Coaxial Dual Starter Generator for Turbine Engine Torque-Speed Demands
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Solution Overview
Problem
Existing turbine engine starting systems face limitations in supporting dual modes of operation and accommodating both high torque and high speed loads, as well as providing sufficient electrical power, due to the design constraints of auxiliary gearboxes and their components.
Innovation Solution
A dual mode starter generator (DMSG) system comprising a first starter and a second starter, which can be either electric or air turbine starters, is coupled to a single gearbox input shaft, allowing for coaxial or radially displaced configurations to support multiple starting modes without requiring gearbox redesign, and enabling the electric starter to function as a generator for increased power generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single starter is used in existing turbine engine starting systems, then the system design is simpler, but the system cannot support dual modes of operation or accommodate both high torque and high speed loads simultaneously
Solution Approach 1:
The patent combines two separate starters (first starter and second starter) into a single integrated starting system that shares common components including the gearbox, control unit, and mounting structure. This merging approach enables dual mode operation (high torque mode and high speed mode) while avoiding the complexity of completely separate starter systems, as the starters share the gearbox input shaft and control electronics.
Solution Approach 2:
The gearbox is designed with universal functionality to accommodate both the first starter and second starter through the same input shaft. The single gearbox serves multiple purposes: transmitting torque from the first starter, transmitting torque from the second starter, and providing a common mounting interface. This multi-functionality resolves the contradiction by enabling versatile starting modes without proportionally increasing device complexity.
2Force
If the electric starter is designed for high torque output, then it can provide sufficient starting torque, but it cannot achieve high speed operation
Solution Approach 1:
The starting system is segmented into two specialized starters: the first starter (electric starter) optimized for high torque output at lower speeds, and the second starter (air turbine starter) optimized for high speed operation. The control unit segments the starting process into different phases, engaging the first starter for initial high torque requirements and the second starter for high speed acceleration, thereby resolving the torque-speed trade-off through functional segmentation.
Solution Approach 2:
The system dynamically switches between the first starter and second starter based on real-time operating conditions. The control unit monitors torque requirements and rotational speed, dynamically engaging or disengaging each starter as needed. This dynamic operation allows the system to optimize performance across the entire torque-speed range, with each starter operating in its optimal performance regime.
3Speed
If a second starter is added to support high speed loads, then high speed operation is enabled, but the system complexity increases
Solution Approach 1:
The second starter is merged with the existing gearbox structure, sharing the input shaft, mounting interface, and control electronics. This integration approach minimizes the increase in device complexity by reusing common components rather than adding entirely separate systems. The gearbox serves as a universal interface for both starters, reducing the overall complexity increase from adding the second starter.
4Adaptability or versatility
If the gearbox is redesigned to accommodate dual starters, then both high torque and high speed loads are supported, but manufacturing cost and complexity increase
Solution Approach 1:
The gearbox is designed with universal functionality from the outset, featuring a single input shaft and mounting interface that can accommodate either the first starter, the second starter, or both simultaneously. This universal design approach enables dual starter accommodation without requiring multiple specialized gearbox variants, thereby maintaining ease of manufacture through standardized production processes and reduced part variety.
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 DMSG system enables efficient dual-mode starting of turbine engines by supporting high torque and high speed loads, and provides additional electrical power without modifying the auxiliary gearbox, thus overcoming the limitations of existing systems.
Implementation Method 1
The first starter may be an electric starter. The second starter may be an air turbine starter or another electric starter.
Data Source
AI summary
A system for starting a turbine engine. The system may comprise a gearbox, a first starter, and a second starter. The gearbox may have a gearbox input shaft. The gearbox may be coupled to the turbine engine. The gearbox input shaft may be rotatively coupled to a spool of the turbine engine. The first starter may be coupled to the gearbox input shaft. The second starter may have a second-starter output shaft. The second-starter output shaft may be coaxial with the gearbox input shaft. The second starter may be coupled to the gearbox input shaft through the first starter.