Eccentric Rubber Engine Mount Structure for Uneven Load Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional vibration damping devices in automobile engine mounts face durability issues due to uneven loads in different directions, leading to localized strain and stress concentrations that compromise the overall durability.
Innovation Solution
The vibration damping device employs a main rubber elastic body with a truncated cone shape and eccentric member central axes, featuring different free lengths and a continuous rubber connection to distribute strain and stress evenly, enhancing durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the main rubber elastic body has uniform thickness, then the structure is simple and easy to manufacture, but the durability is poor due to localized strain and stress concentrations under uneven loads
Solution Approach 1:
The main rubber elastic body employs non-uniform thickness distribution, with thicker portions positioned at locations experiencing higher stress concentrations. This local quality variation allows the structure to better withstand uneven loads from different directions while maintaining overall structural simplicity and manufacturability.
Solution Approach 2:
The inner member and outer cylindrical member are positioned with eccentric axes relative to each other, creating an asymmetric configuration. This asymmetry enables the rubber elastic body to accommodate the uneven load distribution characteristic of engine mount applications, where braking and acceleration loads differ significantly in magnitude.
2Reliability
If the member thickness of the main rubber elastic body is increased to improve durability, then the durability improves, but the spring properties are adversely affected and the device size increases
Solution Approach 1:
Instead of uniformly increasing the thickness of the entire rubber elastic body, the invention applies increased thickness only in specific regions where stress concentrations occur. This localized thickening approach improves durability at critical locations while preserving the overall spring properties and maintaining a compact device size.
3Reliability
If the inner member and outer cylindrical member are positioned coaxially, then the structure is symmetric and simple, but the durability is poor under uneven loads from different directions
Solution Approach 1:
The invention deliberately positions the inner member and outer cylindrical member with eccentric axes rather than coaxially. This asymmetric positioning creates an optimized stress distribution pattern that better accommodates the uneven load conditions typical in engine mount applications, particularly the significant difference between braking and acceleration loads.
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 design effectively distributes strain and stress, improving durability by reducing local concentrations and maintaining vibration damping performance even under varying loads.
Implementation Method 1
a main rubber elastic body... effectively distributes strain and stress, improving durability
Data Source
AI summary
In a vibration damping device, a main rubber elastic body has a truncated cone shape and includes a recess open to a lower surface. A central axis of an inner member is arranged eccentric with respect to a central axis of an outer cylindrical member in an axis-perpendicular direction. The main rubber elastic body that connects the inner member and the outer cylindrical member has different free lengths on one side and the other side in an eccentric direction. A continuous rubber that covers a lower end of the inner member without exposing the lower end of the inner member to the recess and connects the main rubber elastic body on one side in the eccentric direction and the main rubber elastic body on the other side in the eccentric direction is integrally formed with the main rubber elastic body.