Patent ID: 8517783

Claim:
A propeller mechanism comprising: a propeller ( 1 ) having a hub ( 2 ) with a shaft hole at the center thereof, and a number of blades ( 3 ) provided radially around the hub ( 2 ); a shaft ( 4 ) connected at one end to a motor driving the marine vehicle, the shaft ( 4 ) being adapted to the shaft hole, and having a threaded portion ( 10 ) arranged at least partially in the longitudinal direction thereof; at least one bearing ( 5 ) provided on the shaft ( 4 ) for bearing the propeller ( 1 ) to the shaft ( 4 ), the at least one bearing ( 5 ) being rotatable in a single direction; a connection hub ( 6 ) associated with the hub ( 2 ) of the propeller ( 2 ), the connection hub ( 6 ) comprising a threaded portion ( 9 ) being screwable to the threaded portion ( 10 ) of the shaft ( 4 ) in the direction opposite to the rotatable direction of the at least one bearing ( 5 ), and being non-screwable to the threaded portion ( 10 ) of the shaft ( 4 ) in the rotatable direction of the at least one bearing ( 5 ).