Schaeffler is expanding its range of automatic lubricators with two new systems that provide accurate, efficient lubrication of spindle bearings with either oil or grease. FAG CONCEPT PRECISION GREASE and FAG CONCEPT PRECISION OIL are compact lubrication systems developed specifically for spindle bearings. As these rolling bearings support high running speeds, the key points of focus in their development are the correct supply and removal of lubricant, lubricant quantity and heat dissipation from the lubricant itself.
High-performance greases are available today that enable spindle bearings to be lubricated safely and economically over long periods of time, even when running at very high speeds. For this reason, the majority of main spindles are lubricated with grease. However, these bearings are normally sensitive to being over-lubricated, which means that systems are required that supply the correct volume of grease to the correct location on the spindle. In addition, high-performance greases tend to harden and separate under pressure. The relubrication facility must therefore take this into account.
FAG CONCEPT PRECISION GREASE from Schaeffler is a lubrication system designed specifically to meet the demands of main spindles in machine tools with respect to the volume dispensed on each stroke. Grease-filled hoses are connected to the outlets and form the actual lubricant reservoir for relubrication. The cartridge contains only pressurised oil that is pumped into the hoses during lubrication. The grease and pressure medium are separated by a ball positioned in the hose. The system provides 0.025cm³ per stroke and supply line. The grease is under pressure only during the relubrication process in order to prevent the grease from separating in the relubrication unit.
If applications involve very high speeds (> 1.6 millionmm/min), the typical solution is to use a pneumatic oil lubricator. The disadvantage of this lubrication method is the need for compressed air, which is both resource-hungry and expensive. Compressed air costs for relubricating just one motor spindle in a three-shift operation can be as high as £550 per year. Insufficiently filtered air or the formation of condensation due to inadequate drying can also lead to premature spindle failure.
To solve these problems, FAG CONCEPT PRECISION OIL from Schaeffler provides direct oil lubrication in very small doses without the need for compressed air as a carrier. The innovation here is in replacing compressed air as the medium for transporting the lubricant into the bearing with a damper/throttle element, which provides a virtually continuous feed rate to the bearing. The concept was tested with Weiss Spindeltechnologie GmbH in a prototype motor spindle and has since been proven in practice. A speed-dependent control option for the direct oil lubrication system offers further potential for optimisation.
Lubricators for every application
Schaeffler offers a wide range of automatic lubricators to suit every customer’s requirements. FAG CONCEPT2 is a compact, cost-effective lubrication system for rolling bearings that is fitted with two lubrication points that are controlled by either one or two individual piston-dispensing pumps. This enables the system to be adjusted to meet up to two different bearing sizes with varying lubrication requirements. FAG CONCEPT2 is suitable for the relubrication of rotary tables, as well as a variety of industrial rolling bearing applications, including pumps, fans, compressors, gearboxes and electric motors.
FAG CONCEPT8 is an automatic lubrication system from Schaeffler that is fitted with four pairs of lubrication points (eight in total), which are controlled by four individual dispensing pumps. Unlike other multi-point lubricators on the market, FAG CONCEPT8 enables users to individually control each pump in order to optimise cycle times and volumes of dispensed lubricant. This means the system can be adjusted to meet up to four different bearing sizes, each with varying lubrication requirements. The system can be used for lubrication of linear axes in machine tools, pumps, fans, compressors, gearboxes and motors.
For more information about automatic lubricators from Schaeffler, please go to www.schaeffler.co.uk.