Refrigeration Systems for Machine Tools

Machine Tools

Modern production processes use more and more high-tech machine tools characterized by maximum precision and increasingly high cutting speeds.

The thermal loads induced by friction can cause a number of undesirable effects

Without proper cooling, the thermal loads induced by friction between rotating components in the spindle of a CNC machine can cause a number of undesirable effects:

• The thermo-elastic deformation of the spindle, due to different expansion of the bearings with respect to the axes, has negative effects on the dimensional tolerance of the piece, increasing the number of rejects and in some cases leading to the blocking of the machine tool.
• Process instability resulting in surface defects due to changes in bearing preload
• Decrease of available electric motor power due to decreasing flux density
• Reduction in electric motor life due to faster aging of insulating materials
• Reduction in bearing life due to increased wear

The advantages of a liquid chiller

The requirements for optimal machine tool cooling are changing as a result of emerging trends in motor spindles, such as increased spindle power and power density. Higher power leads to shorter machining times due to increased cutting speed, but this generates higher heat loads, which must be disposed effectively.

Effective temperature control of the spindle, workpiece and tools enables both high machining accuracy and the ability to dissipate the high thermal loads associated with ever higher cutting speeds. Another important advantage is the increased service life of the motor, bearings and cutting tools, resulting in reduced production costs. Proper cooling of the cutting fluid also reduces the heat input to the workpiece during machining, minimizing variations in dimensional tolerance and therefore scrap.