Planetary Gear Lubrication Passage for Mode Change Continuity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing gear systems used in vehicles face challenges in smoothly lubricating the planetary gear assembly when the operation mode is changed between driving, neutral, and parking modes, leading to potential interruptions in oil transmission between the carrier and output shaft.

Innovation Solution

A gear system design featuring a sun gear, ring gear, planetary gear, and carrier with a hollow output shaft, including a third lubrication passage that connects radially formed first and second lubrication passages on the carrier and output shaft, ensuring continuous oil flow regardless of the operation mode, with the third passage extending circumferentially around the output shaft at 360 degrees to maintain lubrication connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the carrier and output shaft are selectively engaged to change operation modes (driving, neutral, parking), then the gear system can perform different functions, but the lubrication passage connection between carrier and output shaft is interrupted, causing lubrication failure

Engineering Contradiction:
Improveoperation mode change capabilityVSAvoidlubrication continuity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention introduces an intermediary lubrication passage that connects the carrier lubrication passage and output shaft lubrication passage through the planetary gear assembly. This intermediary passage ensures continuous oil flow even when the carrier and output shaft are disengaged, solving the lubrication interruption problem while maintaining mode-changing capability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The lubrication system is segmented into three parts: carrier lubrication passage, planetary gear lubrication passage, and output shaft lubrication passage. The planetary gear assembly acts as a connection medium, with oil flowing sequentially through these segments to ensure continuous lubrication across all operation modes

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If a simple lubrication passage structure is used, then manufacturing is easier, but lubrication cannot be maintained during mode changes between driving, neutral, and parking

Engineering Contradiction:
Improvelubrication passage structure simplicityVSAvoidlubrication coverage during mode changes
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The planetary gear assembly serves multiple functions: it transmits mechanical power during driving mode and simultaneously acts as a lubrication passage connector during all mode changes. This multi-functionality allows the structure to maintain lubrication continuity without adding separate complex lubrication components

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

Solution Approach 2:

The system uses its own internal structure (planetary gear assembly and existing lubrication passages) to provide the lubrication connection function, rather than requiring an external or separate mechanism. The oil naturally flows through the planetary gear assembly, utilizing the existing mechanical structure for dual purposes

Inventive Principle:
Principle #25Self-service

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 ensures uninterrupted lubrication and reduced friction, wear, and noise across all operation modes by maintaining oil flow between the carrier and output shaft, enhancing the gear system's reliability and performance.

Implementation Method 1

a third lubrication passage formed between the outer surface of the output shaft and the inner surface of the carrier and configured to connect the first lubrication passage and the second lubrication passage

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

The gear system has a lubrication structure to minimize heat generation, wear, and noise due to friction

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP3848617A1Gear system
Publication Date: 2021.07.14 LG MAGNA E POWERTRAIN CO LTD
  • EP3848617A1 patent drawingFigure 1A~1B
  • EP3848617A1 patent drawingFigure 2A~2B
  • EP3848617A1 patent drawingFigure 3A~3B

AI summary

A gear system is provided to secure lubrication passages when the gear system is changed between driving, neutral, and parking modes. The gear system includes a planetary gear assembly, a hollow portion output shaft selectively engaged with a carrier such that the output shaft is configured to rotate with the carrier when the output shaft is engaged with the carrier. The gear system further includes a first lubrication passage formed radially at a first point on the carrier, a second lubrication passage formed radially at a second point on the output shaft, and a third lubrication passage formed between the outer surface of the output shaft and the inner surface of the carrier and configured to connect the first lubrication passage and the second lubrication passage.