Multi-Gear Transmission Layout With Fewer Clutches and Wider Ratios
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Solution Overview
Problem
Current multi-speed transmissions with countershafts are complex and costly due to the increasing number of clutches and gears required for a wide range of gear and speed ratios, which complicates their design and operation.
Innovation Solution
The proposed transmission layout includes an input and direction selection assembly, multiple clutching assemblies, and range clutching assemblies that allow for a compact design with a wide range of gear and speed ratios, utilizing a torque converter and idler shafts to reduce the load on components and enable more equal gear spreads, thereby reducing the size and cost of the transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of clutches and gears is increased to provide a wide range of gear and speed ratios, then the versatility and gear ratio range are improved, but the device complexity and cost increase
Solution Approach 1:
The transmission is divided into multiple independent clutch assemblies (first clutch assembly, second clutch assembly, third clutch assembly) that can operate independently or in combination. Each clutch controls specific gear engagements, allowing the system to achieve multiple gear ratios through selective combination rather than requiring a single complex gear train with numerous components.
Solution Approach 2:
The patent employs a three-dimensional spatial arrangement of clutches and gears, utilizing axial and radial positioning to optimize component layout. The clutches are positioned at different locations along the transmission shaft, and gears are arranged in multiple planes, enabling compact packaging while maintaining access to a wide gear ratio range through selective engagement combinations.
2Adaptability or versatility
If more clutches and gears are added to increase gear selections, then the adaptability is improved, but the manufacturing cost and design complexity increase
Solution Approach 1:
Each clutch assembly is designed to perform multiple functions: the first clutch assembly engages forward gears, the second clutch assembly engages reverse gears, and the third clutch assembly provides additional gear ratio selections. This multi-functionality allows a single clutch mechanism to control multiple gear engagement scenarios, reducing the total number of specialized components needed and simplifying manufacturing.
Solution Approach 2:
The patent combines multiple gear selection functions into a unified clutch control system. Rather than having separate mechanisms for each gear ratio change, the clutch assemblies work in coordination to achieve various gear selections through different engagement combinations, thereby reducing the overall component count and manufacturing complexity.
3Power
If the transmission is designed to handle high power loads, then the power transmission capability is improved, but the size and weight of components increase
Solution Approach 1:
A torque converter is introduced as an intermediary device between the engine and the transmission gear train. The torque converter performs two key functions: it reduces the high-speed, low-torque output from the engine to lower speeds with increased torque before entering the transmission, and it provides smooth, continuous torque multiplication during acceleration. This mediation allows the transmission components to be sized for lower power loads while still handling the vehicle's full power requirements.
Solution Approach 2:
The torque converter dynamically changes the torque and speed parameters transmitted to the gear train based on operating conditions. During acceleration, it multiplies torque; during steady-state cruising, it allows direct torque transmission. This parameter modulation enables the use of smaller, lighter transmission components that can handle the variable reduced loads rather than requiring oversized components capable of handling peak power continuously.
Data Source
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AI summary
Provided herein, is a transmission including an input direction assembly, a first clutching assembly, a second clutching assembly, a first range clutching assembly, a second range clutching assembly and a housing. The input and direction selection assembly includes an input shaft, a first direction selection clutch assembly, a second direction selection clutch assembly and a reversing gear in driving engagement with the second direction selection clutch assembly and the input shaft. The first clutching assembly is selectively drivingly engaged with the input and direction selection assembly and the first range clutching assembly. The second clutching assembly is selectively drivingly engaged with the input and direction selection assembly. The first range clutching assembly is selectively drivingly engaged with the second clutching assembly and the second range clutching assembly.