Gas Turbine Rotor Locking Plate Anti-rotation Design
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Solution Overview
Problem
Existing gas turbine rotors with multiple rotor disks face issues with mechanical vibrations due to the increasing freely vibrating length of tie rods, leading to unacceptably high vibration amplitudes and potential damage, and the use of dummy rotor disks for securing support rings is costly and undesirable.
Innovation Solution
A rotor design where the locking ring is secured to the rotor disk using an antirotation lock and locking plate, eliminating the need for a dummy rotor disk and allowing support rings to be installed without clamping via the tie rod, featuring a bayonet connection and L-shaped recess for cost-effective production and easy installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the overall length of the rotor is increased, then the power and capacity of the rotor are improved, but the freely vibrating length of the tie rod increases causing natural frequency to shift closer to rotational frequency, resulting in unacceptably high vibration amplitudes
Solution Approach 1:
The tie rod is segmented by introducing support rings at intermediate positions along its length. These support rings divide the long tie rod into shorter effective vibrating segments, reducing the freely vibrating length and shifting the natural frequency away from the rotational frequency, thereby reducing vibration amplitudes while maintaining the overall rotor length for power generation
Solution Approach 2:
Support rings are introduced as intermediary elements between the rotor disks and the tie rod. These support rings act as mediators to provide additional support points along the tie rod, reducing its effective span and振动 characteristics without requiring changes to the overall rotor structure or power capacity
2Reliability
If a dummy rotor disk is used to secure the locking ring axially, then the support ring can be retained, but the manufacturing cost and structural complexity increase significantly
Solution Approach 1:
The function of the dummy rotor disk is extracted and separated into dedicated components: a locking ring for axial retention and a locking plate for securing against unscrewing. This eliminates the need for an entire dummy rotor disk, reducing material usage, manufacturing cost, and structural complexity while maintaining the reliability of support ring retention
Solution Approach 2:
The securing function is segmented into two distinct locking mechanisms: axial retention by the locking ring and anti-unscrewing by the locking plate. This segmentation allows each component to be optimized for its specific function and eliminates the need for an oversized dummy rotor disk, reducing overall cost and complexity
3Reliability
If the locking ring is clamped via the tie rod to retain the support ring, then the support ring is secured, but the tie rod is subjected to additional clamping forces and the structure becomes more complex
Solution Approach 1:
The clamping function is extracted from the tie rod and transferred to a dedicated locking ring component. The locking ring independently retains the support ring axially without requiring the tie rod to provide clamping forces, thereby simplifying the tie rod's function and reducing structural complexity
Solution Approach 2:
Instead of using the tie rod to clamp and retain the support ring, the locking ring is designed to actively retain the support ring while the tie rod simply passes through. This inversion of the retention mechanism reduces the functional burden on the tie rod and simplifies the overall 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
This design reduces vibration amplitudes by stabilizing the support rings without increasing costs, enabling simple and inexpensive construction, easy maintenance, and allowing for retrofitting without deforming the rotor disks, while avoiding the use of costly dummy disks.
Implementation Method 1
During operation, the end of the push-on ring which is connected to the rotor disk is widened on account of a centrifugal force stretching of the rotor disk in such a way that the inside diameter of the push-on ring which butts against the outer circumference of the tie rod presses against the tie rod at the end
Implementation Method 2
the locking ring is secured against unscrewing by the use of a locking plate. According to the invention, the support ring is therefore enclosed in the axial direction on one side by the rotor disk to which it is connected, and on the other side by the locking ring which is fastened on the same rotor disk
Data Source
AI summary
A rotor, in particular a gas turbine rotor, having multiple rotor discs, each of which has an axial through-opening, and the rotor discs are axially clamped by at least one tie rod extending through the through-openings and are combined so as to form at least one rotor disc unit. At least one support ring which surrounds the tie rod and is in engagement with a paired rotor disc rests against the outer diameter of the tie rod, and the tie rod is supported against the rotor disc by the support ring. In order to axially secure the at least one support ring, at least one securing ring is provided which is secured to the paired rotor disc by a rotational lock and which holds the support ring against the rotor disc. The securing ring is prevented from unscrewing by a securing plate.