Gear Pump Magnetic Encoder for Precise Fluid Volume Control

Solution Overview

Problem

Existing gear pumps face challenges in achieving accurate volumetric control and dynamic performance due to the complexity and cost associated with mechanical sealing arrangements required for optical encoders, which are necessary for precise rotational position measurement but increase manufacturing complexity and cost.

Innovation Solution

A gear pump design incorporating a motor-driven rotatable drive shaft, an annular magnet arrangement, and a sensor to generate output signals for rotational position, with a controller using PID algorithms to control the motor and adjust torque, enabling precise fluid pumping without the need for mechanical seals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a mechanical sealing arrangement is used to isolate the optical encoder from the fluid, then the rotational position measurement accuracy is maintained, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improverotational position measurement accuracyVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical optical encoder with a magnetic encoder system. The magnetic encoder uses magnetic fields instead of optical components, eliminating the need for mechanical seals while maintaining measurement accuracy. The magnetic encoder is directly coupled to the drive shaft without requiring fluid isolation, thus reducing device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetic coupling mechanism as an intermediary between the drive shaft and the encoder. This magnetic coupling allows the encoder to measure rotational position without direct mechanical contact with the fluid, eliminating the need for mechanical seals while maintaining measurement functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If a mechanical sealing arrangement is used to isolate the optical encoder from the fluid, then the rotational position measurement accuracy is maintained, but the manufacturing cost increases

Engineering Contradiction:

Improverotational position measurement accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical optical encoder with a magnetic encoder system. The magnetic encoder uses magnetic fields instead of optical components, eliminating the need for mechanical seals while maintaining measurement accuracy. The magnetic encoder is directly coupled to the drive shaft without requiring fluid isolation, thus reducing device complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetic coupling mechanism as an intermediary between the drive shaft and the encoder. This magnetic coupling allows the encoder to measure rotational position without direct mechanical contact with the fluid, eliminating the need for mechanical seals while maintaining measurement functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Speed

If PID control algorithm is used to control the motor, then the transient dynamic performance is improved, but the control system complexity increases

Engineering Contradiction:

Improvetransient dynamic performanceVSAvoidcontrol system complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent implements PID control with feedback from the magnetic encoder to the motor controller. The encoder provides real-time rotational position feedback, which the PID algorithm uses to adjust motor control parameters dynamically, improving transient response and dynamic performance while maintaining manageable system complexity through standard control techniques.

Inventive Principle:

Principle #23Feedback

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 solution allows for accurate and controlled fluid pumping with improved transient dynamic performance, reducing manufacturing complexity and cost by eliminating the need for mechanical seals and enhancing the efficiency and accuracy of the gear pump operation.

Implementation Method 1

an annular magnet arrangement disposed coaxially with the drive shaft and operable to rotate therewith

Methodology Applied

Scientific EffectMagnetic field generation: Magnetic Field

Implementation Method 2

a sensor for sensing rotation of the annular magnet arrangement and generating an output signal corresponding to a rotational position of the drive shaft

Methodology Applied

Scientific EffectMagnetic sensing: Magnetic Field

Data Source

PatentUS11624362B2Device for pumping fluid

Publication Date: 2023.04.11 MAGPUMPS

AI summary

The disclosure herein relates to device, for example a gear pump, for pumping fluid. The gear pump comprises 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.