Gear Pump Magnetic Position Sensing
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Solution Overview
Problem
Gear pumps face challenges in achieving accurate volumetric control due to the complexity and cost associated with mechanical sealing arrangements required for optical encoders, which are necessary for precise rotational position measurement of the drive shaft, and suffer from inaccuracies when these seals are breached or absent.
Innovation Solution
A gear pump design that incorporates an annular magnet and a sensor to detect the rotational position of the drive shaft, using a PID control algorithm and viscous drag on the idler gear to maintain accurate volume pumping without the need for mechanical seals, allowing the sensor to operate efficiently and accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mechanical sealing arrangement is used to isolate the optical encoder from the substrate, then the optical encoder can function efficiently and accurately, but the overall complexity and cost of manufacturing increases
Solution Approach 1:
The patent replaces the mechanical sealing arrangement with a magnetic field-based isolation system. A magnetic shield or magnetic coupling mechanism is used to transmit rotational information from the drive shaft to the optical encoder without requiring physical seals that isolate the encoder from the substrate. This eliminates the need for complex mechanical seals while maintaining measurement accuracy.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the drive shaft and the optical encoder. The magnetic shield or magnetic coupling acts as a mediator that allows rotational position information to be transmitted through the substrate without direct mechanical contact, thereby eliminating the need for complex mechanical sealing arrangements.
2Measurement precision
If a mechanical sealing arrangement is used to isolate the optical encoder from the substrate, then the optical encoder can function efficiently and accurately, but the manufacturing cost increases
Solution Approach 1:
The patent replaces the mechanical sealing arrangement with a magnetic field-based isolation system. A magnetic shield or magnetic coupling mechanism is used to transmit rotational information from the drive shaft to the optical encoder without requiring physical seals that isolate the encoder from the substrate. This eliminates the need for complex mechanical seals while maintaining measurement accuracy.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the drive shaft and the optical encoder. The magnetic shield or magnetic coupling acts as a mediator that allows rotational position information to be transmitted through the substrate without direct mechanical contact, thereby eliminating the need for complex mechanical sealing arrangements.
3Device complexity
If the sealing arrangement is breached or absent, then the manufacturing complexity is reduced, but the rotation of the drive shaft cannot be accurately measured
Solution Approach 1:
The patent replaces the mechanical sealing arrangement with a magnetic field-based isolation system. A magnetic shield or magnetic coupling mechanism is used to transmit rotational information from the drive shaft to the optical encoder without requiring physical seals that isolate the encoder from the substrate. This eliminates the need for complex mechanical seals while maintaining measurement accuracy.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the drive shaft and the optical encoder. The magnetic shield or magnetic coupling acts as a mediator that allows rotational position information to be transmitted through the substrate without direct mechanical contact, thereby eliminating the need for complex mechanical sealing arrangements.
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 enables precise control of the rotational position of the drive shaft, ensuring accurate fluid volume pumping while reducing manufacturing complexity and cost, and enhancing the gear pump's reliability and efficiency by eliminating the need for mechanical seals.
Implementation Method 1
Rotation of a rotatable assembly of a medical pumping apparatus such as a pump rotor of a rotary peristaltic pump is monitored via use of electromagnetic radiation (for example, infrared radiation). The rotatable assembly is formed such that it has portions that are selectively reflective and non-reflective with respect to the electromagnetic radiation.
Data Source
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AI summary
The disclosure herein relates to device, for example a gear pump, for pumping fluid. The gear pump comprise a motor for driving a rotatable drive shaft; a drive gear configured to be driven by the drive shaft; an idler gear which meshes with the drive gear; an annular magnet disposed coaxially with the drive shaft and configured to rotate therewith; and a sensor for sensing rotation of the annular magnet and generating an output signal corresponding to a rotational position of the drive shaft.