Page 184 of catalogue Super Precision Bearings of Schaeffler Technologies GmbH & Co. KG

Engineering
Lubrication

Recommendations for oil-air lubrication for B, HCB, HS, HC, XC- Spindle bearings, also in Direct-Lube design (DLR): Oil cleanliness class: Air cleanliness: Air dryness: Air inlet tube pressure: Nozzle diameter: Number of nozzles: 13/10 (ISO 4406) Particle size 0,01 μm max. Dew point at + 2° C approx. 3 bars 0,5 to 1 mm. Extra nozzles for each bearing, one nozzle per every 150 mm of pitch circle circumference Inlet tube parallel to spindle rotational axis between inner ring lip and cage bore See bearing Tables (E tk ) (The injection pitch circle can deviate slightly from table details for spindle bearings with TX-cage). Engineering Inner diameter 2 to 2,5 mm, flexible and transparent tubing of synthetic material; thus the oil stream at the inner tube wall is visible. At least 1 m, optimum 4 m, up to approx. 10 m. Spirals with some five windings, centre axis horizontal or up to 30° inclined, no closer than approx. 500 mm in front of the nozzle. When lubrication is interrupted, the oil will collect in the windings at the bottom and soon be available again when operation is resumed. Thus a short lead time becomes possible for spindle starts. At both sides of each bearing; oil collection can cause high temperature running. For vertical spindles outlet ducts should be provided underneath each bearing so that the bearings below will not be overlubricated. Outlet ducts ø 5 mm if possible. Connect all outlet ducts from all bearings on one spindle for pressure balance reasons.

Nozzle design:

Injection-pitch circle diameter:

Inlet tubes:

Length:

Oil outlets:

Oil-air lubricating devices Normal oil quantities per injection cycle: 3, 5, 10, (30, 60, 100) mm 3 Normal injection cycles per hour: 6 to 10

Further data can be obtained from manufacturers of oil-air lubricating devices.

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