Ship propulsion machine

A ship propulsion machine comprising:

• a power unit configured to generate power;
• a propeller;
• and
• a drive shaft configured to transmit the power generated by the power unit to the propeller,
• wherein the power unit comprises:
• a first motor comprising a first motor shaft;
• a second motor comprising a second motor shaft;
• and
• a power transmission device configured to transmit at least one of a first power output from the first motor shaft and a second power output from the second motor shaft to the drive shaft, and switch power to be transmitted to the drive shaft such that at least one of the first power and the second power is selected,
• wherein the first motor and the second motor are arranged in an upper part of the ship propulsion machine,
• wherein each of the first motor shaft, the second motor shaft, and the drive shaft extends vertically,
• wherein the second motor is arranged above the first motor,
• wherein an upper portion of the drive shaft passes through the first motor shaft so as to be rotatable independently of the first motor shaft and reaches a region between the first motor and the second motor, and
• wherein the power transmission device is arranged between the first motor and the second motor.