Parallel Spring Shaft Holder for Low-Friction Viscometer Torque Measurement
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Solution Overview
Problem
Conventional rotating shaft holding mechanisms, such as ball bearings and air bearings, compromise precision and stability due to frictional resistance and air pressure issues, making high-precision torque measurement challenging, especially in rotational viscometers.
Innovation Solution
A rotating shaft holding mechanism utilizing a plurality of parallel springs with specific length and angle configurations to minimize shaft movement and torque stress, allowing for high-precision rotation within a finite range, and incorporating a structure where the sum of spring constants at the deformable sides equals that of the connecting point, ensuring stability and compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If ball bearings are used to hold the rotating shaft, then the frictional resistance is reduced, but the precision of the rotating shaft deteriorates due to the rotating bodies affecting the shaft precision and causing fluctuating resistance
Solution Approach 1:
The invention extracts and removes the rotating bodies (balls) from the bearing structure, replacing them with a flexible element that provides support without introducing discrete rotating components that would affect shaft precision or cause fluctuating resistance
Solution Approach 2:
The invention changes the fundamental parameter of the bearing mechanism from discrete rigid bodies (balls) to a continuous flexible element (spring), fundamentally altering how the shaft is supported while maintaining low friction and high precision
2Measurement precision
If air bearings are used to achieve high precision and low frictional resistance, then the shaft precision is improved, but the device complexity increases due to requiring high-pressure air sources and the structure becomes less compactible resulting in higher moment of rotation
Solution Approach 1:
The invention uses a spring-based flexible support mechanism that eliminates the need for pneumatic systems, replacing complex air pressure generation and maintenance infrastructure with a simple mechanical spring element
Solution Approach 2:
The invention applies the spring element locally at the shaft support point, providing precision and low friction without requiring system-wide pneumatic infrastructure, thus simplifying the overall device while maintaining high shaft precision
3Device complexity
If a simple holding mechanism with spring deformation is used, then the device complexity is reduced, but the shaft precision deteriorates because the rotating shaft moves as springs deform and torque stress deviates from linearity
Solution Approach 1:
The invention carefully selects and configures the spring parameters (rigidity, initial tension, mounting geometry) to ensure that the spring deformation remains within a range that maintains shaft precision and linear torque stress characteristics
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 achieves a high-precision, compact, and low-friction rotating shaft holding mechanism that enhances the precision and reliability of torque measurements in rotational viscometers, reducing maintenance and operational costs while improving handleability and expanding measurement ranges.
Implementation Method 1
a plurality of parallel spring links, each of the plurality of parallel spring links including: a movable side connected to a rotating shaft by a hinge at a connection point at a distance h radially away from a center of rotation of the rotating shaft; a plurality of deformable sides which are parallel to each other
Data Source
AI summary
A compact and high-precision rotating shaft holding mechanism is provided which can be utilized for a device that requires a small amount of rotation.A rotating shaft holding mechanism includes a plurality of parallel spring links, each of the plurality of parallel spring links including: a movable side connected to a rotating shaft by a hinge at a connection point at a distance h radially away from a center of rotation of the rotating shaft; a plurality of deformable sides which are parallel to each other; hinges each of which connects one end of a corresponding one of the deformable sides to the movable side; and hinges each of which connects the other end of a corresponding one of the deformable sides to the stationary section, the effective length of each of the deformable sides being set to h to permit the rotating shaft, which is connected to the movable side by the hinge at the connecting point at the distance h radially away from the center of rotation of the rotating shaft, to rotate within a range of finite angles, the plurality of parallel spring links including at least two parallel spring links oriented in different directions. A rotational viscometer uses the rotating shaft holding mechanism.