DEVELOPER STORAGE DEVICE AND IMAGE FORMATION DEVICE

PROBLEM TO BE SOLVED: To provide a developer storage device and an image formation device that have a structure capable of effectively restraining a heat generation at a bearing part without increasing the sizes of the devices.SOLUTION: When a conveyance screw shaft 14 rotates, air in an outer space 13B is flowed into a closed space 20 through communicating grooves 21. The air pressurized in the closed space 20 is then flowed out to the outer space 13B through communicating paths 23. The structure therefore allows heat generated between the conveyance screw shaft 14 and a shaft bearing 19 to be directly released to outside by circulating the air from the outer space 13B.