Planetary Gear Housing Flow Path for Gear Chamber Cooling

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Solution Overview

Problem

Existing units face challenges in improving heat exchange efficiency, particularly in cooling gear chambers effectively.

Innovation Solution

A unit design incorporating a housing with a flow path that overlaps a stepped pinion gear, utilizing a coolant different from the oil in the gear chamber to enhance heat exchange efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a conventional housing design is used without overlapping flow path and gear components, then the structure is simple and easy to manufacture, but the heat exchange efficiency is insufficient and gear chamber cooling is inadequate

Engineering Contradiction:
Improvegear chamber temperatureVSAvoidhousing structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies dimensional optimization by positioning the flow path to overlap with the large pinion in the radial direction when viewed axially. This spatial arrangement increases the heat exchange surface area between the coolant flow path and the gear components without adding axial height or radial width to the housing, thereby improving cooling efficiency while maintaining a compact structure.

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

2Productivity

If the flow path is positioned to overlap the large pinion in the radial direction, then heat exchange efficiency is improved, but the housing design becomes more complex

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidflow path configuration complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The housing structure is designed to serve multiple functions: it provides structural support for the planetary gear mechanism, contains the lubricating oil, and incorporates the cooling flow path as an integrated thermal management system. The flow path overlaps with both the large pinion for direct cooling and the small pinion for secondary cooling, enabling the housing to simultaneously perform mechanical and thermal functions without requiring separate cooling components.

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

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 design allows for improved cooling of gear chambers at lower temperatures, enhancing overall heat exchange efficiency.

Implementation Method 1

the flow path has a portion that overlaps the large pinion when viewed in a radial direction

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a housing configured to accommodate a planetary gear mechanism, wherein the housing includes a flow path through which a coolant flows

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4360938B1unit
Publication Date: 2025.11.12 JATCO LTD
  • EP4360938B1 patent drawingFigure 1
  • EP4360938B1 patent drawingFigure 2
  • EP4360938B1 patent drawingFigure 3

AI summary

To provide a unit having improved heat exchange efficiency. A unit (1) includes a housing (HS) configured to accommodate a planetary gear mechanism (4), wherein the housing (HS) includes a flow path (CP1) through which a coolant flows, the planetary gear mechanism (4) includes a stepped pinion gear (43), the stepped pinion gear (43) includes a small pinion (432) and a large pinion (431), and the flow path (CP1) has a portion that overlaps the large pinion (431) when viewed in a radial direction.