Closed-loop hydraulic system with priority-based flow sharing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hydraulic systems face inefficiencies due to excessive flow losses, particularly in closed-loop systems where the third pump is connected in an open-loop manner, leading to suboptimal performance compared to meterless hydraulic systems.
Innovation Solution
A hydraulic system with multiple pumps and actuators connected in closed-loop configurations, utilizing a selector valve and switching valves to manage fluid flow between circuits, allowing for priority-based sharing and efficient operation by directing pressurized fluid selectively between actuators and circuits, thereby minimizing unnecessary fluid restriction and flow losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the third pump is connected in open-loop manner to provide additional flow to first and second circuits, then flow availability is improved, but energy losses increase
Solution Approach 1:
A third closed-loop circuit is introduced as an intermediary pathway between the third pump and the first/second circuits. This mediator circuit allows flow transfer while maintaining closed-loop efficiency, avoiding direct open-loop connections that cause energy losses. The third circuit acts as a buffer that preserves hydraulic efficiency while enabling flow sharing.
Solution Approach 2:
The patent utilizes hydraulic principles by implementing a third closed-loop hydraulic circuit that operates on the same closed-loop principles as the first two circuits. This hydraulic intermediary circuit maintains pressure and flow efficiency through closed-loop operation, allowing the third pump to contribute flow to the system without the energy penalties of open-loop operation.
2Speed
If fluid restriction is used to control actuator speed in open-loop system, then speed control is achieved, but flow losses increase reducing overall efficiency
Solution Approach 1:
The patent replaces the mechanical fluid restriction method with a hydraulic circuit substitution. Instead of using throttling valves to control speed (which waste energy), the system uses a third closed-loop circuit with switching valves to redirect flow. This substitutes the mechanical restriction approach with a hydraulic routing approach that maintains efficiency.
Solution Approach 2:
The patent changes the system configuration parameter from open-loop to closed-loop for the third pump circuit. This parameter change fundamentally alters how flow is managed, allowing speed control through flow distribution rather than restriction, thereby maintaining hydraulic efficiency while achieving the desired actuator speed control.
3Loss of energy
If closed-loop configuration is used for each pump-actuator pair, then energy efficiency is improved, but system complexity increases
Solution Approach 1:
The patent merges three separate closed-loop circuits into an integrated system where the third circuit can share flow with the first two circuits. By combining the benefits of closed-loop operation across all three circuits and enabling them to work together through the selector valve, the system achieves high efficiency while managing complexity through unified design principles.
Solution Approach 2:
The third closed-loop circuit is designed with multi-functionality, capable of operating independently for the third actuator or transferring flow to support the first and second circuits. This universal design allows the same closed-loop configuration to serve multiple purposes, reducing overall system complexity while maintaining energy efficiency across all operating modes.
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 enhances hydraulic efficiency by reducing energy wastage, allowing for priority-based flow sharing and potentially eliminating the need for metering valves, resulting in improved energy usage and system simplicity.
Implementation Method 1
the pump draws fluid from one chamber of the actuator(s) and discharges pressurized fluid to an opposing chamber of the same actuator(s)
Data Source
AI summary
A hydraulic system is disclosed having first, second, and third pumps. The hydraulic system may also have a first actuator connected to the first pump in closed-loop manner, a second actuator connected to the second pump in closed-loop manner, and a third actuator. The hydraulic system may further have a selector valve associated with the third pump, and a first switching valve associated with the third pump and the third actuator. The first switching valve may be movable between a first position at which the third pump is connected to the third actuator in a closed-loop manner to move the third actuator in a first direction, a second position at which the third pump is connected to the third actuator in a closed-loop manner to move the third actuator in a second direction, and a third position at which the third pump is connected to the selector valve.