Method for assembling an assembly for a domestic appliance for treating laundry items, and domestic appliance for treating laundry items

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Solution Overview

Problem

Existing household appliances for laundry care face issues with noise and increased wear due to loose radial rolling bearings, particularly on the drum side, which are exacerbated by mechanical stress, and the assembly process is complex.

Innovation Solution

A method involving a bearing arrangement with a fixed radial rolling bearing on the drum side and a loose radial rolling bearing on the pulley side, utilizing press and clearance fits to enhance stability and efficiency, reducing noise and wear by employing a fixed bearing on the drum side and a loose bearing on the pulley side, with specific assembly steps to ensure precise positioning and connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If loose radial rolling bearings are used on the drum side, then ease of assembly is improved, but noise and wear increase due to increased clearance with mechanical stress

Engineering Contradiction:
Improveease of assemblyVSAvoidnoise and wear
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent applies different bearing configurations to different locations: the drum-side bearing (13) uses a press fit for fixed positioning, while the pulley-side bearing (14) uses a clearance fit for floating capability. This local differentiation optimizes each bearing's performance for its specific operational conditions, reducing noise and wear on the drum side while maintaining ease of assembly.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The bearing arrangement is segmented into two distinct types: a fixed press-fit bearing on the drum side and a loose clearance-fit bearing on the pulley side. This segmentation allows each bearing to be optimized independently for its specific functional requirements, resolving the contradiction between assembly ease and noise reduction.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If floating bearing arrangement is used, then ease of assembly is improved, but mechanical stress increases leading to increased clearance and bearing wear

Engineering Contradiction:
Improveease of assemblyVSAvoidbearing stability
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent implements local quality by providing a press fit (fixed connection) for the drum-side bearing where stability is critical, and a clearance fit (floating connection) for the pulley-side bearing where flexibility is needed. This resolves the contradiction by making each bearing's connection type match its specific stability requirements.

Inventive Principle:
Principle #3Local quality

3Reliability

If specific positioning of loose bearings is required, then bearing stability is improved, but device complexity increases

Engineering Contradiction:
Improvebearing stabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of trying to position loose bearings specifically through complex assembly procedures, the patent inverts the approach by using a press fit for the drum-side bearing that automatically provides fixed positioning during assembly. This eliminates the need for complex positioning procedures while maintaining bearing stability.

Inventive Principle:
Principle #13The other way round (Inversion)

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 method significantly reduces noise and wear over the appliance's lifespan by using a fixed and loose bearing configuration, enabling efficient assembly and high automation, thus improving functional stability and assembly efficiency.

Implementation Method 1

fastening the first radial rolling bearing of the bearing arrangement to the bearing housing, in particular to an inner side of the bearing housing, with a press fit

Methodology Applied
Scientific EffectPress fit: Mechanical Fastener

Implementation Method 2

inserting a second radial rolling bearing into a receiving space created during the joining between the shaft journal and the bearing housing in such a way that the second radial rolling bearing is created as a loose bearing

Methodology Applied
Scientific EffectClearance fit: Mechanical Fastener

Data Source

PatentEP4556730A1Method for assembling an assembly for a domestic appliance for treating laundry items, and domestic appliance for treating laundry items
Publication Date: 2025.05.21 BSH HAUSGERATE GMBH
  • EP4556730A1 patent drawingFigure 1
  • EP4556730A1 patent drawingFigure 2
  • EP4556730A1 patent drawingFigure 3~4

AI summary

One aspect of the invention relates to a method for assembling an assembly (3) for a household appliance (1) for washing laundry, comprising the following steps: a) providing a bearing housing (9) of a bearing arrangement (4) of the assembly (3) and providing a separate first radial roller bearing (13) of the bearing arrangement (4); b) fastening the first radial roller bearing (13) of the bearing arrangement (4) to the bearing housing (9), in particular to an inner side of the bearing housing (9), with a press fit; c) providing a subassembly (22) with a shaft journal (7) of the bearing arrangement (4) and a laundry drum (6) of the assembly (3); d) axially inserting the subassembly (22) and the module (23) comprising the bearing housing (9) and the first radial roller bearing (13) fastened thereto into one another, such that the first radial roller bearing (13) is fastened to the shaft journal (7) with a press fit;e) following step d), axially inserting a second radial rolling bearing (14) into a receiving space (28) created during the mating process between the shaft journal (7) and the bearing housing (9) such that the second radial rolling bearing (14) is created as a floating bearing. Another aspect relates to a household appliance (1).