Cutter Pump Adjustable Shredding Clearance Mechanism

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Solution Overview

Problem

Existing grinder pumps face challenges in adjusting the maceration clearance without requiring new machining, as sharpening the macerator elements often affects the hydraulic clearance, making it difficult to maintain optimal performance.

Innovation Solution

The design incorporates adjustable shredding clearance means, including three screws parallel to the axis and a washer, allowing for independent adjustment of the shredding and hydraulic clearances, ensuring that sharpening the macerator elements does not irreparably damage the hydraulic clearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the macerator elements (knife and ring) are sharpened, then the cutting performance is improved, but the hydraulic clearance is affected and requires re-machining

Engineering Contradiction:
Improvecutting edge sharpnessVSAvoidhydraulic clearance stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent divides the adjustment system into two independent segments: one for hydraulic clearance (adjusting the closing plate position) and one for shredding clearance (adjusting the ring position relative to the knife). This segmentation allows each clearance to be adjusted independently without affecting the other, resolving the contradiction where sharpening one element would previously require re-machining both clearances.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic adjustment mechanisms (screws and washers) that allow the clearances to be adjusted in use rather than being fixed during manufacturing. The hydraulic clearance can be adjusted by moving the closing plate, and the shredding clearance can be adjusted by moving the ring, enabling maintenance of optimal settings after sharpening without requiring re-machining.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the shredding clearance is adjusted by traditional methods, then the cutting performance is optimized, but the adjustment process is complex and requires new machining

Engineering Contradiction:
Improveshredding clearance accuracyVSAvoidadjustment simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent replaces static, fixed clearances with dynamic adjustment mechanisms. Three adjustment screws allow the ring to be moved axially to achieve the correct shredding clearance, and a washer can be added or removed to fine-tune the position. This dynamic system enables precise adjustment without complex machining operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the adjustable parameters from fixed geometric dimensions to variable positions controlled by screws and washers. The shredding clearance becomes a可调 parameter through the position of the ring relative to the knife, controlled by the adjustment screws, rather than a fixed dimension determined solely by machining.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If the macerator elements are resharpened multiple times, then the service life is extended, but the hydraulic clearance deteriorates irreparably

Engineering Contradiction:
Improvemator element lifespanVSAvoidhydraulic clearance integrity
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

By segmenting the adjustment system into independent hydraulic and shredding clearance controls, the patent allows the hydraulic clearance to be restored to its original setting after each sharpening cycle, preventing cumulative deterioration and enabling multiple resharpening cycles.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent incorporates preliminary adjustment features (adjustment screws and washers) that allow the hydraulic clearance to be pre-adjusted to optimal values before operation, and then restored to these values after sharpening, preventing the cumulative degradation that would otherwise occur with repeated sharpening.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2813707B1Cutter pump with adjusting means
Publication Date: 2016.07.13 KSB SAS
  • EP2813707B1 patent drawingFigure 1
  • EP2813707B1 patent drawingFigure 2
  • EP2813707B1 patent drawingFigure 3

AI summary

macerating pump, comprising a shaft (1) driven in rotation by a motor, an impeller (2) fixed in rotation to the shaft (1), conveyed fluid passing between a knife (6) fixed to the shaft (1) and a cutting ring (7), the knife (6) and the ring (7) are opposite each other by surfaces provided with macerating means, the distance or macerating gap between the knife (6) and the cutting ring (7) is adjustable by adjustment means (15).