Variable stator vane linkage system and method

• US 5,549,448 A
• Filed: 02/08/1995
• Issued: 08/27/1996
• Est. Priority Date: 02/08/1995
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Rtx Corporation)
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Langston, Todd A.
• Primary Examiner(s): Larson, James
• Application Number:
  US08/385,414
• Time in Patent Office: 566 Days
• Field of Search: 415/149.4, 415/150, 415/160, 415/162, 29/889.1, 29/889.2, 29/889.22
• US Class Current: 415/149.4
• CPC Class Codes: F01D 17/162 for axial flow, i.e. the vanes turning around axes which are essentially perpendicular to the rotor centre line F01D17/167 takes precedence
• CPC Class Codes: Y10T 29/4932 Turbomachine making
• CPC Class Codes: Y10T 29/49323 Assembling fluid flow directing devices, e.g., stators, diaphragms, nozzles

Abstract

The linkage system for the variable vane stators includes a pumphandle driven by the linear actuator and a cooperating pumphandle slider bracket where the slider bracket includes a machined hard coated stop for limiting travel of the pumphandle when the vanes are at the full opened position. The pumphandle through the drive link circumferentially positions a synchronizing ring that is connected through a plurality of drive links to each of the vanes circumferentially spaced in the stator for changing the angle of each of the vanes as scheduled by a control and actuator for optimizing the performance of the compressor and gas turbine engine. The steps for assembling the linkage system and actuator for synchronizing the positions of the stops on the actuator and slider bracket relative to a given position of the stator vanes defines a method for providing a rigless variable vane system.

Claims

1. The method of assembling a rigless variable vane system to a compressor section encased in a gas turbine engine which is independent of a linear actuator and external connections of the system and adjusting the system so that vanes in the compressor section are always in a given position for all positions of the linear actuator including the steps of:

providing a case for the gas turbine engine, the vanes of the compressor section comprising variable area vanes movable to a full opened position in said case;

providing the linear actuator with an adjustable stop to limit the travel thereof;

providing a pumphandle and pumphandle slider bracket and attaching the pumphandle slider bracket to the case;

providing a bellcrank and connecting the pumphandle to the variable area vanes;

providing a stop having a contact surface on the pumphandle slider bracket that engages the pumphandle;

adjusting the pumphandle relative to the stop provided in the next above step so that the variable area vanes are in the full opened position when the pumphandle is in contact with the stop;

connecting the linear actuator to the bellcrank when the variable vanes are in the full opened position;

adjusting the adjustable stop of the linear actuator so that the stop on the linear actuator and the stop on the slider bracket are in synchronous relationship relative to each other; and

machining the stop directly on the pumphandle slider bracket to assure that the stop on the linear actuator and the stop on the slider bracket are in synchronous relationship relative to each other.

2. The method as claimed in claim 1 including the step of hard coating the contact surface of the stop on the pumphandle slider bracket.

3. The method as claimed in claim 2 including the steps of;

providing a synchronizing ring and providing drive links connecting each of the variable vanes to the synchronizing ring, and connecting the pumphandle to the synchronizing ring.

4. The method as claimed in claim 1 including the step of machining the stop integral with the pumphandle slider bracket.

5. The method as claimed in claim 4 including the step of coating the contact surface of the stop with a hard metallic material.

6. Apparatus for a rigless variable vane system for an axial flow gas turbine engine having a compression section including variable vanes movable to a full opened position mounted in a compressor case of the compression section including a pumphandle and a pumphandle slider bracket attached to said compressor case and an actuator having actuator stop means for positioning said variable vanes by positioning said pumphandle as limited by said actuator stop means, the improvement comprising stop means integrally formed on said pumphandle slider bracket for engaging said pumphandle when said variable vanes are in the full opened position and when said actuator stop means limits the travel of said actuator.

7. Apparatus as claimed in claim 6 wherein said stop means is machined in situ on said pumphandle slider bracket.

8. Apparatus as claimed in claim 7 wherein said stop means is hard coated with a hard metallic material.

9. Apparatus as claimed in claim 8 wherein said hard metallic material is taken from the group consisting of chrome, nickel and the alloys thereof.

10. Apparatus as claimed in claim 8 wherein said actuator is linear and said variable vane system includes a synchronizing ring operatively connected to said pumphandle, said synchronizing ring encircling said compressor case, an internal bellcrank operatively connected to said pumphandle, an external bellcrank disposed between said internal bellcrank and said linear actuator for positioning said pumphandle to move rectilinearly relative to said pumphandle slider bracket and said synchronizing ring in a circumferential direction, and a plurality of drive links interconnecting said synchronizing ring and each of said vanes in said variable vane system whereby the position of said vanes is a function of the position of said linear actuator.