Floating Planetary Range Shift Mechanism for Transfer Case

Solution Overview

Problem

Conventional range shift mechanisms in transfer cases for all-wheel driving systems experience power loss and noise generation in high range mode due to continuous gear rotation, which is inefficient and noisy, as the high range mode is used for the majority of operating time.

Innovation Solution

A floating planetary range shift mechanism is introduced, featuring a sun gear with a clutch, a carrier connected to the output shaft, pinion gears meshed with the sun and ring gears, and a floating ring gear that rotates freely on the output shaft in high range mode, eliminating gear rotation and noise, while allowing for a fixed ring gear in low range mode for efficient power transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If continuous gear rotation is used in high range mode, then power transfer is maintained, but power loss and noise generation occur

Engineering Contradiction:

Improvepower lossVSAvoidpower transfer continuity

Core Design Contradiction:

Loss of energyVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the ring gear movable between two states: freely rotating on the output shaft in high range mode to eliminate gear meshing and power loss, and fixed to the housing in low range mode to enable power transfer through the planetary gear system. This dynamic reconfiguration allows the system to adapt its structure based on operating conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system periodically switches between two operational states based on driving conditions: high range mode (freely rotating ring gear, no power loss) for normal driving conditions and low range mode (fixed ring gear, power transfer enabled) for low-speed or high-torque conditions. This periodic switching optimizes performance across different operating scenarios.

Inventive Principle:

Principle #19Periodic action

2Object-generated harmful factors

If continuous gear rotation is used in high range mode, then power transfer is maintained, but noise generation occurs

Engineering Contradiction:

Improvenoise generationVSAvoidpower transfer continuity

Core Design Contradiction:

Object-generated harmful factorsVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the ring gear movable between two states: freely rotating on the output shaft in high range mode to eliminate gear meshing and power loss, and fixed to the housing in low range mode to enable power transfer through the planetary gear system. This dynamic reconfiguration allows the system to adapt its structure based on operating conditions.

Inventive Principle:

Principle #15Dynamics

3Loss of energy

If fixed ring gear is used for power transfer, then power efficiency is improved, but lubricating oil consumption increases

Engineering Contradiction:

Improvepower efficiencyVSAvoidlubricating oil consumption

Core Design Contradiction:

Loss of energyVSLoss of substance

Solution Approach 1:

The system periodically switches between two operational states based on driving conditions: high range mode (freely rotating ring gear, no power loss) for normal driving conditions and low range mode (fixed ring gear, power transfer enabled) for low-speed or high-torque conditions. This periodic switching optimizes performance across different operating scenarios.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS9109664B2Range shift system for transfer case

Publication Date: 2015.08.18 HYUNDAI WIA CORP

AI summary

Disclosed is a range shift mechanism in the form of a floating planetary gear assembly for a transfer case. The range shift mechanical according to the present invention can improve power efficiency and generate low noises by suppressing gear rotation in a high range mode of the range shift system.