UNDERWATER MOTOR

PURPOSE:To improve the durability of an underwater motor under high temperature or high temperature and high pressure environment by providing a shaft sealing chamber in which a mechanical seal is mounted and a sealed liquid expansion absorbing chamber adjacent to the top of the sealing chamber to communicate between both chambers. CONSTITUTION:A shaft sealing chamber A in which a mechanical seal 47 is mounted is provided in a portion that a motor shaft 13 of a liquid-sealed motor of an entirely cylindrical underwater motor pump driven by upper and lower motors is externally projected. A sealed liquid expansion absorbing chamber B is provided adjacent to the top of the chamber A to communicate between both chambers, and a diaphragm 83 is provided. Thus, the durability can be obtained even under high temperature or high temperature and high pressure environment.