Spring-Suspended Turbine Blade Damper to Prevent Locking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine blades experience vibrational stress due to centrifugal forces, which can lead to locking of damper elements and reduced vibration damping effectiveness, especially during acceleration and deceleration of turbines.
Innovation Solution
A vibration dampening system featuring spring-suspended bearing members that frictionally engage a bearing surface when the turbine rotates at higher speeds, utilizing a spring configuration and mass distribution to allow engagement and disengagement based on rotational speed, providing effective damping without adding significant mass or altering the blade configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If stacked solid damper elements are used in a turbine blade, then vibration damping is provided, but centrifugal forces cause the damper elements to lock together, reducing or eliminating their ability to dampen vibration
Solution Approach 1:
The damper element employs a dynamic configuration where the bearing member is suspended by a spring, allowing it to move relative to the base member. This dynamic arrangement enables the bearing member to engage and disengage from the bearing surface based on operational conditions, preventing permanent locking while maintaining vibration damping capability. The spring suspension creates a compliant connection that adapts to centrifugal forces without rigid locking.
Solution Approach 2:
The invention changes the physical state and positional parameters of the bearing member through spring suspension. The bearing member's position is no longer fixed but varies with spring extension, allowing it to frictionally engage the bearing surface only when needed for vibration damping. This parameter change enables the system to transition between engaged and disengaged states, avoiding the locking problem of solid stacked elements.
2Reliability
If a spring-suspended bearing member is used to prevent locking, then vibration damping effectiveness is maintained, but the device complexity increases
Solution Approach 1:
The spring suspension mechanism is applied locally to the bearing member rather than throughout the entire damper element structure. The base member remains a simple solid component, while only the bearing member incorporates the spring suspension. This localized application of complexity achieves the desired vibration damping effectiveness without unnecessarily complicating the overall device structure.
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 system effectively reduces blade vibration across various rotational speeds, including during startup and shutdown, by using a spring-suspended bearing member that engages to dampen vibrations under centrifugal force, maintaining efficiency even when other dampening interfaces are inoperative.
Implementation Method 1
the spring is configured to achieve an elastically extended state under influence of a centrifugal force caused by rotation of the rotating blade
Implementation Method 2
the spring is configured to achieve an elastically extended state
Implementation Method 3
the elastically extended state of the spring causes the bearing member to frictionally engage a first bearing surface to dampen vibration
Data Source
AI summary
A damper element for a vibration dampening system may be used in a body opening in a rotating blade in a turbine. The damper element includes a base member, and a spring-suspended bearing member having a disc spring fixedly coupled to the base member at a center of the disc spring, and a bearing member coupled to a first side of the disc spring at an outer portion thereof. The bearing member extends radially distal from the first side of the disc spring. With the disc spring in an elastically extended state under influence of a centrifugal force caused by rotation of the rotating blade at higher than a predefined rotational speed, the bearing member frictionally engages a first bearing surface to dampen vibration. The friction-based vibration dampening interface experiences a reduced impact of the centrifugal forces of the rotating blade by providing a counteracting force reduction using the spring.