Propeller assembly

1 . A propeller assembly comprising:

a shaft configured to be connected to a drive shaft of a motor;

a thrust washer disposed on an outer surface of the shaft;

a hub disposed on the outer surface of the shaft adjacent to the thrust washer, the hub including multiple ribs protruding from an outer surface of the hub, wherein each rib has a bottom portion connected to the hub, the bottom portion having a thickness less than or equal to a thickness of opposite portion of corresponding rib such that the multiple ribs are configured to fracture upon external impact so as to minimize transmission of shock to the motor;

a bushing disposed on the outer surface of the hub, the bushing having a polygonal column shape;

a propeller provided on an outer surface of the bushing, with multiple blades arranged to generate thrust; and

an after spacer provided on the outer surface of the shaft, positioned on one side to secure the propeller,

wherein the thrust washer has a cylindrical shape and includes a first side facing the hub, a second side opposite to the first side, and a recessed portion formed concavely on the second side, wherein a thickness of the thrust washer is reduced at the recessed portion and increases again toward an outer end of the second side such that the recessed portion is configured to prevent fishing lines or nets from entangling between the shaft and the thrust washer.

2 . The propeller assembly according to claim 1 , wherein the hub has an outer surface formed in a polygonal column shape, and the multiple ribs include a pair of ribs arranged along each edge of the hub.

3 . The propeller assembly according to claim 1 , wherein the multiple ribs are arranged in a longitudinal direction of the hub.

4 . The propeller assembly according to claim 1 , wherein the bushing is made of a rubber material being configured to transmit torque to the propeller even when the multiple ribs are fractured so as to allow limited operation.