Friction Fitting Coupling for Rotor Balancing

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Solution Overview

Problem

Existing couplings for rotor balancing tests are heavy, causing unbalance issues and require time-consuming, potentially damaging heat shrinking methods, which can compromise test accuracy and safety.

Innovation Solution

A friction fitting coupling design with a main body, extended insert, and torque screws that securely attach to the rotor without heat shrinking, reducing unbalance and improving attachment speed and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional heavy coupling is used for rotor balancing tests, then the coupling can transfer torque effectively, but it introduces significant unbalance and vibration that adversely affects test accuracy

Engineering Contradiction:
Improvetest accuracyVSAvoidcoupling weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The coupling is divided into multiple components: a drive shaft portion, a rotor interface portion, and multiple balancing masses. This segmentation allows each component to be optimized independently, with the balancing masses specifically designed to counteract the unbalance of other components, thereby reducing overall unbalance while maintaining effective torque transfer capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the weight distribution parameters of the coupling by adding adjustable balancing masses. These masses are positioned and sized to counterbalance the inherent unbalance of the coupling components, transforming the coupling from a source of unbalance to a balanced component that does not adversely affect test accuracy

Inventive Principle:
Principle #35Parameter changes

2Strength

If heat shrinking method is used to attach the coupling to the rotor, then the coupling can be securely attached, but the process is time-consuming and may damage the rotor surface

Engineering Contradiction:
Improveattachment strengthVSAvoidattachment time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The invention replaces the thermal process (heat shrinking) with a mechanical attachment system. The coupling is secured to the rotor through mechanical means such as keyways, set screws, or interference fits, which provide secure attachment without requiring thermal processing. This substitution eliminates the time-consuming heat treatment process and avoids potential thermal damage to the rotor surface while maintaining strong attachment

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The heat shrinking process is extracted and removed from the attachment method. Instead of using thermal expansion and contraction to secure the coupling, the invention uses purely mechanical attachment features that are simpler, faster, and less damaging to the rotor

Inventive Principle:
Principle #2Taking out (Extraction)

3Force

If a heavy coupling is used to ensure structural integrity, then the coupling can handle high torque, but it creates larger unbalance forces that ruin bearings during high-speed rotation

Engineering Contradiction:
Improvetorque transfer capabilityVSAvoidunbalance force
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The invention applies counterweight principles by incorporating balancing masses into the coupling structure. These masses are strategically positioned to counteract the unbalance forces generated by the coupling's own weight and geometry. The balancing masses create opposing centrifugal forces that cancel out the harmful unbalance forces, allowing the coupling to maintain its torque transfer capability without generating excessive unbalance forces that would damage bearings during high-speed rotation

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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

The friction fitting coupling reduces unbalance and attachment time, ensuring safer and more accurate rotor balancing tests with lower vibration levels compared to traditional methods.

Implementation Method 1

By providing a friction fitting between the coupling and the rotor to be tested, heat shrinking of the coupling onto the rotor can be avoided

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2510194B1Coupling for rotor balancing
Publication Date: 2016.04.13 NUOVO PIGNONE SPA
  • EP2510194B1 patent drawingFigure 1~2
  • EP2510194B1 patent drawingFigure 3
  • EP2510194B1 patent drawingFigure 4~7

AI summary

Systems, devices and methods according to these exemplary embodiments provide couplings or interfaces usable, for example, in the high speed balance testing of rotors. A coupling (40) includes a main body portion (46) having an extended thin portion (51) therein which is configured to fit a shaft (55) of the balancing machine and an extended insert portion (42) which is configured to fit an opening (32) in the rotor (30). A plurality of connection elements (48) is disposed m holes in the main body portion (46) of the coupling (40) and a ring (44) is disposed over the extended insert (42) and proximate exits of the holes in the main body portion (46).