IBC rolling bearings with ATCoat coating
The material surface of rolling bearings contributes to an ever greater extent to the performance of machines, units and systems. External influences very often change the surface properties of materials or even attack them. A wide range of advantages can be achieved by coating the material surface of rolling bearings.
The ATC thin chromium coating protects surfaces from external environmental influences and thus enables an increase in the operating life of rolling bearings as well as an extension of the service life of machinery and equipment. These advantages are combined with effective material utilization and energy savings. The ATCoat process allows the combination of a tough base material with a firmly adhering, very thin, precise and crack-free chromium layer. Thus, the ATCoat coating offers very good wear and corrosion protection for the same rolling bearing dimensions. ATCoat-coated rolling bearings are an alternative to rolling bearings made of stainless steel; in particular, comparable corrosion behaviour is achieved on the functional surfaces.
The coating thickness of 2-4 μm with a cone-shaped surface structure shows excellent properties under extreme conditions. Particularly in conjunction with ceramic rolling elements, the ATCoat coating enables significant speed increases at lower operating temperatures. Furthermore, the avoidance of fretting corrosion on non-locating bearings, which is caused by the micro-displacement of the rolling bearing outer rings in the event of thermal expansion or vibration, in many cases opens up considerably longer, trouble-free use of the units. The special topography of the surface significantly improves the emergency running properties of the rolling bearings. For example, in case of a failure of the lubrication system, the units can still run under partial load for a certain time or can be shut down properly, thereforeconsequential damages can be limited or avoided. IBC high-precision rolling bearings with ATCoat coating are therefore frequently used in unfavourable lubrication conditions.
These are present, among other things, when:
- if lubrication is not possible at all in certain environments,
- lubrication can only be carried out with low-viscosity media which do not produce a separating lubricating film,
- very low speeds occur at which no elastohydrodynamic lubricating film can form,
- oscillating movements such as swaying or pivoting occur without full revolutions being achieved and a separating lubricating film is not maintained at the reversal points,
- sliding occurs in unloaded rolling bearings,
- smearing occurs due to sliding rolling elements during high accelerations or decelerations due to the inertia caused by mass inertia in conjunction with insufficient preload.
Functions of the ATCoat coating:
- Reduction of friction
- Better adhesion of the lubricating film
- Separation of similar materials
- Reduction of cold welding friction coefficients due to adhesion
- Reduction in the formation of fretting corrosion
- Ensures the sliding properties of a rolling bearing ring relative to the shaft or housing (important for non-locating bearings)
- External corrosion protection and extensive chemical resistance to aggressive materials or tribo-oxidation
- Wear protection due to higher hardness of the coating: 72-78 HRC (1300-1400 HV)
ATCoat-coated rolling bearing prefixes
- AC- rings ATCoat
- ACC- rings ATCoat + rolling elements Si3N4
Suffix ATCoat coated rolling bearing
- A11 Inner and outer ring coated
- A11L Inner and outer ring raceway coated
- A11LF Inner and outer ring raceway coated and finished
- A15 Inner and outer ring coated, rolling element and cage corrosion-resistant
- A21 Inner ring coated
- A31 Outer ring coated
- A31M Outer ring outer diameter surface coated