Design of bearing arrangements
The good running characteristics of shaft guidance systems are dependent not only on the bearings. The geometrical and positional tolerances of the adjacent construction also play a significant role.
The higher the accuracy to which the adjacent construction is produced and assembled, the better the running characteristics.
Location
Linear ball bearings KH
Linear ball bearings KH and KH..-PP are pressed into the housing bore. This provides axial and radial location. No additional means of location are required.
Linear ball bearings KN..-B, KB, KS and plain bearings PAB
Linear ball bearings KN..-B, KB, KS and plain bearings PAB require axial location.
Linear ball bearings KB and plain bearings PAB can be located by means of retaining rings or by the adjacent construction, ➤ Figure to ➤ Figure.
Linear ball bearings KN..-B and KS can be located in accordance with ➤ Figure and ➤ Figure.
Linear ball bearings KN..-B can also be located by means of a screw, ➤ Figure.
ACHTUNG
The series KN..-B and KS should not be located by means of shaft retaining rings according to ➤ Figure. This could impair the function of the bearing.
Retaining rings in the bearing slots
Retaining rings in the housing bore
Linear ball bearings KNO..-B, KBO and plain bearings PABO
Linear ball bearings KNO..-B, KBO and plain bearings PABO must be axially located.
These bearings are located by external means. A dog point screw should preferably be used for location, ➤ Figure. Grub screws are also suitable.
ACHTUNG
The locating screw must not be allowed to deform the bearing. The screw must be secured against loosening.
Retaining ring and housing rib
Location of the bearing using a screw
Linear ball bearing and housing units
Linear ball bearing and housing units and linear plain bearing units are screw mounted into or through the fixing holes, ➤ Figure and ➤ Figure.
Location of the units by means of dowels is only necessary in rare cases, but can be achieved easily by drilling out the centring holes.
Location of a unit from below
Location of a unit from above
Sealing
Clean raceways are necessary in order to prevent premature failure of the shaft and bearing. The bearing position should therefore always be sealed.
Gap seals or contact seals
The seals for the bearing series are shown in the table.
Gap seals protect the bearings against coarse contaminants. Contact seals give protection against fine contaminants and also retain the grease in the bearing.
Linear ball bearings and linear plain bearings with contact seals have the PP, example KH..-PP.
ACHTUNG
If the bearing and shaft are in a highly aggressive environment, it is recommended that the guidance system should be provided with additional protection by means of bellows or telescopic covers.
Seals for bearings and units
Series** | Seal | ||
|---|---|---|---|
Open design | Gap seals | Contact seals | |
KH | ● | ‒ | ● |
KN..-B, KNO..-B | ‒ | ● | ● |
KS, KSO | ‒ | ● | ● |
KB, KBO | ‒ | ● | ● |
PAB, PABO | ‒ | ‒ | ● |
● Available design.
**All linear bearing units have contact seals.