Vehicle Differential Interface Layer for NVH and Wear Reduction
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Solution Overview
Problem
Existing differential systems in vehicle drivetrains cause noise, vibration, and harshness (NVH) issues due to interactions between gear units and stationary parts, particularly from stick-slip behavior, and existing solutions complicate production without effectively addressing these issues.
Innovation Solution
A differential system with an intermediate element comprising a metallic layer and an elastic layer, laminated together, is introduced to reduce wear and friction between gear sets, providing strength and damping properties to mitigate NVH issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gear units interact directly with stationary parts of the differential system, then power transfer is efficient, but noise, vibration and harshness (NVH) issues occur due to stick-slip behavior
Solution Approach 1:
A damping element is introduced as an intermediary component between the gear unit and the housing. This damping element absorbs vibrations and prevents direct transmission of stick-slip behavior to the housing, thereby reducing NVH disturbances while maintaining effective power transfer through the gear meshing interface.
Solution Approach 2:
The damping element is constructed as a composite structure comprising a metallic layer providing structural strength and an elastic layer providing vibration damping properties. This composite material approach allows the single component to simultaneously bear mechanical loads and dampen NVH disturbances generated during gear operation.
2Object-affected harmful factors
If phosphate coating is applied to gear surfaces to reduce NVH issues, then vibration is reduced, but production process becomes more complex
Solution Approach 1:
The vibration reduction function is extracted from the gear surface treatment process and transferred to a separate damping element. Instead of modifying the gear surfaces through complex phosphate coating procedures, the damping element is simply positioned between the gear unit and housing, eliminating the need for additional surface treatment steps in the production process.
Solution Approach 2:
The damping element serves as a mediator that provides vibration reduction without requiring modification of the existing gear or housing components. This intermediary approach allows vibration control to be achieved through a simple additive component rather than complex surface treatment processes.
3Object-affected harmful factors
If a damping element with metallic and elastic layers is introduced between differential unit and housing, then NVH disturbances are reduced, but device complexity increases
Solution Approach 1:
The damping element merges multiple functions into a single component: it provides structural support, vibration damping, and noise reduction simultaneously. By combining the metallic layer for structural integrity and the elastic layer for damping in one integrated element, the design avoids adding multiple separate components that would increase complexity.
Solution Approach 2:
The composite structure of the damping element allows it to fulfill multiple roles with a single component design. The metallic layer handles mechanical loads and positioning, while the elastic layer provides vibration isolation, eliminating the need for separate damping components and simplifying the overall assembly.
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 intermediate element with a metallic and elastic layer combination reduces wear and friction, enhancing the durability and reliability of the differential system while minimizing NVH disturbances.
Implementation Method 1
at least one elastic layer provided on the metallic layer... providing strength and damping properties to mitigate NVH issues
Implementation Method 2
The intermediate element comprises at least one metallic layer and at least one elastic layer provided on the metallic layer
Data Source
Figure 1
Figure 2~3
Figure 4a~6b
AI summary
The disclosure relates to a differential system (1) for a drivetrain of a vehicle and comprises a differential unit (10), a housing (20), and an intermediate element (30) provided between the differential unit and the housing. A first gear set (11) is configured to receive the driving torque from a prime mover and to transfer it to the housing. A second gear set (12) that is rotatably attached to the housing and is configured to distribute the driving torque between at least two gear units (131) of a third gear set (13). The housing is at least partially surrounding the second and third gear sets (12, 13). The intermediate element is provided at an interface between the housing, and one or both of the second and the third gear set, and comprises at least one metallic layer (31) and at least one elastic layer (32) provided on the metallic layer (31).