Tolerance Ring Assembly for Low-Friction Torque Retention
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Solution Overview
Problem
Conventional tolerance rings face challenges in providing optimal torque overload protection and minimizing assembly forces while maintaining low frictional engagement and reducing vibration between moving components, particularly in applications with high torque and low rotation rates, such as in four-wheel drive trucks and seat motors, where brinelling and component failure can occur.
Innovation Solution
A tolerance ring design featuring a band made of resilient material with a low friction layer and strategically positioned projections that prevent axial displacement, allowing for zero-clearance fits and reduced assembly forces, while maintaining torque transmission capabilities and minimizing frictional forces through wave structures that deform to accommodate manufacturing tolerances and thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a close fit between inner and outer components is sought to reduce relative vibration, then vibration reduction is improved, but frictional forces increase
Solution Approach 1:
A tolerance ring is introduced as an intermediary component between the inner and outer components. This tolerance ring absorbs the frictional engagement, allowing the inner and outer components to maintain a close fit for vibration reduction while the tolerance ring handles the frictional forces through its resilient material and wave structures.
Solution Approach 2:
The tolerance ring uses resilient material with varying friction characteristics. The wave structures can deform to change the contact pressure and frictional engagement dynamically, allowing optimization between vibration control and friction reduction by adjusting the physical state and geometry of the tolerance ring.
2Object-affected harmful factors
If strong and substantial contact between components is used to reduce vibration, then vibration reduction is improved, but assembly forces increase
Solution Approach 1:
The tolerance ring serves as a mediator that enables strong contact between components for vibration reduction while absorbing the assembly forces. The resilient material and wave structures of the tolerance ring deform during assembly, reducing the peak forces required while maintaining the necessary contact pressure for vibration control.
3Weight of moving object
If weight reductions in components are pursued, then weight reduction is improved, but assembly forces and costs increase
Solution Approach 1:
The tolerance ring utilizes resilient material with optimized physical parameters including elasticity modulus and friction coefficients. The wave structure geometry can be adjusted to achieve the desired balance between weight reduction and assembly force requirements, allowing lighter components while controlling assembly forces through material and geometric parameter optimization.
4Strength
If heat treatment and thick material are used for torque overload protection, then torque capacity is improved, but frictional forces and assembly complexity increase
Solution Approach 1:
The tolerance ring employs composite construction with resilient material providing both torque capacity and friction management. The combination of base material strength with surface treatments or coatings creates a composite structure that achieves high torque overload protection while maintaining low frictional forces through the multi-layered material system.
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 design reduces sliding forces and torque requirements, enhances assembly efficiency by minimizing assembly forces, prevents brinelling and component failure, and extends the lifespan of components by eliminating the need for additional vents and reducing heat-related installation issues, while maintaining effective torque transmission and vibration reduction.
Implementation Method 1
a low friction layer... maintaining torque transmission capabilities and minimizing frictional forces
Implementation Method 2
a band made of resilient material with a low friction layer and strategically positioned projections that prevent axial displacement, allowing for zero-clearance fits and reduced assembly forces, while maintaining torque transmission capabilities and minimizing frictional forces through wave structures that deform to accommodate manufacturing tolerances and thermal expansion
Implementation Method 3
wave structures that deform to accommodate manufacturing tolerances and thermal expansion
Data Source
AI summary
A tolerance ring including a sidewall and at least one projection from the sidewall that projects radially and axially to prevent axial displacement of the tolerance ring with respect to a component interior or exterior to the tolerance ring.