Oscillating Viscometer Inertia Positioning for Vibration Isolation
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Solution Overview
Problem
Existing devices for measuring viscosity, shearing stress, and specific weight of substances are unreliable due to temperature-dependent materials and vibrations, which affect measurement accuracy.
Innovation Solution
The device positions the center of inertia at the attachment point, uses a partially hollow or narrowed pivot arm, and incorporates an electromechanical drive with a controllable electromagnetic element and a voltage-current converter to minimize temperature effects and vibrations, allowing for accurate measurement of shearing stress and specific weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pivot arm with resilient portion is used to measure shearing stress and viscosity, then the measurement function is enabled, but temperature fluctuations cause material expansion/contraction and frequency changes that reduce measurement reliability
Solution Approach 1:
The patent positions the center of inertia at the attachment point, which fundamentally changes the dynamic parameters of the oscillating system. This parameter change makes the measurement frequency independent of spring constant variations caused by temperature, thereby resolving the contradiction between enabling measurement function and maintaining temperature stability.
Solution Approach 2:
The patent replaces the traditional mechanical resonance frequency determination (which depends on spring constant and mass distribution) with a geometric determination based on center of inertia position. This substitution eliminates the mechanical dependency on temperature-sensitive spring properties.
2Measurement precision
If the pivot arm is in contact with the medium to measure shearing stress, then the measurement function is achieved, but vibrations affect the accuracy of the measurement
Solution Approach 1:
By positioning the center of inertia at the attachment point, the patent changes the vibrational characteristics of the system. This parameter change minimizes the transmission of vibrations from the drive mechanism to the measurement interface, thereby improving measurement precision while maintaining the necessary contact with the medium.
3Object-affected harmful factors
If the center of gravity of the pivot arm is positioned at the rotation point to counteract vibrations, then vibration effects are reduced, but this is insufficient compared to positioning the center of inertia at the attachment point
Solution Approach 1:
The patent deliberately creates an asymmetric mass distribution in the pivot arm so that the center of inertia does not coincide with the center of gravity or the rotation point. Specifically, the center of inertia is positioned at the attachment point, while the center of gravity remains elsewhere in the structure. This asymmetric configuration optimally counteracts vibrations while maintaining measurement reliability.
Solution Approach 2:
The patent uses the mass distribution in the pivot arm to create counterbalancing effects. By positioning the center of inertia at the attachment point, the inertial forces generated during oscillation counteract the vibration effects, providing superior vibration reduction compared to simple center of gravity positioning.
4Reliability
If a voltage-current converter is added to control electromagnetic drive elements, then temperature effects are minimized, but the device complexity increases
Solution Approach 1:
The patent replaces voltage control with current control for the electromagnetic drive elements. This substitution is achieved through a voltage-current converter that transforms voltage signals into precise current signals, eliminating the temperature-dependent resistance variations that would otherwise affect drive accuracy. The added complexity is justified by the significant improvement in operational stability.
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 configuration significantly reduces the impact of vibrations and temperature fluctuations, enhancing the reliability and accuracy of measurements by maintaining the center of inertia at the attachment point and using temperature-independent materials, thereby improving the device's operational stability and precision.
Implementation Method 1
the drive comprises an electromechanical configuration with at least one controllable electromagnetic drive element
Implementation Method 2
the centre of inertia of the device lies at the attachment point... the effects of vibrations are counteracted
Implementation Method 3
The measurement of a shearing stress of a medium can take place by measuring the friction which the medium causes when in contact with the pivot arm
Implementation Method 4
In order to measure the specific weight of the medium a displacement of the medium must take place
Data Source
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AI summary
The present invention comprises a device for measuring at least one property of a substance or medium such as the viscosity, the shearing stress, the specific weight and whether the substance or the medium shows Newtonian behaviour. The device comprises a carrier arranged at least at one attachment point, a pivot arm connected pivotally or rotatably to the carrier at a rotation point located at a distance from the attachment point, a drive acting selectively on the pivot arm for driving the pivot arm in an oscillating movement, and a measurement setup for measuring the oscillation of the pivot arm to be caused with a drive, characterized in that a centre of inertia lies substantially at the attachment point.