Steering Lock Nut Recess Structure to Prevent Loosening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing steering devices face issues with lock nut loosening due to external forces, leading to increased costs and complexity with the need for special loosening prevention mechanisms.
Innovation Solution
A steering device design that incorporates a lock nut with a recessed portion to reduce mechanical stiffness, preventing external forces from causing the lock nut to loosen, thereby maintaining frictional force and preventing loosening without additional mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lock nut with high mechanical stiffness is used to prevent loosening, then the frictional force is maintained, but external forces cause rotational motion that reduces contact area and lowers frictional force
Solution Approach 1:
The patent changes the mechanical stiffness parameter of the lock nut by introducing a recessed portion, transforming it from a high-stiffness structure to a controlled-flexibility structure that can absorb external forces through elastic deformation rather than rigid resistance
Solution Approach 2:
The patent converts the harmful effect of external forces into a beneficial effect by allowing the recessed portion to flex under these forces, thereby preventing the rotational motion that would otherwise reduce contact area and frictional force
2Area of stationary object
If the lock nut is made rigid to maintain contact area, then frictional force is preserved, but external forces cause rotational motion that decreases contact area
Solution Approach 1:
The patent introduces dynamic flexibility to the lock nut structure through the recessed portion, allowing it to adapt its shape in response to external forces while maintaining stable contact area and frictional force
3Reliability
If a special loosening prevention mechanism is added, then lock nut loosening is prevented, but device complexity and cost increase
Solution Approach 1:
The lock nut structure serves itself by incorporating the recessed portion that automatically absorbs external forces through elastic deformation, eliminating the need for separate loosening prevention mechanisms
Solution Approach 2:
The patent merges the loosening prevention function into the lock nut structure itself by integrating the recessed portion, combining multiple functions into a single component
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 design effectively prevents lock nut loosening by buffering external forces through the recessed portion, maintaining contact area and frictional force, and eliminating the need for special loosening prevention mechanisms, thus reducing costs and complexity.
Implementation Method 1
loosening of the lock nut is prevented with a frictional force generated between the loosening prevention protruding portion and the inner wall of the turning nut accommodating portion that is in contact with the loosening prevention protruding portion
Implementation Method 2
the recessed portion for reducing the mechanical stiffness is formed in a part of the loosening prevention protruding portion or a part of the lock nut main body. An external force acting from the outer race is buffered at the lock nut recessed portion
Data Source
AI summary
Provided is a steering device including a lock nut that fixes an outer race of a turning nut threadably engaged with a rack bar. A loosening prevention protruding portion formed on a lock nut main body is brought into contact with a radial-direction abutting portion to prevent loosening of the lock nut with a frictional force. At the same time, a lock nut recessed portion for reducing mechanical stiffness is formed in an outer peripheral surface of the loosening prevention protruding portion so that an external force acting from the outer race is buffered by the lock nut recessed portion. In this manner, a decrease in contact area between the loosening prevention protruding portion and the radial-direction abutting portion is reduced.