IBC Rolling bearings With ATCoat Coating
The material surface of rolling bearings makes an ever increasing contribution to the performance of machines, units and systems. External influences frequently change the surface properties of the materials or even attack them. Treating the material surface of rolling bearings brings a wide variety of advantages.
The ATC thin chrome coating protects surfaces against external environmental influences and bring an extended service life of rolling bearings and also of machines and units.
These advantages are associated with effective use of the material and energy savings of energy. The ATCoat process permits a combination of a tough base material with a firmly adhering, very thin, precise and crack-free coating of chrome. Thus the ATCoat coating offers very good protection against wear and corrosion for the same rolling bearing dimensions. ATCoat-coated rolling bearings represent an alternative to rolling bearings made of corrosion-resistant steel, providing in particular a comparable level of corrosion protection behaviour.
The coat thickness of 2-4 μm with a cone-shaped surface structure displays superlative characteristics even under extreme conditions. In particular, when used in connection with ceramic rolling elements, considerable increases in the speed of rotation at low operating temperatures are possible due to ATCoat coating. Furthermore, the prevention of fretting corrosion in floating bearings that is caused by micro displacement of the rolling bearing outer rings due to thermal expansion or vibration leads in many cases to considerably longer trouble-free use of the unit. The special topography of the surface significantly improves the emergency running properties of the rolling bearings. For example, in the event of a failure of the lubrication system, the units can still be run for a certain time under partial load or shut down in a controlled manner, to prevent subsequent. IBC high-precision rolling bearings with ATCoat coating are therefore frequently used where there are unfavourable lubrication conditions.
Among things, these are:
- if no lubrication at all can be provided in a certain environment,
- if it is only possible to lubricate with low-viscosity media that does not produce a separating lubricating film,
- if very low speeds occur, at which an elastohydrodynamic lubricating film cannot be produced,
- if there are oscillating movements such as weaving or swiveling without full rotations, and a separating lubricating film cannot be maintained at the reversal points,
- if sliding occurs in unloaded rolling bearings,
- if there is smearing by the sliding rolling bearings during rapid acceleration or deceleration due the mass inertia in combination with an inadequate insufficient preload.
Functions of the ATCoat coating:
- Reduction of friction
- Better adhesion of the lubricating film
- Separation of similar materials
- Reduction in cold welding coefficients of friction through adhesion
- Reduction of the formation of fretting corrosion
- Ensuring the sliding property of a rolling bearing ring with respect to a shaft or housing (important in the case of floating bearings)
- External corrosion protection and substantial chemical resistance to aggressive materials or tribooxidation
- Wear protection due to the greater hardness of the coating: 72-78 HRC (1300-1400 HV)
Prefixes ATCoat-coated rolling bearings
- AC- rings ATCoat
- ACC- rings ATCoat + rolling elements Si3N4
Suffixes ATCoat-coated rolling bearings
- 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 elements and cage corrosion-resistant
- A21 inner ring coated
- A31 outer ring coated
- A31M outer ring outer diameter coated