Top-Loading Washing Machine Drum Door with Automatic Flap Mechanism

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Solution Overview

Problem

Existing top-loading washing machines face challenges with the strength and reliability of the drum door assembly, particularly at high spinning speeds, and require significant space for automatic opening mechanisms, which compromises the overall capacity and structural integrity.

Innovation Solution

The drum door features a rotating flap with cam surfaces and a linear actuator, allowing for automatic opening and closing without manual intervention, ensuring high mechanical reliability and structural continuity, while minimizing space usage with a compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a complex mechanical locking system is used to block the door in the closed configuration, then the structural strength is improved, but the device complexity increases

Engineering Contradiction:
Improvestructural strengthVSAvoiddevice complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The door assembly is segmented into a sliding door portion and a rotating flap portion, each performing specific functions. The locking mechanism is segmented into discrete engaging portions rather than a complex continuous structure, reducing overall complexity while maintaining strength

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rotating flap is nested within the door assembly structure, with the flap rotating within the confines of the drum opening. This nested arrangement allows the locking mechanism to be integrated compactly without requiring additional external space or complex external linkages

Inventive Principle:
Principle #7Nested doll (Nesting)

2Extent of automation

If electromagnets with plungers are used for catching means, then the automatic opening function is achieved, but the space required increases

Engineering Contradiction:
Improveautomatic opening functionVSAvoidspace required
Core Design Contradiction:
Extent of automationVSVolume of moving object

Solution Approach 1:

The patent replaces traditional electromagnetic plungers with a cam-based mechanical system. The cam surface converts rotational motion into the necessary linear and rotational movement of the flap, eliminating the need for bulky electromagnets and their associated plungers

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

Solution Approach 2:

The catching means utilizes the radial dimension of the drum by positioning the cam surface on a rotating member that engages the flap from the radial direction. This dimensional approach allows compact integration within the existing drum-tub structure without requiring additional axial or tangential space

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the drum door assembly is designed to be lightweight and easy to manufacture, then the ease of manufacture is improved, but the strength to resist high spinning forces deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidstrength to resist high spinning forces
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent optimizes the geometric parameters of the door assembly, including the thickness and curvature of the sliding door and rotating flap. These parameter adjustments allow the use of lighter gauge materials while maintaining structural integrity through optimized stress distribution

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The door assembly utilizes composite construction with the sliding door and rotating flap formed from different material compositions or thicknesses optimized for their specific functions. The engaging portions may use reinforced materials or geometric reinforcement to maintain strength while keeping overall weight low

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3112517B1Top-loading washing machine comprising a drum door
Publication Date: 2021.09.22 WHIRLPOOL CORP
  • EP3112517B1 patent drawingFigure 1a
  • EP3112517B1 patent drawingFigure 1b
  • EP3112517B1 patent drawingFigure 2a~2b

AI summary

A top-loading washing machine comprises a tub, a perforated drum rotatably mounted within said tub about a horizontal axis and having an aperture on its cylindrical side, a drum door slidably supported by the drum for opening and closing said aperture following a predetermined rotation of the drum, catching means supported by the tub and configured to selectively engage said sliding door for opening and closing thereof. The drum comprises a flap hinged to an edge of said aperture of the drum and having first engaging portions configured to cooperate with second engaging portions of the sliding part, said catching means being also configured to cooperate with said flap in order to free it from the sliding part.