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Welcome to the world of top-class mechanical engineering 3 The lubrication of spindle bearings 4 The lubrication of clamping systems 8 The lubrication of gears in drilling and milling heads 10 The lubrication of drive and guide systems 13 © picture p.2/p.8: FORKARDT DEUTSCHLAND GmbH e Illustration p. 11: HEADTec GmbH 0 Foto p. 13: NSK Precision Europe GmbH

Welcome to the world of top-class mechanical engineering Machinery manufacture without machine tools? Inconceivable! Without machine tools you can‘t manufacture machines in or for other sectors. Also the demands on cutting machine tools as regards production planning are becoming progressively more stringent, so that customers also expect a lot from machine tool lubricants: • Stability during the manufacturing process – for highest machine availability • good production performance – also for future safety and environmental requirements and increasing productivity • high product availability...

The lubrication of spindle bearings The machining times per workpiece are getting progressively shorter, the cutting performance levels ever higher. This is made possible by higher speeds at the main spindles of the machine tools concerned – with simultaneously constant values for cut width and the feed motion. Specific requirements for rolling bearings in high-speed spindles are: • high speed rating (n · dm ) • simultaneous absorption of radial and axial forces • low friction enabling cool running The preferred option for this application are angular contact ball bearings with pressure angles...

The speed factor (n · dm): Bearing n · dm value is determined by the speed of the bearing at standard operating conditions n in [min –1] multiplied by the mean bearing diameter dm in [mm]. The speed factor of a lubricating grease depends largely on its base oil type, viscosity, thickener type, and of course the bearing type used. Under high-speed bearing operating conditions it is important to achieve a constant oil supply at a defined rate within the bearing combined with optimum lubricant adhesion to the bearing surfaces if successful lubrication is to be achieved. For Klüber Lubrication spindle...

Application of grease lubrication Depending on the bearing type, size and its intended application, initial lubrication can be made at the bearing manufacturer. Rolling bearing manufacturers have developed their own initial lubrication techniques for the application of grease. The chosen technique normally involves a central lubricating system conveying the grease from its original container to the filling station, from where it is applied to the bearing via nozzles. How much grease does the bearing need? For lifetime lubrication, the required grease quantities are determined in accordance with...

For instance, the department responsible for spindle bearings at Schaeffler KG recommends the following for its spindle bearings type B, HS and HC:3) a) Rotating speed = 0.5 · n max Five intervals of 20 s running time and 2 min rest period b) Rotating speed = 0.75 · n max Five intervals of 20 s running time and 2 min rest period c) Rotating speed = n max Five intervals of 20 s running time and 2 min rest period Ten intervals of 30 s running time und 2 min rest period Ten intervals of 1 min running time and 1 min rest period According to this recommendation, the intervals featuring longer running...

The lubrication of clamping systems Lubricant and chuck have to be perfectly matched, because their paramount task is to establish constant defined clamping forces – and this over a high number of clamping cycles. If the clamping force weakens, tools or workpieces may become detached. This holds true for all types of chucks – be they scroll chucks, cam chucks or spiral chucks. The specific requirements for the lubricants used in clamping systems are: • consistent clamping forces for all chuck types • protection against frictional and fretting corrosion (tribocorrosion) at frictional or positive...

Clamping force KSP 160, 6 bar Lubricant: ALTEMP Q NB 50 Comparison: Initial lubrication – Relubrication Mean test value Initial lubrication 18 000 Mean test value Relubrication 16 000 14 000 12 000 Clamping force [N] 10 000 8 000 6 000 4 000 2 000 0 0 100 200 300 400 500 Number of clamping cycles Clamping force as a function of the clamping cycles using ALTEMP Q NB 50. Maximum traverse speed of the clamping chucks on Fritz Schunk GmbH‘s KSP 160 clamping force block (tandem clamper) was 0.52 m/min. 9

The lubrication of gears in drilling and milling heads Gears in drilling and milling heads play a major role when it comes to the transmission of load and torque from the machine tool main spindle to the cutting tool. They are operated in cycles and run, depending on the type of application, at high peripheral speeds of more than 20 m/s. The special requirements regarding these components are therefore: • reliable operation and long component service life • high peripheral speeds • high acceleration In most cases, the a.m. components are spur, bevel or spiral bevel wheel gears (palloid gears)....

We would like to point out the importance of running-in and possible refilling up to the required level. We would suggest to perform running-in as described in the chapter on spindle bearing lubrication. Suggestion: The degree of grease fill is about 70–90 % of the available free space, depending on the particular application. It is important to ensure that the grease does not leak from boreholes, gaps or similar apertures. Spindle drive Bevel wheels/spur wheels Grease: ISOFLEX TOPAS NB 52 Worm Grease: ISOFLEX TOPAS NB 152 Milling spindle Grease: ISOFLEX TOPAS NB 52 Example for an intercompatible...

Changing, unsteady operating states, manifested in abrupt changes in temperature or power consumption levels, for example, may have adverse effects on both the grease and the component. These may occur if • after standstill there is an abrupt change from one lubrication mechanism to another, due to the slow warming of the gear unit and the resultant alteration in the consistency of the grease • the transmission of torque and power and hence the load and consistency of the grease vary significantly • the system is being run with too much grease, producing forced fluid lubrication caused by the...