Integral Dust Seal Design for Steering Shaft Assembly
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Solution Overview
Problem
Conventional dust seals for steering shafts have complex assembly processes and inadequate attaching strength, leading to potential loosening and decreased sealing performance due to the separation of bushing components and attaching members.
Innovation Solution
A dust seal design featuring an annular bushing with integral accordion units bonded to the attaching portion using vulcanization, providing enhanced joint strength and simplified assembly by integrating the first and second accordion units with the bushing and attaching portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the bushing is separated from the first bellows and the second bellows, then the assembly process becomes complex and the number of components increases, but the attaching strength is reduced and the fixation may loosen
Solution Approach 1:
The bushing, first bellows, and second bellows are integrated into a single unified structure where the bellows are directly formed as continuous extensions of the bushing body. This merging eliminates the need for separate attaching members and multiple assembly steps, while simultaneously providing continuous structural support that prevents loosening and maintains attaching strength throughout the operational life of the dust seal.
2Device complexity
If the attaching member is used to fix the bellows to the bushing, then the assembly is simplified, but the fixation may loosen due to inadequate attaching strength under vibration and steering shaft movement
Solution Approach 1:
The attaching member is eliminated entirely as the bellows are directly formed as integral continuous extensions of the bushing body. This merging creates a monolithic structure where no separate fixation elements are needed, thereby eliminating the risk of loosening while maintaining simple assembly through the pre-integrated design.
Solution Approach 2:
Instead of using a separate attaching member to connect the bellows to the bushing, the design inverts the approach by making the bellows themselves the continuous structural extension of the bushing. This inversion transforms the attachment from a separate component function to an inherent structural property, ensuring reliable fixation that cannot loosen.
3Adaptability or versatility
If the bushing is movable relative to the column hole to follow steering shaft movement, then the sealing performance is maintained, but the repeated expansion and contraction may cause detachment if the attaching strength is insufficient
Solution Approach 1:
The bushing, first bellows, and second bellows are merged into a single continuous structure that moves as one unified component. This merging provides inherent structural strength that can withstand repeated expansion and contraction during steering operations, while maintaining the adaptability to follow steering shaft movement through the flexible bellows design.
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 achieves high joint strength and simplified assembly, ensuring improved sealing performance and durability against repeated expansion and contraction, reducing the risk of detachment and maintaining effective sealing over time.
Implementation Method 1
the first accordion unit is integral with the attaching portion, is joined to an inner peripheral surface of the attaching portion at an outer periphery, and is bonded to an outer peripheral surface of the bushing at an inner periphery by vulcanization
Data Source
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AI summary
Provided is a dust seal which can be made with a simple assembly process and exhibits high joint strength between a bushing and each accordion unit. A dust seal (1) has an annular shape and includes a bushing (10), a dust seal body (20), and a seal lip (30). The dust seal body (20) includes an attaching portion (21), a first bellows (22), and a second bellows (23), and the attaching portion (21), the first bellows (22), and the second bellows (23) are integrally formed from the same rubber. The first bellows (22) and the bushing (10) are bonded to each other by vulcanization, and the second bellows (23) is engaged with and fixed to the bushing (10). The seal lip (30) is joined to an end portion (11) of the bushing (10) by vulcanization bonding.