PURPOSE: To eliminate the necessity of fastening and loosening work of packing of a stuffing box when a ship is sailed and when it is anchored.

CONSTITUTION: In a stuffing box 3, an outer bearing 30, an inner bearing 6 and an oil seal 5 are provided, and a propeller shaft 12 passes penetratingly through the inside of the inner bearing 6 so as to be rotatable, and a cylindrical shaft collar 7 having a smooth outside surface is fitted around the outer periphery of the propeller shaft 12. The oil seal 5 is arranged on an inside surface of the outer bearing 30 so as to seal a part between the outer bearing and the propeller shaft by moving slidingly on an outer peripheral surface of the shaft collar 7, and packing 40 protrusible from the inside surface of the outer bearing is arranged in an outer peripheral part of the shaft collar 7, and a grease cup 4 is installed to perform sealing by press-fitting this packing to the shaft collar 7 by protruding it to the inside surface side.