Rack And Pinion Steering Sealing Assembly Against Dirt And Moisture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rack and pinion steering systems in motor vehicles are vulnerable to environmental influences such as dirt and moisture, which can lead to damage and are not effectively addressed in autonomously driven vehicles.
Innovation Solution
An electrically driven rack and pinion steering system with bearing assemblies on either side of the drive element, featuring outer and inner contact seals to create a hermetically sealed housing, allowing for a compact design and protection against environmental factors, and incorporating a pressure equalization system to manage internal pressure changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional gaiters are used to cover the ball joint between the track rod and the rack, then the steering system can be protected against environmental influences, but the protection is insufficient and damage detection is delayed
Solution Approach 1:
The invention extracts the sealing function from the conventional gaiter system and relocates it to the bearing assembly. The bearing assembly is separated into distinct sealing components (outer seal at the housing interface, inner seal at the rack interface) that independently perform the sealing function, removing the vulnerability of the ball joint area from environmental exposure.
Solution Approach 2:
The bearing assembly acts as an intermediary component between the housing and the rack, providing a hermetic seal that prevents direct contact between environmental factors and the internal components. The dual-seal configuration creates an intermediate protected zone that isolates the ball joint and drive element from dirt and moisture.
2Volume of moving object
If the steering system is designed for autonomous vehicles without conventional steering rods, then the housing can be more compact, but the protection against environmental influences must be enhanced
Solution Approach 1:
The invention merges the bearing function and sealing function into a single integrated bearing assembly component. This combination allows the housing to be compact while maintaining robust protection, as the bearing assembly simultaneously supports the rack axially and provides hermetic sealing at both the housing and rack interfaces.
Solution Approach 2:
The bearing assembly provides localized hermetic sealing at critical interfaces (housing-bearing and bearing-rack) without requiring a larger overall housing. The sealing lips are positioned precisely at the passage points where environmental factors could penetrate, providing targeted protection in the compact design.
3Object-affected harmful factors
If bearing assemblies with contact seals are used to seal the housing, then protection against moisture and foreign bodies is improved, but the complexity of the bearing assembly increases
Solution Approach 1:
The invention uses flexible sealing lips made of elastomeric material that can deform to maintain contact with the rack surface. These thin film-like seals provide effective protection against moisture and foreign bodies while adding minimal structural complexity to the bearing assembly.
Solution Approach 2:
The bearing assembly combines different materials to achieve both sealing and bearing functions: the carrier cylinder provides structural support, while the elastomeric sealing lips provide flexible sealing. This composite approach allows effective protection without excessive complexity in any 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 system provides enhanced protection against environmental influences, increasing the service life of the steering system and enabling its use in autonomously driven vehicles by preventing moisture and foreign body penetration, while allowing for a more compact housing design.
Implementation Method 1
a bearing assembly (30), arranged on a section (18) of the rack without a toothing system axially on each side of the drive element (22), which bearing assembly (30) comprises a carrier cylinder (31), on the outer shell face (42) of which an outer contact seal (44) is arranged and on the inner shell face (38) of which an inner contact seal (40) is arranged, the contact seals (40, 44) sealing the housing (12) with respect to the rack (14)
Implementation Method 2
the inner contact seal (40) has a radially inwardly pointing, peripheral sealing lip which slides on the rack (14)
Data Source
AI summary
An electrically driven rack and pinion steering system of a motor vehicle has an axially displaceably mounted rack which transmits a steering movement for steered wheels of the motor vehicle, has an electric drive which provides a steering force and interacts with the rack, and has a housing which receives the rack and a drive element of the drive. The drive element is in engagement with a toothing system of the rack. A bearing assembly is arranged on a section of the rack without a toothing system axially on each side of the drive element, with a carrier cylinder, on the outer shell face of which an outer contact seal is arranged and on the inner shell face of which an inner contact seal is arranged, the contact seals sealing the housing with respect to the rack.