Variable Guide Vane Assembly Wear Reduction
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Solution Overview
Problem
Conventional variable guide vanes in gas turbine engines experience wear and fretting due to the use of external actuators and gears, which reduces their lifespan and increases maintenance costs.
Innovation Solution
A variable guide vane assembly with a lubricated cavity housing the vane drive members and a unison transmission member, where the external mechanism is actuated by an external actuator, allowing rotation of the guide vanes and reducing wear through lubrication, with vane drive members secured to the shaft portions and a unison transmission member engaged to these members for coordinated rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If external actuators and gears are used to actuate variable guide vanes, then the vanes can be adjusted in angular orientation, but wear and fretting occur reducing lifespan
Solution Approach 1:
The patent extracts the harmful mechanical contact elements (gears) from the actuation system. Instead of using gears to transmit rotational motion from the actuator to the guide vanes, the invention uses a cable-driven pulley system where the cable passes through a pulley attached to the vane, eliminating gear wear and fretting while maintaining angular adjustment capability
Solution Approach 2:
The patent replaces the traditional mechanical gear system with a cable-pulley mechanical system. The actuator rotates a pulley, and the cable wrapped around the pulley translates this rotation into angular movement of the guide vane without requiring gear engagement, thereby eliminating gear wear
2Ease of operation
If gears are used to communicate angular movements to the vanes, then angular orientation control is achieved, but fretting and wear increase maintenance costs
Solution Approach 1:
The patent removes gears entirely from the angular movement transmission system, replacing them with a cable-pulley mechanism. This extraction of harmful mechanical components eliminates the source of wear and fretting, thereby reducing maintenance requirements and costs while preserving precise angular orientation control
Solution Approach 2:
The cable in the pulley system is a simple, replaceable component that can be easily replaced when worn, unlike gear systems where wear occurs at critical engagement points. The cable can be independently replaced without replacing other components, reducing overall maintenance costs
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution extends the lifespan of the guide vane assembly by reducing wear and tear on components, enhancing durability and lowering maintenance costs by keeping critical parts within a lubricated environment.
Implementation Method 1
a cavity hydraulically connectable to a lubrication system, the casing defining apertures circumferentially distributed around a central axis; variable guide vanes (VGVs) circumferentially distributed around the central axis... vane drive members secured to respective ones of the shaft portion of the VGVs and located within the cavity, a unison transmission member within the cavity
Data Source
Figure 1~2
Figure 3~4
AI summary
A variable guide vane (VGV) assembly (20), has: a casing enclosing a cavity (C) and defining apertures (10c, 10d) distributed around a central axis (19); variable guide vanes (VGVs) (22) distributed around the central axis (19) and having an airfoil portion (22a) extending from a first end (22f) to a second end (22g) along a pivot axis (A), and a shaft portion (22d) pivotably received within the apertures (10c, 10d); vane drive members (28a) secured to the shaft portions (22d) of the VGVs (22) and located within the cavity (C), a unison transmission member (28c) within the cavity (C) and rotatable about the central axis (19) and engaged to the vane drive members (28a), and an external mechanism (30) secured to the second end (22g) of one of the VGVs (22) and disposed outside the cavity (C), the external mechanism (30) engageable by an actuator (32) for rotating the one of the VGVs (22) about its pivot axis (A), thereby rotating the unison transmission member (28c), which, in turn, drives a remainder of the VGVs (22) in rotation.