Header Hydraulic Cooler Isolation Circuit for High-Pressure Bypass
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Solution Overview
Problem
Hydraulic fluid coolers in agricultural harvester headers are prone to damage from high pressures, leading to external oil leaks and downtime due to the inability to withstand pressure drops along the hydraulic system.
Innovation Solution
A hydraulic cooler pressure isolation circuit is implemented, featuring a hydraulic fluid cooler, supply and return lines, and a drain line, along with a series of valves that allow hydraulic fluid to bypass the cooler during high-pressure conditions, directing excess pressure through a drain line to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the hydraulic cooler is located on the low-pressure return line, then the cooler is protected from high pressure damage, but the cooler cannot effectively cool the hydraulic fluid under high-pressure conditions
Solution Approach 1:
A pressure isolation valve is introduced as an intermediary component between the hydraulic cooler and the high-pressure hydraulic circuit. This valve acts as a mediator that allows the cooler to remain connected to the hydraulic system while blocking high-pressure fluid from reaching the cooler, thereby protecting the cooler while maintaining its cooling function.
Solution Approach 2:
The hydraulic circuit is segmented into high-pressure and low-pressure zones using the pressure isolation valve. The cooler is positioned in the low-pressure zone while the main hydraulic circuit operates at high pressure, allowing both high-pressure operation and cooler protection to coexist.
2Loss of energy
If the hydraulic cooler is placed closer to the reservoir, then pressure drops are reduced, but the cooler is still exposed to high-pressure conditions that can cause damage
Solution Approach 1:
The pressure isolation valve serves as a mediator that decouples the pressure conditions from the cooler location. Even when the cooler is positioned close to the reservoir to minimize pressure drops, the valve ensures that the cooler operates in a low-pressure environment, protecting it from high-pressure damage.
3Temperature
If high-pressure hydraulic fluid flows through the cooler, then cooling efficiency is improved, but the cooler experiences damage and external oil leaks occur
Solution Approach 1:
The pressure isolation valve is positioned between the high-pressure hydraulic circuit and the cooler, acting as a protective mediator. It allows cooling to occur while preventing high-pressure fluid from directly contacting the cooler, thereby eliminating the harmful effect of high pressure on the cooler.
Solution Approach 2:
The system converts the potentially harmful high-pressure condition into a beneficial arrangement by using the pressure isolation valve to create a pressure differential that protects the cooler while still allowing effective cooling to occur through the controlled flow of hydraulic fluid.
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 circuit effectively isolates the hydraulic fluid cooler from damaging high pressures, preventing damage and reducing downtime by diverting high-pressure fluid away from the cooler and into the reservoir.
Implementation Method 1
a hydraulic fluid cooler positioned at a location in the air stream path to provide cooling of the hydraulic fluid
Implementation Method 2
a first valve positioned in the supply line upstream of the hydraulic fluid cooler, a second valve positioned in the return line downstream of the hydraulic fluid cooler
Data Source
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AI summary
A hydraulic cooler pressure isolation circuit (200, 200A, 200B) for a header (102) of an agricultural harvester (100) equipped with a reservoir (202, 202a, 202b) and a pump (204, 204a, 204b). The circuit comprises a hydraulic fluid cooler (270, 270a, 270b), a supply line (206, 206a, 206b) extending from the hydraulic fluid cooler (270, 270a, 270b) to the pump (204, 204a, 204b), a return line (207, 207a, 207b) extending from the hydraulic fluid cooler (270, 270a, 270b) to the reservoir (202, 202a, 202b), and a drain line (208, 208a, 208b) operatively in fluid communication with the return line (207, 207a, 207b) for connecting to the reservoir (202, 202a, 202b). A first valve (210, 210a, 210b), a second valve (220, 220a, 220b), a return valve (250, 250a, 250b), and a bypass valve (260, 260a, 260b) of the circuit operate to direct hydraulic fluid flow through the cooler (270, 270a, 270b) under normal system operating conditions, and direct hydraulic fluid flow to bypass the cooler (270, 270a, 270b) when the system experiences high pressure operating conditions at the cooler (270, 270a, 270b).