Wiper Arm Drive Mechanism for Adaptive Attack Angle Control
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Solution Overview
Problem
Existing drive mechanisms for windshield wiper arms fail to maintain optimal attack angles consistently, leading to poor wiping quality, noise, and increased wear, especially on vehicles with aerodynamic and curved windshields, due to their complexity and high cost.
Innovation Solution
A drive mechanism featuring a support assembly with a rotating assembly and an inclination adjustment assembly, including a radial pin and biasing element, allows for adjustable attack angles by rotating the wiper arm relative to the windshield curvature, ensuring optimal contact and reducing wear through a simple and cost-effective design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If complex mechanisms such as gear and endless screws are used to adapt the attack angle, then the attack angle can be adjusted, but the device complexity and cost increase significantly
Solution Approach 1:
The patent employs a dynamic cam profile that automatically adjusts the attack angle based on the wiper arm's position and windshield curvature. The cam's contoured surface transforms rotational motion into the required inclination adjustments without complex gearing, allowing continuous adaptation while maintaining mechanical simplicity.
Solution Approach 2:
The cam acts as an intermediary element between the wiper shaft rotation and the inclination adjustment mechanism. It mediates the motion transformation through its profiled surface, converting simple rotational input into the complex coupled motion needed for attack angle adaptation without requiring direct mechanical linkages.
2Adaptability or versatility
If articulated wiper axles are used, then attack angle adaptation is achieved, but wear on cam and cam ball insert increases due to loads and accelerations
Solution Approach 1:
The patent replaces the traditional ball-and-socket articulation with a cam-follower mechanism. This substitution eliminates the high-contact-stress ball insert while achieving the same inclination adjustment function through distributed contact along the cam profile, significantly reducing localized wear and improving reliability.
Solution Approach 2:
The cam profile is designed to dynamically distribute loads throughout the wiper cycle rather than concentrating forces at discrete articulation points. The continuous surface contact allows smooth load transitions that reduce impact forces and accelerate-induced wear on the cam mechanism.
3Device complexity
If the attack angle is not properly maintained, then the wiper arm structure remains simple, but poor wiping quality, noise, and chatter occur
Solution Approach 1:
The cam mechanism is self-adjusting, automatically maintaining the optimal attack angle through its geometric profile without requiring external sensors or control systems. The mechanism self-regulates the inclination based purely on mechanical geometry, ensuring consistent wiping quality while keeping the overall system relatively simple.
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 mechanism maintains optimal attack angles across various windshield curvatures, enhancing wiping quality, reducing noise and wear, and providing a durable and cost-effective solution for both driver and passenger sides.
Implementation Method 1
the biasing element being configured to rotate the inclination shaft depending on a displacement of the rotating assembly according to the primary axis with respect to the support assembly
Data Source
Figure 1~3
Figure 4~5
Figure 6~8
AI summary
Drive mechanism (5) configured for moving a wiper arm, the drive mechanism (5) comprising a support assembly (9) configured to cooperate with a wiper shaft extending according to a primary axis (13) to allow a rotation of the wiper shaft (11) with respect the support assembly (9) according to the primary axis (13); a rotating assembly (15) configured to be mounted in a rotationally fixed manner with the wiper shaft, the rotating assembly (15) including at least one cylindrical bearing extending according to a secondary axis (19), the secondary axis (19) being transverse to the primary axis (13); an inclination adjustment assembly (21) including an inclination shaft configured to be fixed to the wiper arm and to cooperate with the at least one cylindrical bearing so as to be allowed to rotate according to the secondary axis (19), the inclination adjustment assembly (21) further including a radial pin (25) mounted on the inclination shaft and configured to cooperate with a biasing element (27) of the support assembly (9), the biasing element (27) being configured to rotate the inclination shaft depending on a displacement of the rotating assembly (15) according to the primary axis (13) with respect to the support assembly (9).