GB2352701A - A ducted marine propeller - Google Patents

A ducted marine propeller Download PDF

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Publication number
GB2352701A
GB2352701A GB9917911A GB9917911A GB2352701A GB 2352701 A GB2352701 A GB 2352701A GB 9917911 A GB9917911 A GB 9917911A GB 9917911 A GB9917911 A GB 9917911A GB 2352701 A GB2352701 A GB 2352701A
Authority
GB
United Kingdom
Prior art keywords
propeller
duct
blades
reduced
exit
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.)
Withdrawn
Application number
GB9917911A
Other versions
GB9917911D0 (en
Inventor
Michael Bill Douglas Purt
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to GB9917911A priority Critical patent/GB2352701A/en
Publication of GB9917911D0 publication Critical patent/GB9917911D0/en
Publication of GB2352701A publication Critical patent/GB2352701A/en
Withdrawn legal-status Critical Current

Links

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
    • B63H1/16—Propellers having a shrouding ring attached to blades

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)

Abstract

A bladed marine propeller comprises a duct 1 attached to the outer edges of the blades 2 whereby the duct 1 rotates with the blades 2, thereby providing for much safer operation with enhanced strength, less susceptibility to damage and greater efficiency. The diameter of the duct exit 7 is slightly less than that of the entry 8.

Description

2352701
DESCRIPTION
THE DUCTED SAFETY PROPELLER (DUCSPROP) This invention relates to marine propellers.
The marine propeller when in motion is extremely dangerous to forms of life and structures which are in close proximity to it and is itself vulnerable to damage, if accidental contact is made.
This invention is extremely simple in concept and involves attaching a duct (1) to the outer edges of the blades (2), the duct rotates with the propeller.
The drawings illustrate a conventional propeller (3) & (4) and a front and side view of the ducted propeller (5) & (6).
Also to be noted on the ducted propeller, is the slight reduction in diameter of the duct exit (7) to the entry (8).
a

Claims (5)

1. SAFETY: Inadvertent contact with the ducted propeller will expose life and structures to much less chance of injury. In the case of divers or sea mammals, it is likely they would only suffer mild abrasions or friction bums as opposed to the chopping injuries of an exposed conventional propeller.
2. REDUCED SUSCEPTIBILITY TO FOULING: Ducted propellers are less likely to pick up ropes or fishing nets and become fouled.
3. REDUCED SUSCEPTABILITY TO DAMAGE: The duct on the propeller will also protect it from damage in shallow waters. Accidental contact with the bottom is far less likely to result in severe damage to the blades. As the blades are now supported at both the inboard and outboard ends, the strength is greatly enhanced and propeller mass may be reduced.
4. REDUCED PROPELLER EROSION: Having the duct fitted will also reduce the cavitation associated with high speed propellers and subsequent erosion of blades.
5. IMPROVED EFFICIENCY: Efficiency can be enhanced not only by the reduction of cavitation and spanwise flow along the blades which is associated with the conventional propeller but also by a small reduction in area of the duct exit.The reason for this is as follows.If the volume of water driven by one rotation of the propeller is the area of the duct inlet x the pitch of the blade,then if the area of the exit is reduced by a small amount,say 5 %,the only way the same volume of water can exit the duct is by an increased acceleration. This equals increased thrust. Optional exit reductions would have to be done by experiment with the individual propeller with regard to pitch,size and power available.
GB9917911A 1999-07-31 1999-07-31 A ducted marine propeller Withdrawn GB2352701A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9917911A GB2352701A (en) 1999-07-31 1999-07-31 A ducted marine propeller

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9917911A GB2352701A (en) 1999-07-31 1999-07-31 A ducted marine propeller

Publications (2)

Publication Number Publication Date
GB9917911D0 GB9917911D0 (en) 1999-09-29
GB2352701A true GB2352701A (en) 2001-02-07

Family

ID=10858226

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9917911A Withdrawn GB2352701A (en) 1999-07-31 1999-07-31 A ducted marine propeller

Country Status (1)

Country Link
GB (1) GB2352701A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004002817A1 (en) * 2002-06-29 2004-01-08 Triton Developments (Uk) Limited Rotor assembly
WO2004067377A1 (en) * 2003-01-24 2004-08-12 Lothar Bieschewski Boat drive and method for producing the same

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1325395A (en) * 1971-11-16 1973-08-01 Townshend R C Marine ring propellers
US3826591A (en) * 1971-06-02 1974-07-30 E Wilson Centrifugal marine propeller
US4370096A (en) * 1978-08-30 1983-01-25 Propeller Design Limited Marine propeller
US4836748A (en) * 1983-12-09 1989-06-06 Church Holdings Ring propeller
US5044884A (en) * 1989-09-05 1991-09-03 Trustees Of The University Of Pennsylvania Safety propeller
US5096382A (en) * 1989-05-17 1992-03-17 Gratzer Louis B Ring-shrouded propeller
US5213525A (en) * 1991-06-06 1993-05-25 Sanford Michael P Jacketed marine propeller
US5415524A (en) * 1993-06-01 1995-05-16 Gamble; Christopher L. Fluid propulsion device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3826591A (en) * 1971-06-02 1974-07-30 E Wilson Centrifugal marine propeller
GB1325395A (en) * 1971-11-16 1973-08-01 Townshend R C Marine ring propellers
US4370096A (en) * 1978-08-30 1983-01-25 Propeller Design Limited Marine propeller
US4836748A (en) * 1983-12-09 1989-06-06 Church Holdings Ring propeller
US5096382A (en) * 1989-05-17 1992-03-17 Gratzer Louis B Ring-shrouded propeller
US5044884A (en) * 1989-09-05 1991-09-03 Trustees Of The University Of Pennsylvania Safety propeller
US5213525A (en) * 1991-06-06 1993-05-25 Sanford Michael P Jacketed marine propeller
US5415524A (en) * 1993-06-01 1995-05-16 Gamble; Christopher L. Fluid propulsion device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004002817A1 (en) * 2002-06-29 2004-01-08 Triton Developments (Uk) Limited Rotor assembly
WO2004067377A1 (en) * 2003-01-24 2004-08-12 Lothar Bieschewski Boat drive and method for producing the same

Also Published As

Publication number Publication date
GB9917911D0 (en) 1999-09-29

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)