Variable-pitch fan with low pitch of a turbine engine

Patent metadata

Field	Value
Publication number	US-10316857-B2
Application number	US-201715398133-A
Country	US
Kind code	B2
Filing date	Jan 4, 2017
Priority date	Jan 5, 2016
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A fan of a turbine engine, the fan including a fan disk provided with blades on its periphery, the blades being pivotally mounted on the disk around a pivoting axis and having a center of gravity, and a pitch change mechanism for the blades, each blade being configured so that its center of gravity is positioned on or at a small distance from a fictitious plane which passes through the pivoting axis of the blade and which is perpendicular to the axis of revolution of the fan when the blade is in a minimum drag position.

First claim

The invention claimed is:

1. A fan of a turbine engine, said fan comprising: a disk of annular overall shape and defining an axis of revolution of the fan, said disk being provided with blades at a periphery thereof, each blade being pivotally mounted on the disk around a pivoting axis and having a center of gravity, and a pitch change mechanism of each blade, said pitch change mechanism being configured to adjust an angular position of each blade around the pivoting axis, wherein each blade has a first portion, which extends in an airstream of the fan, and a second portion, which extends outside said airstream, a center of gravity of the second portion of each blade extending substantially on the pivoting axis while a center of gravity of the first portion of each blade is offset with respect to said pivoting axis by being on a fictitious plane or at a small distance from a fictitious plane which passes through the pivoting axis of each blade and which is perpendicular to the axis of revolution of the fan when each blade is in a minimum drag position.

2. The fan according to claim 1 , wherein each blade is configured so that the center of gravity of each blade is located between two secant planes along a straight line corresponding to which is the same as the pivoting axis and each forming an angle of ten degrees with the fictitious plane.

3. The fan according to claim 1 , wherein each blade is configured so that the center of gravity of each blade is positioned in proximity to the pivoting axis.

4. The fan according to claim 1 , comprising a hub ratio less than or equal to 0.35.

5. The fan according to claim 1 , having an external diameter comprised between eighty inches (203.2 centimeters) and a hundred inches (254.0 centimeters).

6. The fan according to claim 1 , wherein the fan is free of a feathering system having an eccentric counterweight or a flyweight.

7. A turbine engine comprising a fan housed in a fan casing, said fan comprising: a disk of annular overall shape and defining an axis of revolution of the fan, said disk being provided with blades at a periphery thereof, each blade being pivotally mounted on the disk around a pivoting axis and having a center of gravity, and a pitch change mechanism of each blade, said pitch change mechanism being configured to adjust an angular position of each blade around the pivoting axis, wherein each blade has a first portion, which extends in an airstream of the fan and a second portion, which extends outside said airstream, a center of gravity of the second portion of each blade extending substantially on the pivoting axis while a center of gravity of the first portion of each blade is offset with respect to said pivoting axis by being on a fictitious plane or at a small distance from a fictitious plane which passes through the pivoting axis of each blade and which is perpendicular to the axis of revolution of the fan when each blade is in a minimum drag position.

8. The turbine engine according to claim 7 , further comprising a turbine in fluid communication with the fan and a reduction mechanism coupling the turbine and the fan, the reduction mechanism being of the star gear or planetary gear type and having a reduction ratio comprised between 2.5 and 5.

9. The turbine engine according to claim 7 , having a bypass ratio greater than or equal to 10.

10. The turbine engine according to claim 9 , wherein the bypass ratio is between 12 and 18.

11. The turbine engine according to claim 7 , wherein the fan is free of a feathering system having an eccentric counterweight or a flyweight.

Assignees

• Safran Aircraft Engines

Inventors

• Bordoni Nils Edouard Romain
• Brault Michel Gilbert Roland
• Cuvillier Romain Guillaume
• Kubiak Guillaume Patrice
• Negri Arnaud Nicolas
• Nowakowski Nathalie

Classifications

• F05D2260/71

  as a function of flow velocity · CPC title

• F04D29/323

  adjustable · CPC title

• F04D29/36 Primary

  adjustable {(flexible blades F04D29/382)} · CPC title

• F05D2220/36

  specially adapted for the fan of turbofan engines · CPC title

• F01D7/02

  having adjustment responsive to speed · CPC title