Integrated Drive Generator Pump Sleeve for Dual-Pump Speed Stability

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Solution Overview

Problem

The existing pump sleeve design for combined charge and scavenge pumps in integrated drive generators faces challenges in maintaining a constant input speed and desired frequency of electric power generation due to variable input shaft speed from gas turbine engines, requiring a solution that can effectively manage speed trimming across both pumps.

Innovation Solution

A pump sleeve with specific geometrical features, including opposed windows for inlet and outlet ports, Belleville spring washers for bias force, and keyways for securement, is designed to provide a common sleeve for both pumps, ensuring efficient operation and speed management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single pump sleeve is used for both charge and scavenge pumps, then device complexity is reduced, but it becomes difficult to maintain constant input speed and desired frequency for both pumps simultaneously

Engineering Contradiction:
Improvepump sleeve configurationVSAvoidfrequency consistency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The pump sleeve is segmented into two distinct functional portions: a charge pump portion with first inlet/outlet windows and a scavenge pump portion with second inlet/outlet windows. Each portion has independently configured ports and chambers, allowing separate optimization for charge and scavenge functions while maintaining a unified sleeve structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the pump sleeve have different geometrical configurations tailored to specific pump functions. The charge pump portion has specific window arrangements and chamber volumes optimized for charge operations, while the scavenge pump portion has different configurations for scavenge operations, allowing each local region to perform its function optimally.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the pump sleeve has separate inlet and outlet ports for both pumps, then each pump can operate independently, but the device complexity increases

Engineering Contradiction:
Improvepump operation independenceVSAvoidpump sleeve structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The charge pump and scavenge pump are merged into a single pump sleeve structure that houses both pump chambers, inlet ports, and outlet ports. This consolidation allows independent operation of both pumps through separate port configurations while reducing the number of separate components needed.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pump sleeve is designed as a universal component that performs multiple functions: it serves as the housing for both charge and scavenge pumps, provides separate inlet and outlet ports for each pump, and maintains constant speed for both operations simultaneously through its unified rotational structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Speed

If the pump sleeve maintains constant rotation speed, then desired frequency of electric power generation is achieved, but the design must accommodate variable input shaft speed from gas turbine engine

Engineering Contradiction:
Improveinput shaft speedVSAvoidfrequency stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The pump sleeve acts as an intermediary component between the variable-speed input shaft and the frequency requirements of the generator. By maintaining constant rotational speed despite variable input conditions, it mediates the speed variations and ensures stable frequency output for electric power generation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3511521B1Pump sleeve for a charge and scavenge pump of an integrated drive generator
Publication Date: 2021.03.03 HAMILTON SUNDSTRAND CORP
  • EP3511521B1 patent drawingFigure 1
  • EP3511521B1 patent drawingFigure 2
  • EP3511521B1 patent drawingFigure 3A~3B

AI summary

A pump sleeve (210) for an integrated drive generator has a pump sleeve body (250) extending between a first end (256) and a second end (258). The first end (256) is at a location adjacent a radially enlarged end plate (252). The body (250) extends to the second end (258) with a generally cylindrical body portion (254) having an inner bore diameter defining a first distance. The body (250) extends between the first and second ends (256, 258) for a second distance. A ratio of the first distance to the second distance is between 0.15 and 0.30. An integrated drive generator and a method are also disclosed.