Fig. (1) Spherical mechanical structure drawing 1-rotary ring seat; 2- rotary ring; 3-stator ring; 4- stator ring seat; 5- spring; 6- spring seat; 7- stern tube; 8- engine room 25°C; 9- stern shaft; 10- O-seal ring; 11- fix ring; 12- seawater 25°C.