Browse Prior Art Database

INLET GUIDED VANE NONLINEAR SCHEDULE GENERATION MECHANISM

IP.com Disclosure Number: IPCOM000246003D
Publication Date: 2016-Apr-26
Document File: 9 page(s) / 328K

Publishing Venue

The IP.com Prior Art Database

Abstract

This paper discloses an engine having a variable geometry and multiple stages. The multiple stages are actuated by a ganged variable stator vanes (VSV) actuation system that includes a single actuator. Each unison ring is mechanically connected to multiple variable vanes by lever arms such that movement of the unison ring results in a predetermined movement of each variable vane. Positioned between at least one of the unison rings and the gang variable actuation system is a cam configured such that the associated unison ring moves differently in response to the gang VSV actuation system than the other unison rings.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 47% of the total text.

Page 01 of 9

INLET GUIDED VANE NONLINEAR SCHEDULE GENERATION MECHANISM

ABSTRACT


[0001] This paper discloses an engine having a variable geometry and multiple stages. The multiple stages are actuated by a ganged variable stator vanes (VSV) actuation system that includes a single actuator. Each unison ring is mechanically connected to multiple variable vanes by lever arms such that movement of the unison ring results in a predetermined movement of each variable vane. Positioned between at least one of the unison rings and the gang variable actuation system is a cam configured such that the associated unison ring moves differently in response to the gang VSV actuation system than the other unison rings.

BACKGROUND


[0002] The concept of this disclosure relates to engines having a variable geometry and more specifically to actuation of a unison ring included in the engine wherein the unison ring is connected to an actuator via a mechanical cam system configured to move the unison ring according to a predetermined schedule in response to movement of the actuator.


[0003] Conventional control of multiple unison rings in a variable geometry engine is generally provided through mechanical linkages. In these engines, an actuator is mechanically linked to multiple independent unison rings through a variety of mechanisms that include, but are not limited to levers, shafts or bell-crank assemblies mechanically linked to each unison ring. One problem with this conventional arrangement is that movement of all unison rings is uniform: Stated another way, the relationship between the stroke of the actuator and the angular motion of the ring- attached levers, corresponds to a quasi-sinusoidal continuous function. Conventional ganged VSV actuation systems having an actuator are unable to move a single predetermined unison ring according to a predetermined schedule that is different from the scheduled movement of the other rings in response to movement of the

- 1 -


Page 02 of 9

actuator. In conventional ganged VSV actuation systems, it may be required to decouple the schedule movement of the first unison ring, the one driving the Variable Inlet Vane (IGV), in order to improve the compressor operability, performance and aeromechanics. If so, a separate actuator is provided to actuate the IGV unison ring according to a predetermined schedule that is different than the movement schedule of the other unison rings in the ganged VSV actuation system. The additional actuator adds additional weight, cost and complication to the engine.


[0004] BRIEF DESCRIPTION


[0005] This need is addressed by providing a cam mechanically linked to the IGV unison ring such that the cam is configured to translate motion of the ganged VSV actuation system to the IGV unison ring according to a predetermined individual schedule.

BRIEF DESCRIPTION OF THE DRAWINGS


[0006] The invention may be best understood by reference to the following description taken in conjunction with the accompanying dra...