Resonance Torsion Test Bench Fluidic Stiffness Control

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Solution Overview

Problem

Existing resonance torsion testing devices face limitations in design of the torsional vibration system, soft coupling of static loads, and axial length, as well as options for influencing torsional stiffness, which affect the efficiency and flexibility of testing.

Innovation Solution

A mechanical-fluidic torsional vibration system is introduced, utilizing a fluid to influence rigidity and damping, allowing for adjustable static test load components and reduced axial length, with a rotary cylinder and vane mechanism that changes fluid chamber volumes to generate dynamic and static test loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a mechanical-fluidic torsional vibration system is used with adjustable fluid pressure, then the torsional stiffness and resonant frequency can be influenced, but the device complexity increases

Engineering Contradiction:
Improveoptions for influencing torsional stiffnessVSAvoiddesign of the torsional vibration system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies pneumatic principles by introducing a fluid (gas or liquid) into the torsional vibration system. The fluid pressure can be adjusted to influence the torsional stiffness of the system. When the fluid pressure increases, the torsional stiffness increases, which in turn affects the resonant frequency. This allows for continuous adjustment of system parameters without changing the mechanical structure, thereby resolving the contradiction between adaptability and device complexity.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent changes the physical parameter of the fluid (pressure) to control the torsional stiffness of the vibration system. By adjusting the fluid pressure, the resonant frequency can be tuned without modifying the mechanical components. This parameter-based control approach provides versatility while maintaining a relatively simple device structure, as it avoids complex mechanical adjustment mechanisms.

Inventive Principle:
Principle #35Parameter changes

2Force

If a loading sleeve with loading lever is used to apply static load, then the static test load component can be generated, but the axial length of the device increases

Engineering Contradiction:
Improvestatic test load componentVSAvoidaxial length
Core Design Contradiction:
ForceVSLength of stationary object

Solution Approach 1:

The patent extracts the function of the loading sleeve and loading lever from the mechanical structure and replaces it with a fluid-based loading mechanism. The static load is applied through fluid pressure acting on a piston or diaphragm, which eliminates the need for long mechanical leverage arms. This extraction of the mechanical loading function reduces the axial length while maintaining the ability to generate the required static test load component.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses pneumatic or hydraulic pressure to generate the static test load component directly, replacing the mechanical loading sleeve and lever system. The fluid pressure can be controlled to provide the desired static load without requiring additional axial space for mechanical leverage, thereby reducing the overall device length while maintaining force application capability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Power

If resonance vibration is used to generate dynamic test load, then large dynamic test load components can be generated with small energy input, but the device complexity increases

Engineering Contradiction:
Improvedynamic test load componentVSAvoidtorsional vibration system
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent utilizes mechanical vibration at the resonant frequency of the torsional system to generate large dynamic test load components. By exciting the system at its natural resonant frequency, the dynamic amplification effect allows a small actuator to produce large torsional moments on the test specimen. This resonance-based approach efficiently generates high power output from a low-power actuator.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent adjusts the resonant frequency of the torsional vibration system by changing the fluid pressure in the pneumatic or hydraulic system. Since the resonant frequency depends on the torsional stiffness, and the fluid pressure controls the stiffness, tuning the fluid pressure allows optimization of the resonance condition. This enables the system to operate at maximum efficiency with minimal energy input from the actuator.

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

This design enhances the flexibility and efficiency of resonance torsion testing by allowing for adjustable test loads and reduced device length, improving the testing process for components like shafts.

Implementation Method 1

The fluid, the resilient property of which is utilized, makes it possible to influence the torsional vibration system in a variety of ways. The choice of fluid can thus influence the rigidity and/or the damping of the torsional vibration system. Furthermore, it is possible for a rigidity or a resonant frequency to be influenced by the selection of the pressure of the fluid.

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

A rotary vane is twisted with the torsional vibration of the torsional vibration system, so that it can be coupled to the rotational mass of the torsional vibration system. The rotary wing has a wing surface that delimits a fluidic chamber, in particular a gas chamber or a gas reservoir, the volume of which depends on the twisting of the rotary wing as a result of the torsional vibration.

Methodology Applied
Scientific EffectFluid displacement: Hydraulic Press

Data Source

PatentEP3524955B1Resonance torsion test bench
Publication Date: 2020.11.04 HUG JOACHIM
  • EP3524955B1 patent drawingFigure 1
  • EP3524955B1 patent drawingFigure 2
  • EP3524955B1 patent drawingFigure 3

AI summary

The invention relates to a resonance torsion test device (1) by means of which a test specimen (2) can be loaded with a test load. The test specimen (2) is clamped in a fixture (6). A load shaft (9) non-rotatably connected to the test specimen (2) extends into a hydraulic rotary cylinder (28). The rotary cylinder (28) is divided into two chambers (33, 34) by a rotary vane supported by the load shaft (9), the volume of which depends on the angle of rotation of the load shaft (9) and the rotary vane. The chambers (33, 34) are each fluidically connected to a compensating cylinder (37, 38). In the torsional vibration system (26) the stiffness can be influenced by the pressure and the fluid in the chambers (33, 34), in hydraulic chambers (39, 40) of the compensating cylinders (37, 38) and/or in gas chambers (41, 42) of the compensating cylinders (37, 38).