Self-Locking Threaded Engagement Element with Variable Pitch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bolted joints with standard threaded engagement elements often experience unintentional loosening due to operational conditions such as part bending, temperature changes, and applied forces, which existing solutions attempt to address by increasing friction or using additional components like washers or chemicals, but these methods increase assembly costs and time while still failing to prevent loosening.
Innovation Solution
A threaded engagement element with a body having a longitudinal axis and threads characterized by different parameters, including a steeper thread geometry and higher thread count closer to the head, which self-lock when engaged with a cooperatively configured second element, preventing relative loosening without the need for additional components or increased torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard threaded engagement elements are used, then assembly is simple and cost-effective, but unintentional loosening occurs under operational conditions
Solution Approach 1:
The thread structure transitions from uniform to non-uniform, with different pitch values at different locations along the thread length. Specifically, the thread has a first pitch in the initial engagement portion and a second pitch in the locking portion, creating localized functional differences that enable both easy installation and self-locking
Solution Approach 2:
The thread pitch parameter is changed along the length of the thread engagement element. The transition from a coarser pitch to a finer pitch creates a mechanical interference effect that prevents loosening while maintaining ease of initial engagement
2Reliability
If friction is increased to prevent loosening, then joint stability improves, but installation torque requirement increases
Solution Approach 1:
The thread structure is divided into functional zones: an initial engagement portion with standard pitch for easy installation, and a locking portion with different pitch for stability. This localized differentiation allows low installation torque while achieving high joint stability through the interference fit in the locking portion
3Reliability
If additional components like washers or adhesives are used to prevent loosening, then joint stability improves, but assembly cost and time increase
Solution Approach 1:
The patent combines multiple functions into a single thread structure. The threaded engagement element itself provides both the joining function and the anti-loosening function through its non-uniform pitch design, eliminating the need for separate washers, lock nuts, or adhesive applications
Solution Approach 2:
The thread structure is designed to automatically lock itself through the pitch differential. When the engagement element is screwed in, the transition from the first pitch to the second pitch creates a self-locking effect that prevents back-out without requiring external components or additional operations
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 solution effectively prevents unintentional loosening of bolted joints while maintaining ease of installation, reducing assembly time and costs, and allowing for repeated use without performance degradation, overcoming the limitations of prior methods.
Implementation Method 1
The parts remain fixed due to the frictional force that is generated at the interfaces between threads, the parts and the surfaces of the engaging elements (nut and bolt) that contact the parts.
Implementation Method 2
The threads are characterized by a thread parameter. The element body has first and second portions each with a different value of the thread parameter.
Data Source
AI summary
A threaded engagement element comprising a body having a longitudinal axis and a thread adapted to be received by a corresponding thread of a second element. The threads are characterized by a thread parameter. The body has first and second portions that each has a different value for the thread parameter. The body may have more than one thread count or more than one geometry. This configuration creates a threaded engagement element with self-locking threads, which prevents unintentional loosening.