Brushless DC Pump System with Rack and Pinion Converter

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Solution Overview

Problem

Existing drive systems for reciprocating positive displacement pumps, such as air motors and electric motors, are inefficient in energy consumption, produce noise, and require complex mechanical devices to convert uni-directional rotation into bi-directional reciprocating motion, leading to issues like icing and wear.

Innovation Solution

A pump system utilizing a reversible brushless DC motor with a motion converter, specifically a rack and pinion system with gear reduction, to efficiently convert rotational motion into linear reciprocating motion, reducing the need for complex mechanical devices and minimizing noise and energy wastage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If air motors are used to drive reciprocating pumps, then the pump can operate, but energy consumption is high and noise is produced

Engineering Contradiction:

Improvepump operation capabilityVSAvoidenergy consumption

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent replaces the air motor mechanical system with an electronic control system. The motor driver circuit directly controls the motor to reverse rotation, eliminating the need for complex mechanical conversion devices like crankshafts or cam systems. This substitution reduces mechanical losses and improves overall energy efficiency while maintaining pump operation capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If crankshaft or cam systems are used to convert rotary motion to reciprocating motion, then the pump can be driven, but device complexity increases

Engineering Contradiction:

Improvereciprocating motion conversionVSAvoidmechanical conversion devices

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent substitutes mechanical motion conversion systems (crankshaft, cam) with an electronic control approach. The motor driver circuit electronically reverses motor rotation to achieve reciprocating pump operation, dramatically simplifying the mechanical structure while maintaining the required motion conversion function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The motor serves multiple functions: it provides both the driving force and the motion conversion capability through electronic control. The single motor with reversible rotation replaces what would traditionally require separate components for force generation and motion conversion, reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Power

If air motors and compressors are used, then the pump can operate, but noise and icing issues occur

Engineering Contradiction:

Improvepump operation capabilityVSAvoidnoise and icing

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the air motor-compressor system with an electric motor system. This eliminates the noise-generating components (compressor, air intake/exhaust) and prevents icing issues that occur with compressed air systems, while maintaining pump operation capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Loss of energy

If electric motors with mechanical conversion devices are used, then energy efficiency is improved, but device complexity remains high

Engineering Contradiction:

Improveenergy efficiencyVSAvoidmechanical conversion devices

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent eliminates mechanical conversion devices from the electric motor system by using electronic control to directly reverse motor rotation. This maintains the energy efficiency benefits of electric motors while removing the complexity of additional mechanical components.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 system achieves efficient energy use, reduced noise, and extended wear life by using a brushless DC motor to directly control the reciprocating motion of the pump shaft, maintaining constant pressure output and minimizing mechanical complexity.

Implementation Method 1

A pump system utilizing a reversible brushless DC motor with a motion converter

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

A pump system utilizing a reversible brushless DC motor with a motion converter, specifically a rack and pinion system with gear reduction

Methodology Applied

Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP2753832B1A pump system and a method of operating a pump

Publication Date: 2019.04.24 GRACO MINNESTOA INC

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AI summary

A pump system comprises an electric motor, a pump, a converter and a controller. The electric motor has a rotational output shaft that is rotatable in a first rotational direction and an opposite second rotational direction. The pump has a linearly displaceable input shaft that is movable in a first linear direction and an opposite second linear direction. The converter couples the output shaft to the input shaft such that rotation of the output shaft in the first rotational direction translates the input shaft in the first linear direction, and rotation of the output shaft in the second rotational direction translates the input shaft in the second linear direction. The controller repeatedly reverses rotation of the output shaft to produce reciprocating motion of the input shaft.