Dual Variable Displacement Pumping System with Electrohydraulic Servo Control
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Solution Overview
Problem
Current pumping systems for fuel delivery to engines, such as aircraft or automobile engines, lack efficient control mechanisms to manage the displacement of multiple pumps, leading to suboptimal fuel flow rates and potential backflow issues.
Innovation Solution
A pumping system comprising two variable displacement pumps with actuators and an electrohydraulic servo valve, controlled by an electronic engine controller, which senses linear displacements and adjusts the pumps' displacement mechanisms to optimize fuel flow through check valves and hydraulic pressure lines, ensuring efficient fuel delivery and preventing backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple variable displacement pumps are used to increase fuel flow capacity, then the fuel delivery capability is improved, but the control complexity and device complexity increase
Solution Approach 1:
The patent combines multiple variable displacement pumps into a single integrated pumping system with a common electrohydraulic servo valve that controls all pumps through a unified control architecture. The electronic engine controller manages multiple pumps as a coordinated system rather than independent units, reducing overall control complexity while maintaining increased fuel flow capacity.
Solution Approach 2:
The electrohydraulic servo valve serves as a universal control component that manages displacement for multiple pumps simultaneously. The electronic engine controller performs multiple functions including sensing linear displacements from all pumps, processing fuel flow requirements, and coordinating actuator commands across the entire pumping system, thereby simplifying the control architecture.
2Manufacturing precision
If actuators are added to control pump displacement, then the fuel flow rate control precision is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent incorporates linear displacement sensors on each actuator that provide real-time feedback to the electronic engine controller. This feedback mechanism enables precise control of pump displacement by continuously monitoring actuator position and making adjustments to maintain desired fuel flow rates, thereby achieving high control precision.
Solution Approach 2:
The system replaces manual or purely mechanical control mechanisms with an electrohydraulic control system. The electrohydraulic servo valve converts electrical signals from the electronic engine controller into hydraulic actuation forces, providing precise and responsive control of pump displacement without complex mechanical linkages.
3Reliability
If check valves are installed downstream from each pump, then backflow prevention is improved, but the device complexity and pressure losses increase
Solution Approach 1:
The patent installs individual check valves downstream from each pump outlet, creating segmented backflow protection for each pump circuit. This segmentation ensures that backflow prevention is localized to each pump, allowing independent operation and maintenance of check valves without affecting the entire system.
Solution Approach 2:
The check valves convert the potential harmful effect of backflow into a beneficial pressure differential that can be utilized by the system. By allowing backflow to occur against the check valve closure, the system creates pressure differentials that can be sensed and used for control purposes while still preventing actual reverse flow.
4Speed
If an electrohydraulic servo valve is used to control multiple actuators, then the fuel flow control responsiveness is improved, but the manufacturing cost and device complexity increase
Solution Approach 1:
The electrohydraulic servo valve acts as an intermediary component that translates electrical control signals into hydraulic actuation forces. This intermediary function enables rapid and precise control of multiple pump actuators by converting electronic commands from the engine controller into proportional hydraulic pressure, achieving fast response times.
Solution Approach 2:
The system utilizes hydraulic principles to achieve rapid actuator response. The electrohydraulic servo valve modulates hydraulic fluid flow to the actuators, leveraging the incompressibility and high energy density of hydraulic fluid to produce fast, responsive, and powerful actuation forces for precise pump displacement control.
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 system effectively manages the displacement of multiple pumps to achieve precise control over fuel flow rates, preventing backflow and optimizing engine performance by using an electrohydraulic servo valve and position sensors to communicate with the actuators and check valves.
Implementation Method 1
An electrohydraulic servo valve hydraulically connected to the first and second actuators
Implementation Method 2
A first check valve is downstream from the first pump. The first check valve prevents backflow into the first pumping assembly
Data Source
AI summary
A pumping system includes a first variable displacement pump having a first inlet and a first outlet. The first outlet is fluidically connected to a system outlet. A first actuator is mechanically coupled to a first displacement mechanism of the first variable displacement pump A second variable displacement pump includes a second inlet and a second outlet. The second outlet is fluidically connected to the system outlet. The pumping system also includes a second actuator mechanically coupled to a second displacement mechanism of the second variable displacement pump. An electrohydraulic servo valve is hydraulically connected to the first and second actuators. An electronic engine controller is in communication with the electrohydraulic servo valve and is configured to send electrical current to the electrohydraulic servo valve to drive the first actuator and the second actuator.