Diffuser Blade Drive Gearing for Compact Dual-Stage Adjustment
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Solution Overview
Problem
Existing mechanisms for adjusting the orientation of turbomachine blades are either too large and imprecise due to numerous components or complex and difficult to install due to precise positioning requirements and component expansions.
Innovation Solution
A compact drive mechanism using a single toothed wheel coupled with each adjustment member, featuring a variable transmission ratio that changes with the angular position of the drive wheel, and a non-linear coupling mechanism with a groove and axial finger to transmit torque between toothed wheels, allowing for differential movement speeds of adjustment members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single control shaft is used to drive blades of two rectifier stages, then the number of components is limited, but the system size becomes particularly large
Solution Approach 1:
The single control shaft is segmented into two separate control shafts, each driving one rectifier stage. This segmentation reduces the overall system size while maintaining a limited number of components, as each shaft can be optimized independently for its specific function and position.
Solution Approach 2:
The control mechanism transitions from a single longitudinal shaft to a distributed arrangement where multiple shafts are positioned at different radial distances from the rotation axis. This dimensional change allows compact packaging of the control system within the turbomachine structure.
2Adaptability or versatility
If a control box is used to adjust blade orientation, then the system adapts to any turbomachine size, but the number of components increases reducing accuracy
Solution Approach 1:
The control mechanism is extracted from a complex control box into simple, direct mechanical linkages between the control shafts and blade adjustment members. This extraction eliminates unnecessary intermediate components that would accumulate clearances and deformations, thereby improving accuracy while maintaining adaptability through scalable shaft design.
Solution Approach 2:
The patent introduces toothed wheels and gear mechanisms as precise intermediaries between the control shafts and blade adjustment members. These toothed intermediaries provide positive mechanical engagement with minimal clearance, ensuring accurate transmission of rotational motion from the control shafts to the blade adjustment members across different turbomachine sizes.
3Manufacturing precision
If a toothed wheel mechanism is used to drive adjustment members, then positioning difficulties are limited and mass is reduced, but the transmission ratio must accommodate different movement speeds
Solution Approach 1:
The transmission ratio between the control shafts and adjustment members is made variable through the use of toothed wheels with different numbers of teeth. This dynamic configuration allows each adjustment member to rotate at its required speed relative to its control shaft, accommodating different movement speed requirements while maintaining simple, precise positioning through direct toothed engagement.
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 provides a compact, easy-to-install, and precise mechanism for adjusting turbomachine blades, reducing the system's mass and improving precision by minimizing component interactions and accommodating varying operational conditions.
Implementation Method 1
one of the two wheels has a groove and the other wheel has a finger projecting axially from the main axis of said other wheel, the finger being received in the groove and being able to cooperate with the groove to transmit a torque from the first toothed wheel to the secondary toothed wheel
Data Source
Figure 1
AI summary
The invention relates to a mechanism (10) for driving a first member (12) for adjusting the orientation of the blades (14) of a first stage (16) of a turbine engine diffuser and a second member (18) for adjusting the orientation of the blades (20) of a second stage (16) of the turbine engine diffuser, comprising a single drive wheel (24) which simultaneously drives the first adjustment member (12) and the second adjustment member (18) and a set of gears which is arranged between the drive wheel (24) and the two adjustment members (12, 18), characterised in that the set of gears comprises a first gearwheel (30) which is directly coupled with the drive wheel (24) and with the first adjustment member and which is coupled with the second adjustment member by means of a secondary gearwheel (32) which is directly coupled with the second adjustment member.