Flywheel Housing Vent Path for Blow-By Gas Without Engine Growth

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Solution Overview

Problem

The existing engine designs face challenges in efficiently discharging blow-by gases without enlarging the engine, as there is limited space on the crankcase's upper face, making it difficult to place a gas pipe for blow-by gas output from the blow-by gas path.

Innovation Solution

The engine incorporates a flywheel housing with a blow-by gas path that allows for the discharge of blow-by gases on one end face of the cylinder block in the crankshaft direction, eliminating the need for lengthening the crankcase and enabling easy placement of the gas pipe without interfering with other components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the blow-by gas path outlet is provided on the upper face of the crankcase, then the blow-by gas can be discharged from the crankcase, but the gas pipe placement becomes difficult due to limited space and the crankcase length needs to be increased

Engineering Contradiction:
Improveblow-by gas discharge efficiencyVSAvoidcrankcase length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent relocates the blow-by gas path outlet from the upper face of the crankcase to the side face of the crankcase. This dimensional change in outlet positioning allows the gas pipe to be routed along the side of the crankcase rather than requiring extended crankcase length, thereby resolving the space constraint issue while maintaining effective blow-by gas discharge.

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

2Ease of operation

If the crankcase length is increased to accommodate the gas pipe, then the gas pipe can be placed without contact with the cylinder head, but the overall engine size becomes larger

Engineering Contradiction:
Improvegas pipe placementVSAvoidengine size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

By changing the outlet position to the side face of the crankcase, the patent enables gas pipe routing in a different spatial dimension (along the side rather than through extended length), achieving easy gas pipe placement without increasing the overall engine volume.

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

3Reliability

If the outlet is provided on the upper face of the crankcase, then the blow-by gas path can function properly, but the gas pipe interferes with the cylinder head and other components

Engineering Contradiction:
Improveblow-by gas path functionVSAvoidcomponent interference
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent resolves component interference by relocating the outlet to the side face of the crankcase, which changes the spatial arrangement and allows the gas pipe to be routed in a path that does not intersect with the cylinder head or other components, while maintaining the blow-by gas path's functional integrity.

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

Data Source

PatentEP4242433A1Engine and flywheel housing
Publication Date: 2023.09.13 YANMAR HLDG CO LTD
  • EP4242433A1 patent drawingFigure 1
  • EP4242433A1 patent drawingFigure 2
  • EP4242433A1 patent drawingFigure 3

AI summary

[Problem] To provide, while avoiding enlarging of an engine, a technology that can properly discharge a blow-by gas out of a cylinder block. [Solution] An exemplary engine includes: a cylinder block that has a cylinder included in a combustion chamber; a crankshaft that is placed in the cylinder block; a flywheel that is mounted to one end portion of the crankshaft; and a flywheel housing that is placed on a side of one end face of the cylinder block in a direction of the crankshaft and that houses the flywheel. The flywheel housing has a blow-by gas path through which a blow-by gas passes.