Double Piston Pump with Pressure-Sensitive Motor Engagement

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Solution Overview

Problem

Existing fluid delivery devices with motors coupled to pumps face challenges in achieving low energy requirements and low losses while maintaining a simple mechanical design and high safety levels, particularly in applications requiring pressure regulation without electrical components.

Innovation Solution

A delivery device featuring a double piston pump with a non-positive connection to a motor, where the piston rod engages only when the working-side pressure falls below a target pressure, utilizing mechanical check valves and an eccentric disk mechanism to self-regulate and minimize energy consumption, eliminating the need for pressure sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a motor is coupled to a pump with a double piston to achieve pressure regulation, then pressure control capability is improved, but energy consumption increases and mechanical complexity increases

Engineering Contradiction:
Improvepressure control capabilityVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The pump operates in periodic cycles, engaging the motor only when pressure falls below the target pressure. The non-positive connection allows the piston rod to automatically disengage when target pressure is reached, creating a periodic on-demand operation pattern that reduces energy consumption compared to continuous operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system uses the pressure differential itself to control the engagement and disengagement of the piston rod with the motor. The mechanical design allows automatic self-regulation where the pressure conditions directly control the operational state without requiring external monitoring or control systems.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If pressure sensors and electrical components are used to control pump operation, then pressure regulation precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvepressure regulation precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces electrical pressure sensors and electronic control systems with a purely mechanical pressure-sensitive connection mechanism. The piston rod's non-positive connection to the motor provides automatic mechanical control based on pressure conditions, eliminating the need for electrical components while maintaining precise pressure regulation.

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

Solution Approach 2:

The mechanical connection automatically responds to pressure changes through the inherent mechanics of the system. When target pressure is reached, the pressure differential causes automatic disengagement of the piston rod from the motor, providing self-regulating control without external monitoring systems.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If the piston rod is always connected to the motor to maintain continuous pressure, then pressure stability is improved, but energy consumption and mechanical wear increase

Engineering Contradiction:
Improvepressure stabilityVSAvoidenergy loss
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

Instead of continuous connection, the system uses periodic engagement where the piston rod connects to the motor only when pressure drops below the target. This periodic action maintains adequate pressure stability while avoiding the energy waste and mechanical wear associated with continuous operation at maximum pressure.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The connection between the piston rod and motor is made dynamic rather than static. The non-positive connection allows the system to adapt its degree of connection based on operational needs, being connected when pressure is low and disconnected when target pressure is reached, optimizing both stability and energy efficiency.

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

The solution enables efficient, low-noise, and low-wear fluid delivery with minimal energy usage, achieving maximum pressure with minimal force and ensuring safety without monitoring or control systems, suitable for both hydraulic and pneumatic applications.

Implementation Method 1

the piston rod engages only when the working-side pressure falls below a target pressure

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

The check valves are mechanical components. When the pressure in the working circuit increases, the first and second check valves open the corresponding flow cross-sections

Methodology Applied
Scientific EffectPressure-driven valve operation: Valve

Implementation Method 3

the free end of the piston rod 4 is associated with an eccentric disk 5 which is connected to a motor

Methodology Applied
Scientific EffectEccentric mechanism: Eccentric

Data Source

PatentEP3084212B1Conveying device for a fluid
Publication Date: 2020.06.10 STOCK GERHARD
  • EP3084212B1 patent drawingFigure 1

AI summary

The invention relates to a conveying device for a fluid, comprising a motor coupled to a pump (1). The pump (1) comprises a double piston (3), which is movably supported in a cylinder (2) and has a piston rod (4) on one side, which is detachably connected to the motor in a force-closed manner in such a way that there is a connection only if the charge pressure on a working side of the double piston (3) is less than a target pressure, the cylinder (2) is coupled to a supply (9) on the side facing the piston rod (4), and the cylinder (2) is connected on the side facing away from the piston rod (4) to the working side and and the supply (9) by means of valves.