In order to achieve reduced temperature development during operation, Kammerer has further developed its ball screw drives with driven nut. The material selection of the components has been optimized with regard to thermal properties. The cooling of the axes and machine is variably adjustable. The spring-loaded stretching of the ball screws and the cooling bore in the spindle and nut minimize the displacement of the axes. The linear displacement is compensated by a direct position measuring system.

"The partial heating of certain spindle areas, which results from reversing movements in certain sub-areas, can only be achieved through temperature control," explains Reinhard Besenbeck, Technical Manager and Product Manager Ball Screws at Kammerer in Hornberg in the Black Forest.

"With a temperature difference of 5 °C, for example, and an assumed deflection length of 100 mm, this results in a distortion between the nut and spindle of 5.5 µm. This increases the preload and therefore the temperature into undesirable ranges. All this leads to a loss of service life, vibrations and preload dissolution in the ball contact area. In order to have a beneficial effect on energy costs, an average temperature should be determined and set at which only the minimum amount of energy is required - this does not necessarily have to be 21 °C. The spiral cooling channel on the circumference of the nut housing dissipates the heat generated from the bearing and ball contact area. This is because the main sources of heat are load, speed and preload. The same applies to the four axial and radial bearings installed, which act on the compact nut housing. The new design sustainably improves the accuracy and service life of the ball screw drive."

In addition to low heat generation, the ball screw drives are characterized by low noise levels. The hard-peeling process developed by Kammerer during production demonstrably reduces noise generation during use. The drive concept of the driven cooled nut enables high linear speeds with a long effective stroke of the ball screws. In conjunction with a large lead, speeds of over 120 ^min-1 can be achieved, and under ideal conditions speeds of up to 4000 ^min-1 are possible. This has a positive effect on cycle times for long travel distances. The preloaded spindle system increases the overall rigidity of the drive train. The critical bending speed is not limited. Spindle accelerations of up to 30 m/s² are possible. The use of hybrid bearings and ceramic balls can further increase existing speed limits.

Ball screws with cooled nuts are available in sizes from 16 to 160 mm diameter with different pitches. In addition to machine tools such as portal milling machines or broaching machines, the areas of application include plastic injection molding machines, lifting and assembly equipment for aircraft and rail vehicles, and other lifting and hoisting equipment.