Turbine Engine Starter Torque Augmentation via Gearbox Accessories
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Solution Overview
Problem
Turbine engines require external systems, such as electric starters or air turbine starters, to provide initial work input to drive the compressor before reaching self-sustaining operation, which can be heavy and inefficient due to the need for high torque at low speeds.
Innovation Solution
A method involving a gearbox coupled to the turbine engine spool, where a first and second application of power are applied to different accessory components, such as a starter and a permanent magnet alternator or barring motor, to achieve initial rotation and increased rotational speed of the turbine engine spool, reducing the size and weight of the dedicated starter by augmenting its torque with accessory components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a dedicated starter is used to provide high torque at low speeds to drive the turbine engine compressor, then the engine can be started from rest, but the starter becomes heavy and inefficient
Solution Approach 1:
The patent combines the starter function with accessory components (such as the permanent magnet alternator or barring motor) that are already part of the engine system. Instead of using a standalone heavy starter, the system merges multiple functions into existing components, allowing them to collectively provide the necessary starting torque while reducing overall weight.
Solution Approach 2:
The accessory components are designed to serve multiple functions: they can act as starters during engine startup, generators during operation, or perform other auxiliary functions. This multi-functionality eliminates the need for dedicated single-purpose components, reducing weight while maintaining the capability to provide high torque when needed.
2Power
If a dedicated starter is used to overcome the inertia of the turbine spool, then the engine can reach self-sustaining operation, but the starter and associated systems become larger and heavier
Solution Approach 1:
The patent merges the starting function with existing accessory components rather than using a separate dedicated starter system. By combining multiple components' output through the gearbox, the system achieves the necessary starting power without the weight penalty of a standalone high-power starter.
Solution Approach 2:
The starting function is segmented across multiple accessory components rather than concentrated in a single starter. Each component contributes a portion of the required torque, and their combined effect through the gearbox provides sufficient power to overcome spool inertia, distributing the weight burden across lighter individual components.
3Weight of moving object
If accessory components are used to augment starter torque, then the dedicated starter can be smaller and lighter, but the system requires coordination of multiple power applications
Solution Approach 1:
The accessory components are designed to serve multiple functions including starting, power generation, and auxiliary operations. This multi-functionality justifies the added control complexity by eliminating the need for separate dedicated components, making the overall system more efficient despite requiring coordinated operation of multiple elements.
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 method allows for a smaller, lighter dedicated starter and associated systems, as the accessory components assist in overcoming the inertia of the turbine spool, enabling efficient startup and reducing the torque requirements of the starter, thus enhancing the overall efficiency and weight reduction of the turbine engine starting process.
Implementation Method 1
A first accessory (e.g., a permanent magnet alternator) can be selectively coupled to the gearbox... applying a second application of power to the other of the first accessory and first starter
Implementation Method 2
An air turbine starter may be coupled to the gearbox via a first input shaft
Implementation Method 3
A first starter may be coupled to the gearbox via an input shaft... The rotation of the output shaft of the gearbox may be coupled to the rotation of the spool
Data Source
AI summary
A method of starting a turbine engine utilizing multiple components. The turbine engine may comprise a gearbox coupled to a spool of the turbine engine via an output shaft. A first starter may be coupled to the gearbox via an input shaft. A first accessory may be coupled to the gearbox via another input shaft. The rotation of the output shaft of the gearbox may be coupled to the rotation of the spool. The rotation of each of the first starter and first accessory may be coupled to the rotation of the respective input shaft of the gearbox. The method may comprise applying a first application of power to one of the first starter and the first accessory and applying a second application of power to the other of the first accessory and the first starter.