Contactless Pump Drive Through Tank Wall for Continuous Refilling

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Solution Overview

Problem

Existing hand tools, such as portable sprayers, face interruptions due to fluid depletion, leading to pump cavitation and potential damage, and require frequent refilling, disrupting continuous operation.

Innovation Solution

A contactless machine drive system is implemented, where a drive device is positioned on one side of a wall separating two sides, interacting electromagnetically with a receiver device on the other side through magnetic fields, allowing for continuous operation without mechanical penetration, and a tank design with separable portions for seamless refilling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical drive system is used to drive the pump, then the pump can be driven reliably, but the drive shaft must penetrate the tank wall which complicates the structure and reduces reliability

Engineering Contradiction:
Improvedrive system reliabilityVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical drive system with a magnetic drive system. The drive magnet assembly (212) and driven magnet assembly (214) are positioned on opposite sides of the tank wall (204) without mechanical penetration. Magnetic fields transmit rotational force through the non-magnetic tank wall, eliminating the need for shafts that penetrate the tank structure, thus improving reliability while reducing structural complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If the tank is designed as a single integrated unit, then the structure is simple, but refilling requires emptying the entire tank which interrupts operation

Engineering Contradiction:
Improvestructural simplicityVSAvoidcontinuous operation capability
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The tank (202) is divided into a first tank portion (206) and a second tank portion (208) that can be selectively separated. The pump (210) is positioned within the second tank portion. This segmentation allows the first tank portion to be removed and refilled independently while the second tank portion with the pump remains in place, enabling continuous operation without interrupting the pump system.

Inventive Principle:
Principle #1Segmentation

3Duration of action of moving object

If the pump operates when the tank is empty, then the system can continue running, but the pump will cavitate and suffer damage

Engineering Contradiction:
Improveoperational continuityVSAvoidpump reliability
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The system incorporates a float (216) that moves with the fluid level in the tank. When the fluid level drops and the tank becomes empty, the float rises and mechanically actuates a switch (218) that automatically shuts off power to the pump motor (220). This feedback mechanism prevents the pump from operating without fluid, avoiding cavitation and damage, while maintaining operational continuity by stopping the pump before damage occurs.

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

Enables continuous operation of hand tools without fluid interruptions, allowing for seamless refilling and reducing mechanical wear, thus enhancing usability and efficiency.

Implementation Method 1

A drive device is positioned at the first side in electromagnetically proximate arrangement to the machine drive device. A first gap is formed between at least a portion of the drive device and the wall

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

interacting electromagnetically with a receiver device on the other side through magnetic fields, allowing for continuous operation without mechanical penetration

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4295959B1Contactless machine drive and hand tool
Publication Date: 2026.02.25 MILWAUKEE ELECTRIC TOOL CORP
  • EP4295959B1 patent drawingFigure 1
  • EP4295959B1 patent drawingFigure 2
  • EP4295959B1 patent drawingFigure 3

AI summary

A machine drive system (100) is provided including a wall (130) forming a first side (131) fluidly separated from a second side (132) and a machine drive device (120) disposed at the second side (132). The machine drive device (120) includes a receiver device (122) in which a second gap (134) is formed between the receiver device (122) and the wall (130) at the second side (132). A drive device (110) is positioned at the first side (131) in electromagnetically proximate arrangement to the machine drive device (120). A first gap (133) is formed between at least a portion of the drive device (110) and the wall (130).