Coplanar Gear Set Axial Space Savings Transmission
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Solution Overview
Problem
Existing transmission designs face challenges in packaging gear sets and selectively engageable torque-transmitting mechanisms to achieve desired modes of operation while meeting dimensional limitations and assembly requirements, particularly in achieving fuel efficiency and compactness.
Innovation Solution
A transmission with a coplanar gear set comprising two annular gears, two sun gear members, and a ring gear member, supported by a common carrier, which allows for axial space savings, a wider gear ratio range, high contact ratio, and quiet operation by utilizing a first gear set with offset axes of rotation and meshing teeth configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a multi-speed transmission with increased number of speed ratios is designed to improve fuel efficiency, then fuel efficiency is improved, but device complexity and packaging difficulty increase
Solution Approach 1:
The patent employs nested planetary gear sets where smaller planetary gear sets are positioned within the annular gears of larger planetary gear sets. This nesting arrangement allows multiple speed ratios to be achieved within a compact structure, increasing fuel efficiency through more speed ratios while controlling device complexity by sharing common components such as the ring gear and carrier across multiple planetary stages.
2Adaptability or versatility
If more gear sets and torque-transmitting mechanisms are added to achieve desired modes of operation, then gear ratio range and fuel efficiency are improved, but dimensional limitations and assembly requirements become more challenging
Solution Approach 1:
The patent designs planetary gear sets where components serve multiple functions across different operating modes. The ring gear and carrier are shared among multiple planetary gear sets, and the same components can be engaged or disengaged to achieve different speed ratios. This multi-functionality expands the gear ratio range while simplifying assembly by reducing the total number of unique components that must be manufactured and installed.
Data Source
AI summary
A transmission includes a first gear set with a first sun gear member rotatable about a first axis of rotation, a second sun gear member rotatable about the first axis of rotation, a carrier member, and a ring gear member radially outward of and concentric with the first sun gear member. A first annular gear meshes with the first sun gear member, and a second annular gear meshes with the first annular gear, the second sun gear member, and with the ring gear member. The first annular gear is rotatable about a second axis of rotation and the second annular gear is rotatable about a third axis or rotation.