Reciprocating Diaphragm Pump Piston Guidance Integration

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Solution Overview

Problem

The existing reciprocating positive-displacement diaphragm pumps for liquids face high manufacturing costs due to the need for a guide cylinder, which increases production and management expenses, and results in a larger, heavier pump with more environmental impact.

Innovation Solution

The rear pump tank serves both to contain oil and guide the piston, eliminating the need for a separate guide cylinder, allowing for a more compact and lighter design with reduced oil volume and lower production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate guide cylinder is used to guide the piston, then the piston guidance function is achieved, but the pump becomes larger, heavier, and more expensive to manufacture

Engineering Contradiction:
Improvepiston guidanceVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the guidance function into the piston rod itself by adding guide surfaces directly to the rod, eliminating the separate guide cylinder. This merging of functions reduces the number of components while maintaining reliable piston guidance throughout the pumping cycle.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The piston rod is designed to serve multiple functions: it transmits the reciprocating motion from the drive mechanism, provides guidance for the piston through its guide surfaces, and maintains sealing with the pump chamber. This multi-functionality eliminates the need for a dedicated guide cylinder.

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

2Reliability

If a separate guide cylinder is used to guide the piston, then the piston guidance function is achieved, but the production costs and management expenses increase

Engineering Contradiction:
Improvepiston guidanceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By integrating the guide surfaces directly onto the piston rod, the patent eliminates the separate guide cylinder component. This reduces manufacturing costs by removing an additional machining operation, assembly step, and inventory item, while still providing reliable piston guidance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The guidance function is extracted from the separate guide cylinder and transferred to the piston rod itself. This extraction eliminates the need for the additional component and its associated manufacturing and management expenses.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If a separate guide cylinder is used, then the piston can be guided, but the pump design becomes larger and heavier

Engineering Contradiction:
Improvepiston guidanceVSAvoidpump weight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent merges the guidance function into the existing piston rod structure, eliminating the need for a separate guide cylinder. This integration reduces the overall weight of the pump while maintaining reliable piston guidance throughout the reciprocating motion cycle.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If a separate guide cylinder is used, then the piston can be guided, but the pump occupies more space

Engineering Contradiction:
Improvepiston guidanceVSAvoidpump volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

By integrating the guide surfaces onto the piston rod and eliminating the separate guide cylinder, the patent reduces the overall volume occupied by the pump components. This merging of functions creates a more compact design while maintaining reliable piston guidance.

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 design reduces manufacturing costs, minimizes environmental impact, and simplifies assembly by eliminating the guide cylinder, resulting in a more economical and environmentally friendly pump.

Implementation Method 1

a flexible diaphragm (15), which separates the chamber (10) from the cylinder mouth (11 a)... subject to a reciprocating movement... which, together with a cylinder head (26) circumscribes a volume variable between a maximum value and a minimum value (capacity) into which the fluid enters and exits in a reciprocating motion

Methodology Applied
Scientific EffectReciprocating motion:

Implementation Method 2

the flow being regulated by valves (27a and 27b) of the unidirectional type, respectively aspirating and delivery, with automatic opening

Methodology Applied
Scientific EffectValve operation:

Implementation Method 3

The piston (12) comprises an elastic wiper ring (13), which realizes the seal by acting against the guide surface (11 b) of the cylinder (11)

Methodology Applied
Scientific EffectSealing:

Implementation Method 4

The pressure energy is transferred to the liquid (water) to be pumped directly from the diaphragm (15) which is pushed, during this phase, by the piston (12), in part by direct action, and in part by the mass of thrust oil enclosed in the thrust chamber (17)

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP2871362B1A reciprocating positive-displacement diaphragm pump for liquids
Publication Date: 2016.06.15 IMOVILLI POMPE
  • EP2871362B1 patent drawingFigure 1
  • EP2871362B1 patent drawingFigure 2
  • EP2871362B1 patent drawingFigure 2A

AI summary

The pump comprises at least a piston-cylinder group, having a liquid pump chamber (30), and a piston-cylinder pair. A flexible diaphragm (35) separates the pump chamber (30) from the cylinder mouth (31), which is connected to the front thrust surface of the piston (32); a thrust chamber (37), external of the pump chamber (30), is delimited between the diaphragm (35), the thrust surface of the piston (32) and the guide surface (31 b) of the cylinder, and is sealedly closed and filled with non-compressible thrust oil. The rear tank is delimited on the front transversal side by the piston and on the lateral side by a tubular lateral wall (41), comprising a front portion having an internal surface which defines the cylindrical guide surface (31 b) for the piston (32) and a rear portion (41 a) joined to the front portion. To restore the thrust oil level, lost by leakage from the thrust chamber to the rear tank, the tubular wall 41 comprises at least an open-topped groove (31 b), and facing the lateral surface (32b) of the piston, which develops substantially axially, having a rear end connected to the rear tank (40) and a front end that when the piston (32) is in the environs of the bottom dead centre, opens frontally of the front seal edge (33a) and communicates with the thrust chamber (37).