Geared Motor Unit Vibration Damping via Viscoelastic Composite
Solution Overview
Problem
Geared motors in windscreen wiper systems produce vibrations and noise that are not adequately attenuated by existing damping solutions, leading to discomfort in vehicles.
Innovation Solution
The use of a laminated composite material with at least two layers, including a viscoelastic material, in the fixing plate, closing plate, or base of the geared motor to decouple vibrations and noise, along with metallic layers for improved stiffness and electromagnetic compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional damping studs are used to reduce vibrations, then vibration reduction is partially achieved, but the vibration reduction is insufficient and noise is not attenuated
Solution Approach 1:
The patent applies composite materials by integrating a viscoelastic damping layer between rigid structural layers (metal base and plastic cover) to create a multi-functional component that simultaneously reduces vibrations and attenuates noise, overcoming the limitations of traditional single-material damping solutions
Solution Approach 2:
The patent changes the material parameter from traditional rigid or simple damping materials to a viscoelastic material with specific loss factor properties (tan δ > 0.1 at 200 Hz), which provides superior vibration and noise attenuation characteristics across a broader frequency range
2Object-affected harmful factors
If a laminated composite material with viscoelastic layer is used, then vibration and noise attenuation are improved, but the structural complexity increases
Solution Approach 1:
The patent merges multiple functions (structural support, vibration damping, noise attenuation, and electromagnetic shielding) into a single laminated composite component, eliminating the need for separate damping studs or additional noise reduction elements, thus reducing overall assembly complexity
Solution Approach 2:
The laminated composite base/cover structure serves multiple functions simultaneously: it provides mechanical support, reduces vibrations, attenuates noise, and shields electromagnetic signals, replacing what would traditionally require multiple separate components
3Object-affected harmful factors
If metallic layers are added to the laminated composite for electromagnetic compatibility, then electromagnetic shielding is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent incorporates metallic layers (such as aluminum or steel foils) within the laminated composite structure to provide electromagnetic shielding, creating a multi-layer composite that integrates structural, damping, and EMI shielding functions in a single manufacturable 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
This solution effectively reduces vibration and noise transmission between the geared motor and the vehicle structure, enhancing both mechanical decoupling and acoustic insulation, while simplifying assembly and production.
Implementation Method 1
at least one of the layers is made of a viscoelastic material, that is to say a material with a high damping coefficient over a certain frequency range
Implementation Method 2
the viscoelastic material has a tangent damping factor δ greater than 0.1 at 200 Hz
Implementation Method 3
The use of a metallic layer also makes it possible to filter the electromagnetic waves and to improve the electromagnetic compatibility between the geared motor and the rest of the vehicle
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to a geared motor (1) for a motor vehicle wiper system, the geared motor comprising: - an electric motor (3) housed in a casing (4), - a reduction mechanism (5) connected to the electric motor (3), - a base (9) receiving the reduction mechanism (5), - a fixing plate (11) and/or a closing plate (110) intended to be fixed on the one hand to the base (9) and on the other hand to a structural element of the vehicle, in which at least one element among: - the fixing plate (11), - the closing plate (110), - the base (9) and, - the casing (4), is made of a laminated composite material (39) comprising at least two layers (C1, C2, C3) of material and of which at least one of the layers (C2) is made of a viscoelastic material.