Eccentric Joint for Torque and Axial Force Transmission

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Solution Overview

Problem

Existing solutions for transmitting and absorbing torques and axial forces in connection with eccentric rotary movements, particularly in pumps, are not economical, reliable, or uncomplicated, often relying on elastomers that can contaminate products and fail in aggressive media and varying temperatures.

Innovation Solution

A joint comprising a first rigid, elastic or freely rotatable part for axial force transmission/absorption and a torsion-resistant, flexible part for torque transmission, connected via a hydraulic clamping element without elastomers, allowing for efficient force transfer without contamination or media resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If elastomers are used for transmitting forces in the joint, then the joint can accommodate eccentric rotary movements, but the elastomers can contaminate products and fail in aggressive media and varying temperatures

Engineering Contradiction:
Improveability to accommodate eccentric rotary movementsVSAvoidresistance to aggressive media and temperature variations
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention extracts and removes elastomers from the force transmission path. The joint now transmits axial forces through a first joint part (pin, hinge, or flexure) and torques through a second joint part (casing), completely eliminating elastomers from the load-bearing components. This resolves the contradiction by maintaining movement accommodation through the articulated geometry while eliminating contamination and reliability issues associated with elastomers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a hydraulic clamping element as an intermediary connection between the drive and the joint. This clamping element provides a secure, elastomer-free connection that can accommodate movement while maintaining reliability in aggressive media. The hydraulic clamping mechanism allows for easy assembly and disassembly while ensuring firm mechanical connection without using elastomeric materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If elastomers are used in the joint, then the joint can provide flexible force transmission, but the elastomers require protection from aggressive media and temperature extremes

Engineering Contradiction:
Improveflexibility of force transmissionVSAvoidexposure to aggressive media and temperature
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The invention removes elastomers entirely from the force transmission system. Instead of protecting elastomers from harmful factors, the design eliminates them and uses rigid or semi-rigid components (first joint part for axial forces, second joint part for torques) that are inherently resistant to aggressive media and temperature variations. The flexibility is achieved through the articulated geometry of the joint parts rather than elastomeric materials.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If traditional joints with multiple components are used, then the joint can transmit forces, but the joint becomes complex and difficult to assemble

Engineering Contradiction:
Improveforce transmission capabilityVSAvoidnumber of components and assembly steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the functions of multiple traditional joint components into an integrated structure. The first joint part and second joint part work together as a unified system, with the first part handling axial forces and the second part handling torques. The hydraulic clamping element provides both connection and positioning functions. This integration reduces the number of separate components and simplifies assembly while maintaining reliable force transmission.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The joint design incorporates multi-functional elements. The first joint part serves both as a structural component and as the axial force transmission element. The second joint part provides both torque transmission and protective enclosure. The hydraulic clamping element simultaneously provides connection, positioning, and easy assembly/disassembly functionality. This multi-functionality reduces overall complexity.

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

4Reliability

If the joint uses separate parts for axial forces and torques, then the force transmission is optimized, but the joint requires precise alignment and assembly

Engineering Contradiction:
Improveoptimized force transmissionVSAvoidalignment and assembly precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The hydraulic clamping element serves as an intermediary that facilitates precise alignment during assembly. It provides a self-aligning mechanism that guides the first and second joint parts into their correct relative positions. The clamping action ensures proper positioning while allowing for minor adjustments, thereby reducing the stringency of manufacturing precision requirements without compromising the optimized force transmission through separate axial and torque components.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2686557B1Coupling to transmit torque and axial forces
Publication Date: 2015.08.19 NETZSCH PUMPEN & SYST
  • EP2686557B1 patent drawingFigure 1~2
  • EP2686557B1 patent drawingFigure 3~4

AI summary

The invention discloses a joint (10) for transmitting torques and axial forces in conjunction with an eccentric rotational movement. In a preferred embodiment, the joint according to the invention is used in an eccentric screw pump for connecting the drive input to the pump rotor. The joint connects a coupling rod (18) and a tool (20) and/or a drive input to one another. In the case of the joint being used in an eccentric screw pump, the tool is the rotor of the pump. The joint is furthermore provided with at least one casing. The axial forces which act on the joint can be transmitted by a first joint part (12) and the torques can be transmitted by a second joint part (14).