Propeller unit for marine vessel propulsion device and marine vessel propulsion device including the same

A marine vessel propulsion device comprising:

• an engine;
• a driveshaft arranged to be rotated by the engine;
• a drive gear fixed to the driveshaft;
• a forward drive gear arranged to engage with the drive gear;
• a reverse drive gear arranged to engage with the drive gear and to rotate in an opposite direction of the forward drive gear;
• a dog clutch arranged to selectively engage with the forward drive gear and the reverse drive gear;
• a propeller shaft arranged to rotate together with the dog clutch;
• and
• a propeller unit coupled to the propeller shaft, the propeller unit including:
• an inner cylinder fixed to the propeller shaft;
• an outer cylinder having a cylindrical shape coaxial with the inner cylinder and including blades fixed on an outer circumferential surface of the outer cylinder;
• a first driving force transmitting member including a cylindrical elastic member arranged between the inner cylinder and the outer cylinder;
• a second driving force transmitting member arranged between the inner cylinder or the propeller shaft and the outer cylinder and aligned with the first driving force transmitting member in an axial direction of the outer cylinder;
• a pair of first engaging portions arranged on the outer cylinder and the first driving force transmitting member and arranged to mutually engage such that a driving force is transmittable to each other;
• and
• a pair of second engaging portions arranged on the outer cylinder and the second driving force transmitting member arranged such that a mutual engaging of the respective second engaging portions is disengaged when a driving force is not transmitted to the propeller shaft, and arranged such that the respective second engaging portions become mutually engaged in a driving force transmittable manner by elastic deformation of the first driving force transmitting member when a driving force that is not less than a reference driving force not exceeding a critical load of the first driving force transmitting member is transmitted to the propeller shaft.