Four-Planetary Gear Transmission for Heavy Load Shiftability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicle transmission arrangements for working machines, such as articulated haulers, require a large number of components, leading to increased costs and reduced packaging efficiency, while also lacking optimal gear shiftability for heavy load operations in rough terrain.
Innovation Solution
A transmission arrangement using four planetary gear sets with specific connections between sun gears, planet carriers, and ring gears, along with clutch and brake mechanisms, to achieve nine forward and three reverse gears with reduced component count and improved shiftability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If five planetary gear sets are used to provide sufficient gear ratios, then the number of gears is sufficient, but the number of components increases and costs increase
Solution Approach 1:
The patent merges the functions of five planetary gear sets into four planetary gear sets by implementing direct operational connections between planet carriers and strategically connecting sun gears to ring gears of other planetary sets. This consolidation maintains the necessary gear ratio range while reducing the total component count and associated costs.
Solution Approach 2:
The planet carriers in the four planetary gear sets are designed to serve multiple functions: they act as output elements for one planetary set, input elements for another, and are selectively connectable to the housing via brakes. This multi-functionality allows the reduced number of planetary sets to achieve the same gear ratio coverage that would otherwise require five separate sets.
2Ease of operation
If five planetary gear sets with three clutches and five brakes are used, then the desired gear shifts are achieved, but the device complexity and cost increase
Solution Approach 1:
The patent reduces the total number of clutches and brakes by merging their functions across the four planetary gear sets. The selective connection mechanisms are designed to control multiple gear ratios simultaneously, and the brakes are positioned to lock multiple planet carriers at once, thereby achieving the desired gear shifts with fewer individual components.
Solution Approach 2:
Each clutch and brake in the four-planetary-set configuration is designed with multi-functionality to control multiple gear ratios. For example, a single brake can lock the planet carriers of multiple planetary sets simultaneously, and clutches are positioned to engage multiple power flow paths, thereby achieving comprehensive gear shiftability with reduced component count.
3Adaptability or versatility
If more components are used to provide sufficient gear ratios, then the gear shiftability is sufficient, but the packaging efficiency is reduced
Solution Approach 1:
The patent merges five planetary gear sets into four by implementing shared operational paths and direct connections between planet carriers. This consolidation reduces the overall volume of the transmission arrangement while maintaining the necessary gear ratio range through strategic operational connections rather than physically separate components.
Solution Approach 2:
The four planetary gear sets are arranged in a nested or compact configuration where planet carriers of one set are operatively connected to planet carriers of adjacent sets. This nesting allows the gear sets to share space and reduces the total packaging volume while maintaining all necessary gear ratios through the operational connections.
Data Source
Figure 1~2
AI summary
The present invention relates to a transmission arrangement (100) for a vehicle, the transmission arrangement comprising a first (102), a second (104), a third (106), and a fourth (108) planetary gear set comprising a sun gear, a planet carrier and a ring gear, respectively, wherein said transmission arrangement (100) further comprises a transmission housing (160), an input shaft (136) and an output shaft (112), wherein the ring gear (102R) of the first planetary gear set (102) and the input shaft (136) are operatively connected to each other; the planet carrier (102P) of the first planetary gear set (102) and the planet carrier (104P) of the second planetary gear set (104) are operatively connected to each other; the sun gear (102S) of the first planetary gear set (102) and the ring gear (106R) of the third planetary gear set (106) are operatively connected to each other; the ring gear (104R) of the second planetary gear set (104) and the planet carrier (106P) of the third planetary gear set (106) are operatively connected to each other; the planet carrier (106P) of the third planetary gear set (106) and the sun gear (108S) of the fourth planetary gear set (108) are operatively connected to each other; and the planet carrier (108P) of the fourth planetary gear set (108) and the output shaft (112) are operatively connected each other.