Rotor disk blade with friction-held root, rotor disk, turbomachine and associated assembly method

Patent metadata

Field	Value
Publication number	US-2016108744-A1
Application number	US-201414893744-A
Country	US
Kind code	A1
Filing date	May 26, 2014
Priority date	May 28, 2013
Publication date	Apr 21, 2016
Grant date	—

Abstract

A rotor disk blade for a turbine engine, the blade being made of composite material including fiber reinforcement obtained by multilayer weaving of yarns and densified by a matrix. The blade has a portion constituting an airfoil and a blade root forming a single piece, the blade root having two substantially plane opposite lateral flanks that are formed respectively extending the pressure side surface and the suction side surface of the airfoil. The blade root is clamped between two metal plates fastened against the lateral flanks of the blade root by a bolt and a nut passing through the plates and the blade root. The bolt has a head bearing against one of the two plates. The nut has a head bearing against the other plate.

First claim

1 . A rotor disk blade for a turbine engine, the blade being made of composite material comprising fiber reinforcement obtained by multilayer weaving of yarns and densified by a matrix, the blade having a portion constituting an airfoil and a blade root forming a single piece, the blade root having two substantially plane opposite lateral flanks that are formed respectively extending the pressure side surface and the suction side surface of the airfoil, the blade root being clamped between two metal plates fastened against the lateral flanks of the blade root by a bolt and a nut passing through the plates and the blade root, wherein the bolt has a head bearing against one of the two plates and in that the nut has a head bearing against the other plate, the bolt and the nut applying some minimum level of clamping force against the metal plates for ensuring that a determined centrifugal force applied to the blade is taken up by friction between the metal plates and the lateral flanks of the blade root.

2 . A blade according to claim 1 , wherein the minimum clamping force is determined by dividing the determined centrifugal force with the coefficient of friction between the metal plates and the lateral flanks of the blade root.

3 . A blade according to claim 1 , wherein the bolt and the nut have respective heads of conical shape, and wherein the metal plates include corresponding countersinks.

4 . A blade according to claim 1 , wherein each metal plate includes on its face opposite from its face in contact with the blade root at least one projecting portion, said projecting portion presenting a shape suitable for providing one or both of the following functions: opposing tilting and providing sealing.

5 . A blade according to claim 1 , wherein the blade root includes an oblong hole or festooning extending in the long direction of the blade for passing the bolt and the nut.

6 . A blade according to claim 1 , wherein the face of each plate facing the blade root presents a surface that is structured.

7 . A blade according to claim 6 , wherein the face of each plate facing the blade root includes knurling.

8 . A blade according to claim 1 , wherein the metal plates have a coefficient of thermal expansion that is less than the coefficient of thermal expansion of the bolt and of the nut.

9 . A blade according to claim 1 , wherein the blade, the metal plates, the bolt, and the nut present coefficients of thermal expansion that vary in similar manner over all or part of a temperature range extending from 0° C. to 800° C.

10 . A turbine engine rotor disk having a plurality of substantially axial metal slots in its outer periphery, the disk further comprising a plurality of blades according to claim 1 , each blade being assembled by means of its root in a slot of the disk.

11 . A turbine engine including at least one rotor disk according to claim 10 .

12 . A method of assembling plates on a blade root, said blade being made of a composite material comprising fiber reinforcement obtained by multilayer weaving of yarns and densified by a matrix, the blade having a portion constituting an airfoil and a blade root forming a single piece, the blade root having two substantially plane opposite lateral flanks that are formed respectively extending the pressure side surface and the suction side surface of the airfoil, the blade root being clamped between two metal plates fastened against the lateral flanks of the blade root by a bolt and a nut passing through the plates and the blade root, wherein the bolt has a head bearing against one of the two plates, the nut having a head bearing against the other plate, and in that when tightening the bolt with the nut, some minimum level of clamping force is applied to the metal plates to ensure that a determined centrifugal force applied to the blade is taken up by friction between the metal plates and the lateral flanks of the blade root.

13 . A method according to claim 12 , wherein the minimum clamping force is determined by dividing the determined centrifugal force by the coefficient of friction between the metal plates and the lateral flanks of the blade root.

Assignees

• Herakles
• Snecma

Inventors

• Locatelli David
• Roussille Clement
• Herraiz Ivan

Classifications

• F01D5/282

  Selecting composite materials, e.g. blades with reinforcing filaments · CPC title

• F01D5/3015 Primary

  with side plates · CPC title

• F01D5/147 Primary

  Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18) · CPC title

• F05D2250/294

  grooved · CPC title

• F01D5/3007

  of axial insertion type · CPC title