Variable Spring Constant Support for Rotating Machine Vibration Measurement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional vibration measurement devices for high-speed rotating machines face challenges in accurately measuring unbalance vibrations over a wide speed range due to fixed supporting stiffness, difficulty in attaching acceleration sensors, and inadequate simulation of practical operation conditions, leading to incomplete balance measurements of both rigid-body and elastic modes.

Innovation Solution

A vibration measurement device with an elastic support structure having a variable spring constant, which elastically supports the rotating machine, allowing for flexible support and adjustable damping, enabling accurate measurement of both low-speed and high-speed operations and reducing unbalance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a rigid support structure with fixed supporting stiffness is used, then the device complexity is reduced, but the measurement precision of unbalance vibration cannot be maintained over a wide speed range

Engineering Contradiction:
Improveunbalance vibration measurement accuracyVSAvoidsupport structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The support structure is designed with variable spring constant, allowing it to dynamically adjust its supporting characteristics. The spring constant can be changed from first to second values, enabling the system to adapt to different operating conditions and maintain measurement precision across a wide speed range while avoiding the need for complex rigid structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the physical parameter of the support structure by using springs with variable spring constants. This allows the supporting stiffness to be adjusted according to different measurement requirements, improving measurement precision without requiring multiple fixed-structure configurations.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If acceleration sensors are attached on scrolls for mass production, then the ease of operation is improved, but the measurement precision is degraded due to modal mass influence and partial support

Engineering Contradiction:
Improvesensor attachment convenienceVSAvoidvibration measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The invention introduces an elastic support structure with variable spring constant as an intermediary between the rotating machine and the support base. This intermediary provides stable, full-area support that reduces vibration propagation and eliminates the problems of partial support and modal mass influence, while still allowing for practical sensor attachment procedures.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If natural frequencies of support conditions are set lower than practical operation conditions, then rigid-body mode balance can be measured, but elastic mode balance cannot be adequately measured

Engineering Contradiction:
Improverigid-body mode balance measurementVSAvoidmeasurement coverage for different modes
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The variable spring constant support structure can dynamically adjust its characteristics to match different measurement requirements. By changing the spring constant between first and second values, the system can be tuned to measure either rigid-body modes or elastic modes as needed, providing comprehensive measurement coverage that a fixed support structure cannot achieve.

Inventive Principle:
Principle #15Dynamics

4Measurement precision

If the balance of rigid-body modes is prioritized in support conditions, then low-speed measurement is improved, but high-speed elastic mode measurement capability is lost

Engineering Contradiction:
Improvelow-speed vibration measurement accuracyVSAvoidmeasurement speed range
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The invention changes the spring constant parameter of the support structure to match different operating speed ranges. At low speeds, one spring constant value optimizes rigid-body mode measurement, while at high speeds, a different spring constant value optimizes elastic mode measurement, enabling accurate measurements across the entire speed range.

Inventive Principle:
Principle #35Parameter changes

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 solution improves the accuracy of vibration measurements, allows for continuous balancing adjustments across different operational speeds, and reduces unbalance in rotating machines, enhancing productivity and noise reduction.

Implementation Method 1

an elastic support portion (4) that elastically supports the rotating machine (10) with respect to a support structure (2)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a vibration detection unit (3) that detects vibration of the rotating machine (10)

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP3163279B1Vibration measurement device for high-speed rotating machine, and vibration measurement method
Publication Date: 2021.08.04 MITSUBISHI HEAVY IND ENGINE & TURBOCHARGER LTD
  • EP3163279B1 patent drawingFigure 1
  • EP3163279B1 patent drawingFigure 2
  • EP3163279B1 patent drawingFigure 3

AI summary

This vibration measurement device is configured to measure the balancing vibration of the cartridge, a kind of rotating machines, who has a rotor and a cartridge body to support the rotor rotatably for variable operating speed, and is provided with a rigidly fixed support structure, acceleration sensors which detect the vibration of the cartridge, and a flat spring which elastically supports the cartridge with respect to the support structure and has a variable spring constant of elastic support.