Fan propeller, in particular for a motor vehicle

Patent metadata

Field	Value
Publication number	US-9353764-B2
Application number	US-201013514153-A
Country	US
Kind code	B2
Filing date	Nov 8, 2010
Priority date	Dec 7, 2009
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A fan propeller comprises blades ( 14 ), each of which has a general profile of the aircraft wing type, with a leading edge ( 28 ) and a trailing edge ( 30 ), a neutral axis ( 32 ) and a span ( 36 ) between the leading edge ( 28 ) and the trailing edge ( 30 ). According to one embodiment, the blade ( 14 ) has, on at least part of its length, a profile shaped such that the neutral axis ( 32 ) makes possible a point of contraflexure ( 34 ), and has two opposite concavities, i.e. a positive concavity (C 1 ) between the leading edge ( 28 ) and the point of contraflexure ( 34 ), and a negative concavity (C 2 ) between the point of contraflexure ( 34 ) and the trailing edge ( 30 ). Application to motor vehicles.

First claim

The invention claimed is:

1. A fan propeller comprising:
a hub and blades which extend radially towards the exterior from the hub wherein each blade has a developing profile with a neutral axis and a span which extends between a leading edge and a trailing edge of said blade,
wherein each blade has, on at least part of a length of each blade, a first profile formed in the shape of a flattened S, such that the neutral axis makes possible a point of contraflexure, and has two opposite concavities comprising a positive concavity between the leading edge and the point of contraflexure, and a negative concavity between the point of contraflexure and the trailing edge,
wherein each blade has a second profile which starts from the second profile in a region at the level of the hub, and ends in a profile of an aircraft wing type, without a point of contraflexure of the neutral axis in an end re ion of the blade.

2. The fan propeller as claimed in claim 1 , wherein the point of contraflexure is situated at between 20% and 80% of the length of the span, starting from the leading edge.

3. The fan propeller as claimed in claim 1 , wherein the point of contraflexure is situated closer to the trailing edge than to the leading edge.

4. The fan propeller as claimed in claim 1 , wherein a tangent to the neutral axis at a level of the point of contraflexure intersects the span and forms an angle of at least 4°.

5. The fan propeller as claimed in claim 1 , wherein the positive concavity of the first profile has a camber of at least 2%, the camber being defined as the ratio between a height of the neutral axis relative to the span and a length of the span.

6. The fan propeller as claimed in claim 5 , wherein the negative concavity of the first profile has a camber of at least 2%, the camber being defined as the ratio between the height of the neutral axis relative to the span and the length of the span.

7. The fan propeller as claimed in claim 1 , wherein the fan propeller comprises solidity which is at least 0.5, the solidity being defined as a length of span of the blade, multiplied by a number of blades, and divided by a perimeter in a given radius.

8. The fan propeller as claimed in claim 7 , wherein the solidity decreases from a root of the blades at a level of the hub, going towards an end of the blades.

9. The fan propeller as claimed in claim 8 , wherein the solidity varies from approximately 0.9 to approximately 0.5 from the root of the blades to the end of the blades.

10. A fan propeller comprising:
a hub and blades which extend radially towards the exterior from the hub, wherein each blade has a developing profile with a neutral axis and a span which extends between a leading edge and a trailing edge of each blade,
wherein each blade has, on at least part of a length of each blade, a first profile shaped such that the neutral axis has positive concavity between the leading edge and an intermediate point, and a flat part between the intermediate point and the trailing edge,
wherein each blade has a second profile which starts from the second profile in a region at the level of the hub, and ends in a profile of an aircraft wing type, without a point of contraflexure of the neutral axis, in an end region of the blade.

11. The fan propeller as claimed in claim 10 , wherein a tangent to the neutral axis intersects the span and forms an angle of at least 4°, said angle being in a location where the angle between the tangent to the neutral axis and the span is maximal.

12. The fan propeller as claimed in claim 11 , wherein the angle is between 8° and 12°.

13. The fan propeller as claimed in claim 10 , wherein the intermediate point corresponds substantially to a point of contraflexure of the neutral axis.

14. The fan propeller as claimed in claim 10 , wherein the flat part has a length of between 20% and 60% of a length of the span.

15. The fan propeller as claimed in claim 10 , wherein the fan propeller comprises solidity which is at least 0.5, the solidity being defined as a length of span of the blade, multiplied by a number of blades, and divided by a perimeter in a given radius.

16. The fan propeller as claimed in claim 15 , wherein the solidity decreases from a root of the blades at a level of the hub, going towards an end of the blades.

17. The fan propeller as claimed in claim 16 , wherein the solidity varies from approximately 0.9 to approximately 0.5 from the root of the blades to the end of the blades.

Assignees

• Henner Manuel
• Demory Bruno
• Valeo Systemes Thermiques

Inventors

• Henner Manuel
• Demory Bruno

Classifications

• F04D29/384

  characterised by form · CPC title

• F04D29/386 Primary

  Skewed blades · CPC title

• F05D2240/304

  related to the trailing edge of a rotor blade · CPC title

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• F05D2240/301

  Cross-sectional characteristics · CPC title