Propeller for outboard motor

Abstract

An outboard motor is generally mounted to a hull of a boat, for example, and includes a propeller fixed to a rear portion of a propeller shaft pivotally supported in an anteroposterior direction of the hull on a lower portion of the outboard motor. The propeller includes a cylindrically formed propeller hub, and blades provided radially on an outer side of the propeller hub, and having surfaces of the blades, including blade body and root portion, to which a shot-peening treatment is applied. The propeller may be formed of a metal material having a surface on which an oxide coating is formed by heating the metal material.

1 . A propeller for an outboard motor fixed to a rear portion of a propeller shaft pivotally supported in an anteroposterior direction of a hull to which the outboard motor is mounted on a lower portion of the outboard motor, comprising:
 a cylindrically formed propeller hub; and   a plurality of blades provided radially on an outer side of the propeller hub, and having surfaces of the blades to which a shot-peening treatment is applied.   
     
     
         2 . The propeller for an outboard motor according to  claim 1 , wherein the each of blades has a blade body having a surface of which the shot-peening treatment is applied. 
     
     
         3 . The propeller for an outboard motor according to  claim 1 , wherein the each of blades has a blade root portion having a surface of which the shot-peening treatment is applied. 
     
     
         4 . The propeller for an outboard motor according to  claim 1 , wherein the shot-peening treatment for mirror finishing is applied. 
     
     
         5 . The propeller for an outboard motor according to  claim 1 , wherein the propeller is formed of a metal material having a surface on which an oxide coating is formed by heating the metal material forming the propeller. 
     
     
         6 . The propeller for an outboard motor according to  claim 5 , wherein the metal member forming the propeller contains at least one material of titanium, stainless steel and copper. 
     
     
         7 . The propeller for an outboard motor according to  claim 5 , wherein the metal member forming the propeller is subjected to mirror finishing by a shot-peening treatment before the oxide coating is formed.