| 摘要 |
PROBLEM TO BE SOLVED: To provide a propeller including a propeller blade having such a pitch angle not at its root portion but at its blade end edge portion with respect to a relative flow in the rotational direction, as to raise the internal pressure of a fluid to thereby prevent generation of a cavity, a water bubble or cavitation at the blade root portion at the time of high-speed rotation so that the propeller can be rotated at a high speed by a small mover and can move a large amount of fluid backward. SOLUTION: In the propeller 1 rotated by the prime mover, a bending base point line 2a having an equal radius of gyration is formed by connecting leading ends of a rotational front side end 2c and a rotational rear side end 2d on both sides of a back face of the propeller blade 2. A top end of the propeller blade 2 is tapered so as to be formed into a blade end slope portion 2b. An inclination boundary line 2e is formed to extend from the leading end of the rotational front side end 2c toward the blade root portion of the rotational rear side end 2d. An inclination back face 2f arranged on a rotational rear side with respect to the inclination boundary line 2e is inclined backward with the inclination boundary line 2e as the border so as to form the pitch angle with respect to the relative flow in the rotational forward direction. A rotational front side edge portion of the blade end slope portion 2b is curved and inclined backward from the bending base point line 2a. COPYRIGHT: (C)2008,JPO&INPIT |
