Ship propulsion machine

Abstract

A ship propulsion machine for propelling a ship, the ship propulsion machine includes a propeller, an engine configured to rotate the propeller, the engine serving as a first power source, a motor configured to rotate the propeller, the motor serving as a second power source, an inverter configured to control driving of the motor, an engine drive shaft connected to a crank shaft of the engine, a motor drive shaft connected to an output shaft of the motor, a transmission shaft connected to a propeller shaft provided with the propeller, and a power switching mechanism configured to switch a connection mode of the engine drive shaft, the motor drive shaft, and the transmission shaft to switch a power source for rotating the propeller between the engine and the motor.

What is claimed is: 
     
         1 . A ship propulsion machine for propelling a ship, the ship propulsion machine comprising:
 a propeller;   an engine configured to rotate the propeller, the engine serving as a first power source;   a motor configured to rotate the propeller, the motor serving as a second power source;   an inverter configured to control driving of the motor;   an engine drive shaft connected to a crank shaft of the engine;   a motor drive shaft connected to an output shaft of the motor;   a transmission shaft connected to a propeller shaft provided with the propeller; and   a power switching mechanism configured to switch a connection mode of the engine drive shaft, the motor drive shaft, and the transmission shaft to switch a power source for rotating the propeller between the engine and the motor,   wherein the engine is arranged vertically such that an extension direction of a rotation axis of the crank shaft is in an upper-lower direction,   in a state where the engine disposed vertically, the engine includes a lower extension portion extending downward from a front portion of an engine body of the engine or a middle portion of an engine body of the engine in a front-rear direction,   the engine drive shaft is arranged so as to extend in the upper-lower direction in front of the lower extension portion,   the motor is arranged below a rear portion of the engine body such that an extension direction of the output shaft is in the front-rear direction and a position of the output shaft is further downward than the lower extension portion,   the motor drive shaft is arranged so as to extend in the front-rear direction below the lower extension portion,   the power switching mechanism is arranged below a lower end of the engine drive shaft and in front of a front end of the motor drive shaft, and   the inverter is arranged behind the lower extension portion and between the rear portion of the engine body and the motor.   
     
     
         2 . The ship propulsion machine according to  claim 1 ,
 wherein the lower extension portion is an oil pan.   
     
     
         3 . The ship propulsion machine according to  claim 1 , further comprising:
 a heat exchanger configured to cool a cooling medium and supply the cooled cooling medium to the motor and the inverter,   wherein the heat exchanger is arranged behind the lower extension portion and between the rear portion of the engine body and the inverter.   
     
     
         4 . The ship propulsion machine according to  claim 1 ,
 wherein a recessed portion recessed upward is provided in a rear portion of a lower surface of the lower extension portion, and   at least a part of the motor is arranged in the recessed portion.   
     
     
         5 . The ship propulsion machine according to  claim 1 , further comprising:
 an inverter bracket configured to attach the inverter to the engine and the motor,   wherein the inverter bracket includes:
 an inverter fixing portion configured to fix the inverter to the inverter bracket; 
 a leg portion extending downward from the inverter fixing portion; and 
 an arm portion extending forward from the inverter fixing portion or the leg portion, and 
   the leg portion of the inverter bracket is connected to the motor, the arm portion of the inverter bracket is connected to the engine such that the inverter bracket is supported on each of the motor and the engine.   
     
     
         6 . The ship propulsion machine according to  claim 5 ,
 wherein the inverter fixing portion includes:
 a left support portion configured to support a left portion of the inverter from a left side of the inverter; 
 a right support portion configured to support a right portion of the inverter from a right side of the inverter; and 
 a rear support portion configured to support a rear portion of the inverter from a rear side of the inverter. 
   
     
     
         7 . The ship propulsion machine according to  claim 5 ,
 wherein a boss protruding upward is provided on the inverter fixing portion, and   a heat exchanger is fixed to the boss.