Machine tools

Machine tool cooling systems

Modern production processes are increasingly using high-technology machine tools characterised by maximum precision and ever-higher cutting speeds.

Frictional heat loads can cause numerous undesirable effects.
In the absence of adequate cooling, thermal loads induced by friction between the rotating components in a CNC machine spindle can cause a series of undesirable effects:

 The thermo-elastic deformation of the spindle, due to different expansions of the bearings compared to the axes: leads to negative effects on the dimensional tolerance of the workpiece, increasing the number of rejects and in some cases leading to the blockage of the machine tool.

• Process instability with resulting surface defects due to variations in bearing preload
• The decrease in available electric motor power due to decreasing flux density
• The reduction of the electric motor's lifespan due to the faster ageing of insulating materials.
• The reduction in bearing lifespan due to increased wear

The advantages of a liquid chiller

The requirements for optimal cooling of machine tools are changing as a result of emerging trends in motor spindles, such as increasing spindle power and power density. Higher power leads to shorter processing times due to increased cutting speeds, but this generates higher thermal loads, which must be effectively dissipated.

Effective control of the spindle, workpiece, and tool temperatures allows for highly accurate machining, as well as the ability to dissipate the high thermal loads associated with ever-increasing cutting speeds. Another significant advantage is the increased lifespan of the motor, bearings, and cutting tools, leading to reduced production costs. Proper cooling of the cutting fluid also helps to reduce heat transfer to the workpiece during machining, minimising dimensional tolerance variations and therefore scrap.

What do cosmotec products offer?

Cosmotec liquid chillers are an optimal solution for cooling machine tools; they are designed for continuous and reliable operation and comply with the highest energy efficiency standards defined by the Ecodesign ErP 2021 regulation. They guarantee adequate protection against dust and water ingress, offering IP54 protection ratings. Cosmotec liquid chillers can meet the most varied application needs as they offer numerous options and configurations such as:

• Energy Efficiency:All liquid chillers comply with the limits required by the ErP2021 directive – SEPR HT (EU) 2016/2281 – SEPR MT (EU) 2015/1095.
• Extended Operating Limits.
• Suitable for outdoor installation:The electrical panel, manufactured in accordance with EN 60204 and with IP54 protection rating, allows all units to be installed outdoors.
• Corrosion protection:The HDPE plastic tank, and the non-ferrous (stainless steel/polymers) hydraulic circuit and pump are free from corrosion, preserving the purity of the process fluid.
• LASERPACK ±0.5K and ±0.1K
• Electronic Expansion Valve
• EC Brushless Axial Fans
• Inverter centrifugal pumps
• Standard automatic hydraulic bypass valve
• Dynamic set point with standard ambient probe
• Bi-frequency versions 50/60 Hz
• 60 Hz UL Versions

Application Sectors

• CNC Machining centres
• Press brakes
• Punching tools
• Towers
• Milling machines
• EDM machines
• Arc welders
• Waterjet cutting machines