Multi-Speed Transmission with Four Planetary Gear Sets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-speed transmissions for heavy machines require a large number of gears and control elements, leading to increased manufacturing costs, fuel inefficiency, and performance issues due to excessive components and complex gear ratios.
Innovation Solution
A multi-speed transmission design utilizing four planetary gear sets and six control elements to achieve nine forward and two reverse gear ratios, reducing the number of components while maintaining efficient gear shifting and engine operation within a desired range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a large number of gears and control elements are used to provide multiple forward and reverse gear ratios, then the transmission can achieve a wide range of speed ratios, but the manufacturing cost increases and fuel efficiency decreases
Solution Approach 1:
The patent combines multiple planetary gear sets (first, second, third, and fourth planetary gear sets) into a single integrated transmission system where the gear sets work together to provide multiple forward and reverse gear ratios. This merging approach reduces the total number of separate components compared to using individual gear trains for each ratio, thereby achieving wide adaptability while controlling device complexity
Solution Approach 2:
Each planetary gear set is designed to serve multiple functions by engaging different combinations of sun gears, planet carriers, and ring gears through control elements. The same planetary gear set can provide both forward and reverse gear ratios depending on which components are engaged, making each component universal and reducing the need for dedicated components for each gear ratio
2Adaptability or versatility
If more control elements such as clutches and brakes are added to achieve multiple reverse gear ratios, then the transmission versatility improves, but the manufacturing cost and assembly complexity increase
Solution Approach 1:
The control elements (clutches and brakes) are designed to control multiple planetary gear sets simultaneously, allowing the same control element to engage different gear sets for both forward and reverse operations. This multi-functionality reduces the total number of control elements needed compared to having dedicated control elements for each reverse gear ratio
Solution Approach 2:
The patent merges the control functions for multiple reverse gear ratios into a coordinated system where control elements work in combination across different planetary gear sets. This integrated control approach reduces the number of separate control elements needed while achieving multiple reverse gear capabilities
3Adaptability or versatility
If numerous clutches and brakes are used to provide multiple gear ratios, then the transmission can achieve high versatility, but fuel efficiency deteriorates due to increased drag
Solution Approach 1:
The patent combines multiple planetary gear sets into a single efficient transmission system where power flows through integrated gear paths. This merging reduces the number of separate power transmission paths and associated drag losses compared to using multiple independent gear trains, thereby improving fuel efficiency while maintaining gear ratio versatility
4Productivity
If a greater number of forward gear ratios are provided, then the transmission can maintain engine operating range more effectively, but the number of required gears and control elements increases
Solution Approach 1:
The planetary gear sets are designed so that each gear set can contribute to multiple forward gear ratios through different engagement combinations. This multi-functionality allows the transmission to achieve a greater number of forward gear ratios while using a relatively limited number of physical gears, thereby maintaining engine operating efficiency without proportionally increasing device complexity
Data Source
AI summary
A multi-speed transmission may include an input member and an output member disposed in a housing. A first planetary gear set, a second planetary gear set, a third planetary gear set, and a fourth planetary gear set may also be disposed in the housing, each planetary gear set including a sun gear, a planet carrier, and a ring gear. Six control elements may be operably coupled to the planetary gear sets and selectively engageable to create a set of different gear ratios between the input member and the output member, the set of different gear ratios including at least nine forward gear ratios and at least two reverse gear ratios.