Axial Reciprocating Pump Mounting to Reduce Pump Rod Side Loading

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Solution Overview

Problem

Axial displacement pumps in fluid dispensing systems face challenges with the time-intensive process of attaching and detaching the pump rod from the reciprocating drive, and experience wear due to non-coincident driving forces, leading to reduced efficiency and lifespan.

Innovation Solution

A clamp arrangement with a movable tightening ring and a fixed axial ring is used to secure the displacement pump to the drive housing, aligning the pump rod's forces with the centerline and reducing side loading, while allowing for easy installation and removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pump rod is attached to the reciprocating drive by a pin, then the pump rod can be secured to the reciprocating drive, but the attachment and detachment process becomes time-intensive and requires loose parts and several tools

Engineering Contradiction:
Improvesecure attachment of pump rodVSAvoidtime-intensive attachment and detachment process
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The pump rod is integrated directly with the reciprocating drive mechanism, eliminating the need for separate pins and fasteners. The pump rod head is received within the drive cavity and secured through the clamp arrangement, merging previously separate components into a unified assembly that reduces attachment complexity and time

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pump rod is divided into functional segments (shaft, neck, head) with the head specifically designed to interface with the reciprocating drive. This segmentation allows the head to be received within the drive cavity and secured independently, facilitating easier attachment and detachment without requiring multiple loose parts

Inventive Principle:
Principle #1Segmentation

2Reliability

If the pump rod is secured with traditional mounting methods, then the pump can be attached to the drive housing, but the pump rod experiences driving forces not coincident with the centerline, causing wear on various components

Engineering Contradiction:
Improvesecure mounting of pumpVSAvoidwear on pump components due to misaligned forces
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The clamp arrangement employs an asymmetric configuration with a first clamp member positioned on one side of the pump rod and a second clamp member positioned on the opposite side. This asymmetric positioning of clamping elements creates balanced, symmetric clamping forces that align with the pump rod centerline, preventing misalignment and reducing wear on pump components

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The clamp arrangement acts as an intermediary mechanism between the drive housing and the pump rod. It provides a mounting interface that ensures driving forces are transmitted coincident with the pump rod centerline, mediating the force transmission to eliminate misalignment and reduce harmful wear on pump components

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If threaded connection is used to secure the axial displacement pump to the drive housing, then concentricity is provided, but the installation and removal process becomes complex and time-consuming

Engineering Contradiction:
Improveconcentricity of pumpVSAvoidinstallation and removal process
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The clamp arrangement employs movable clamping members that can be dynamically adjusted and positioned. The first and second clamp members can be moved into place and secured without requiring threaded fasteners, allowing for quick installation and removal while maintaining concentricity through proper positioning relative to the pump rod centerline

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3240956B1Integral mounting system on axial reciprocating pumps
Publication Date: 2024.07.17 GRACO MINNESTOA INC
  • EP3240956B1 patent drawingFigure 1
  • EP3240956B1 patent drawingFigure 2
  • EP3240956B1 patent drawingFigure 2A

AI summary

A displacement pump includes a pump rod having a load concentrating feature extending from the head of the pump rod. The head of the pump rod is received within a slot of a drive link, and the drive link is configured to contact the load concentrating feature. Having the drive link contact the smaller diameter load concentrating feature reduces the misalignment between the driving force and the center of the pump rod and thereby reduces side-loading experienced by the pump rod. The displacement pump is configured to be used in a fluid dispensing system.