Shaft Seal Conveying Thread for Uniform Lubricant Distribution

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Solution Overview

Problem

Existing container designs for holding thick materials, such as liquid concrete, face issues with uneven contamination flushing and maintenance challenges due to the lack of guaranteed even lubrication and contamination removal around the shaft bearing, leading to potential damage and maintenance difficulties.

Innovation Solution

The shaft seal is enhanced with a radially facing delivery thread that communicates with the container interior via a check valve, ensuring even lubrication and flushing, and an anti-twist device ensures consistent lubricant delivery, while a multi-start helix design facilitates active flushing and contaminant removal, with redundant sealing levels for durability and easy maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a shaft seal with a circumferential lip seal is used to bridge the annular gap, then the seal provides basic protection, but the lubricant is forced out at an undefined location and contaminants are not flushed uniformly across the entire circumference

Engineering Contradiction:
Improvesealing performanceVSAvoidcontaminant flushing uniformity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The delivery thread is pre-formed on the shaft seal surface to guide and direct the lubricant flow before it exits the bearing sleeve. This preliminary structural arrangement ensures that lubricant is systematically distributed across the entire shaft circumference rather than being randomly forced out, achieving uniform contaminant flushing while maintaining sealing effectiveness

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The delivery thread acts as an intermediary structure between the lubricant supply and the external environment. It mediates the lubricant flow by channeling it through a controlled path that ensures even distribution around the shaft circumference, thereby solving the problem of non-uniform contaminant removal while preserving the seal's protective function

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the shaft seal is designed as a single integrated component, then the structure is simple, but disassembly is required for maintenance which is complex and time-consuming

Engineering Contradiction:
Improveseal structure simplicityVSAvoidmaintenance accessibility
Core Design Contradiction:
Device complexityVSEase of repair

Solution Approach 1:

The shaft seal is segmented into multiple independent components that can be separately installed and removed. This segmentation allows the seal to be maintained by simply replacing the seal elements without disassembling the entire bearing sleeve or pipe diverter, thereby simplifying maintenance procedures while maintaining structural simplicity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The seal components are designed to nest within the bearing sleeve structure, with seal elements positioned inside the sleeve that can be accessed and replaced through the same opening used for lubricant supply. This nested arrangement allows easy maintenance access while preserving the compact overall structure

Inventive Principle:
Principle #7Nested doll (Nesting)

3Productivity

If the lubricant pressure is increased to improve flushing effectiveness, then contaminant removal improves, but the risk of lubricant leakage and seal damage increases

Engineering Contradiction:
Improvecontaminant flushing efficiencyVSAvoidseal damage risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The delivery thread creates localized flow channels on the shaft seal surface that efficiently direct lubricant flow exactly where needed - across the shaft circumference. This localized quality of flow distribution achieves effective contaminant flushing with moderate lubricant pressure, avoiding the need for high pressure that could damage the seal or cause leakage

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2992211B1Container for accommodating high-viscosity materials
Publication Date: 2020.06.24 PUTZMEISTER ENG GMBH
  • EP2992211B1 patent drawingFigure 1a~1d
  • EP2992211B1 patent drawingFigure 2
  • EP2992211B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a container for accommodating high-viscosity materials, such as liquid concrete. The container (10) has at least one bearing sleeve (58), which extends through a wall opening and is fastened in the container wall in a liquid-tight manner. A shaft (28) extends through the bearing sleeve (58) in such a way that an annular gap (62) is left open. A shaft seal (64), which bridges the annular gap (62) and is made of elastomeric material, is located at the container-interior end of the bearing sleeve (58). A lubricant is applied to the annular gap (62) from the container exterior. The invention is characterised in that the shaft seal (64) has, on the side thereof radially facing the shaft (28), a conveying thread (68) that supports the conveying of the lubricant in the direction of the container interior, which conveying thread advantageously communicates with the container interior via a check valve (70) open to the container interior.