Centerless Grinding Active Damping for Vibration Attenuation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Centerless grinding machines face challenges in attenuating vibrations generated during the grinding process, which affect precision and productivity, as existing solutions require precise knowledge of vibration dynamics and are not adaptable to varying vibration modes.

Innovation Solution

An active damping process using an inertial actuator introduces a damping force parallel to the grinding machine's force flow, measured and applied in real-time to attenuate vibrations, without modifying the machine's original properties, and can adapt to different vibration frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a passive actuator with suspended mass is used to attenuate vibrations, then damping is introduced, but the actuator becomes bulky and occupies excessive space in the machine

Engineering Contradiction:
ImprovevibrationsVSAvoidactuator volume
Core Design Contradiction:
Object-affected harmful factorsVSVolume of moving object

Solution Approach 1:

The patent replaces the passive mechanical actuator system (suspended mass) with an active control system using piezoelectric actuators and sensors. This substitution eliminates the need for bulky mechanical components while achieving vibration attenuation through controlled mechanical stress application.

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

Solution Approach 2:

The patent changes the approach from passive mass-based damping to active stress-based damping. By using piezoelectric actuators to apply controlled mechanical stress in response to sensor feedback, the system achieves vibration attenuation without requiring large physical mass, thus reducing actuator volume.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If a passive actuator with suspended mass is used to attenuate vibrations, then damping is introduced, but the actuator only works for a specific vibration mode and does not adapt to different vibration modes

Engineering Contradiction:
ImprovevibrationsVSAvoidvibration mode adaptability
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent implements a feedback control system where mechanical stress sensors detect vibrations and the controller processes this information to adjust piezoelectric actuator output in real-time. This closed-loop feedback enables the system to adapt to different vibration modes and frequencies dynamically.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from a static passive damping system to a dynamic active control system. The piezoelectric actuators can dynamically adjust their output based on real-time vibration conditions, allowing the system to adapt to varying vibration modes and frequencies during operation.

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If the piezoelectric actuator is arranged in series with the force flow of the grinding machine, then the damping force is introduced, but the actuator must provide rigidity at all times and the machine cannot work suitably if the actuator fails

Engineering Contradiction:
ImprovevibrationsVSAvoidmachine reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent introduces the piezoelectric actuator as an intermediary element arranged parallel to the force flow rather than in series. This allows the actuator to apply damping forces without bearing the full grinding load, reducing stress on the actuator and maintaining machine functionality even if the actuator fails.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent designs the actuator arrangement to prevent catastrophic failure. By positioning the actuator parallel to the force flow and using it as a supplemental damping element rather than a primary load-bearing component, the system cushions against potential actuator failure, ensuring the machine can continue to operate.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Object-affected harmful factors

If cancellation control strategy is used to eliminate constant vibrations, then vibrations are cancelled, but precise knowledge of vibration dynamics is required and the system is not adaptable to varying vibration modes

Engineering Contradiction:
ImprovevibrationsVSAvoidcontrol system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses feedback control where sensors continuously monitor vibrations and the controller adjusts actuator output in real-time. This feedback mechanism simplifies the control approach compared to cancellation strategies by directly responding to actual vibration conditions rather than requiring pre-programmed knowledge of vibration dynamics.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent implements a self-adjusting system where the vibration detection and control mechanisms work autonomously. The sensors detect vibrations and the controller automatically adjusts the piezoelectric actuators without requiring external intervention or precise pre-knowledge of vibration characteristics, making the system self-sufficient and adaptable.

Inventive Principle:
Principle #25Self-service

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

This approach effectively attenuates vibrations during the grinding process, improving precision and dynamic rigidity of the machine, reducing the force required for damping and eliminating the need for precise vibration knowledge, while ensuring machine operation even if the actuator fails.

Implementation Method 1

introducing an active damping force which attenuates vibrations produced due to the grinding process itself

Methodology Applied
Scientific EffectActive damping: Damping

Implementation Method 2

an inertial actuator acting directly on one of the heads

Methodology Applied
Scientific EffectInertial force: Inertia

Data Source

PatentEP3653336B1Actively dampened centerless grinding process
Publication Date: 2023.05.03 IDEKO SCOOP
  • EP3653336B1 patent drawingFigure 1~2
  • EP3653336B1 patent drawingFigure 3~4
  • EP3653336B1 patent drawingFigure 5~6

AI summary

The present invention relates to an actively dampened centerless grinding process for a centerless grinding machine having wheels (1, 2), between which there is arranged a part (3) to be ground, and heads (5, 6) carrying the wheels (1, 2), which process comprises moving the wheels (1, 2) closer to one another by applying pressure on the part (3) for the grinding thereof, such that vibrations are generated in the grinding machine due to grinding, measuring the vibrations due to grinding, and introducing, depending on said measurement, an active damping force (Fact) parallel to the force flow of the grinding machine and by means of using an inertial actuator (10) acting directly on one of the heads (5, 6), such that the vibrations due to grinding are attenuated.