Dishwasher Spray Arm Rotation Detection Using Pump Impingement Signals

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Solution Overview

Problem

Existing automatic dishwashers face challenges in determining the rotational status of rotatable spray arms, which can lead to inefficiencies and incomplete washing cycles due to potential blockages, as current methods lack effective sensors to detect impingement of sprays and rotation accurately.

Innovation Solution

The method involves operating a pump to supply liquid through a stationary supply conduit to a rotatable spray arm, emitting first and second sprays from specific apertures, and determining the rotational status by sensing changes in pump signals indicative of impingement, allowing for real-time monitoring and potential cycle adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional sensors are added to detect spray arm rotation, then measurement precision improves, but device complexity increases

Engineering Contradiction:

Improverotational status detectionVSAvoidsensor integration

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The spray arm rotation detection system utilizes the existing pump and spray mechanism to generate detection signals. The pump serves dual purposes: delivering cleaning liquid and generating the signal waveform that indicates spray arm rotation status, eliminating the need for separate detection sensors

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The pump is designed to perform multiple functions simultaneously: it delivers cleaning liquid to the spray arm and generates electrical signal waveforms through the interaction between the spray liquid and pump components. This multi-functionality allows the same component to serve both operational and detection purposes

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If additional sensors are installed to detect spray impingement, then measurement precision improves, but ease of manufacture deteriorates

Engineering Contradiction:

Improvespray impingement detectionVSAvoidassembly complexity

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The detection functionality is merged with the existing pump structure. The pump housing and components serve as both fluid delivery elements and signal generation elements, combining what would traditionally be separate detection components into the existing manufacturing framework

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the system continuously monitors spray arm rotation, then reliability improves, but use of energy increases

Engineering Contradiction:

Improvewashing cycle completionVSAvoidmonitoring energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The pump operates continuously throughout the washing cycle to deliver cleaning liquid, and this continuous operation inherently generates continuous detection signals. The same continuous fluid flow that performs the cleaning function also provides the signal waveform for monitoring, eliminating the need for separate continuous monitoring systems

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The system generates real-time feedback signals through the pump's interaction with the spray liquid. These signals provide continuous information about spray arm rotation status, enabling the control system to monitor washing cycle completion and reliability without additional energy-intensive sensing mechanisms

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 approach enables accurate detection of spray arm rotation and potential blockages, allowing for automatic cycle adjustments and improved cleaning performance by integrating existing dishwasher components without additional sensors, ensuring comprehensive washing and user feedback.

Implementation Method 1

operating a pump to supply liquid through a stationary supply conduit to the rotatable spray arm

Methodology Applied

Scientific EffectPump: Pump

Implementation Method 2

emitting a first spray of the pumped liquid from a first aperture in the rotatable spray arm, with the first spray defining a spray path as the rotatable spray arm rotates

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

determining a rotational status of the rotatable spray arm by sensing a pump signal corresponding to impingement of the first spray and the second spray along the spray path

Methodology Applied

Scientific EffectElectrical signal detection:

Data Source

PatentUS11896181B2Dishwasher and method of operating

Publication Date: 2024.02.13 WHIRLPOOL CORP

AI summary

A dishwasher and method of operating a dishwasher according to a cycle of operation are described herein. The dishwasher includes a tub at least partially defining a treating chamber, a rotatable spray arm comprising a nozzle outlet, and a liquid supply conduit fluidly coupled to the spray arm. A pump can be fluidly coupled to the liquid supply conduit and operated to flow liquid through an aperture in the liquid supply conduit.