Dual-Source Hydraulic Actuator Make-Up System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In hydraulic systems for dumping loads, particularly with materials like those from the Canadian oil sands that tend to adhere and dump as a single unit (loafing), the existing passive fluid make-up arrangements are inadequate to prevent severe vacuum formation and rapid retraction of actuators, posing risks to operators and machinery.
Innovation Solution
A hydraulic system with a dual-source fluid supply and selectively actuatable valves that provide supplemental fluid to the head chamber when the second pressure is greater than the first, ensuring adequate fluid flow to prevent vacuum formation during overrunning loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a passive hydraulic tank is provided as an external source of make-up flow, then the system structure is simple, but the make-up flow is inadequate to meet the needs of an overrunning actuator
Solution Approach 1:
The patent combines the hydraulic tank and pump into an integrated hydraulic power unit. The tank provides fluid storage while the pump actively delivers controlled make-up flow to the actuator head chamber, ensuring adequate fluid supply during overrunning conditions without requiring separate external components.
Solution Approach 2:
The hydraulic system is designed to self-regulate fluid make-up during actuator operation. The pump automatically provides supplemental flow when the actuator experiences overrunning conditions, eliminating the need for external active control systems or additional make-up components.
2Reliability
If the flow of fluid to the head chamber is inadequate, then the system structure is simple, but a severe vacuum develops in the head chamber causing rapid actuator retraction
Solution Approach 1:
The hydraulic tank is pre-filled with sufficient hydraulic fluid to provide make-up flow during actuator operation. The pump is positioned and configured to immediately deliver supplemental flow when needed, preventing vacuum formation before it can cause actuator retraction.
Solution Approach 2:
The system incorporates a cushioning effect through the hydraulic tank's fluid reservoir and the pump's ability to deliver supplemental flow. This cushioning prevents the severe vacuum conditions that would otherwise cause rapid actuator retraction by maintaining adequate fluid pressure and flow to the head chamber.
3Reliability
If a dual-source fluid supply with selectively actuatable valves is used, then adequate fluid flow is provided to prevent vacuum formation, but the device complexity increases
Solution Approach 1:
The selectively actuatable valve is controlled by a sensor that detects pressure or flow conditions in the actuator head chamber. When the sensor detects inadequate fluid flow or pressure drop indicating overrunning conditions, it automatically activates the pump to provide supplemental make-up flow, creating a closed-loop feedback control system.
Solution Approach 2:
The selectively actuatable valve acts as an intermediary between the pump and the actuator head chamber. It controls when the pump's supplemental flow is delivered, allowing precise regulation of make-up flow based on actual actuator needs without requiring direct complex control of the pump itself.
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 solution effectively reduces the risk of rapid actuator retraction and associated hazards by maintaining stable fluid pressure, minimizing the impact of overrunning loads and loafing phenomena, thereby enhancing operator safety and machine reliability.
Implementation Method 1
a first pump adapted to provide hydraulic fluid from the first source to the head chamber. The hydraulic fluid from the first pump is provided to the head chamber at a first pressure Ph
Implementation Method 2
The second source is adapted to provide hydraulic fluid at a second pressure Pb. The at least one valve provide hydraulic fluid from the second source to supplement hydraulic fluid provided to the head chamber from the first pump when the second pressure Pb is greater than the first pressure Ph
Implementation Method 3
at least one selectively actuatable valve fluidly coupled to the second source. The at least one valve provide hydraulic fluid from the second source to supplement hydraulic fluid provided to the head chamber from the first pump when the second pressure Pb is greater than the first pressure Ph
Implementation Method 4
ensuring adequate fluid flow to prevent vacuum formation during overrunning loads
Data Source
AI summary
A hydraulic system having an actuator having a piston and associated rod forming head and rod chambers and being adapted to move between retracted and extended positions within a cylinder, and first and second sources of fluid. A first pump provides fluid from the first source to the head chamber at a first pressure. At least one valve provides fluid from the second source at a second pressure to supplement fluid provided to the head chamber from the first pump when the second pressure is greater than the first pressure.