Helicopter Tail Folding Coupling for Reliable Shaft Alignment
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Solution Overview
Problem
Current helicopter tail folding mechanisms face issues with alignment, low reliability, limited flexibility, low load-bearing capacity, and frequent maintenance due to the use of face gear couplings, which hinder efficient folding and unfolding processes.
Innovation Solution
A helicopter tail folding mechanism utilizing a helically-shaped spline gear design with a transmission element that allows for efficient power transmission and decoupling, featuring a first and second shaft with threaded couplings, a crown-shaped hub, and a dampener to facilitate smooth folding and unfolding while preventing decoupling, along with a sealing element to prevent foreign substances from entering the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If face gear coupling is used for tail folding mechanism, then the coupling mechanism can be implemented, but alignment difficulty and low reliability occur
Solution Approach 1:
A spherical intermediate element (ball) is introduced between the drive shaft and tail rotor shaft to enable universal joint coupling. This intermediary allows angular misalignment and facilitates smooth engagement/disengagement during folding operations, eliminating the alignment difficulties associated with direct face gear coupling while maintaining reliable power transmission.
Solution Approach 2:
The coupling mechanism transitions between different operational states (engaged/disengaged) by changing the angular position parameter. During folding, the tail rotor shaft rotates to disengage the coupling; during flight, it returns to the engaged position. This parameter change enables the system to adapt between coupled and uncoupled states reliably.
2Strength
If face gear coupling is used for tail folding mechanism, then the coupling mechanism can be implemented, but load bearing capacity is limited
Solution Approach 1:
The spherical intermediate element acts as a load-distributing mediator that accommodates angular variations while transmitting torque. This universal joint configuration increases load bearing capacity by distributing forces across multiple contact points and accommodating misalignment, thereby improving both strength and reliability simultaneously.
3Duration of action of stationary object
If traditional coupling mechanism is used, then power transmission can be achieved, but maintenance intervals are short
Solution Approach 1:
The spherical intermediate element simplifies the coupling mechanism by eliminating complex toothed gear interfaces. This ball-and-socket type coupling has fewer wear points and simpler geometry, reducing maintenance frequency and easing repair procedures while extending maintenance intervals.
4Volume of moving object
If tail is folded to reduce space, then compactness is achieved, but power transmission must be decoupled
Solution Approach 1:
The spherical intermediate element enables a simple rotational disengagement mechanism. When the tail needs to be folded, the tail rotor shaft simply rotates to disengage the ball from the socket, achieving compact storage position without complex locking or disconnect mechanisms. This maintains low device complexity while enabling volume reduction.
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 mechanism provides a more reliable, efficient, and practical solution for folding and unfolding the helicopter tail, ensuring stable power transmission and reducing maintenance needs, while maintaining aerodynamic stability and compactness.
Implementation Method 1
a helical spring coaxial with shaft and compressed between an outer intermediate shoulder of sleeve and an annular supporting element fitted to shaft
Implementation Method 2
There is a dampener to facilitate smooth folding and unfolding
Data Source
AI summary
A helicopter tail folding mechanism for a tail located on the helicopter has a front region located on the tail, a rear region connected to the front region to make a folding movement around the axis on which it is supported, a first shaft located on the front region and a second shaft located on the rear region enables power to be transmitted to the tail rotor during the flight movement of the helicopter, a first coupling and a second coupling located on the first shaft both with a threaded form, a first hub located on the first shaft surrounding the first coupling all around that is form-fitting to the first coupling to enable the first coupling to make at least a partial spherical rotational movement, and a second hub located on the second shaft to be arranged opposite to the second coupling and being form-fitting to the second coupling.