Balanced rotor disc, and balancing method

Patent metadata

Field	Value
Publication number	US-9920626-B2
Application number	US-201514715488-A
Country	US
Kind code	B2
Filing date	May 18, 2015
Priority date	May 19, 2014
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A rotor disc (1) for a turbomachine, including a radial flange (2) that includes a plurality of fastening holes (3), and a plurality of scallops (4) forming notches in the flange (2), and being separated by inter-scallop flange portions (7). The flange alternatively has, in its circumferential direction: a fastening hole (3) and an inter-scallop flange portion (7) arranged in the radial extension of the fastening hole (3), and a scallop (4), in such a way that one or more of the scallops (47, 48, 49; 42, 45-47, 48-411, 414) has a volume greater than the volume of each of the other scallops (41-46, 410-414; 41, 43, 44, 412, 413), and one or more of the inter-scallop flange portions (73) has a volume less than the volume of each of the other inter-scallop flange portions (71, 72, 74), in order to balance said disc (1). A turbomachine including that rotor disc and a method for balancing a turbomachine rotor disc are also disclosed.

First claim

The invention claimed is:

1. A rotor disc ( 1 ) for a turbomachine, comprising a radial flange ( 2 ) that has a plurality of fastening holes ( 3 ), and a plurality of scallops ( 4 ) forming notches in the flange ( 2 ), and being separated by inter-scallop flange portions ( 7 ), the flange comprising around its circumference in an alternating arrangement:
a single fastening hole ( 3 ) and an inter-scallop flange portion ( 7 ) arranged in the radial extension of the fastening hole ( 3 ), and
a single scallop ( 4 ),

wherein
one or more of the scallops ( 4 7 , 4 8 , 4 9 ; 4 2 , 4 5 - 4 7 , 4 8 - 4 11 , 4 14 ) has a volume greater than the volume of each of the other scallops ( 4 1 - 4 6 , 4 10 - 4 14 ; 4 1 , 4 3 , 4 4 , 4 12 , 4 13 ), and
one or more of the inter-scallop flange portions ( 7 3 ) has a volume less than the volume of each of the other inter-scallop flange portions ( 7 1 , 7 2 , 7 4 ),

in order to balance said disc ( 1 ).

2. The disc ( 1 ) according to claim 1 , wherein:
the scallops ( 4 ) have an apex ( 21 ) on the radial axis, and
all the apexes ( 21 ) of the scallops ( 4 ) are positioned in such a way as to belong to one and the same circle.

3. The disc ( 1 ) according to claim 1 , wherein:
the scallops having a volume greater than the volume of the other scallops are not adjacent to each other, and/or
the inter-scallop flange portions having a volume less than the volume of the other inter-scallop flange portions are not adjacent to each other.

4. The disc according to claim 1 , wherein the flange ( 2 ) extends toward the outside of the disc ( 1 ).

5. A turbomachine comprising a rotor, at least one disc ( 1 ) of which is in accordance with claim 1 .

6. A method for balancing a turbomachine rotor disc ( 1 ) comprising a radial flange ( 2 ) that has a plurality of fastening holes ( 3 ), and a plurality of scallops ( 4 ) forming notches in the flange ( 2 ), and being separated by inter-scallop flange portions ( 7 ), characterized in that the flange alternatively has, in its circumferential direction:
a single fastening hole ( 3 ) and an inter-scallop flange portion ( 7 ) arranged in the radial extension of the fastening hole ( 3 ), and
a single scallop ( 4 ),

the method comprising the steps:
measuring (E 1 ) the imbalance of the disc ( 1 );
machining (E 3 )
one or more scallops ( 4 7 , 4 8 , 4 9 ; 4 2 , 4 5 - 4 7 , 4 8 - 4 11 , 4 14 ), in order for the latter ( 4 1 , 4 2 , 4 3 ) to have a volume greater than the volume of each of the other scallops ( 4 1 - 4 6 , 4 10 - 4 14 ; 4 1 , 4 3 , 4 4 , 4 12 , 4 13 ), and
one or more inter-scallop flange portions ( 7 3 ) in order for the latter to have a volume less than each of the other inter-scallop flange portions ( 7 1 , 7 2 , 7 4 ),

in such a way as to balance the disc ( 1 ) with respect to the measured imbalance.

7. The method according to claim 6 , comprising a step (E 2 ) selecting the scallops and/or inter-scallop flange portions to be machined as a function of the amplitude and/or angular position of the measured imbalance.

8. The method according to claim 6 , wherein:
prior to the machining step, the scallops ( 4 ) have an apex ( 21 ) on the radial axis of the disc, and
the step of machining the scallops ( 4 ) does not alter the position of said apexes on a radial axis of the disc ( 1 ).

Assignees

• Snecma

Inventors

• Casaliggi Pascal
• Bourion Remi
• Capolungo Thierry

Classifications

• F05D2240/24

  for turbines · CPC title

• F05D2260/15

  Load balancing · CPC title

• F01D5/02

  Blade-carrying members, e.g. rotors (rotors of non-bladed type F01D1/34; stators F01D9/00 {; selecting particular materials F01D5/28}) · CPC title

• Y10T29/49334

  Utilizing hollow tube blank · CPC title

• F16F15/32

  Correcting- or balancing-weights or equivalent means for balancing rotating bodies, e.g. vehicle wheels {(suppression of vibrations in rotating systems by using freely rotating masses F16F15/14; compensation of inertia forces F16F15/22; compensating imbalance for testing purposes G01M1/30)} · CPC title