Propeller
A propeller. The blade thrust surfaces of the propeller correspond to the surface of a cone, and the hub axis is set at an angle relative to a first generator line of the cone which passes through the hub axis and a second generator line of the cone which passes through the blade thrust surface to achieve desired gamma angles over the blade thrust surface. A propeller whose blade center axis does not conform to a generator line of a cone also is disclosed.
1 . A propeller comprising:
a hub characterized by a hub axis and an axis of rotation; and
one or more blades characterized by a root, a tip, a leading edge and a corresponding trailing edge, and a thrust surface; wherein, for each of the one or more blades:
the blade thrust surface conforms to a surface of a reference cone characterized by a vertex, a base, a vertical axis, and a plurality of generator lines; wherein
in reference to the reference cone, the hub axis intersects a first generator line of the reference cone, and the blade thrust surface contains a straight path over the thrust surface corresponding to a second generator line; and
the hub axis intersects the surface of the reference cone but is not tangent to the surface of the reference cone and does not intersect the vertical axis; wherein
the hub axis is perpendicular to the first generator line.
2 . A propeller comprising:
a hub characterized by a hub axis and an axis of rotation; and
one or more blades characterized by a root, a tip, a leading edge and a corresponding trailing edge, and a thrust surface; wherein, for each of the one or more blades:
the blade thrust surface conforms to a surface of a reference cone characterized by a vertex, a base, a vertical axis, and a plurality of generator lines; wherein
in reference to the reference cone, the hub axis intersects a first generator line of the reference cone, and the blade thrust surface contains a straight path over the thrust surface corresponding to a second generator line; and
the hub axis intersects the surface of the reference cone but is not tangent to the surface of the reference cone and does not intersect the vertical axis; wherein
the hub axis is perpendicular to the straight path on the blade surface which corresponds to the second generator line.
3 . A propeller comprising:
a hub characterized by a hub axis and an axis of rotation; and
one or more blades characterized by a root, a tip, a leading edge and a corresponding trailing edge, and a thrust surface; wherein, for each of the one or more blades:
the blade thrust surface conforms to a surface of a reference cone characterized by a vertex, a base, a vertical axis, and a plurality of generator lines; wherein
in reference to the reference cone, the hub axis intersects a first generator line of the reference cone, and the blade thrust surface contains a straight path over the thrust surface corresponding to a second generator line; and
the hub axis intersects the surface of the reference cone but is not tangent to the surface of the reference cone and does not intersect the vertical axis; wherein
the hub axis is perpendicular to the first generator line; and
the hub axis is perpendicular to the straight path on the blade surface which corresponds to the second generator line.
4 . A propeller comprising:
a hub characterized by a hub axis and an axis of rotation; and
one or more blades characterized by a root, a tip, a leading edge and a corresponding trailing edge, and a thrust surface; wherein, for each of the one or more blades,
the blade thrust surface conforms to a surface of a reference cone, said blade thrust surface characterized by an arc spanning the blade from the leading edge to the trailing edge along which the gamma angle is 90 degrees, excepting an area of the thrust surface proximate the hub and proximate the trailing edge in which all gamma angles are acute.
5 . A propeller comprising:
a hub characterized by a hub axis and an axis of rotation; and
one or more blades characterized by a root, a tip, a leading edge and a corresponding trailing edge, and a thrust surface; wherein, for each of the one or more blades:
the blade thrust surface conforms to a surface of a reference cone, said blade thrust surface characterized by an arc spanning the blade from the leading edge to the trailing edge along which the gamma angle is 90 degrees; wherein
the blade thrust surface is characterized by an arc spanning the blade from the leading edge to the trailing edge along which the gamma angle is 90 degrees, excepting an area of the thrust surface proximate the hub and proximate the leading edge in which all gamma angles are obtuse.
6 . A propeller of claim 5 , wherein:
in areas of the blade between the arc and the tip of the blade, gamma angles are acute, and in areas of the blade between the arc and the hub, gamma angles are obtuse.
7 . A propeller comprising:
a hub characterized by a hub axis and an axis of rotation; and
one or more blades characterized by a root, a tip, a leading edge and a corresponding trailing edge, and a thrust surface; wherein, for each of the one or more blades;
the blade thrust surface conforms to a surface of a reference cone, said blade thrust surface characterized by an arc spanning the blade from the leading edge to the trailing edge along which the gamma angle is 90 degrees; wherein
in areas of the blade between the arc and the tip of the blade, gamma angles are acute, and in areas of the blade between the arc and the hub, gamma angles are obtuse.