ALL-SPEED-RANGE PROPELLER HAVING STERN FINS
An all-speed-range propeller having stern fins comprises an all-speed-range propeller installed on a propelling shaft of a boat, and a plurality of stern fins installed between the all-speed-range propeller and a hull of the boat. When the all-speed-range propeller having stern fins is applied to the oblique boat on which the propelling shaft is disposed obliquely, the stern fins directly guide the water flow toward the all-speed-range propeller, so that the uneven inflow caused by the obliquely-designed propelling shaft can be conquered to promote the operating efficiency of the all-speed-range propeller.
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The present invention relates to an all-speed-range propeller having stern fins.
2. DESCRIPTION OF THE RELATED ARTCurrently, the propellers of NACA series or KCA series are only suited to the speed of the boat under 30 knots, and the propellers of supercaviating series are only suited to the speed of the boat above 30 knots. In order to conquer afore restrictions, the inventor of the present invention disclosed “ADVANCED FOIL DESIGN METHOD AND STRUCTURE FOR MULTI SPEEDS” of the Patent Publication No. US 2011/0059663 A1, “METHOD OF AN ALL-SPEED PROPELLER” of the Patent Publication NO. US 2012/0065942 A1, and “MARINE PROPELLER APPLICABLE TO ALL SPEED RANGES” of a U.S. patent application Ser. No. 13/324,589. These publications and application discloses an all-speed-range propeller that contains the advantages of the propeller of the supercaviating series when it is driven by a high speed, and the performance of the propeller will not be influenced when it is driven by a low speed. Thus, these propellers are suited to all speed ranges.
However, although such all-speed-range propellers are practical and popular in the market, the inventor finds out that the propelling shaft of the all-speed-range propeller is an oblique design. Herein, when the inflow angle of the all-speed-range propeller is over 5 degrees, the operating efficiency of the all-speed-range propeller is largely reduced. Accordingly, the inventor of the present invention endeavors to improve the all-speed-range propeller and bring out the present invention.
SUMMARY OF THE INVENTIONThe object of the present invention is to provide an all-speed-range propeller that is suited to an oblique propelling shaft of an oblique boat, and concurrently keeping the efficiency of the all-speed-range propeller.
The all-speed-range propeller having stern fins of the present invention is able to be installed on an oblique boat. Wherein, the oblique boat has a hull established along a horizontal line. At least one propelling shaft is disposed on the hull, and the propelling shaft is set with respect to the horizontal line by an included angle. The all-speed-range propeller having stern fins further comprises: an all-speed-range propeller is disposed on the propelling shaft, and a plurality of stern fins are installed surroundingly on the propelling shaft at intervals, between the hull and the all-speed-range propeller.
Accordingly, the all-speed-range propeller of the present invention is utilized on the oblique propelling shaft of the oblique boat. The stern fins guide the water flow to the all-speed-range propeller so as to conquer the uneven inflow caused by the oblique propelling shaft. Thereby, the operating efficiency of the all-speed-range propeller can be promoted, which preferably amends the problems existing in the current all-speed-range propeller.
Referring to
an all-speed-range propeller 10 disposed on the propelling shaft 202 has a plurality of blades 11; the detailed structure of the all-speed-range propeller 10 has been disclosed before, thus hereby being omitted; and
a plurality of stern fins 20 installed surroundingly on the propelling shaft 202 at intervals, between the hull 201 and the all-speed-range propeller 10. Wherein, there are 3 to 7 stern fins 20 surroundingly established on the propelling shaft 202. The fin type of the stern fins 20 adopts a NACA 66 type. A height of the stern fins 20 is 0.5 to 1.5 times of a height of the blades 11 of the all-speed-range propeller 10. A distance between the stern fins 20 and the all-speed-range propeller 10 is 0.5 to 1.5 times of a radius of the blades 11 of the all-speed-range propeller 10. A camber direction of the stern fins 20 is the same as a rotating direction of the propelling shaft 202.
Referring to
Further, referring to
Claims
1. An all-speed-range propeller having stern fins being able to be installed on an oblique boat; wherein, said oblique boat having a hull established along a horizontal line; at least one propelling shaft being disposed on said hull, and said propelling shaft being set with respect to said horizontal line by an included angle; said all-speed-range propeller having stern fins further comprising:
- an all-speed-range propeller disposed on said propelling shaft having a plurality of blades; and
- a plurality of stern fins installed surroundingly on said propelling shaft at intervals, between said hull and said all-speed-range propeller.
2. The propeller as claimed in claim 1, wherein, said included angle formed by said propelling shaft and said horizontal line is between 6 degrees and 14 degrees.
3. The propeller as claimed in claim 1, wherein, a fin type of said stern fins adopts a NACA 66 type.
4. The propeller device as claimed in claim 1, wherein, a height of said stern fins is 0.5 to 1.5 times of a height of said blades of said all-speed-range propeller.
5. The propeller as claimed in claim 1, wherein, a distance between said stern fins and said all-speed-range propeller is 0.5 to 1.5 times of a radius of said blades of said all-speed-range propeller.
6. The propeller as claimed in claim 1, wherein, 3 to 7 stern fins are adopted.
7. The propeller as claimed in claim 1, wherein, a camber direction of said stern fins is the same as a rotating direction of said propelling shaft.
Type: Application
Filed: Mar 18, 2013
Publication Date: Sep 18, 2014
Applicant: Ship and Ocean Industries R&D Center (New Taipei)
Inventors: Ya-Lin TSAI (New Taipei), Ching-Yeh Hsing (New Taipei), Shang-Sheng Chin (New Taipei), Kuan-Kai Chang (New Taipei)
Application Number: 13/845,803
International Classification: B63H 5/07 (20060101);