Electric propulsion machine

Abstract

An electric propulsion device includes a motor for rotating a propeller and a cooling device for cooling the motor. The cooling device includes a first cooling system and a second cooling system. The first cooling system includes a heat exchanger that uses water from outside the electric propulsion device as cooling water and cools refrigerant, and a supply passage that supplies the water from outside the electric propulsion device as the cooling water to the heat exchanger. The second cooling system includes a motor cooling jacket that is provided in the motor and cools the motor with the refrigerant, and a circulation passage that circulates the refrigerant between the heat exchanger and the motor cooling jacket.

1 . An electric propulsion device comprising:
 a motor configured to rotate a propeller; and   a cooling device configured to cool the motor, wherein   the cooling device includes a first cooling system and a second cooling system,   the first cooling system includes:   a heat exchanger that uses water from outside the electric propulsion device as cooling water and configured to cool refrigerant; and   a supply passage that supplies the water from outside the electric propulsion device to the heat exchanger as the cooling water, and   the second cooling system includes:   a motor cooling jacket that is provided in the motor and configured to cool the motor with the refrigerant; and   a circulation passage that circulates the refrigerant between the heat exchanger and the motor cooling jacket.   
     
     
         2 . The electric propulsion device according to  claim 1 , further comprising:
 an electric propulsion device body including: the motor; a propeller shaft disposed below the motor and provided with the propeller; and a drive shaft extending in a vertical direction between the motor and the propeller shaft; and   a mounting mechanism configured to mount the electric propulsion device on a boat, wherein   the mounting mechanism includes a swivel bracket configured to support the electric propulsion device body to be pivotable in a left-right direction relative to the boat, and   the motor and the heat exchanger are disposed below an upper end of the swivel bracket.   
     
     
         3 . The electric propulsion device according to  claim 2 , wherein
 the mounting mechanism includes two mounts that connect each of two portions spaced from each other in the vertical direction at an upper part of the electric propulsion device body to the swivel bracket, and   the heat exchanger is positioned between the two mounts in the vertical direction.   
     
     
         4 . The electric propulsion device according to  claim 1 , wherein
 an outer shape of the heat exchanger is a cylinder or a polygonal prism with an axial dimension greater than a radial dimension, and   the heat exchanger is disposed behind the motor so that the axial direction of the heat exchanger is the vertical direction of the electric propulsion device.   
     
     
         5 . The electric propulsion device according to  claim 1 , further comprising:
 an inverter configured to control driving of the motor, wherein   the second cooling system includes an inverter cooling jacket that is provided in the inverter and configured to cool the inverter using the refrigerant, and   the circulation passage is a passage that circulates the refrigerant between the heat exchanger and the motor cooling jacket and the inverter cooling jacket.   
     
     
         6 . The electric propulsion device according to  claim 5 , wherein the circulation passage includes: a first refrigerant passage connecting the heat exchanger to the motor cooling jacket; a second refrigerant passage connecting the motor cooling jacket to the inverter cooling jacket; and a third refrigerant passage connecting the inverter cooling jacket to the heat exchanger. 
     
     
         7 . The electric propulsion device according to  claim 5 , wherein the heat exchanger is disposed behind the motor, the inverter is disposed above the motor, and the inverter cooling jacket is disposed in the rear part of the inverter. 
     
     
         8 . The electric propulsion device according to  claim 5 , wherein
 the second cooling system includes a degassing tank that is connected to the circulation passage and configured to separates gas from the refrigerant, and   the inverter is disposed above the motor and the degassing tank is disposed above the inverter.   
     
     
         9 . The electric propulsion device according to  claim 1 , wherein
 the second cooling system includes a refrigerant pump configured to circulate the refrigerant in the circulation passage, and   the refrigerant pump is disposed above the heat exchanger.   
     
     
         10 . The electric propulsion device according to  claim 1 , further comprising:
 a propeller shaft disposed below the motor and provided with the propeller;   a drive shaft extending in a vertical direction between the motor and the propeller shaft; and   a case configured to accommodate an upper part or a lower part of the drive shaft, wherein   the second cooling system includes:   a refrigerant pump configured to circulate the refrigerant in the circulation passage; and   a refrigerant reservoir provided in the case and configured to store the refrigerant circulating in the circulation passage,   the circulation passage includes: a first refrigerant passage connecting the heat exchanger to the refrigerant reservoir; a second refrigerant passage connecting the refrigerant reservoir to the motor cooling jacket; and a third refrigerant passage connecting the motor cooling jacket to the heat exchanger, and   the refrigerant pump circulates the refrigerant so that the refrigerant flows from the heat exchanger to the refrigerant reservoir, then from the refrigerant reservoir to the motor cooling jacket, and then from the motor cooling jacket back to the heat exchanger.   
     
     
         11 . The electric propulsion device according to  claim 1 , further comprising:
 a drive shaft;   a first transmission mechanism configured to transmit rotation of the motor to the drive shaft;   a propeller shaft provided with the propeller; and   a second transmission mechanism configured to transmit rotation of the drive shaft to the propeller shaft, wherein   the first cooling system includes a transmission mechanism cooling jacket that uses the water from outside the electric propulsion device as the cooling water and cools the first transmission mechanism, and   the supply passage is a passage that supplies the water from outside the electric propulsion device to the heat exchanger and the transmission mechanism cooling jacket as the cooling water.   
     
     
         12 . The electric propulsion device according to  claim 11 , wherein the supply passage includes: a first cooling water passage connecting a water intake port that takes in the water from outside the electric propulsion device as the cooling water into the electric propulsion device to the transmission mechanism cooling jacket; and a second cooling water passage connecting the transmission mechanism cooling jacket to the heat exchanger. 
     
     
         13 . The electric propulsion device according to  claim 12 , wherein the heat exchanger is disposed behind the motor, the transmission mechanism cooling jacket is disposed below the motor, one end portion of the second cooling water passage is connected to a rear part of the transmission mechanism cooling jacket, and the other end portion of the second cooling water passage is connected to a lower part of the heat exchanger. 
     
     
         14 . The electric propulsion device according to  claim 5 , wherein
 the inverter is disposed above the motor,   first ports that connect inside of the motor cooling jacket to outside of the motor cooling jacket are provided at each of both ends of the motor cooling jacket, and one of the first ports provided at the motor cooling jacket is disposed on an upper surface of the motor, and   second ports that connect inside of the inverter cooling jacket to outside of the inverter cooling jacket are provided at each of both ends of the inverter cooling jacket, and one of the second ports provided at the inverter cooling jacket is disposed on a lower surface of the inverter.   
     
     
         15 . The electric propulsion device according to  claim 14 , wherein, when the electric propulsion device is viewed from above, at least a portion of the one port of the inverter cooling jacket overlaps with the one port of the motor cooling jacket.