Passive Rotor Oscillation During Gas Turbine Engine Transport
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Solution Overview
Problem
Gas turbine engines experience shock loads during transportation, which can damage internal components such as bearings, leading to maintenance and repair costs and downtime.
Innovation Solution
A passive actuation system is used to rotate the rotating structures of the gas turbine engine during transportation, utilizing an eccentric mass, spring, and damper to oscillate the structures about their rotational axis, reducing the impact of shock loads on bearings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gas turbine engine is secured in a fixed position during transportation, then the engine structure is stable and easy to transport, but the internal components such as bearings are subject to shock loads that can cause damage
Solution Approach 1:
The patent applies mechanical vibration by using an unbalanced mass mounted on the rotating structure to generate oscillatory motion. The unbalanced mass creates centrifugal forces that induce vibrations in the rotating structure, which in turn protect the bearings from shock loads during transportation. This vibrational approach transforms the static transportation condition into a dynamic protective state.
Solution Approach 2:
The patent implements dynamics by allowing the rotating structure to oscillate about its rotational axis during transportation rather than remaining completely static. The system transitions from a fixed state to a dynamically active state where controlled oscillations occur, enabling the bearings to remain lubricated and protected while the engine is being transported.
2Reliability
If a passive actuation system with unbalanced mass is used to rotate the rotating structure during transportation, then bearing protection is improved, but the device complexity and weight increase
Solution Approach 1:
The unbalanced mass serves multiple functions: it acts as both a protective mechanism for the bearings and a component of the rotating structure itself. By integrating the unbalanced mass into the existing rotating structure rather than adding a separate actuation system, the patent achieves bearing protection while minimizing additional weight and complexity.
Solution Approach 2:
The system uses the existing rotational inertia and structure of the gas turbine engine to generate the protective oscillations. The unbalanced mass leverages the natural rotation and movement of the engine during transportation to create the protective effect, rather than requiring an external power source or complex active control system.
3Reliability
If the rotating structure is allowed to oscillate freely during transportation, then bearing damage is reduced, but control and stability become difficult
Solution Approach 1:
The patent applies preliminary anti-action by using the spring element to pre-bias the system and counteract excessive oscillations. The spring provides a restoring force that opposes deviations from the equilibrium position, preventing the oscillations from becoming uncontrolled while still allowing sufficient movement to protect the bearings from shock loads.
Solution Approach 2:
The damper element provides feedback control by dissipating energy from the oscillations and providing damping forces that oppose the direction of motion. This feedback mechanism automatically adjusts to the oscillation amplitude and frequency, maintaining stable controlled oscillations without requiring external control systems.
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 passive actuation system minimizes bearing damage by transforming lateral and vertical movements into controlled rotational oscillations, thereby reducing maintenance needs and downtime.
Implementation Method 1
The actuation system includes a spring configured to maintain the mass in a position that is laterally offset from the rotational axis
Implementation Method 2
The actuation system includes a damper configured to damp oscillations of the rotating structure
Implementation Method 3
The actuation system includes a mass configured to rotationally imbalance the rotating structure about the rotational axis
Data Source
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AI summary
A powerplant system includes a gas turbine engine system (14) and an actuation system (68). The gas turbine engine system (14) includes a rotating structure (18A), a stationary structure (20) and one or more bearings rotatably mounting the rotating structure (18A) to the stationary structure (20). The actuation system (68) is configured to passively rotate the rotating structure (18A) about a rotational axis (32) during transportation of the gas turbine engine system (14).