Linear Spool Pump Eliminates Rotary Friction

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Solution Overview

Problem

Conventional rotary volumetric pumps face inefficiencies due to high friction and internal leakage, requiring complex mechanical components and high initial force for operation, which increases costs and reduces pump life.

Innovation Solution

A pump architecture utilizing a spool and cooperating valve system, eliminating piston shoes and valve ports, and employing solenoid, piezoelectric, or memory material actuators to synchronize spool movement and valve positions for efficient fluid transfer between reservoirs, reducing friction and internal leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional rotary volumetric pumps use rotary shafts and mechanical devices (cams, sliding shoes) to convert rotational motion to linear motion, then fluid pumping function is achieved, but friction increases and pump efficiency decreases

Engineering Contradiction:
Improvepump efficiencyVSAvoidfriction
Core Design Contradiction:
Loss of energyVSForce

Solution Approach 1:

The patent replaces the conventional rotary mechanical system (rotary shafts, cams, sliding shoes) with a direct linear motion system using spools that move axially within cylinders. This substitution eliminates the need for rotary-to-linear motion conversion, thereby reducing friction and improving pump efficiency while maintaining the fluid pumping function.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention extracts and removes the rotary motion conversion components (cams, sliding shoes, rotary shafts) from the pump system. By taking out these friction-generating mechanical devices and replacing them with direct linear actuation via spools, the system achieves lower friction and higher efficiency without compromising pumping capability.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If conventional pumps use rotary shafts with high static friction, then rotational motion is achieved, but high initial force is required to start operation

Engineering Contradiction:
Improveinitial force requirementVSAvoidstatic friction
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The patent substitutes the rotary shaft system with high static friction with a linear spool system actuated directly by solenoids, piezoelectric actuators, or memory material actuators. This replacement eliminates the high static friction barrier to starting rotation, significantly reducing the initial force required to commence pump operation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If conventional pumps use complex mechanical components (piston shoes, valve ports, bearings), then motion conversion is achieved, but device complexity and cost increase

Engineering Contradiction:
Improvenumber of partsVSAvoidpump cost
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The invention extracts and removes complex mechanical components such as piston shoes, valve ports, and bearing assemblies from the pump system. By eliminating these parts and replacing them with simpler spool-and-cylinder assemblies actuated by modern actuators, the device complexity is reduced and manufacturing cost is lowered while maintaining pumping functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the fundamental operating parameters from rotary motion to linear motion, which enables the elimination of components designed for rotary operation (bearings, cam mechanisms, piston shoes). This parameter change simplifies the overall device structure and reduces manufacturing complexity and cost.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If conventional pumps use mechanical motion conversion devices, then rotary to linear motion transformation is achieved, but internal leakage increases and pump life decreases

Engineering Contradiction:
Improvepump lifeVSAvoidinternal leakage
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces the mechanical motion conversion system with a direct linear spool system that eliminates the wear and clearance issues associated with rotary-to-linear conversion mechanisms. This substitution reduces internal leakage paths and wear, thereby extending pump life and improving reliability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 configuration enhances pump efficiency, reduces initial force requirements, and extends pump life by minimizing friction and internal leakage, while also offering cost savings and redundancy in fluid pathways.

Implementation Method 1

Movement of the first spool in the first axial direction may draw fluid from the fluid inlet into the first chamber of the first valve, and push fluid from the second chamber of the first valve to the fluid outlet

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

employing solenoid, piezoelectric, or memory material actuators to synchronize spool movement and valve positions

Methodology Applied
Scientific EffectSolenoid effect: Solenoid

Implementation Method 3

employing solenoid, piezoelectric, or memory material actuators to synchronize spool movement and valve positions

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3425201B1Volumetric pump
Publication Date: 2020.03.04 GOODRICH ACTUATION SYST
  • EP3425201B1 patent drawingFigure 1A~1B
  • EP3425201B1 patent drawingFigure 1C~1D
  • EP3425201B1 patent drawingFigure 2A~2B

AI summary

An apparatus for pumping a fluid from a fluid inlet (90;92) to a fluid outlet (92;90) is disclosed. The apparatus comprises: a spool (14) axially movable within a cavity (40), wherein a first chamber (42) is located at a first axial end (46) of the cavity (40) and a second chamber (44) is located at a second axial end (48) of the cavity (40), wherein the volume of the first chamber (42) and the second chamber (44) varies depending upon the axial position of the spool (14) within the cavity (40); a valve (52) movable between a first position and a second position, wherein in the first position the valve (52) is configured to convey fluid from the fluid inlet (90;92) to the first chamber (42) and from the second chamber (44) to the fluid outlet (92;90), and in the second position the valve (52) is configured to convey fluid from the fluid inlet (90;92) to the second chamber (44) and from the first chamber (42) to the fluid outlet (92;90); and a control system configured to control the movement of the spool (14) and the valve (52).