sending member is an air take-in fan and is disposed near the air take-in opening.

3. The development apparatus according to claim 1 , wherein the wind sending member is an air discharge fan and is disposed near the air discharge opening.

4. The development apparatus according to claim 1 , wherein the wind sending member is composed of an axial-flow fan.

5. The development apparatus according to claim 1 , wherein the stir gear, the development gear, the stir rotation shaft and the development rotation shaft are composed of a heat conductive material.

6. The development apparatus according to claim 5 , wherein a heat sink is provided on at least one rotation shaft of the stir rotation shaft and the development rotation shaft.

7. The development apparatus according to claim 6 , wherein the heat sink is composed of a plurality of fans that extend radially from the rotation shaft.

8. The development apparatus according to claim 1 , wherein the wind sending member is disposed on at least one rotation shaft of the stir rotation shaft and the development rotation shaft in the housing box.

9. The development apparatus according to claim 8 , wherein the wind sending member is disposed on a rotation shaft disposed near the air take-in opening and is so disposed as to face the air take-in opening.

10. The development apparatus according to claim 9 , wherein the wind sending member flows the air in a circumferential direction of the rotation shaft.

11. The development apparatus according to claim 9 , wherein the wind sending member is composed of a sirocco fan.

12. An image forming apparatus comprising the development apparatus according to claim 1 .