Steered Shaft Rotation Stopper for Backlash-Free Steering
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Solution Overview
Problem
The existing steering device suffers from wobbly shakes or backlash due to gaps between the D-shaped cross section member and the steered shaft, caused by machining tolerances and wear over time, which affects the stability of the steering mechanism.
Innovation Solution
A steering device with a steered shaft rotation stopper comprising a contact member and a forcing member that pushes against either the steered shaft or the contact member to maintain contact and prevent rotation, ensuring the steered shaft is stopped effectively, thereby reducing backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a D-shaped cross section member is inserted into a cylindrical bush to support the steered shaft, then the steered shaft can be supported and rotation can be stopped, but gaps appear between the D-shaped cross section member and the steered shaft due to machining tolerances and wear, causing wobbly shakes
Solution Approach 1:
A forcing member (spring) is introduced as an intermediary element between the contact member and the steered shaft. This spring continuously pushes the contact member against the steered shaft, eliminating gaps caused by machining tolerances and wear. The intermediary forcing member maintains constant contact pressure, preventing wobbly shakes while allowing for manufacturing variations.
Solution Approach 2:
The forcing member (spring) is pre-installed in the rotation stopper to preliminarily apply contact force between the contact member and the steered shaft before operation begins. This preliminary action ensures that the contact member is already pressed against the steered shaft with appropriate force, preventing gap formation from the start of operation and eliminating the need for precise machining tolerances.
2Reliability
If the contact member directly contacts the steered shaft to stop rotation, then rotation can be prevented, but wear occurs at the contact surfaces over time, widening the gap and increasing backlash
Solution Approach 1:
The forcing member (spring) provides beforehand cushioning by continuously maintaining contact pressure between the contact member and the steered shaft. This cushioning effect compensates for wear that occurs during operation, ensuring that the contact member remains pressed against the steered shaft throughout the service life, thereby extending the functional duration while maintaining rotation stopping capability.
3Reliability
If machining tolerances are reduced to eliminate gaps between the D-shaped cross section member and the steered shaft, then wobbly shakes can be suppressed, but manufacturing complexity and cost increase
Solution Approach 1:
The forcing member (spring) acts as an intermediary that compensates for machining tolerances. Instead of requiring high-precision machining to eliminate gaps, the spring intermediary automatically adjusts to accommodate normal tolerance ranges, maintaining reliable contact between the contact member and steered shaft without increasing manufacturing complexity.
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 suppresses wobbly shakes or backlash between the steered shaft and the contact member, enhancing the stability and precision of the steering mechanism.
Implementation Method 1
The forcing member forces at least either one of a steered shaft or the contact member in a direction in which the steered shaft and the contact member push against each other
Data Source
AI summary
A steering device of the present invention has a steered shaft rotation stopper (100) having a contact member (101) and a forcing member (102). The forcing member (102) forces at least either one of a steered shaft (6) or the contact member (101) in a direction in which the steered shaft (6) and the contact member (101) push against each other. In a state in which the contact member (101) contacts a contact portion (6D) of the steered shaft (6), the contact member (101) stops a rotation of the steered shaft (6).