Variable Speed Transmission Using Braking Device on Ring Gear
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Solution Overview
Problem
Current variable speed transmissions in rotorcraft face instability due to friction-based clutch mechanisms, which lead to heat generation, wear, and the need for larger components and cooling systems, limiting their reliability and speed range.
Innovation Solution
A variable speed transmission system utilizing a planetary gear set with a ring gear and sun gear, powered by a primary engine, and featuring a braking device and controller to adjust the rotational speed of the ring gear, allowing continuous speed variation without friction clutches, using Virtual Elliptical Drives (VEDs) to alter the orbital speed of planet gears.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If friction-based clutch mechanisms are used for speed variation, then speed adjustment is achieved, but heat generation and wear increase
Solution Approach 1:
The patent replaces friction-based clutch mechanisms with a braking device that applies forces to the ring gear in a planetary gear system. This substitution eliminates the harmful friction-based speed adjustment method while achieving the same speed variation function through a different mechanical approach that reduces heat generation and wear.
Solution Approach 2:
The patent changes the operating parameters by using a braking device that can apply controlled forces to the ring gear, allowing speed variation through force application rather than friction engagement. This parameter change enables speed adjustment while minimizing the harmful effects of heat and wear associated with traditional clutch mechanisms.
2Speed
If friction-based clutch mechanisms are used, then speed adjustment is possible, but component wear and reliability decrease
Solution Approach 1:
The patent substitutes friction-based clutch mechanisms with a braking device acting on the ring gear, eliminating the wear and tear problems that reduce reliability. This replacement maintains speed adjustment capability while significantly improving component reliability by avoiding frequent engagement and disengagement of friction-based clutches.
3Reliability
If larger components and cooling systems are added to compensate for friction clutch limitations, then reliability improves, but weight increases
Solution Approach 1:
The patent extracts and eliminates the need for large cooling systems and oversized components by removing the friction-based clutch mechanisms that generated excessive heat. The braking device approach inherently produces less heat, allowing for a more compact, lighter transmission system while maintaining or improving reliability.
Solution Approach 2:
By replacing friction-based clutches with a braking device system, the patent eliminates the need for heavy cooling infrastructure and oversized components, achieving both improved reliability and reduced weight simultaneously.
4Speed
If friction-based clutch mechanisms are used, then speed variation is achieved, but device complexity increases
Solution Approach 1:
The patent merges the speed variation function into the existing planetary gear system by using a braking device that acts on the ring gear. This integration approach eliminates the need for separate friction clutch mechanisms, thereby reducing device complexity while maintaining speed variation capability.
Solution Approach 2:
The substitution of friction-based clutches with a braking device integrated into the planetary gear system simplifies the overall transmission design, reducing the number of separate components and mechanisms needed to achieve speed variation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides a reliable and stable wide-range speed variation, reducing heat generation and wear, enabling efficient operation with improved power-to-weight ratios and maintaining constant accessory drive speeds, enhancing rotorcraft performance and efficiency.
Implementation Method 1
a braking device engaging the ring gear, and a controller configured to alter the rotational speed of the ring gear by adjusting the braking device
Implementation Method 2
a planetary gear set having a ring gear and a sun gear
Data Source
AI summary
A variable speed transmission is disclosed, with a transmission apparatus which includes a planetary gear set having a ring gear and a sun gear. The variable speed transmission further includes a primary engine for powering the sun gear, a braking device engaging the ring gear, and a controller configured to alter the rotational speed of the ring gear by adjusting the braking device.