Slide Bearing Hard Coating for Wear Resistance
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Solution Overview
Problem
Slide bearings operating in mixed friction conditions experience premature wear and failure due to surface contact between the friction partner and counterpart, especially when using a material pairing of hardened steel and white metal or bronze, leading to reduced service life.
Innovation Solution
Coating either the friction partner or the counterpart with a hard material layer, such as a diamond-like carbon (DLC) coating, to enhance wear resistance and transition from mixed friction to hydrodynamic operation, with a Vickers hardness between 800 HV and 2500 HV, and surface roughness less than 1.5 μm, to reduce friction and increase durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a material pairing of hardened steel and white metal or bronze is used, then the friction partner has higher microhardness than the counterpart, but the counterpart experiences high surface wear and premature failure in mixed friction conditions
Solution Approach 1:
The invention changes the material parameters of the counterpart by applying a hard material coating (such as DLC, CVD, PVD, or plasma-coated layers) with Vickers hardness of at least 800 HV, preferably at least 1000 HV. This parameter change enables the counterpart to withstand mixed friction conditions while maintaining low wear, resolving the contradiction between the friction partner's high microhardness requirement and the counterpart's durability requirement.
Solution Approach 2:
The invention creates a composite structure by coating the counterpart with a hard material layer over a substrate (white metal or bronze). This composite construction combines the advantages of the soft substrate (good conformability and damping) with the hard coating (high wear resistance), allowing the counterpart to survive prolonged operation in mixed friction regions without premature failure.
2Force
If the friction partner and counterpart operate in mixed friction state with surface contact, then the bearing can support high loads, but wear occurs on both the friction partner and the counterpart
Solution Approach 1:
The invention modifies the surface parameters of the counterpart through hard material coating with specific hardness (≥800 HV) and surface roughness (Rz < 1.5 μm). These parameter changes enable the surface to withstand direct contact in mixed friction state without excessive wear, allowing the bearing to operate under high loads while minimizing material loss on the counterpart.
3Loss of energy
If the surface quality of the friction partner and counterpart is optimized for hydrodynamic operation, then friction is reduced in hydrodynamic state, but the transition to hydrodynamic operation is delayed at low rotational speeds
Solution Approach 1:
The invention changes the surface parameters of the counterpart by applying a hard material coating with controlled surface roughness (Rz < 1.5 μm, preferably Rz < 1.0 μm) and high hardness. These parameter changes improve the surface quality to reduce friction in hydrodynamic state while also enabling the bearing to transition to hydrodynamic operation at lower rotational speeds by providing a durable surface that can withstand the mixed friction transition period.
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 hard material coating significantly reduces wear and extends the service life of the slide bearing by minimizing friction and maintaining elasticity, allowing operation in hydrodynamic conditions even at low rotational speeds, thereby preventing premature damage.
Implementation Method 1
The friction in the so-called hydrodynamic state, that is, in the sliding friction state in which the friction partner is completely supported by the lubricating film and is thus also completely separated from the counterpart, is determined by the surface quality, that is, the roughness and tolerances, as well as its interaction with the lubricant used as the lubricating film.
Implementation Method 2
a lubricating film between the friction partner and the counterpart
Data Source
AI summary
A slide bearing including a rotating friction partner, a counterpart and a lubrication film between the friction partner and the counterpart, wherein the friction partner or the counterpart is coated with a hard material.