Ship propulsion device

Abstract

A ship propulsion device includes three or more propulsion units, a malfunction detection unit, and a control unit. The control unit is configured to control the three or more propulsion units. The three or more propulsion units are disposed with left-right symmetry. Based on a malfunction detected in any one of the three or more propulsion units by the malfunction detection unit while the three or more propulsion units are operating, the control unit is configured to stop the propulsion unit in which the malfunction is detected, and, on a left side and a right side of a hull, stop at least one propulsion unit of the three or more propulsion units disposed on the side opposite from the side on which the propulsion unit in which the malfunction is detected is disposed.

1 . A marine vessel propulsion device comprising:
 three or more propulsion units mounted to a hull of a marine vessel, the three or more propulsion units arranged left-right symmetrically;   a fault detection unit configured to detect, for each propulsion unit of the three or more propulsion units, whether a fault occurred at the propulsion unit; and   a control unit configured to:
 control the three or more propulsion units, and 
 based on detection by the fault detection unit of a first fault associated with a first propulsion unit of the three or more propulsion units while the three or more propulsion units are in operation, stop:
 the first propulsion unit of the three or more propulsions units for which the first fault is detected, and 
 a second propulsion unit of the three or more propulsion units on either a left side or a right side of the hull, the a second propulsion unit arranged on a side opposite the first propulsion unit. 
 
   
     
     
         2 . The marine vessel propulsion device according to  claim 1 , wherein the second propulsion unit includes a propulsion unit that is in a left-right symmetrical relationship with the first propulsion unit. 
     
     
         3 . The marine vessel propulsion device according to  claim 1 , wherein the control unit is further configured to:
 based on detection of a second fault associated with a third propulsion unit of the three or more propulsion units by the fault detection unit, stop the third propulsion unit,   based on a determination that the three or more propulsion units will include a single propulsion unit in operation as a result of the third propulsion unit being stopped, maintain operation of the single propulsion unit or resume operation of the second propulsion unit, and   based on a determination that zero propulsion units of the three or more propulsion units will be in operation as a result of the third propulsion unit being stopped, resume operation of the second propulsion unit.   
     
     
         4 . The marine vessel propulsion device according to  claim 3 , wherein the control unit is configured to:
 based the determination that the three or more propulsion units will include the single propulsion unit in operation as a result the third propulsion unit being stopped, maintain operation of the single propulsion unit and resume operation of the second propulsion unit.   
     
     
         5 . The marine vessel propulsion device according to  claim 3 , wherein the control unit is further configured to, based on a determination that the three or more propulsion units will include the single propulsion unit in operation as a result of the third propulsion unit being stopped, stop operation of the single propulsion unit and resume operation of the second propulsion unit. 
     
     
         6 . The marine vessel propulsion device according  claim 1 , wherein:
 the three or more propulsion units is an odd number of propulsion units,   one propulsion unit of the three or more propulsion units is arranged at a lateral center of the hull, and   the control unit is configured to control the one propulsion unit that is arranged at the lateral center of the hull independent of other two propulsion units of the three or more propulsion units.   
     
     
         7 . The marine vessel propulsion device according to  claim 6 , wherein the control unit is further configured to:
 based on detection of a third fault associated with the one propulsion unit that is arranged at the lateral center of the hull by the fault detection unit, stop the one propulsion unit, and   based on a determination that zero propulsion units of the three or more propulsion units will be in operation as a result of the one propulsion unit being stopped, resume operation of the second propulsion unit.   
     
     
         8 . The marine vessel propulsion device according to  claim 1 , wherein the three or more propulsion units are arranged left-right symmetrically with respect to a lateral center of the hull. 
     
     
         9 . The marine vessel propulsion device according to  claim 1 , wherein the control unit is further configured to, based on detection of a second fault associated with a third propulsion unit of the three or more propulsion units by the fault detection unit, stop the third propulsion unit. 
     
     
         10 . The marine vessel propulsion device according to  claim 9 , wherein the control unit is further configured to, based on a determination that the three or more propulsion units will include a single propulsion unit in operation as a result of the third propulsion unit being stopped, maintain operation of the single propulsion unit in operation or resume operation of the second propulsion unit. 
     
     
         11 . The marine vessel propulsion device according to  claim 9 , wherein the control unit is further configured to, based on a determination that zero propulsion units of the three or more propulsion units will be in operation as a result of the third propulsion unit being stopped, resume operation of the second propulsion unit. 
     
     
         12 . The marine vessel propulsion device according to  claim 9 , wherein the control unit is configured to, based on a determination that the three or more propulsion units will include a single propulsion unit in operation as a result of the third propulsion unit being stopped, maintain operation of the single propulsion unit and resume operation of the second propulsion unit. 
     
     
         13 . The marine vessel propulsion device according to  claim 9 , wherein the control unit is further configured to, based on a determination that the three or more propulsion units will include a single propulsion unit in operation as a result of the third propulsion unit being stopped, stop operation of the single propulsion unit and resume operation of the second propulsion unit. 
     
     
         14 . The marine vessel propulsion device according  claim 1 , wherein the three or more propulsion units is an odd number of propulsion units. 
     
     
         15 . The marine vessel propulsion device according  claim 1 , wherein one propulsion unit of the three or more propulsion units is arranged at a lateral center of the hull. 
     
     
         16 . The marine vessel propulsion device according  claim 15 , wherein the control unit is configured to control the one propulsion unit independent of the other propulsion units of the three or more propulsion units. 
     
     
         17 . The marine vessel propulsion device according to  claim 15 , wherein the control unit is further configured to, based on detection by the fault detection unit of a third fault associated with the one propulsion unit the one propulsion unit, stop the one propulsion unit. 
     
     
         18 . The marine vessel propulsion device according to  claim 17 , wherein the control unit is further configured to, based on a determination that zero propulsion units of the three or more propulsion units will be in operation as a result of the one propulsion unit being stopped, resume operation of the second propulsion unit.