Hydraulic Spool Valve Recirculation Between Actuation Chambers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing hydraulic fluid control systems for internal combustion engines are inefficient in recirculating and reusing hydraulic fluid, leading to increased power requirements and fluid consumption, which can be reduced by implementing a hydraulic fluid control valve that effectively routes and recirculates hydraulic fluid between actuation chambers.

Innovation Solution

A hydraulic fluid control valve with a spool and one-way valves that continuously connect apertures to allow fluid flow from one actuation chamber to another, reducing fluid consumption by routing excess hydraulic fluid back to the other chamber for replenishment, thereby optimizing fluid usage and reducing venting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If hydraulic fluid is not recirculated from the reservoir after actuation, then the hydraulic system can operate simply, but the pump size and power consumption increase due to high fluid volume requirements

Engineering Contradiction:
Improvehydraulic fluid volumeVSAvoidpump power consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent implements a recirculation system that recovers hydraulic fluid from the actuation chambers and returns it to the reservoir, then recirculates it back to the actuation chambers. This continuous recovery and reuse of hydraulic fluid reduces the total volume of fluid needed in the system, thereby reducing pump size and power consumption requirements.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The patent establishes a continuous recirculation loop where hydraulic fluid is constantly moved from the actuation chambers through the reservoir and back to the actuation chambers. This continuous cycle ensures that fluid is always available for actuation without requiring large volumes of fresh fluid, optimizing pump performance and reducing energy consumption.

Inventive Principle:
Principle #20Continuity of useful action

2Use of energy by moving object

If hydraulic fluid is recirculated from the reservoir, then pump size and power consumption are reduced, but the valve structure becomes more complex with multiple apertures and annuli

Engineering Contradiction:
Improvepump power consumptionVSAvoidvalve structure complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The spool assembly is designed as a multi-functional component that simultaneously performs several functions: controlling fluid flow between actuation chambers, managing recirculation paths, regulating pressure, and directing fluid to the reservoir. By integrating these multiple functions into a single spool structure with strategically positioned apertures and annuli, the patent achieves efficient recirculation without proportionally increasing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent employs a nested configuration where the spool is positioned within the valve body, with the spool itself containing internal apertures and annular structures. The first aperture is arranged within the spool, the second aperture within the spool's annular region, and the third aperture at the spring end. This nested arrangement allows multiple fluid paths to be integrated within a compact geometry, reducing the need for separate external components.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Productivity

If a spool with multiple apertures and annuli is used for fluid recirculation, then hydraulic fluid management efficiency is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvehydraulic fluid management efficiencyVSAvoidaperture and annulus dimensional precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent combines multiple fluid control functions into a single integrated spool assembly, merging the control of primary actuation flow and secondary recirculation flow into one component. By consolidating these functions, the design reduces the number of separate precision-critical features that would otherwise require independent manufacturing and assembly, thereby lowering overall manufacturing precision requirements while maintaining high fluid management efficiency.

Inventive Principle:
Principle #5Merging (Combining)

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 reduces hydraulic fluid consumption and enhances the system's responsiveness to pressure changes, improving the efficiency of hydraulic actuation in camshaft phasers and similar components by recirculating fluid, thus minimizing the power required from the hydraulic fluid pump.

Implementation Method 1

a one-way valve arranged between the spool and an inner surface of the bore of the housing. The one-way valve can be configured to: i) allow hydraulic fluid to flow from the outer annulus to the first and second hydraulic actuation chambers, and ii) prevent hydraulic to flow from the first and second hydraulic actuation chambers to the outer annulus

Methodology Applied
Scientific EffectOne-way valve: Valve

Implementation Method 2

The first aperture can be configured to receive hydraulic fluid from a pressurized hydraulic fluid source. The inner fluid chamber is configured to flow hydraulic fluid from the first aperture to the second aperture, and from the first aperture to the third aperture

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Data Source

PatentUS20220298933A1Recirculating hydraulic fluid control valve
Publication Date: 2022.09.22 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • US20220298933A1 patent drawing
  • US20220298933A1 patent drawing
  • US20220298933A1 patent drawing

AI summary

A hydraulic fluid control valve (HFCV) configured to recirculate an exiting hydraulic fluid from a first hydraulic actuation chamber to a second hydraulic actuation chamber is provided. The HFCV includes a selectively movable spool having an outer annulus configured to receive and deliver the exiting hydraulic fluid to one or both of either a sump or one of the first or second hydraulic actuation chambers.