PROBLEM TO BE SOLVED: To provide the support structure of tilling shaft, having a simple structure, which effectively prevents invasion of dust such as soil, etc., on the installation space of a bearing member and an oil seal member for supporting a tilling shaft in fluid-tight.SOLUTION: The support structure 100 of the tilling shaft 110 equipped with a tilling final shaft 111 having a shaft main body 111a and a connection flange 111b and a tilling tine shaft 112 is equipped with a first dust cover 130 for screening the installation space P of the bearing member 410 and the oil seal member 420 from outside and a second dust cover 140 for screening the first dust cover 130 from the outside.COPYRIGHT: (C)2008,JPO&INPIT【課題】耕耘軸を液密に支持する為のベアリング部材及びオイルシール部材の設置空間内に土等のダストが侵入することを有効に防止し得る構造簡単な耕耘軸の支持構造を提供する。【解決手段】軸本体111a及び連結フランジ111bを有する耕耘ファイナル軸111と、耕耘爪軸112とを備えた耕耘軸110の支持構造100は、ベアリング部材410及びオイルシール部材420の設置空間Pを外部から遮閉する第1ダストカバー130と、第1ダストカバー130を外部から遮閉する第2ダストカバー140とを備えている。【選択図】図3