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US 10,294,956 B2Granted
Propeller blade
AssigneeSP Tech
InventorsStephen R. Topaz, Peter A. Topaz, Warren L. Powers
Life of this patent
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Abstract
A propeller blade includes a body configured to extend radially from the hub of a propeller. The body can include a front surface, a back surface, a leading edge, and a trailing edge. The top of the body can form a tippet that generally transitions the front and back surfaces from extending in a generally radial direction to a generally axial direction. The tippet can reduce radial flow and force losses, redirect the radial flow in an axial direction, reduce the exit flow area of the propeller, and increase the inlet flow area of the propeller. The front surface of the blade can have a planar configuration that prevents or reduces the creation of low or negative pressure across the front surface of the blade and associated cavitation.
Claims20
A propeller blade configured to be attached to a hub of a propeller, the propeller blade comprising:
- a body having a base and an upper end, the body comprising a front surface and an opposing back surface each extending laterally between a leading end of the body and a trailing end of the body and longitudinally between the base and the upper end, the back surface of the body being the high positive pressure surface of the body;
- and
- a tippet extending longitudinally from the upper end of the body to a top end, the tippet extending laterally between a leading end and a trailing end, the tippet curving from the body in a direction generally away from the front surface and toward the back surface so that the top end between the leading and trailing ends of the tippet overhangs the back surface of the body so as to form a channel extending between the leading and trailing ends of the tippet, the channel having a curve extending between the top end of the tippet and the upper end of the body along a lateral length of the tippet, a radius of curvature of the curve varying along the lateral length of the tippet, the tippet being shaped such that when the propeller blade is radially attached to a hub of a propeller and the propeller is rotated in a fluid about a rotational axis, the tippet:
- draws fluid radially inward toward the hub from a radial inlet flow that enters the channel along the lateral length of the tippet as well as along the leading end of the tippet, and
- redirects the fluid from the radially inward direction to an axial direction that is generally parallel to the rotational axis so as to expel the fluid as an outlet flow that adds to a force moving the propeller forward, such that the leading end of the body and the top end of the tippet respectively form first and second leading edges of the propeller blade along which fluid is concurrently drawn into the propeller,
- wherein the front surface of the body is planar, the front surface extending between the leading end and the trailing end of the body in a single plane, and
- wherein the back surface of the body is curved and does not extend in a single plane between the leading end and the trailing end of the body.
4 more elements
A propeller, comprising:
- a hub having a rotational axis;
- and
- a plurality of blades extending radially outward from the hub, each blade of the plurality of blades comprising:
- a body having a base and an upper end, the body comprising a front surface and an opposing back surface each extending laterally between a leading end of the body and a trailing end of the body and longitudinally between the base and the upper end, the back surface of the body being the high positive pressure surface of the body, the leading end forming a first leading edge of the propeller blade along which fluid is drawn into the propeller;
- and
- a tippet extending longitudinally from the upper end of the body to a top end, the tippet extending laterally between a leading end and a trailing end, the tippet curving in a direction generally away from the front surface and toward the back surface so that the top end between the leading and trailing ends of the tippet overhangs the back surface of the body so as to form a channel extending between the leading and trailing ends of the tippet, the channel having a curve extending between the top end of the tippet and the upper end of the body along a lateral length of the tippet, a radius of curvature of the curve varying along the lateral length of the tippet, the top end of the tippet between the leading and trailing ends of the tippet forming a second leading edge of the propeller blade along which fluid is drawn into the propeller, the tippet being shaped such that upon rotation of the propeller in a fluid, the tippet:
- draws fluid radially inward toward the hub from a radial inlet flow that enters the channel along the top end of the tippet as well as along the leading end of the tippet, and
- redirects the fluid from the radially inward direction to an axial direction that is generally parallel to the rotational axis so as to expel the fluid as an outlet flow that adds to a force moving the propeller forward, such that fluid is concurrently drawn into the propeller along the leading end of the body and the top end of the tippet respectively acting as the first and second leading edges of the propeller blade,
- wherein the front surface of the body is planar, the front surface extending between the leading end and the trailing end of the body in a single plane, and
- wherein the back surface of the body is curved and does not extend in a single plane between the leading end and the trailing end of the body.
7 more elements
A propeller, comprising:
- a hub having a rotational axis;
- and
- a plurality of blades extending radially outward from the hub, each blade of the plurality of blades comprising:
- a body having a base coupled to the hub and extending radially outward from the hub to an upper end, the body comprising:
- a first leading edge and a trailing edge each extending from the base to the upper end;
- and
- a front surface and an opposing back surface each extending between the first leading edge and the trailing edge, and between the base and the upper end, the back surface of the body being the high positive pressure surface of the body;
- and
- a tippet comprising a front surface and an opposing back surface respectively extending radially outward from the front and back surfaces of the body at the upper end of the body to a top end and laterally between a leading end and a trailing end, the tippet curving generally away from the front surface of the body and toward the back surface of the body as the tippet extends radially outward, so that the back surface of the tippet overhangs the back surface of the body so as to form a channel extending between the leading and trailing end of the tippet, the channel having a curve extending between the top end of the tippet and the upper end of the body along a lateral length of the tippet, the radius of curvature of the curve being varied along the lateral length of the tippet, the top end of the tippet forming a second leading edge between the leading and trailing end of the tippet the back surface of the tippet being shaped such that upon rotation of the propeller in a fluid, the tippet:
- draws fluid radially inward toward the hub from a radial inlet flow that enters the channel along the top end of the tippet as well as along the leading end of the tippet, and
- redirects the fluid in an axial direction so as to expel the fluid as an outlet flow that is parallel to the rotational axis, such that fluid is concurrently drawn into the propeller along the first leading edge of the body and the top end of the tippet acting as the second leading edge
- wherein the front surface of the body is planar, the front surface extending between the leading end and the trailing end of the body in a single plane, and
- wherein the back surface of the body is curved and does not extend in a single plane between the leading end and the trailing end of the body.
10 more elements
Dependencies are inferred from the claim text.