CN114476000A - Blade structure based on improved usability, application method of blade structure and propeller - Google Patents

Blade structure based on improved usability, application method of blade structure and propeller Download PDF

Info

Publication number
CN114476000A
CN114476000A CN202210167100.8A CN202210167100A CN114476000A CN 114476000 A CN114476000 A CN 114476000A CN 202210167100 A CN202210167100 A CN 202210167100A CN 114476000 A CN114476000 A CN 114476000A
Authority
CN
China
Prior art keywords
blade
propeller
paddle
airfoil
angle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202210167100.8A
Other languages
Chinese (zh)
Other versions
CN114476000B (en
Inventor
朱秋阳
段旭鹏
赵涛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen Weidu Intelligent Technology Co ltd
Original Assignee
Shenzhen Weidu Intelligent Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenzhen Weidu Intelligent Technology Co ltd filed Critical Shenzhen Weidu Intelligent Technology Co ltd
Priority to CN202210167100.8A priority Critical patent/CN114476000B/en
Publication of CN114476000A publication Critical patent/CN114476000A/en
Application granted granted Critical
Publication of CN114476000B publication Critical patent/CN114476000B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H1/00—Propulsive elements directly acting on water
    • B63H1/02—Propulsive elements directly acting on water of rotary type
    • B63H1/12—Propulsive elements directly acting on water of rotary type with rotation axis substantially in propulsive direction
    • B63H1/14—Propellers
    • B63H1/26—Blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H1/00—Propulsive elements directly acting on water
    • B63H1/02—Propulsive elements directly acting on water of rotary type
    • B63H1/12—Propulsive elements directly acting on water of rotary type with rotation axis substantially in propulsive direction
    • B63H1/14—Propellers
    • B63H1/20—Hubs; Blade connections
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H1/00—Propulsive elements directly acting on water
    • B63H1/02—Propulsive elements directly acting on water of rotary type
    • B63H1/12—Propulsive elements directly acting on water of rotary type with rotation axis substantially in propulsive direction
    • B63H1/14—Propellers
    • B63H1/28—Other means for improving propeller efficiency
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/72—Wind turbines with rotation axis in wind direction

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)

Abstract

The invention discloses a blade structure based on improved service performance, an application method thereof and a propeller, and belongs to the technical field of hydrodynamic fluid mechanics design. The blade comprises a blade, wherein the airfoil family to which the blade belongs is a laminar flow airfoil, and the blade is respectively provided with a blade tip end and a blade root end; the cross-sectional shape of the blade gradually changes in a direction from the tip end of the blade to the root end of the blade. The propeller solves the technical problems that the existing streamline design blades have limited help for improving the power efficiency, the whole size design and the weight of the propeller structure are large, the carrying and the transportation are inconvenient, the motor power is limited to be converted into the propulsion power to a greater extent, the energy consumption is improved, and the propeller structure is difficult to exert the optimal performance.

Description

Blade structure based on improved usability, application method of blade structure and propeller
Technical Field
The invention relates to the technical field of hydrodynamic fluid mechanics design, in particular to a paddle structure for a water surface and underwater vehicle based on improving service performance, an application method of the paddle structure and a propeller.
Background
At present, the propeller structure of the water wing plate is formed by combining a columnar propeller rod and a shovel-shaped propeller blade. The blade is generally in a special streamline shape, namely, the section shape of the blade can be synchronously changed along with the continuous change of the distance between the blade and a blade rod, so that the power efficiency is increased on the basis of the conventional blade.
However, when a requirement of a certain power efficiency needs to be met, because the existing streamline design has limited help for improving the power efficiency, the size of the blade has to be increased to improve the efficiency, so that the blade with the existing streamline design still has the problems of large size design and large overall weight of the propeller structure in practical application, further causing inconvenience in carrying and transportation, and limiting the motor power to be converted into propulsion power to a greater extent, improving the energy consumption, and the propeller structure is difficult to exert the optimal performance.
Disclosure of Invention
Therefore, the invention provides a blade structure based on performance improvement, an application method thereof and a propeller, and aims to solve the technical problems that the propeller structure is large in overall size design and weight and inconvenient to carry and transport, the motor power is limited to be converted into propulsion power to a greater extent, and the propeller structure is difficult to exert optimal performance due to the fact that the streamlined blades in the prior art are limited in assistance in improving power efficiency.
In order to achieve the above purpose, the invention provides the following technical scheme:
a paddle structure based on improving service performance comprises paddles, wherein the airfoil family to which the paddles belong is a laminar flow airfoil, and the paddles are respectively provided with a paddle tip end and a paddle root end;
the cross-sectional shape of the blade gradually changes in a direction from the tip end of the blade to the root end of the blade.
On the basis of the above technical solution, the present invention is further explained as follows:
as a further scheme of the invention, the shape of the paddle is a Kaplan series shape, and the tip of the paddle is a flat head.
As a further aspect of the invention, the blades form an outer duct, and the blade tips correspond to the outer duct in parallel.
As a further aspect of the present invention, two surfaces of the blade respectively have a pressure surface and a suction surface in a one-to-one correspondence, the pressure surface and the suction surface are disposed away from each other, and the suction surface is a smooth convex outer surface.
As a further aspect of the present invention, the blades respectively have a section airfoil maximum thickness and a section airfoil chord length, the section airfoil maximum thickness is an airfoil maximum thickness of the section airfoil chord length in a normal direction thereof, and a ratio between the section airfoil maximum thickness and the section airfoil chord length forms a relative thickness value of the airfoil.
Along the direction of oar tip to oar root end, the section airfoil chord length progressively reduces, the relative thickness numerical value's of airfoil progressively changes order for increasing earlier afterwards reduces.
As a further scheme of the invention, the propeller outer diameter formed by the blades is 0.12m, the propeller radius formed by the blades is half of the propeller outer diameter, and the propeller radius is 0.06 m.
As a further aspect of the invention, the blades have a pitch, the pitch being the distance over which the plane in which the blades lie makes one revolution in the non-flowing medium, the ratio between the pitch and the outer diameter of the propeller forming a speed factor.
Along the direction from the propeller tip end to the propeller root end, the cross section shape of the blade at the real-time position between the propeller tip end and the propeller root end is gradually changed, the ratio of the section airfoil chord length to the outer diameter of the propeller is gradually reduced, and the progressive speed coefficient is gradually changed in a sequence of firstly reducing, then increasing and then reducing.
As a further aspect of the invention, the blade also has a blade angle, a side cant angle and a pitch angle.
The blade angle is the twist angle of the blade, the twist angle of the blade is the included angle between the straight line where the chord length of the section airfoil is located and the rotating plane where the blade is located, the included angle is changed synchronously along with the change of the radius of the propeller, the cross section shape of the blade at the real-time position between the blade tip end and the blade root end is gradually changed along the direction from the blade tip end to the blade root end, and the blade angle is gradually reduced.
The blade is provided with an orthographic projection, the outline of the orthographic projection is a projection outline, the projection outline is a symmetrical blade shape based on a central reference line, and the lateral oblique angle and the pitch angle are unchanged.
The application method of the blade structure based on the service performance improvement is characterized in that the blade structure based on the service performance improvement is applied to the service working condition that the revolution is 3000rpm, the tensile force is 13kg, and the navigational speed is 25 km/h.
The propeller comprises a columnar propeller rod and the blade structure based on the improved service performance. The paddle is provided with three blades, and the three blades are uniformly and fixedly connected to the outer side of the paddle rod.
The paddle tip end is located at one side end of the paddle, which is far away from the paddle rod, and the paddle root end is located at one side end of the paddle, which is close to the paddle rod.
The invention has the following beneficial effects:
this structural shape can effectively promote the power efficiency of screw in practical application under specific operating mode, can accomplish the minimum with the screw size simultaneously under the prerequisite of guaranteeing efficiency, and the aspect is carried, lightens weight.
Drawings
In order to clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly introduced, and the structures, the proportions, the sizes, and the like shown in the specification are only used for matching with the contents disclosed in the specification, so that those skilled in the art can understand and read the modifications of any structures, the changes of the proportion relationships, or the adjustments of the sizes, without affecting the functions and the achievable purposes of the present invention, and still fall within the scope of the technical contents disclosed in the present invention.
Fig. 1 is a schematic view of an overall structure of a propeller and a blade structure based on improved performance in use according to an embodiment of the present invention.
Fig. 2 is a schematic view of a blade structure based on performance improvement and a projection structure of a propeller in the axial direction of a blade shaft according to an embodiment of the present invention.
Fig. 3 is a schematic view of a blade structure based on performance improvement and a projection structure of a propeller on a radial direction of a blade rod according to an embodiment of the present invention.
Fig. 4 is a schematic distribution diagram of a blade structure based on performance improvement in a cross-sectional shape from a blade tip to a blade root according to an embodiment of the present invention.
Fig. 5 is a schematic diagram of a performance curve of a propeller provided in an embodiment of the present invention.
Fig. 6 is a schematic diagram of a performance curve of a propeller provided in an embodiment of the present invention.
In the drawings, the components represented by the respective reference numerals are listed below:
a paddle lever 1; the paddle 2: tip 21, root 22, pressure surface 23, suction surface 24.
The outer diameter D of the propeller, the radius R of the propeller, the chord length c of the section airfoil and the maximum thickness t of the section airfoil0The pitch P.
Detailed Description
The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the present specification, the terms "upper", "lower", "left", "right", "middle", and the like are used for clarity of description, and are not intended to limit the scope of the present invention, and changes or modifications in the relative relationship thereof may be made without substantial technical changes.
As shown in fig. 1 to 4, the embodiment of the present invention provides a blade structure based on performance improvement, an application method thereof, and a propeller, including a columnar blade shaft 1 and three blades 2 uniformly fixed on the outer side of the blade shaft 1, so as to overcome medium resistance through the rotation of the blades 2 to achieve a predetermined propulsion function.
Specifically, with continued reference to fig. 1 and 2, the blade 2 is in the shape of a kaplan series of shapes, and the blades 2 respectively have a tip 21 end far away from the shaft 1 and a root 22 end near the shaft 1, wherein the tip 21 end is a flat end, and the tip 21 end and the outer duct of the propeller (the air flow channel of the blade 2) are in parallel correspondence.
Referring to fig. 3 and 4, the blade 2 formed from the root 22 to the tip 21 is an airfoil of NACA65A0xx series (where xx is a percentage of a cross-sectional airfoil thickness to a cross-sectional airfoil chord length c), the airfoil family to which the blade 2 belongs is a laminar airfoil, two surfaces of the blade 2 respectively correspond to a pressure surface 23 and a suction surface 24 one by one, the pressure surface 23 and the suction surface 24 are disposed away from each other, and the suction surface 24 is a smooth outer convex surface, so that a surface pressure distribution generated by the suction surface 24 when the medium with a predetermined flow velocity passes through the suction surface 24 is relatively flat, on one hand, a laminar area is enlarged, and a resistance is relatively low; on the other hand, a higher pressure peak value is avoided, cavitation is not easy to occur, and the propelling efficiency is improved.
On any of the blades 2, the cross-sectional shape of the blade 2 gradually changes along the direction from the tip 21 end to the root 22 end, and the specific geometrical information of the cross-section at a typical position is shown in the following table.
Figure BDA0003516751890000051
Figure BDA0003516751890000061
In the embodiment of the present invention, referring to fig. 2, the diameter of the blade shaft 1 is 0.04m, the outer diameter D of the propeller is 0.12m, and the radius R of the propeller is D/2 ═ 0.06 m.
Referring to FIG. 3, c is the chord length of the airfoil section, i.e., the maximum length of the connecting line between two end points of the airfoil section, and c/D is the ratio of the chord length to the maximum length; t is t0Is the maximum thickness of the sectional airfoil, i.e. the maximum thickness of the sectional airfoil in the direction of the normal of the chord length c thereof, t0The/c is the ratio of the two, and refers to the relative thickness value of the airfoil; p is the pitch, namely the distance covered by the plane where the propeller rotates for one circle in the non-flowing medium and the blade 2 is located, and P/D is the ratio of the two, and the P/D refers to the advancing speed coefficient. Pitch is a blade angle, that is, a twist angle of the blade 2, and refers to an included angle between a straight line where a section airfoil chord length c of the blade 2 is located and a rotation plane where the blade 2 is located, and the included angle changes with the change of the propeller radius R, and the change rule is the most important factor influencing the working performance of the blade 2.
The propeller needs to be specially designed according to common working conditions in order to achieve optimal efficiency, otherwise the propeller cannot achieve optimal performance, and cannot convert the motor power into propulsion power to the maximum extent.
The data design provided by the embodiment of the invention is specially designed near the use condition that the revolution is 3000rpm, the tension is 13kg and the speed is 25km/h, so that the propeller has the maximum propelling efficiency performance. The specific performance curve is shown in fig. 5, where KT is the coefficient of tension, KQ is the coefficient of torque, EFFY is the efficiency, and Js is the forward ratio.
As a preferred solution of the present embodiment, besides applying the above-identified geometrical shape to the thickness of the existing propeller blade, it is also within the scope of the present invention to increase the thickness of the blade 2 by a geometrical shape of 0.2mm to 0.4mm over its entire pressure surface 23 and/or suction surface 24.
The suction surface 24 of the blade 2 in the above embodiment adopts a smooth outer convex surface, so that a performance curve that the surface pressure distribution generated by the suction surface 24 when passing through a medium with a given flow velocity is relatively flat is shown in fig. 6, and a first line from top to bottom can be seen as relatively flat, which means that the pressure peak value is relatively low and cavitation is not easy to occur, and if the laminar flow airfoil and the suction surface 24 are not arranged, the line is greatly expanded, so that the laminar flow area is expanded on one hand, and the resistance is relatively low; on the other hand, a higher pressure peak value is avoided, cavitation is not easy to occur, and the propelling efficiency is improved.
Although the invention has been described in detail above with reference to a general description and specific examples, it will be apparent to one skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims (10)

1. A paddle structure based on improving service performance comprises a paddle and is characterized in that an airfoil family to which the paddle belongs is a laminar flow airfoil, and the paddle is provided with a paddle tip end and a paddle root end respectively;
the cross-sectional shape of the blade gradually changes in the direction from the tip end of the blade to the root end of the blade.
2. Blade construction based on increased performance in use according to claim 1,
the shape of the paddle is a Kaplan series shape, and the tip of the paddle is a flat head.
3. Blade construction based on increased performance in use according to claim 2,
the blades form an outer duct, and the tips of the blades correspond to the outer duct in parallel.
4. Blade construction based on increased performance in use according to claim 1,
the two sides of the paddle are respectively provided with a pressure surface and a suction surface in a one-to-one correspondence mode, the pressure surface and the suction surface are arranged in a back-to-back mode, and the suction surface is a smooth outer convex surface.
5. Blade construction based on increased performance in use according to claim 1,
the blade is respectively provided with a section airfoil maximum thickness and a section airfoil chord length, the section airfoil maximum thickness is the airfoil maximum thickness of the section airfoil chord length in the normal direction of the section airfoil chord length, and the ratio of the section airfoil maximum thickness to the section airfoil chord length forms the relative thickness value of the airfoil;
along the direction of oar tip to oar root end, the section airfoil chord length progressively reduces, the relative thickness numerical value's of airfoil progressively changes order for increasing earlier afterwards reduces.
6. Blade construction based on increased performance in use according to claim 5,
the propeller outer diameter that the paddle formed is 0.12m, the propeller radius that the paddle formed is half of the propeller outer diameter, the propeller radius is 0.06 m.
7. Blade construction based on increased performance in use according to claim 6,
the propeller is characterized in that the propeller blade has a pitch, the pitch is the distance which the plane of the propeller blade rotates for one circle in a non-flowing medium, and the ratio of the pitch to the outer diameter of the propeller forms a speed advancing coefficient;
along the direction from the propeller tip end to the propeller root end, the cross section shape of the blade at the real-time position between the propeller tip end and the propeller root end is gradually changed, the ratio of the section airfoil chord length to the outer diameter of the propeller is gradually reduced, and the progressive speed coefficient is gradually changed in a sequence of firstly reducing, then increasing and then reducing.
8. Blade construction based on increased performance in use according to claim 7,
the blade further has a blade angle, a side cant angle, and a pitch angle;
the blade angle is the twist angle of the blade, the twist angle of the blade is the included angle between the straight line where the chord length of the section airfoil is located and the rotating plane where the blade is located, the included angle is synchronously changed along with the change of the radius of the propeller, the cross section shape of the blade at the real-time position between the blade tip end and the blade root end is gradually changed along the direction from the blade tip end to the blade root end, and the blade angle is gradually reduced;
the blade is provided with an orthographic projection, the outline of the orthographic projection is a projection outline, the projection outline is a symmetrical blade shape based on a central reference line, and the lateral oblique angle and the pitch angle are unchanged.
9. Method for applying a blade structure according to any of claims 1-8, characterised in that the blade structure for improving the performance is applied in a service situation where the number of revolutions is 3000rpm, the pulling force is 13kg and the speed is 25 km/h.
10. A propeller comprising a cylindrical shaft, characterized in that it further comprises a blade structure based on enhanced performance as claimed in any one of claims 1 to 8;
the number of the blades is three, and the three blades are uniformly and fixedly connected to the outer side of the paddle rod;
the paddle tip end is located at one side end of the paddle, which is far away from the paddle rod, and the paddle root end is located at one side end of the paddle, which is close to the paddle rod.
CN202210167100.8A 2022-02-23 2022-02-23 Paddle structure based on service performance improvement, application method of blade structure and propeller Active CN114476000B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210167100.8A CN114476000B (en) 2022-02-23 2022-02-23 Paddle structure based on service performance improvement, application method of blade structure and propeller

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210167100.8A CN114476000B (en) 2022-02-23 2022-02-23 Paddle structure based on service performance improvement, application method of blade structure and propeller

Publications (2)

Publication Number Publication Date
CN114476000A true CN114476000A (en) 2022-05-13
CN114476000B CN114476000B (en) 2023-06-30

Family

ID=81482838

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210167100.8A Active CN114476000B (en) 2022-02-23 2022-02-23 Paddle structure based on service performance improvement, application method of blade structure and propeller

Country Status (1)

Country Link
CN (1) CN114476000B (en)

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1058355A (en) * 1990-07-26 1992-02-05 通用信号公司 The mixing of wide range of viscosities liquid and liquid suspension and mixing impeller and impeller system
JP2004161208A (en) * 2002-11-15 2004-06-10 National Maritime Research Institute Marine propeller
JP2006111046A (en) * 2004-10-12 2006-04-27 Ihi Marine United Inc Propeller for vessel
US20100329870A1 (en) * 2008-02-14 2010-12-30 Daniel Farb Shrouded turbine blade design
CN102530212A (en) * 2011-12-27 2012-07-04 中国船舶重工集团公司第七○二研究所 Self-adaptive biomimetic composite propeller blade
AU2014277656A1 (en) * 2013-12-17 2015-07-02 Ringprop Marine Ltd Marine propellers
US9745948B1 (en) * 2013-08-30 2017-08-29 Brunswick Corporation Marine propeller and method of design thereof
CN210284569U (en) * 2019-08-02 2020-04-10 中国船舶重工集团公司第七一一研究所 Blade of marine propeller and marine propeller structure thereof
CN111132899A (en) * 2017-07-21 2020-05-08 洛马林螺旋桨和海洋技术有限公司 Propeller for watercraft

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1058355A (en) * 1990-07-26 1992-02-05 通用信号公司 The mixing of wide range of viscosities liquid and liquid suspension and mixing impeller and impeller system
JP2004161208A (en) * 2002-11-15 2004-06-10 National Maritime Research Institute Marine propeller
JP2006111046A (en) * 2004-10-12 2006-04-27 Ihi Marine United Inc Propeller for vessel
US20100329870A1 (en) * 2008-02-14 2010-12-30 Daniel Farb Shrouded turbine blade design
CN102530212A (en) * 2011-12-27 2012-07-04 中国船舶重工集团公司第七○二研究所 Self-adaptive biomimetic composite propeller blade
US9745948B1 (en) * 2013-08-30 2017-08-29 Brunswick Corporation Marine propeller and method of design thereof
AU2014277656A1 (en) * 2013-12-17 2015-07-02 Ringprop Marine Ltd Marine propellers
CN111132899A (en) * 2017-07-21 2020-05-08 洛马林螺旋桨和海洋技术有限公司 Propeller for watercraft
CN210284569U (en) * 2019-08-02 2020-04-10 中国船舶重工集团公司第七一一研究所 Blade of marine propeller and marine propeller structure thereof

Also Published As

Publication number Publication date
CN114476000B (en) 2023-06-30

Similar Documents

Publication Publication Date Title
EP0236409B1 (en) Foil
WO2007052626A1 (en) Quiet propeller
US10040528B2 (en) Propulsion device for ship
CN216834228U (en) Paddle structure and propeller based on improvement of service performance
CN216834227U (en) Laminar flow wing blade structure and propeller
CN114476000A (en) Blade structure based on improved usability, application method of blade structure and propeller
CN114476001A (en) Laminar flow airfoil blade structure, application method thereof and propeller
CN211107957U (en) Blade deformation structure of cross-medium aircraft
WO1990008061A1 (en) Marine propulsion apparatus
US4653418A (en) Rudder with wings and method for manufacture thereof
CN218986924U (en) Web propeller structure
CN212921936U (en) Novel energy-saving device behind oar
CN219838689U (en) Propeller guide pipe with built-in fan blades
CN208085982U (en) Propeller for vessels steerage improves device
WO1993024360A1 (en) A propeller having optimum efficiency in forward and rearward navigation
CN212267811U (en) Underwater tandem type co-rotating propeller equipment
CN213566415U (en) Pod propeller fin structure for increasing hydrodynamic performance
CN114750913A (en) Propeller structure for reducing cavitation
CN220164150U (en) Ship propeller and ship
CN2421246Y (en) Bradawl type propeller
CN212290292U (en) Rotatable rudder with bulge front edge for ship
CN2081371U (en) Energy-saving contra-fin front paddle
CN219524214U (en) Energy-saving guide wheel and ship
JP3916404B2 (en) propeller
CN218641050U (en) Marine front warping propeller

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant