Tolerance Ring Process Control via Remaining Assembly Force
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Solution Overview
Problem
The existing methods for determining the initial slip force of tolerance rings are unreliable due to influences from elastic deformation, plastic deformation, roughness, and surface treatment effects, making it difficult to accurately assess the axial slip resistance between mating components.
Innovation Solution
A process control method involving constraining a tolerance ring and measuring the force required to move a component beyond its projections, which provides a more reliable representation of the initial slip force, known as the remaining assembly force, to ensure acceptable axial slip resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If peak assembly force is measured to determine initial slip force, then process control can be implemented, but the measurement is unreliable due to elastic deformation, plastic deformation, roughness, and surface treatment effects
Solution Approach 1:
The patent extracts the harmful influence of surface treatment effects, elastic deformation, and plastic deformation by measuring the force required to move the plug gauge beyond the projections of the tolerance ring, rather than measuring the peak force during initial contact. This isolates the measurement from the distorting factors while capturing the essential friction characteristic.
Solution Approach 2:
The method performs preliminary action by moving the plug gauge beyond the projections of the tolerance ring before taking the force measurement. This preliminary movement ensures that the measurement is taken after the effects of surface treatment and deformation have been overcome, providing a more reliable indication of initial slip force.
2Reliability
If surface treatment steps such as passivation are applied to tolerance rings, then corrosion resistance is improved, but the peak assembly force measurement becomes unreliable
Solution Approach 1:
The patent removes the harmful influence of surface treatment effects on the measurement by changing when the measurement is taken. Instead of measuring peak assembly force during initial contact where surface treatment effects dominate, the measurement is taken after the plug gauge has moved beyond the projections, where surface treatment effects are minimized.
3Strength
If the plug gauge head contacts the projecting ridge of the tolerance ring during assembly, then the tolerance ring can be compressed and secured, but a peak in assembly force occurs that does not represent initial slip force
Solution Approach 1:
The patent segments the assembly process into distinct phases: the compression phase where the plug gauge head contacts the projections to secure the tolerance ring, and the measurement phase where the plug gauge has moved beyond the projections. By separating these phases, the measurement is taken when the compression function has been completed and the relevant slip force characteristics are revealed.
Solution Approach 2:
The compression of the tolerance ring between the plug gauge and ring gauge is performed as a preliminary action before the force measurement is taken. This ensures that the tolerance ring is properly secured and the projections are compressed, allowing the subsequent force measurement to accurately reflect initial slip force rather than compression force.
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 method effectively correlates the remaining assembly force with initial slip force, reducing the impact of surface treatment effects and providing a consistent measurement for process control, ensuring reliable axial slip resistance between components.
Implementation Method 1
a peak in assembly force can occur when the head of the plug gauge initially contacts a projecting ridge of a tolerance ring and energy is required to deform the ridge to enable the gauge to slide over it
Data Source
AI summary
A method of process control including constraining a tolerance ring relative to one of an inner and an outer component. The tolerance ring including an annular band of resilient material having a plurality of projections projecting radially therefrom. Additionally, the method includes moving the other of the inner or outer component with respect to the constrained tolerance ring so as to compress the projections of the tolerance ring between the inner and outer components, and continuing movement of the inner or outer component, respectively, beyond the projections. The method further including measuring a force required for continuing movement, and using the force for process control.