Elastomer Damped Steering Rack Thrust Piece
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rack and pinion steering gears suffer from rattling noises due to friction between the pressure piece and the housing, and existing solutions are either complex, expensive to manufacture, or prone to wear, failing to provide a reliable and low-noise assembly.
Innovation Solution
A pressure piece with an outer metal sleeve and coaxially arranged elastomer damping elements, where the metal pressure piece core is surrounded by an elastomer damping element, preventing direct metallic contact and relative movement, thus eliminating rattling noises and reducing wear through a permanent connection via vulcanization or pressing, allowing for simplified assembly and reduced parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a metal pressure piece slides in a cylindrical bore, then the structure is simple, but friction causes rattling noises and wear
Solution Approach 1:
An elastomer damping element is introduced as an intermediary between the metal pressure piece and the metal bore. This elastomer layer prevents direct metallic contact, thereby eliminating the rattling noises and friction wear while maintaining the simple overall structure. The elastomer absorbs vibrations and dampens movements that would otherwise cause noise.
Solution Approach 2:
The pressure piece assembly becomes a composite structure combining metal (pressure piece and bore) with elastomer (damping element). This composite material approach allows the metallic components to provide structural strength and the elastomer to provide noise damping and friction reduction, resolving the contradiction between simple metal-on-metal structure and noise-free operation.
2Object-generated harmful factors
If plastic or rubber elements are used to dampen pressure piece movement, then rattling is reduced, but the structure becomes more complex and expensive
Solution Approach 1:
The elastomer damping element is integrated directly into the cylindrical bore of the steering housing, merging the damping function with the existing structural component. This eliminates the need for separate metal sleeves or complex assembly steps, reducing overall device complexity while maintaining noise reduction benefits.
Solution Approach 2:
The elastomer serves as a simple intermediary layer within the bore, providing noise dampening without requiring complex external structures or multiple components. This straightforward implementation avoids the complexity of previous solutions involving metal sleeves, O-rings, and multiple assembly steps.
3Manufacturing precision
If a metal tolerance band is used for exact fit, then play-free assembly is achieved, but manufacturing becomes very complex requiring precise measurements and multiple tolerance bands
Solution Approach 1:
Instead of relying on precise dimensional tolerances and multiple tolerance bands, the elastomer damping element provides compliance that accommodates normal manufacturing variations. The elastomer's inherent flexibility allows the assembly to achieve play-free operation without requiring extremely tight tolerances, significantly simplifying manufacturing.
Solution Approach 2:
The combination of rigid metal components with the compliant elastomer material creates a hybrid assembly that achieves precision through material properties rather than dimensional precision alone. This eliminates the need for complex tolerance control and multiple tolerance bands.
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 results in a low-noise, durable, and cost-effective rack and pinion steering gear with reduced wear and improved dynamic vibration control, as the elastomer damping elements absorb movements without causing frictional wear and eliminate rattling, enhancing the overall reliability and controllability.
Implementation Method 1
an elastomeric damping element, with which the pressure piece is inserted into the bore with an exact fit and without play... the elastomer damping element absorbs movements without causing frictional wear
Implementation Method 2
elastomer damping elements absorb movements without causing frictional wear and eliminate rattling
Implementation Method 3
a metal pressure piece that slides in the cylindrical bore... Due to the friction between the toothed rack and the pressure piece
Data Source
AI summary
The invention relates to a toothed-rack steering gear for a motor vehicle, having a steering pinion (1) which is connected to a steering column and which is in engagement with a toothed rack (2) which is mounted in a movable fashion in a housing (3), and having a thrust piece (8) which is arranged in the housing (3) in a thrust piece bore (7) and which holds the toothed rack (2) in play-free engagement with the steering pinion (1), and to a thrust piece (8) for a toothed-rack steering gear, wherein the thrust piece (8) has an outer metallic sleeve (15) which is inserted with an interference fit into the thrust piece bore (7), and in the metallic sleeve (15) there is arranged at least one elastomer damping element, in particular an elastomer sleeve (14), and a metallic thrust piece core (10) which is surrounded by the at least one elastomer damping element.