New high speed bearing greases provide improved performance over costly oil lubrication in super precision bearings

September 23, 2003

By: Mark Harris
Website: http://www.bearing-n-bearings.com

New high speed bearing greases provide improved performance over costly oil lubrication in super precision bearings

At MACH 2002, FAG/Barden will be introducing their new high speed bearing grease FAG-Arcanol L75, which provides the overall performance improvements necessary to allow costly and complicated oil lubrication systems to be replaced. FAG-Arcanol L75 enables OEMs and users to employ the convenience and operational advantages of sealed bearings lubricated with a grease that excels for its non-critical run-in behaviour, high temperature stability, non- toxicity and favourable viscosity- temperature behaviour.

FAG-Arcanol L75 is another phase in FAG/Barden's continuing development of greases as the primary means of lubrication for super precision bearings, not only in machine tool spindles, but also for other applications, such as high-speed Canning operations and Formula 1 cars. On its own FAG-Arcanol L75 provides much improved performance, at high operating speeds of up to 1.2 x 106dmN with steel balls and 1.6 x 106 dmN with ceramic balls. However, when FAG-Arcanol L75 is used in conjunction with FAG/Barden's Cronidur*30 bearing material, in spindle bearings that are uniquely sealed, the combined effect is a synergy that provides users with even higher speed and load capability.

Critical "Run-In" Period Reduced By 50%

One of the unique qualities of FAG-Arcanol L75 is its excellent "Run-In" behaviour. Run -in is the ability of a lubricant to reach a steady operating state in as short a time as possible. L75 does this in less time than that of FAG/Barden's well proven FAG-Arcanol L74, the Barium-based grease that it is replacing. Importantly, the temperature of L75 during the critical run-in period is typically half that of L74 grease when tested under the same conditions. What these results reveal is that in the critical phase of grease distribution with L75 the damaging effects of thermal stress conditions and lubricant degradation are clearly eased and a significantly higher degree of operational reliability is achieved as a result.

New Thickener Is Non-Toxic

Another major feature of FAG-Arcanol L75 is that it uses Polyurea as a thickener instead of Barium complex soap. The advantages of Polyurea are many: it is environmentally friendly, contains no toxic components and exhibits extremely high thermal stability. In addition, Polyurea has better continuous and constant oil delivery characteristics (i.e. the way in which base oil is dispensed to the bearing) and it lasts longer than metal soap thickeners.

Favourable Viscosity/Temperature Behaviour Maintains Load Carrying Capacity

Polyurea offers the additional advantage that it can be used as a thickener with a number of different types of oil - mineral or synthetic. It helps to overcome the limitations of the oil at higher temperatures and also ensures a more structurally stable mixture. In the case of FAG-Arcanol L75 the base oil is fully synthetic. The special feature of this base oil is its favourable Viscosity-Temperature (V-T) behaviour. V-T is a measure of the change in base oil viscosity in relation to temperature. If the oil viscosity changes only slightly with changing temperature, as is the case with FAG-Arcanol L75, this is favourable V-T behaviour. The operational benefit of this to users is that the load carrying capacity of the lubricating film inside the bearing is sustained over a wider range of operating temperatures.

About The Author:

Mark Harris is a successful author and regular contributor to http://www.bearing-n-bearings.com. Keep things running smoothly with ball bearings, roller bearings, ball thrust bearings and tapered bearings.