SKF Super-precision Bearing Lubrication Unit

Improved reliability, profitability and reduced environmental impact

To meet the ever-growing performance requirements of high-speed
precision applications, SKF has developed the new Super-precision Bearing Lubrication Unit for use with oil-air lubrication in high-speed applications. This system can not only simplify new spindle designs but can also improve the performance of existing designs.
This highly effective solution improves lubricant flow and reduces frictional heating in the bearings, enabling them to operate at speeds up to approximately 2.5-3 million n dm. By reducing the operating temperatures and improving oil-air flow, oil consumption and noise levels can also be reduced.

Advantages of oil-air lubrication

The rotational speed at which a bearing reaches its operating temperature limit depends primarily on the heat generated in the bearing (frictional heat) and the amount of heat that can be transferred away from the bearing. One way to reduce frictional heat, particularly in bearings, is to be sure that the correct quantity of the appropriate lubricant reaches all necessary components.
Many high speed applications can be lubricated with grease. However, as speeds and the resulting frictional heat increase, grease is typically replaced with an oil lubrication system.
Very high-speed applications generally require a precise lubricant delivery system: the precise amount of oil required to adequately lubricate the bearing is continuously delivered by the oil-air lubrication system, thus minimizing friction and operating temperature.
Oil-air lubrication system provides the following advantages:
  • increases the bearing attainable speed
  • reduces friction torque and energy consumption
  • reduces environmental impact
  • reduces lubricant consumption
  • maximizes the effectiveness of the lubricant
  • positive pressure within the housing virtually eliminates the ingress of contaminants.

Lower operating temperatures

SKF compared the temperature rise of the SKF Super-precision Bearing Lubrication Unit to other commonly used alternatives. The high-speed test results showed that the SKF Super-precision Bearing Lubrication Unit was able to reduce operating temperatures by 10 to 15 %.


SKF Super-precision Bearing Lubrication Units can extend bearing service life and allow increased operating speeds for high speed applications such as machining centres, milling machines, internal grinding machines and spindles for printed circuit boards drilling.
The unit works on high-speed spindles, with an air-oil lubrication system, in horizontal and vertical position.

The assortment

An SKF Super-precision Lubrication Unit consists of a set of precision-matched spacer rings and a
super-precision high-speed single row angular contact ball bearing in the 70 .. E series (ISO 10 dimension series) with either a 15 or 18° contact angle.
Units are available for shaft diameters ranging from 30 to 70 mm.
All-steel bearings and hybrid bearings, which have steel rings and balls made of bearing grade silicon nitride, are available. As silicon nitride (ceramic) balls are considerably lighter and harder than steel balls, hybrid bearings can provide a higher degree of rigidity and run considerably faster than comparably sized all-steel bearings.
SKF Super-precision Bearing Lubrication Units are designed exclusively for the following 70 .. E series bearing arrangements:
  • single universally matchable bearing
  • a set of two bearings arranged in tandem
  • a set of two bearings arranged back-to-back

Bearing arrangements can be of different types: single or tandem with spring preload, back-to-back with rigid preload.
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