Windscreen Wiper Drive Mechanical Retaining Means
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Windscreen wipers on motor vehicles are unintentionally pulled onto the window pane due to wind loads, leading to potential obstruction of the driver's view, and existing solutions involve permanent energization of the electric motor, which can cause thermal overload.
Innovation Solution
A windscreen wiper drive with a mechanical holding mechanism, such as a snap-action means, that secures the drive shaft against unwanted rotation during strong wind loads without continuous motor energization, allowing the drive shaft to be released when the motor exceeds the holding force, and includes a linkage system for adjusting the wiper position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor is permanently energized to hold the windscreen wipers in the parked position, then the wipers are protected against unintentional movement due to wind load, but the electric motor experiences thermal overload
Solution Approach 1:
The patent replaces the electrical holding mechanism (permanent motor energization) with a mechanical holding means (snap-action means) that physically secures the drive shaft in the parked position. This mechanical system provides reliable holding without continuous electrical power, thereby preventing thermal overload of the motor while maintaining protection against wind load-induced movement.
Solution Approach 2:
The mechanical holding means is designed to automatically engage and disengage based on the drive shaft position and applied loads. The snap-action mechanism self-activates when the drive shaft reaches the parked position and self-releases when sufficient force is applied in the direction of rotation, eliminating the need for continuous electrical control and reducing motor burden.
2Temperature
If a mechanical holding means is introduced to secure the drive shaft against unwanted rotation, then the electric motor is protected from thermal overload, but the device complexity increases
Solution Approach 1:
The mechanical holding means is implemented as a localized snap-action mechanism positioned at a specific location on the drive shaft where it can effectively engage without interfering with other components. This localized approach provides the necessary holding function while minimizing the overall structural complexity of the windscreen wiper drive system.
Solution Approach 2:
The snap-action holding means is designed as a simple, disposable-like component that can be easily manufactured, installed, and potentially replaced if needed. Its straightforward mechanical design allows for cost-effective production and maintenance, offsetting the added complexity through ease of serviceability.
3Reliability
If the holding force is increased to secure the wipers against strong wind loads, then the protection against unintentional movement is improved, but the force required to release the holding means increases
Solution Approach 1:
The snap-action holding means utilizes dynamic mechanical advantage through its lever-like structure. The holding force is amplified at the engagement point to securely resist wind loads, while the release mechanism is designed so that rotational movement of the drive shaft in the direction of rotation naturally overcomes the holding force through mechanical leverage, allowing release without requiring excessive force.
Solution Approach 2:
The mechanical holding means creates a counterbalancing effect where the snap-action mechanism provides strong holding force in one direction (against unwanted rotation from wind load) while the drive shaft's rotational movement in the intended direction naturally overcomes this holding force. This creates an asymmetric force relationship where holding is strong but release is facilitated by the system's own operational movement.
Data Source
Figure 1a
Figure 1b
Figure 2
AI summary
The present invention relates to a windscreen wiper drive for driving at least one first windscreen wiper of a motor vehicle, which comprises an electric motor that is provided for driving a drive shaft, which drive shaft extends in the direction of a drive axis and, in an operating state, can be rotated around the drive axis in a rotational direction to an upper turning point and against the rotational direction to a lower turning point, wherein the windscreen wiper drive comprises a mechanical retaining means which is provided to releasably retain the drive shaft in a loaded idle state against an undesired rotation in the rotational direction in a retaining position which is arranged below the lower turning point against the rotational direction. The present invention additionally relates to a motor vehicle comprising a windscreen wiper drive of this type and a method for operating the windscreen wiper drive.