Passive Dynamic Inertial Rotor Balance System
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Solution Overview
Problem
Current rotor balancing systems for turbomachinery are time-consuming, expensive, and prone to inconsistency, with traditional methods requiring removal of the rotor for rebalancing and failing to passively self-correct for unbalance during operation.
Innovation Solution
A dynamic balance system comprising rings with hollow chambers containing heavy metal ball bearings and a non-corrosive viscous fluid, positioned at predicted maximum shaft modal deflection locations, allowing the weights to move opposite to the unbalance point, thereby self-correcting unbalance during rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional balancing methods are used to balance rotors, then initial balance can be achieved, but the system becomes unbalanced over time due to fouling, erosion, or operational changes requiring removal and rebalancing
Solution Approach 1:
The patent applies the dynamics principle by implementing movable balance weights that can automatically adjust their position in response to changing rotor conditions. The balance weights are not fixed but can move along the rotor shaft to compensate for unbalance caused by fouling, erosion, or operational changes, eliminating the need for removal and rebalancing
Solution Approach 2:
The patent implements self-service by enabling the rotor balancing system to automatically detect and correct its own unbalance conditions. The movable weights respond to operational changes and fouling/erosion autonomously, allowing the system to self-correct without external intervention or downtime
2Reliability
If traditional balancing methods are used, then balance correction can be performed, but the process is time-consuming and expensive requiring rotor removal and rebalancing in bunkers
Solution Approach 1:
The system uses movable balance weights that can dynamically adjust their position along the rotor shaft in response to unbalance conditions, enabling continuous correction without stopping the rotor or removing it from service, thus maintaining high productivity
Solution Approach 2:
The rotor balancing system performs self-correction automatically during operation, detecting unbalance conditions and adjusting the movable weights accordingly, eliminating the need for external balancing facilities and maintaining operational efficiency
3Manufacturing precision
If fixed balance weights are used, then initial balancing can be achieved, but the system cannot adapt to changes in stiffness, fouling, or erosion during operation
Solution Approach 1:
The patent replaces fixed balance weights with movable weights that can adjust their position along the rotor shaft in response to changing operational conditions such as stiffness variations, fouling, or erosion, maintaining balance precision throughout the rotor's service life
Solution Approach 2:
The system automatically detects changes in balance conditions caused by fouling, erosion, or stiffness variations and adjusts the movable weights accordingly, enabling the rotor to self-correct and adapt to operational changes without external intervention
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 or eliminates unbalance and vibration by passively adjusting to changes in rotor balance, ensuring consistent operation without the need for frequent removal and rebalancing.
Implementation Method 1
The viscous fluid can comprise a non-corrosive fluid material, such as a petroleum or glycol based substance... the fluid material can comprise a material, such as a non-corrosive viscous material, capable of providing damping for the movable weights preventing excess movement thereof and to provide lubrication for the ball bearings
Implementation Method 2
as the shaft accelerates toward an unbalance point, the weights are configured to move within the at least one chamber to a location which is opposite from the unbalance point
Data Source
Figure 1~2B
Figure 2C
Figure 3A~3B
AI summary
A passive dynamic inertial rotor balance system including a plurality of balancing members fitted onto a rotor shaft at locations of predicted maximum shaft modal deflection. Each of the balancing members has at least one chamber and located within the at least one chamber is a plurality of movable weights and a viscous fluid. As the shaft accelerates toward an unbalance point, the weights move within the at least one chamber to a location which is opposite from the unbalance point. The viscous fluid provides damping for the movable weights to prevent excess movement within the chamber and to provide lubrication thereof. A system for self-correcting an unbalance of a turbomachinery rotor during rotation of the rotor and a method for balancing a rotor in a turbomachinery is also provided.