Propeller with an elastic sleeve

• US 5,176,501 A
• Filed: 12/17/1990
• Issued: 01/05/1993
• Est. Priority Date: 12/17/1990
• Status: Expired due to Fees

• Current Assignee: University of British Columbia
• Original Assignee: University of British Columbia
• Inventors: Yellowley, Ian
• Primary Examiner(s): Denion, Thomas E.
• Application Number:
  US07/628,353
• Time in Patent Office: 750 Days
• Field of Search: 416/224, 416/227 R, 416/227 A, 416/237, 416/223, 416/240 A
• US Class Current: 416/224
• CPC Class Codes: B63H 1/26 Blades
• CPC Class Codes: F03B 17/06 using liquid flow with predominantly kinetic energy conversion, e.g. of swinging-flap type , "run-of-river", "ultra-low head" F03B13/264 takes precedence
• CPC Class Codes: F03D 1/0608 characterised by their aerodynamic shape
• CPC Class Codes: F03D 3/061 characterised by their aerodynamic shape, e.g. aerofoil profiles
• CPC Class Codes: F05B 2250/314 the axes being inclined in relation to each other
• CPC Class Codes: Y02E 10/20 Hydro energy
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 10/74 Wind turbines with rotation axis perpendicular to the wind direction

Abstract

A propeller system is formed on a shaft by at least one pair of axially spaced propeller blades each having a first and a second blade section extending at a selected acute (or obtuse) angle to the axis of the shaft, the first sections and second sections respectively of the pair of propeller blades are substantially parallel to each other and the tips of the first sections of each of the blades are connected to the tips of the second section of each of the blades respectively to form a box shape. The shaft is connected to the propeller system in a manner so that the axis of the shaft extends substantially diagonally of the box shape whereby the parallel sections of the blades move in opposite directions relative to the fluid in which they are contained when the shaft is rotated to facilitate improvement of the efficiency of the propeller system. The shaft preferably is mounted oriented to the direction of relative fluid flow between the propeller blades and the fluid so that each blade section extends substantially perpendicular to the direction of relative flow over a significant portion of its rotation and each blade section will be substantially parallel to the direction of fluid flow relative to the propeller blade during a further portion of the rotation of the propeller blades.

Claims

1. A propeller system comprising at least one pair of axially spaced propeller blades mounted on a shaft, each of said propeller blades having a first blade section and a second blade section, each of said propeller blades having each of its blade sections extending at an angle to the axis of said shaft and circumferentially spaced relative to each other around said axis, said first blade section of one of said pair of blades being substantially parallel to said first section of the other of said pair of blades and said second blade section of said one of said pair of blades being substantially parallel to said second blade section of said other of said pair of blades, a tip of said first section and of said second section of said one of said blades remote from said axis being connected respectively to an adjacent tip of said second blade section and said first blade section of said other of said pair of blades to form a box shape, said axis of said axle extending substantially diagonally of said box shape whereby rotation of said axis causes movement of said parallel blade sections of said one and said other of said pair of blades to move in opposite directions through a fluid, elastic sleeve means formable by fluid pressure to substantially foil shape, said elastic sleeve means containing each of said blade sections, said elastic sleeve means being supported by its respective said blade section adjacent the edges of said blade section with an intermediate portion of said sleeve at least on one side of said blade being unsupported between its points of support at said edges of said blade sections.

2. A propeller system as defined in claim 1 wherein said angle is 45 degrees.

3. A propeller system as defined in claim 1 wherein said propeller system is formed from a single flat strip of material by bending to provide a first connecting means connecting said first and second blade sections of said one of said blade to each other and to said shaft and a second connecting means connecting said first and second blade sections of the other of said propeller blades together and to said shaft.

4. A propeller system as defined in claim 1 further comprising a plurality of said pairs propeller blades are uniformly circumferentially spaced about said shaft.