Optical Flow Rate Sensor with Radial Shaft Arrangement
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Solution Overview
Problem
Existing flow rate measurement devices face issues with durability and accuracy due to imbalance in the supporting force of the rotating shaft, leading to wear and inefficient sensing, particularly when objects with magnetic forces are nearby, affecting the reed switch's on/off action.
Innovation Solution
A flow rate measurement device with a rotating shaft perpendicular to the fluid flow direction, featuring a sensor positioned radially to the shaft, using light-emitting and light-receiving components to detect rotations, and a control portion that adjusts the light emission period based on rotation speed, minimizing power consumption and enhancing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a reed switch is used to sense rotation by magnetic force, then the flow rate can be measured, but the presence of objects with magnetic force near the reed switch causes inefficient on/off action and measurement errors
Solution Approach 1:
The patent replaces the magnetic field-based reed switch sensing system with an optical sensing system. A light source emits light toward a reflective surface on the rotating portion, and a light receiver detects the reflected light. This optical substitution eliminates susceptibility to magnetic interference from external objects while maintaining rotation detection capability, directly resolving the measurement accuracy issue caused by magnetic interference.
2Device complexity
If the rotating portion and sensor portion are sequentially arranged in the longitudinal direction of the rotating shaft, then the device structure is simplified, but imbalance in supporting force occurs leading to wear and shortened life
Solution Approach 1:
The patent transitions the sensor arrangement from a longitudinal sequence along the rotating shaft to a radial configuration where the light source and light receiver are positioned on opposite sides of the rotating shaft in the radial direction. This dimensional change allows the sensor portion to be distributed symmetrically around the shaft, achieving both structural simplicity and balanced supporting force that prevents wear and extends reliability.
3Measurement precision
If the sensor portion is positioned to sense rotation, then flow rate measurement is enabled, but vibration and partial damages to the rotating portion occur due to supporting force imbalance
Solution Approach 1:
The patent employs asymmetric positioning of the light source and light receiver relative to the rotating shaft, placing them on opposite sides in the radial direction. This asymmetric radial arrangement creates symmetric load distribution on the rotating shaft, balancing the supporting force and eliminating vibration and instability issues while preserving accurate rotation sensing capability through the optical path.
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 significantly improves durability and accuracy, extends the replacement cycle, and optimizes power usage by accurately measuring flow rates with reduced wear and vibration, while preventing shaft imbalance and magnetic interference issues.
Implementation Method 1
a first light emitting portion (311) that generates light in an axial direction of the rotating shaft (210)
Implementation Method 2
a sensor portion arranged to be spaced apart from the rotating shaft (210) in a radial direction of the rotating shaft (210) so as to sense a number of rotations of the rotating portion (200)
Data Source
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AI summary
The present invention relates to a flow rate measurement device and, more specifically, to a flow rate measurement device and a flow rate measurement method, wherein a flow rate is measured by sensing a rotation caused by a flow of a fluid. The present invention provides a flow rate measurement device characterized by comprising: a housing (100) having a fluid inlet port (111) and a discharge port (112) formed to face each other; a rotating portion (200) comprising a rotating shaft (210) arranged perpendicularly to a virtual line (C) connecting the inlet port (111) and the discharge port (112) inside the housing (100), and a blade (220) rotated by a flow of a fluid around the rotating shaft (210); a sensor portion arranged to be spaced apart from the rotating shaft (210) in the radial direction of the rotating shaft (210) so as to sense the number of rotations of the rotating portion (200); and a control portion (330) for measuring the flow rate of the fluid on the basis of the number of rotations of the rotating portion (200) sensed by the sensor portion.