Accessory Gearbox Centrifugal Pump Integration
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Solution Overview
Problem
Current accessory boxes for turbomachines are too bulky, making it difficult to integrate them into increasingly constrained aeronautical engine environments due to their large size and the additional bulk of equipment like centrifugal pumps.
Innovation Solution
The accessory box design integrates the centrifugal pump directly into its casing by mounting the rotating part of the pump directly onto the tail of a pinion, eliminating the need for a separate shaft and its guide bearings, thereby reducing the axial size and mass while improving assembly reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rotating part of the pump is mounted on a separate shaft with guide bearings, then the pump can be properly supported and guided, but the accessory box becomes too bulky and difficult to integrate into the turbomachine
Solution Approach 1:
The patent merges the pump rotating part directly with the gear tail, eliminating the separate shaft and its guide bearings. The gear tail itself serves as the mounting axis for the rotating part (impeller), integrating two previously separate components into one unified structure. This reduces the number of parts and the overall volume of the accessory box while maintaining the necessary support and guidance functions through the gear tail's inherent structural integrity and the pinion tail guide bearings that already exist in the system.
2Volume of stationary object
If the rotating part of the pump is directly mounted on the gear tail, then the accessory box size and mass are reduced, but the reliability of the assembly may be affected
Solution Approach 1:
The gear tail is designed to serve multiple functions simultaneously: it acts as the structural connection between the pinion and the pump, serves as the mounting axis for the rotating part (impeller), and provides the necessary support and guidance for the rotating part. This multi-functional design eliminates the need for separate shafts and bearings while maintaining reliability through the inherent strength and precision of the gear tail structure.
Solution Approach 2:
The pinion tail guide bearings serve as intermediaries that provide the necessary guidance and support for the gear tail, which in turn supports the rotating part of the pump. This intermediary arrangement allows the system to maintain proper alignment and reduce friction without requiring additional shafts or bearings, thereby preserving reliability while minimizing size.
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 integration results in a significant reduction in the overall size and mass of the accessory box and pump, enhancing the reliability of the assembly and facilitating easier integration into turbomachines.
Implementation Method 1
The centrifugal pump is of the volute type, the volute being part of the stationary part, or stator, of the pump and generating the pressure necessary for its proper operation
Data Source
Figure 1~3
Figure 4~5
AI summary
The invention relates to an accessory gearbox (10) for a turbomachine, said gearbox being equipped with a pump (12) and comprising intermeshing pinions (14-20), one of which is formed as a single piece with a coaxial shank (22) for driving a rotary part (36) of the pump, characterised in that said rotary part is directly mounted on the shank.