Open-Center Hydraulic Valve Warmup for Cold Oil Response

Solution Overview

Problem

Existing methods for warming hydraulic oil in hydraulic systems, such as those in heavy machinery, often require additional components like valves and flushing circuits, increasing complexity and cost, and are not effective in Electro-Hydraulic (EH) systems where pilot passageways are restricted.

Innovation Solution

Utilizing existing open center valves in hydraulic systems to control the flow of hydraulic oil through neutral or intermediate positions, creating pressure drops to warm the oil without additional components, and adjusting pump flow rates to enhance warming efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If additional components like valves and flushing circuits are added to warm hydraulic oil, then the warming effectiveness is improved, but the device complexity and cost increase

Engineering Contradiction:

Improvehydraulic oil temperatureVSAvoidsystem complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The open center valve is designed to perform multiple functions: it serves as both a flow control valve for actuator operation and as a warming valve for hydraulic oil temperature control. By positioning the valve in neutral or intermediate states, the system creates pressure drops that generate heat to warm the oil, eliminating the need for separate warming components

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The hydraulic system uses its own existing components and operational states to warm the oil. The pump, valve, and actuator are utilized to create the necessary pressure differential for heating, with the system's own hydraulic oil serving as both the fluid to be warmed and the medium for heat transfer

Inventive Principle:

Principle #25Self-service

2Temperature

If additional components like valves and flushing circuits are added to warm hydraulic oil, then the warming effectiveness is improved, but the manufacturing cost increases

Engineering Contradiction:

Improvehydraulic oil temperatureVSAvoidmanufacturing cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The open center valve is designed to perform multiple functions: it serves as both a flow control valve for actuator operation and as a warming valve for hydraulic oil temperature control. By positioning the valve in neutral or intermediate states, the system creates pressure drops that generate heat to warm the oil, eliminating the need for separate warming components

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The hydraulic system uses its own existing components and operational states to warm the oil. The pump, valve, and actuator are utilized to create the necessary pressure differential for heating, with the system's own hydraulic oil serving as both the fluid to be warmed and the medium for heat transfer

Inventive Principle:

Principle #25Self-service

3Temperature

If conventional warming methods are used in Electro-Hydraulic systems, then warming is achieved, but the restricted pilot passageways reduce effectiveness

Engineering Contradiction:

Improvehydraulic oil temperatureVSAvoidwarming efficiency

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The system creates localized pressure drops at specific locations in the hydraulic circuit where the open center valve is positioned. By concentrating the pressure differential at these strategic points, the system generates sufficient heat locally to warm the oil effectively, overcoming the limitations of restricted pilot passageways

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The valve is dynamically positioned between neutral and intermediate states to create variable pressure drops. This dynamic positioning allows the system to optimize the pressure differential for warming purposes, adapting to different operating conditions and maintaining effectiveness despite restricted passageways

Inventive Principle:

Principle #15Dynamics

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 method effectively warms hydraulic oil without adding complexity or cost, improving system performance by maintaining or enhancing response in EH systems with restricted pilot passageways.

Implementation Method 1

pumping the oil though open center valves of the hydraulic system... cause the pump to flow the hydraulic oil to the valve... creating pressure drops to warm the oil

Methodology Applied

Scientific EffectPressure drop heating: Viscous Heating

Data Source

PatentUS20250382773A1Systems, methods and non-transitory computer-readable media for active hydraulic system warmup

Publication Date: 2025.12.18 DEERE & CO

AI summary

Systems, methods, and non-transitory computer-readable media for warming hydraulic oil. A system includes a pump, a valve including an open center passage, the valve being configured to return a hydraulic oil flow received from the pump to a hydraulic reservoir through the open center passage when the valve is in a first position, and pass the hydraulic oil flow to an actuator when the valve is in a work position, and processing circuitry configured to cause the hydraulic system to determine whether a current temperature of hydraulic oil is less than or equal to a target temperature, cause a position of the valve to be set to the first position in response to determining that the current temperature of the hydraulic oil is less than or equal to the target temperature, and cause the pump to flow the hydraulic oil to the valve.