PROBLEM TO BE SOLVED: To solve such a problem that a gap which foreign substances enter exists in the part where a rotating pivot protrudes from a transmission case, and thereby a sealing material of the transmission case may be damaged due to the foreign substances wound around a rotating pivot.SOLUTION: A leveling device includes: a transmission case to which power from an engine is transmitted a drive shaft protrudingly provided from a boss section projected from both side surfaces of the transmission case toward the side through an oil seal to the side and a plurality of leveling rotors fixed to the drive shaft. The drive shaft comprises: a rotor input shaft laterally protruding from the boss section of the transmission case and a rotor drive shaft connected through the rotor input shaft and a joint. The end part on the transmission case side of the joint is increased in diameter to provide an enlarged diameter part for covering the outside end part of the boss section of the transmission case.
