Power Tool Air Passage Cooling for Sealed Gear Case Heat

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Power tools with sealed gear cases experience heat accumulation due to gear meshing, leading to component damage and difficulty in cooling, as the sealed environment prevents airflow and heat dissipation.

Innovation Solution

A power tool design featuring a motor-driven fan to generate cooling air, which is directed through an air passage to cool components like pulleys and belts within the transmission mechanism, and discharged to improve visibility and dust removal during operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the gear case is sealed to prevent lubricant leakage, then lubricant retention is improved, but heat dissipation deteriorates due to heat accumulation from gear meshing

Engineering Contradiction:
Improvelubricant retentionVSAvoidheat accumulation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The housing is divided into multiple chambers: a sealed gear case chamber for lubricant retention and an open transmission mechanism chamber for heat dissipation. This segmentation allows the gear case to remain sealed while the transmission mechanism components (pulleys and belts) are exposed to airflow for cooling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A fan is introduced as an intermediary device to generate forced airflow through the housing. The fan creates a wind passage that directs cooling air over the transmission mechanism components, enabling heat dissipation without compromising the sealed gear case.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the gear case is sealed to prevent lubricant leakage, then lubricant retention is improved, but cooling of components deteriorates because components cannot be directly exposed to airflow

Engineering Contradiction:
Improvelubricant retentionVSAvoidcooling efficiency
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The housing is divided into multiple chambers: a sealed gear case chamber for lubricant retention and an open transmission mechanism chamber for heat dissipation. This segmentation allows the gear case to remain sealed while the transmission mechanism components (pulleys and belts) are exposed to airflow for cooling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A fan-driven airflow system is implemented to provide forced convection cooling. The fan generates a wind passage that directs cooling air over the transmission mechanism components, enabling effective heat dissipation through pneumatic means without compromising the sealed gear case.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Reliability

If a sealed gear case is used, then lubricant leakage is prevented, but heat dissipation from transmission components deteriorates

Engineering Contradiction:
Improvelubricant retentionVSAvoidheat dissipation
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The housing is divided into multiple chambers: a sealed gear case chamber for lubricant retention and an open transmission mechanism chamber for heat dissipation. This segmentation allows the gear case to remain sealed while the transmission mechanism components (pulleys and belts) are exposed to airflow for cooling.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A fan is introduced as an intermediary device to generate forced airflow through the housing. The fan creates a wind passage that directs cooling air over the transmission mechanism components, enabling heat dissipation without compromising the sealed gear case.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design enhances heat dissipation from transmission components, prevents dust entry, and improves visibility by using airflow to blow away cutting dust, thereby extending component lifespan and enhancing operational performance.

Implementation Method 1

a fan configured to be rotated by the motor to generate a cooling air

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

the cooling air directly impinges on the rotation member to cool the rotation member, so that heat dissipation from the rotation member can be efficiently performed

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3549704B1Power-driven tool
Publication Date: 2024.07.17 KOKI HLDG CO LTD
  • EP3549704B1 patent drawingFigure 1
  • EP3549704B1 patent drawingFigure 2
  • EP3549704B1 patent drawingFigure 3

AI summary

A power tool facilitates cooling to components accommodated in a gear case. The power tool 1 includes a motor 6, a fan 7 rotated by the motor 6 to generate a cooling air, housings 42, 44, and 45 accommodating therein the motor 6 and the fan 7 and defining an air passage P for the cooling air, an output shaft 43 rotatable by the motor 6 and to which an end tool 41 is detachably attachable, and a transmission mechanism 5 for transmitting rotation of the motor 6 to the output shaft 43. The transmission mechanism 5 includes a rotation member 51 rotatable integrally with the output shaft 43. The rotation member 51 is positioned within the air passage P.