Bearings with Solid Oil

fig. 1

The SKF standard assortment of bearings and bearing units with Solid Oil (fig. 1) includes:

Deep groove ball bearings

Spherical roller bearings

Insert bearings and ball bearing units

Tapered roller bearings

Cylindrical roller bearings

Self-aligning ball bearings

On request, SKF can supply other bearing types with Solid Oil to meet the needs of a particular application, except for CARB toroidal roller bearings which are unsuitable for use with Solid Oil. Bearings fitted with a large-volume cage are not suitable for Solid Oil because there is too little free space inside the bearing.

Solid Oil variants

Standard variant (designation suffix W64, table 1)

contains a high-quality synthetic oil

meets the needs of most applications

Food-grade variant (designation suffix W64F, table 1)

contains an oil registered by NSF as a category H1

meets the needs of food applications

Sealed bearings

with integral contact seals are strongly recommended in wet environments

with Solid Oil increase the sealing effectiveness, as the Solid Oil supports the seals axially, preventing them from deflecting and opening under pressure

For information about sealing options, contact the SKF application engineering service.

Where carbon steel bearings are exposed to wet environments, additional external seals are recommended to protect the bearing’s external surfaces from corrosion.

Dimension standards, tolerances, internal clearance

Refer to Bearing (unit) data in the relevant product section of the standard bearing (unit).

Load carrying capacity

The basic dynamic and static load ratings for bearings with Solid Oil are the same as for corresponding SKF standard bearings.

The permissible operating temperature for bearings with Solid Oil can be limited by:

the dimensional stability of the bearing rings and rolling elements

the cage(s)

the seals

the Solid Oil

For limits of bearing rings, rolling elements, cage(s) and seals, refer to Temperature limits of the relevant product section of the standard bearing.

The relevant limits for Solid Oil are listed in table 1.

Where temperatures outside the permissible range are expected, contact SKF.

The recommended speed values for bearings and bearing units with Solid Oil (table 2), operating in an ambient temperature of 20 °C (70 °F), are limited by the maximum continuous operating temperature of 85 °C (185 °F). Ambient temperature is the temperature closest to the bearing position, not necessarily room temperature. 

For bearing types or variants not listed in table 2, contact the SKF application engineering service.

For ambient temperatures above 20 °C (70 °F), the speed limit should be reduced using the reduction factor f_T (diagram 1).

Calculation example

A deep groove ball bearing 6208/W64 is to operate at an ambient temperature of 50 °C (120 °F). What is the reduced speed limit?

Recommended speed limit for 20 °C (70 °F) ambient temperature

From table 2: speed value nd_m = 300 000 mm/min (single row deep groove ball bearing with a stamped metal cage)

Dimensions: d = 40 mm, D = 80 mm

n = 300 000 / d_m = 300 000 / (0,5 (40 + 80)) = 5 000 r/min

Reduction for 50 °C (120 °F) ambient temperature

From diagram 1: speed reduction factor f_T ≈ 0,53

n_reduced = 5 000 f_T = 5 000 x 0,53 = 2 650 r/min

If a bearing with Solid Oil is to be hot mounted, it should be heated to a maximum of 120 °C (250 °F) by using an induction heater.

Heating plates or heated oil baths should not be used.

Refer to Designation system in the relevant product section of the standard bearing/unit.

The designation suffixes used to identify bearings with Solid Oil are explained in the following: