Boat propulsion device and boat

A boat propulsion device comprising:

• an engine;
• a propeller shaft;
• a transmission to transmit a propulsion force of the engine to the propeller shaft, and including:
• a drive gear rotatable by the propulsion force of the engine;
• and
• a driven gear to mesh with the drive gear;
• a rotating member arranged around the propeller shaft and movable in an axial direction of the propeller shaft, the rotating member being rotatable around the propeller shaft along with a rotation of the propeller shaft;
• a non-rotating member arranged around the propeller shaft, adjacent to the rotating member in the axial direction, and movable in the axial direction, the non-rotating member being non-rotatable around the propeller shaft;
• an elastic member to push at least one of the rotating member and the non-rotating member to a first side of the propeller shaft in the axial direction and exert a force to cause the rotating member and the non-rotating member to come into contact with each other;
• a housing to surround an outer circumference of the propeller shaft and including:
• a first surface that faces a second side of the propeller shaft in the axial direction and is inclined so that it extends toward the second side of the propeller shaft in the axial direction from a center outward in the radial direction of the propeller shaft;
• wherein
• the housing is rotatable around the propeller shaft along with the rotation of the propeller shaft;
• a contact member to contact the first surface and movable in the radial direction;
• and
• a pusher movable in the axial direction and including:
• a first portion to contact an end of the contact member on the second side in the axial direction;
• and
• a second portion to contact an end on the first side in the axial direction of one of the rotating member and the non-rotating member located on the second side in the axial direction.