Variable Displacement Pump Pressure Feedback Control

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Solution Overview

Problem

Variable displacement pumps in the aerospace industry require effective control methods to ensure system responsiveness and stability, as traditional methods often result in oversized pumps for peak demand conditions.

Innovation Solution

A variable displacement pump system that includes a variable displacement pump, a pressure port, a pressure regulating valve, a mechanical linkage, and a controller. The system controls the displacement of the pump by adjusting the position of the pressure actuated piston, which is driven by a pressure actuated piston and controlled by a controllable valve, based on the pressure of the main line and the position of the pressure regulating valve.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fixed displacement pump is sized to meet peak demand, then the pump can satisfy maximum flow requirements, but the pump becomes oversized and inefficient for the remainder of operating conditions

Engineering Contradiction:
Improvepeak flow capabilityVSAvoidpump efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent applies a variable displacement pump mechanism that dynamically adjusts the pump displacement based on real-time system pressure feedback. The pressure feedback signal modifies the displacement control signal to the mechanical linkage, enabling the pump to adapt its output to actual system demands rather than operating at fixed displacement, thus resolving the contradiction between meeting peak demand and maintaining efficiency during partial load conditions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the pump by continuously adjusting the displacement volume based on pressure conditions. When system pressure reaches a threshold, the pressure feedback signal triggers a reduction in pump displacement, thereby changing the pump's operational parameter from maximum displacement to a reduced displacement state, eliminating energy waste while maintaining the ability to meet peak flow requirements when needed

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the pump displacement is adjusted to improve efficiency, then energy loss is reduced, but system responsiveness and stability may deteriorate

Engineering Contradiction:
Improvepump efficiencyVSAvoidsystem stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent implements a pressure feedback control mechanism where a pressure sensor continuously monitors system pressure and feeds this information back to the controller. The controller uses this feedback signal to adjust the pump displacement in real-time, creating a closed-loop control system that maintains system stability while optimizing energy efficiency. The feedback ensures that displacement adjustments do not compromise system responsiveness

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system replaces traditional purely mechanical displacement control with an integrated electro-hydraulic control mechanism. The controller processes pressure feedback signals and generates appropriate control signals to the mechanical linkage, substituting simple mechanical adjustment with a smarter control system that balances energy efficiency and system stability through intelligent decision-making algorithms

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If traditional control methods are used, then the system structure remains simple, but the pump remains oversized for non-peak conditions resulting in energy waste

Engineering Contradiction:
Improvecontrol system structureVSAvoidpump efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent integrates multiple functions into a unified control system that combines pressure sensing, signal processing, and displacement control. The controller serves multiple purposes: monitoring system pressure, comparing it against thresholds, generating control signals, and coordinating with the mechanical linkage. This multi-functional approach achieves energy efficiency without proportionally increasing system complexity

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

Solution Approach 2:

The patent introduces a pressure feedback signal as an intermediary element that mediates between the hydraulic system and the displacement control mechanism. This feedback signal acts as a communication bridge, translating system pressure conditions into actionable control commands that adjust pump displacement, thereby connecting system state to control action without requiring complex direct mechanical linkages

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4170161B1Variable displacement pumps
Publication Date: 2025.06.11 HAMILTON SUNDSTRAND CORP
  • EP4170161B1 patent drawingFigure 1

AI summary

In accordance with at least one aspect of this disclosure, a variable displacement pump (102) system can include, a variable displacement pump (102) disposed in a main line (104) and configured to supply pressure to receive a low pressure fluid and to output a high pressure fluid. The main line (104) can connect a hydraulic fluid source to a plurality of system actuators, where the variable displacement pump (102) is disposed in the main line (104) between the hydraulic fluid source and the plurality of system actuators to pressurize the hydraulic fluid.