Powder Metal Variator Components for Spalling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rolling traction type variators face premature failure due to excessive traction force leading to slippage, surface distress, and spalling, which reduces their efficiency and lifespan, especially when using conventional wrought steel components with high Hertzian contact pressure and tangential shear forces.
Innovation Solution
Powder metal variator components with specific morphology, including low alloy steel formed using powder metallurgy, which provides improved durability and traction coefficients, featuring internal voids and random microstructures that prevent spalling and enhance traction, allowing for the use of ordinary mineral-based variator fluids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional wrought steel components are used in rolling traction type variators, then manufacturing precision and surface finish can be achieved, but the components suffer from spalling and surface distress due to excessive Hertzian contact pressure and tangential shear forces
Solution Approach 1:
The patent applies composite materials by combining metal powder particles with a binder material to create a sintered composite structure. This composite morphology provides both the necessary surface finish and inherent resistance to spalling through the distributed particle structure that accommodates Hertzian contact pressure and tangential shear forces better than conventional wrought steel.
Solution Approach 2:
The patent utilizes porous materials by creating a sintered structure with controlled porosity from the metal powder compilation. The porous morphology formed during sintering provides stress distribution characteristics that resist spalling while maintaining adequate surface finish for rolling traction contact.
2Power
If high traction force is applied to increase drive transmission capability, then power transmission improves, but slippage occurs at the rolling contact leading to component damage
Solution Approach 1:
The composite sintered material structure provides optimized surface characteristics that maintain stable traction coefficients under high load conditions. The distributed particle-matrix structure allows for better stress distribution at the contact interface, preventing the slippage that leads to component damage while maintaining high power transmission capability.
3Reliability
If high end load is applied to increase contact normal force and prevent slippage, then traction coefficient improves, but component efficiency reduces and effective life decreases
Solution Approach 1:
The sintered composite material structure achieves improved traction coefficients through its inherent surface morphology and stress distribution characteristics, rather than requiring excessive end loads. This reduces the energy loss associated with high contact forces while maintaining reliable traction, thereby improving overall component efficiency and extending effective life.
Data Source
AI summary
The use of powder metal components in a variator is disclosed. Traction fluid of various sorts may be used in the variators, not just high performance synthetics or application specific lubricants.