Generator Motor Drain Hole Design for Water Management

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Solution Overview

Problem

Generator motors in construction machines are prone to failures due to water ingress and dew condensation caused by temperature differences, leading to short-circuits and corrosion, which existing designs fail to adequately address.

Innovation Solution

A generator motor design featuring a drain hole system between the cover and housing main body, with a covered section below the drain hole to prevent water entry from outside, allowing internal water to be drained and incorporating a temperature sensor's conducting wire to pass through the drain hole for external signal transmission, reducing the need for additional waterproofing measures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the housing is sealed to prevent water ingress, then reliability is improved, but water condensation inside the housing cannot be drained

Engineering Contradiction:
Improveprevention of water ingressVSAvoidwater condensation inside housing
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The housing is segmented into multiple parts (housing main body and cover) with a dedicated drain hole structure. The drain hole is formed between the lower end of the cover and the end surface of the housing main body, creating a separate water drainage pathway that is distinct from the sealed housing structure. This segmentation allows the housing to maintain its sealed nature while providing a specific pathway for condensation drainage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A covered section acts as an intermediary element between the drain hole and the external environment. This covered section prevents water from entering through the drain hole while allowing condensed water inside the housing to drain out. The intermediary structure resolves the contradiction by providing directional selectivity - permitting internal water to escape while blocking external water from entering.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If a drain hole is added to drain water, then water drainage is improved, but water may enter through the drain hole from outside

Engineering Contradiction:
Improvewater drainage capabilityVSAvoidwater entry from outside
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The covered section serves as a mediator that selectively controls water flow through the drain hole. It allows water generated inside the housing to drain outward while preventing external water from entering inward. This intermediary structure resolves the contradiction by providing asymmetric functionality - permitting drainage in one direction while blocking water ingress from the opposite direction.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of trying to prevent water from entering through the drain hole with complex sealing mechanisms, the invention inverts the approach by allowing water to freely drain through the covered section while using the covered section itself as the barrier against external water. The covered section is positioned to cover the drain hole from the outside, creating a one-way drainage system.

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

3Reliability

If waterproofing measures are added to prevent water ingress, then reliability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvewaterproofing capabilityVSAvoidwaterproofing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cover serves multiple functions: it seals the opening of the housing main body, provides structural support, and incorporates the drain hole with the covered section for water drainage. By making the cover multi-functional, the invention eliminates the need for separate waterproofing components, thereby reducing device complexity and manufacturing cost while maintaining reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The drainage function is merged into the existing cover component rather than being implemented as a separate system. The drain hole and covered section are integrated into the cover structure, combining the sealing and drainage functions into a single component. This merging reduces the number of parts and simplifies the overall housing structure.

Inventive Principle:
Principle #5Merging (Combining)

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

Effectively drains water from the housing, prevents external water ingress, and simplifies maintenance by eliminating the need for adjusting waterproofing during cover attachment and detachment, while reducing costs by using existing components for the covered section.

Implementation Method 1

a drain hole is formed between a lower end of the cover and an end surface of the housing main body... water inside the housing can be drained to the outside of the housing

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

a covered section below the drain hole to prevent water entry from outside

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP3082230B1Generator motor
Publication Date: 2019.06.12 KOBELCO CONSTR MASCH CO LTD
  • EP3082230B1 patent drawingFigure 1
  • EP3082230B1 patent drawingFigure 2
  • EP3082230B1 patent drawingFigure 3

AI summary

The invention is to drain water inside a housing to the outside of the housing. A generator motor includes a stator 20, a rotor 19 that rotates relative to the stator 20, and a motor housing 21 that houses the stator 20 and the rotor19. The motor housing 21 includes a housing main body 29 that encloses a periphery of the stator 20 and the rotor 19 and a cover 30 that is attached to an end surface of the housing main body 29 so as to cover an opening 35a formed on the end surface, which is on an opposite side to an engine 14, of the housing main body 29. A drain hole for draining water inside the motor housing 21 to below the motor housing 21 is formed between a lower end of the cover 30 and the end surface of the housing main body 29. The motor housing 21 includes a covered section 37 that covers the drain hole from below at a position that is lower than the drain hole.