Windshield Wiper Drive End Stop Safety Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Windshield wiper direct drives face safety risks due to the wiper arm being pivoted out of the vehicle window region during high-speed journeys, as the wiper shaft can rotate 360° under external displacement forces, leading to a safety hazard.
Innovation Solution
A windshield wiper drive with limited rotational range is achieved by incorporating first and second end stop surfaces on a fastening plate or components, which restrict the wiper shaft's rotation, preventing it from exceeding a maximum angle and ensuring the wiper arm stays within the window region, using a direct drive mechanism without a crank assembly and incorporating toothed or worm wheel gear mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a direct drive mechanism without crank assembly is used, then device complexity is reduced, but the wiper shaft can rotate 360° under external forces causing safety hazards
Solution Approach 1:
The patent applies preliminary anti-action by incorporating end stop surfaces on the motor housing that prevent the wiper shaft from rotating beyond safe angular limits. These stops are positioned beforehand to counteract the potential harmful rotation caused by external forces during high-speed travel, thus maintaining safety without requiring complex additional mechanisms.
Solution Approach 2:
The patent resolves the contradiction by adding a spatial constraint dimension through the end stop surfaces. Rather than relying solely on the rotational dimension control, the end stops introduce a physical boundary in the radial dimension that limits the wiper shaft's rotational range, preventing 360° rotation while maintaining the simplicity of the direct drive mechanism.
2Reliability
If end stop surfaces are added to limit rotation, then safety is improved, but device complexity increases
Solution Approach 1:
The patent merges the end stop surfaces directly into the motor housing structure, combining the safety limiting function with the existing housing component. This integration approach adds the safety function without requiring separate, additional parts, thus minimizing the increase in device complexity while effectively preventing over-rotation.
3Reliability
If the wiper shaft rotation is limited, then safety is improved, but the wiping coverage area may be reduced
Solution Approach 1:
The patent optimizes the angular position and orientation of the end stop surfaces to define a rotational range that prioritizes safety while maintaining adequate wiping coverage. By carefully selecting the parameters of the stop surfaces' positions, the system achieves a balance between limiting rotation to safe angles and preserving sufficient wiping area for effective operation.
Data Source
AI summary
A windshield wiper drive for a motor vehicle, with a reverse-operating driving motor for driving a wiper shaft which is connected in a rotationally fixed manner to a wiper arm, and with a fastening plate for fastening the windshield wiper drive to a vehicle body or to a component mounted on the body, wherein a first end stop surface for limiting the rotational movement of the wiper shaft in a first direction of rotation is provided on the fastening plate and/or on a component fixed to the fastening plate.