Dishwasher Upper Hydraulic Circuit With Low-Friction Sprayer Coupling

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Solution Overview

Problem

Washing machines, particularly dishwashers, face issues with noise and reduced efficiency due to the 'air break' between the upper nozzle and cone-shaped receiving element, and high friction between the sprayer and connection means, leading to increased fluid consumption and pressure drop, especially when the upper rack is adjusted to different positions or under heavy loads.

Innovation Solution

The use of a bush made of acetalic resin for connecting the tubular element to the sprayer, which is made of polypropylene, reduces friction and eliminates the need for fluid leakage, along with a linking device with adjustable inlets and compensation means to facilitate easy connection to the hydraulic outlet, ensuring proper rotation and operation regardless of rack position or load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an air break is provided between the nozzle and receiving element to allow rack sliding, then the rack can be adjusted to different positions, but noise increases and wash efficiency decreases

Engineering Contradiction:
Improverack adjustabilityVSAvoidnoise
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a flexible hose as an intermediary element between the nozzle and the receiving element. This hose acts as a mediator that transmits the pressurized liquid flow while accommodating the rack's movement and adjustment, eliminating the need for a rigid air break structure that causes noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical state and properties of the connection between nozzle and receiving element by using a flexible hose instead of a rigid structure with air break. This parameter change allows the system to adapt to rack position changes while maintaining efficient liquid flow and reducing noise.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If connection means allow wash fluid to leak to provide lubricating effect, then friction between sprayer and connection means is reduced, but wash fluid pressure drops and consumption increases

Engineering Contradiction:
Improvesprayer rotationVSAvoidwash fluid pressure
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent replaces the mechanical friction-based connection system with a magnetic coupling system. The magnetic field substitutes for the mechanical contact that previously required lubrication, eliminating friction without needing fluid leakage, thereby maintaining wash fluid pressure and reducing consumption.

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

Solution Approach 2:

The patent utilizes the pressurized wash fluid flow itself to create a hydrodynamic bearing effect, where the fluid film between the sprayer and connection means provides lubrication without leakage, reducing friction while maintaining system pressure.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Adaptability or versatility

If connection device has multiple inlets for rack in any position, then adaptability to different rack positions is improved, but difficulty in inserting connection device into hydraulic outlet increases

Engineering Contradiction:
Improveconnection to hydraulic outletVSAvoidinsertion operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent makes the connection device dynamically adjustable with movable inlet positions that can adapt to different rack positions. This dynamic capability allows the connection device to be easily inserted into the hydraulic outlet while maintaining adaptability to various operating conditions.

Inventive Principle:
Principle #15Dynamics

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 configuration minimizes noise, maintains wash fluid pressure, and prevents fluid wastage, ensuring effective washing performance even with adjustable racks and heavy loads, while allowing easy connection to the hydraulic outlet.

Implementation Method 1

the provision of a leakage of wash fluid, in particular at friction points between the sprayer and the connection means connecting it to the tubular element, inevitably implies a higher consumption of wash fluid and a reduction in the wash fluid pressure

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2059160B1Household washing machine, in particular a dishwasher, comprising an upper hydraulic circuit
Publication Date: 2015.03.04 INDESIT COMPANY SPA
  • EP2059160B1 patent drawingFigure 1
  • EP2059160B1 patent drawingFigure 2
  • EP2059160B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a washing machine, in particular a dishwasher, of the type comprising a wash tub (10), a liquid supply duct (11) connected to a hydraulic outlet (70) located on a wall of said tub (10), and at least one upper rack (20) associated with an upper hydraulic circuit which comprises: - a sprayer (30) made of plastic material; a tubular element (40) comprising a first end (41) and a second end (42); connection means (50) providing the hydraulic and mechanic connections between said first end (41) of the tubular element (40) and said sprayer (30); and a linking device (60) adapted to engage into said hydraulic outlet (70). The invention is mainly characterized in that said connection means (50) comprise a bush (50) made of a material which is different from that used for manufacturing said sprayer (30).